Great War Historical Archive

[Bletchley 8]

Aviation Maps and The Small-Scale Mapping of the Western Front

 

If you mention "World War One" and "Maps" the mind is instantly drawn to the prodigious number of large-scale (1:10,000 or less) 'trench maps' of the opposing trench systems that were the result of the gradual and painstaking survey and re-survey of the front-line areas by the field survey units of both sides, from the Spring of 1915 onwards. These maps were drawn and printed in their thousands, and were frequently revised and overprinted, with millions of individual map sheets being distributed to the armies on the ground: a total of 34 million sheets by the British, 33 million by the French and a staggering 775 million by the Germans (Chasseaud). There is a good deal of information out there on these trench maps, which were often carried home by demobilised soldiers and, although fragile, have survived in enough numbers to become collectors' items. McMaster have a wide selection of these that can be viewed online here:

 

http://library.mcmaster.ca/maps/ww1/home.htm

 

and for those who would like their own digital copies a large number of those held in the British National Archives collection are available for purchase on CD-ROMs here:

 

http://www.naval-military-press.com/cd-rom-c-250.html

 

But this is not going to be about these large-scale trench maps. For the aviators of both sides these maps, although they certainly used them in their army-cooperation, art.obs. and photo recon. roles to precisely mark the position of enemy batteries, strongpoints, supply dumps or troop concentrations, their use as a tool for navigation was strictly limited by their scale (1:10,000 being just over 6" to the mile, so a map at this scale would be overflown in a matter of minutes). You will find little indication on these maps that they were designed with aerial naviagation in mind, and there is no concession to the aviator in the colouring or the features identified on the map. For this you have to turn to some of the larger-scale maps, at a scale of 1:20,000 and above, which were printed and distributed in smaller numbers as 'special' sheets for the artillery, cavalry, tanks, aviators and General Staff. It is also of some interest to note that although 'corps' maps were produced for the various arms, 'administration' maps for the General Staff, and various 'special' maps showing road and rail networks, telephone and telegraph lines, the water suppy and potential 'inundation' areas...very few maps have survived that were made primarily for the air services, or for their use in navigation. For most of the war the airmen of both sides appear to have used whatever suitable maps that they could find for air navigation, taking whatever was available in scales ranging from 1:40,000 (approx, 1.5" to the mile), through 1:100,000 (approx. 1.5 miles to the inch), to 1:250,000 (approx. 4 miles to the inch). But as the war progressed there was some concession to this use, at least in the British maps, as over-printing a standardised map colouring and features of use to air navigation were added to some of these otherwise general purpose maps. See examples here:

 

http://lt1.mcmaster.ca/ww1/wrz4mp.php?grid...id=304&view

http://lt1.mcmaster.ca/ww1/wrz4mp.php?grid...id=322&view

http://lt1.mcmaster.ca/ww1/wrz4mp.php?grid...ophoto&view

http://lt1.mcmaster.ca/ww1/wrz4mp.php?grid...ophoto&view

 

The French air service, although they experimented with the use of a small-scale map of the Chalons manouevre area before the war, remained largely dependent on a somewhat innaccurate pre-war 1:80,000 scale series black and white hachured map, and the Germans used a 1:100,000 map series based largely on the French 1:80,000 map. As the war progressed, like the British, their Field Survey units compiled larger-scale maps of the trench systems and operations areas.

 

French 1:80,000: http://library.mcmaster.ca/maps/ww1/French1889.htm

 

German 1:100,000: http://209.85.229.132/search?q=cache:l74aR...lient=firefox-a

 

The first known aviation map predates the First World War by several years, although in 1910 'Flight' magazine commended the Ordnance Survey's layered half-inch (2 miles to the inch, or approximately 1:125,000) scale map as the best compromise for "motorists and aviators", as its layering of colour was useful in showing elevations at a glance to the pilot. The issue was discussed at a meeting of the British Association in 1911, but this standard OS half-inch map was criticised for being on too large a scale, a smaller scale being necessary to the pilot to keep the map sheet down to a manageable size. It was also pointed out that the map should be as free of unneccessary ground 'clutter' as possible, but with features of use to aviators identified prominently (roads, railways, towns, airfields). Following on from this meeting a map for military aviators, a coloured map at the standard quarter-inch scale (4 miles to the inch, or approx. 1:250,000) was drawn up by the Geographical Section of the General Staff (GSGS) for the British Army manoeuvres of 1911, and although the British manoeuvres were cancelled that year it was used in the subsequent manoeuvres held in 1912. Normal topographical detail was almost entirely absent, and the map was reduced to emphasising what a pilot would be able to pick out from the air - roads were depicted as white lines on an olive-green base, towns were red, woods were green, whilst water courses and railways were in heavy blue and black respectively. Landmarks such as church spires, and even individual trees, were emphasised in heavy black. The Ordnance Survey then produced its own aviation map between 1911 and 1914, on this quarter-inch scale with hillshading, red roads, red outlines to towns, heavy blue rivers and black rail lines - but otherwise identical to their standard 2nd edition quarter-inch map of the period. But there is no evidence that the Army adopted the OS map, or produced any plans to print a series to the GSGS format, although an amended version of the OS map was issued by the Admiralty in 'Air Packets' for use by the RNAS in 1916. Hillshading was omitted from this series of coastal maps, a compass rose was added, and marine lights and other seamarks were added in the form of useful little engravings of the actual lighthouse, headland, etc (Nicholson).

 

The first RFC squadrons therefore went to war with no maps of their own, and also remained largely dependent on adapting those available from Army and other sources. The British Expeditionary Force itself was equiped with maps of the French and Belgian frontier, on a map scale suitable for a war of maoeuvre. A small-scale layered map at 1:380,000, or about 6 miles to the inch (GSGS 2517), named 'Belgium and the North East of France', was issued to the BEF and would have been available to the RFC as a map for air navigation. There was also a General Staff map at 1:100,000 (GSGS 2364) of the Belgian frontier, adapted from the Belgian 1:100,000 series - and it would have been of value to RFC pilots, as it was contoured in brown and coloured with roads depicted by red lines, water in blue and woods picked out in green. There were also quantities of the 1:40,000 scale Belgian 'tactical' maps for units in the field. For the French border areas, however, the British had to rely upon the outdated and 'miserable' black and white hachured 1:80,000 scale French 'Carte de l'Etat Major' that was issued to their own Army: http://library.mcmaster.ca/maps/ww1/French1889.htm (the French also had an excellent series of fortress 'Plan Directeurs' at a scale of 1:20,000 for the frontier areas, but these were kept secret even from their allies and were not made available to the British until October 1914, by which time they had mostly been overrun by the German Army). This was photographically enlarged to 1:40,000 scale and redrawn in colour, with contour lines added, by the British GSGS - but this had the unfortunate effect of merely amplifying the errors contained in the original: http://library.mcmaster.ca/maps/ww1/ContourOverlay.htm . The French 1:80,000 scale map series was seriously out of date by the outbreak of war in 1914 - the original survey for northern and eastern France had been done between 1818 and 1835, and although periodically revised since then it failed to adequately reflect changes such as new railways, roads, urban and industrial development. It was at a scale that was unfamiliar to the British Army, it was in black and white with elevations depicted in hachuring with only spot hights marked, and was often several hundred yards in error which made it of very limited use to the artillery. It must have been very difficult to read from the air, although it was also issued to pilots in the series GSGS 2526.

 

With the rapid advance of the German Army into Belgium and North Eastern France, much of these pre-war GSGS maps of the frontier areas turned out to be largely useless. In the retreat from Mons thousands of them were discarded as the Army retreated back into areas that were covered by the French 1:80,000 series map only. These were in short supply, however, so small-scale motoring maps were ordered from the French firm of Taride to supplement them - and cycling maps, even Michelin guides in some cases. On 11th September a series of 1:250,000 scale maps (GSGS 2733 and 2738) arrived from the OS in Southampton to replace the dated 1:380,000 GSGS 2517, and this 'administrative' scale map series appears to have subsequently become the main map series for air navigation in WWI. Chasseaud notes a map in this scale (GSGS 2823) from August 1916, which shows the location of airfields, and there is another one on the same scale from 1917/1918 and retained in the British National Archives that has been overprinted with German airfields. This 1:250,000 (4 miles to the inch) map series had been prepared from the French 1:80,000 series, but had been redrawn in full colour with red roads, blue water, green woods, towns and the railway network marked in black - but without contours, layering or hachuring.

 

With the British line stabilised on the Aisne, the French 1:80,000 maps were gradually replaced by fully coloured and redrawn maps at 1:100,000 and 1:40,000 based on a combination of the French map, local cadastral maps and field surveys (cadastral maps being the often very old larger-scale mapping of land ownership, showing property and field boundaries, held by local government). Although useful, these contained many errors and were therefore of limited use to artillery units firing by map coordinates, which led to the decision to start surveying the Front down to 1:20,000 scale or below for the preparation of barrage maps. It is likely that the RFC found them to be useful and were involved in their preparation, however, as they were coloured and marked in the same way as the 1:250,000 series maps and, by the end of 1915 covered the operational area from North to South "extending from the heaviest and furthest back English gun to its German 'opposite number'"" (Winterbotham) either side of the line but as far as St. Omer in the west. This series was eventually extended further west and south-west, but not until after the German Spring Offensive in 1918. It is likely that it it these maps that are referred to by the No.66 Squadron pilot Gordon Taylor, in his memoirs, when he comments that "For quick and easy reference I had pasted maps of the region for about 30 miles each side of the lines on pieces of plywood, and had made a holder for them which I had fitted beside my seat" (Taylor).

 

With the lines stabilised, the Field Survey Companies switched their focus to the production of accurate barrage maps at 1:20,000 scale, and trench maps at 1:10,000 scale and below. These were clearly of little use to pilots, and coloured marking of roads, rivers and woods disappeared to be replaced by the use of colour over-printing to mark German trench systems and the British front-line trench. On these early maps, the British trench system was depicted in full only on the 'secret' maps held at Corps and Army HQ (and similarly, only 'secret' editions of the small-scale maps at 1:250,000 scale had the locations of British airfields marked on them). The introduction of over-printed grid-squares for referencing that became a common feature of maps at this scale is attributed to an RFC officer at the Aisne, D.S. Lewis, who squared two copies of a 1:80,000 map in pencil, giving one to the battery commander that he was spotting for. Another officer, Lt. C.C. Darley of No.3 Squadron RFC, clearly regarded the French and GSGS series maps to be inadequate - and over the winter of 1914/15 made his own map of the squadron's front by taking photographs from above the lines, developing these plates in a makeshift darkroom in the stables of his chateau billet, and fitting them together until he had enough prints to produce a map of his own. Shortly after that, in the Spring of 1915, the army cooperation units of the RFC were issued with the first purpose-built cameras and started the sytematic photo recon. of the German trench system that was to have such a huge impact on survey and map making along the whole front. One type of map that was peculiar to the RFC in this period was a series of large-scale reconnaisance plans on card. 'Railway Sidings - Card for Airmen' GSGS 3076, covering the main railway centres that lay behind the German lines. These were double-sided, and some were double-length and hinged with linen. They were clearly designed for pilots' and observers' use in the air.

 

Maps for use by aviators made a re-appearance in a new series of 'breakthrough' maps at 1:40,000 scale prepared by the 3rd FSC for the Cavalry and the Flying Corps in the build-up to the Battle of Arras in the Spring of 1917. The map sheet GSGS 3488 'The Scarpe Valley' was sheet 51b of the regular 1:40,000 series, but with a strip added from sheet 57c to the south. There were two versions of this, the second one showing woodland and village perimeters in green, railways in red, and the roads in yellow. It omitted contours, which were regarded as unnecessary as the ground appeared to be flat from the air. After this, it became standard practice in 3rd FSC (Field Survey Compnay) to overprint the woods and the village perimeters in green on the 1:20,000 scale 'position' maps as well (the 'hostile battery position maps' with enemy batteries included as black dots). In the Messines operation 'special' sheets of this type were issued to No.53 Squadron RE8s flying contact patrols - they were to mark up the maps in the air and drop them on IX Corps 'dropping ground' at Scherpenberg. At Third Ypres two 'special' sheets were once again printed at 1:20,000 scale by 5th FSC with the woods overprinted in green for use in the air, and some large-scale plans of communications centres behind the German lines which were also probably intended for RFC use in identifying important targets for heavy artillery. At 3rd Ypres the 2nd FSC produced a special series of 1:20,000 scale maps for artillery/air cooperation, with the woods overprinted in green.

 

At the Battle of Cambrai 3rd FSC again made 'special' maps at 1:20,000 scale with green woods and village boundaries, and also a new type of 'going' map for the cavalry and tanks at 1:40,000 scale that was clearly also intended for the RFC to use, as it included the now familiar green overprinting to the woods and village boundaries. Shortly after this a series of 'corps squadron' maps for army cooperation units were printed at 1:20,000 scale, with the now familiar green woods and village outlines, and with water courses marked in blue. These also included the zone-call over-print for use from the air, to bring down an immediate artillery barrage on targets of opportunity identified by RFC pilots or observers. Later, the hostile battery 'position' maps were produced with tree-lined roads identified by green borders.

 

After the German Spring offensive on the Lys in April 1918, the back-area mapping was extended to the west and south west as a priority, and there was some attempt to coordinate survey and mapping with the French Service Geographique on a metric scale using the 'Lambert' projection. It appears that nothing much came of this before the Armistice, and both British and French armies regularly mapped and re-surveyed the others sector as they moved in or out. The Independent Air Force, created on 6th June, also experimented with a special 'aeronautical map' of its own, on ten sheets 19x25 inches square, at 1:250,000 scale in both a night version (GSGS 2861) and possibly a day version. These are said to be similar to the manoeuvres map of 1911, with white roads on a grey background, blue rivers and black railway lines, dark green woods, red towns and metric spot heights in white, with large expanses of water depicted in white hatched by thin blue lines. There are some examples of these sheets in the Salmon Collection in the Royal Geographical Society's map room. But it wasn't until 1919 that the GSGS took overall responsibility for service aviation mapping and produced the first sheet of a new series, the British Isles Aeronautical Series (Provisional ed.), a quarter inch (approx. 1:250,000 scale) in 1921.

 

Bletchley

 

Sources

 

Chasseaud, Peter. Artillery's astrologers: a history of British survey and mapping on the Western Front, 1914-1918. Mapbooks, 1999.

 

Nicholson, Tim. 'An introduction to the Ordnance Survey aviation maps of Britain, 1925-39' in Sheetlines, vol.23 pp.5-18, 1988.

 

Winterbotham, H. 'Geographical work with the Army in France', in The Geographical Journal, vol.54 pp.12-28, 1919

 

Taylor, Gordon. Sopwith Scout 7309. Cassell, 1968.

Edited April 25, 2009 by Bletchley

[shredward 12]

Halberstadt Fighters, rockets, and misadventures

 

From the Halberstadt Fighters Datafile, Peter Grosz:

 

With the exception of the engine and machine gun installation, there was little difference between the Halb DI, DII, and DIII.

DI 100hp Mercedes DI - one or two built and tested

DII 120hp Mercedes DII - 96 production a/c

DIII 120hp Argus ASII - 50 production a/c

Of the 57 DV fighters built, 31 were sent to Turkey, including all of the last production batch D3500-3024/17...Halberstadt fighters served in Palestine well into 1918.

 

Leutnant Rudolf Nebel of Ja 5, the noted German rocket pioneer, recorded how he wanted to increase the distance at which HA could be attacked. He mounted two stovepipes under each wing, installed four signal rockets and attached ignition cables connected to a firing button. As Ja5 took off to intercept, Nebel recalled:

Twenty-five HA closing from the west. I no longer paid any attention to my squadron mates, who could climb faster than my a/c with its four stovepipes. There was no time to reflect. I flew directly at the enemy squadron and automatically pressed the small button on the steering column. The distance about 100m was an enormous one compared to the accepted machine-gun range. Under my wings a woosh of fireworks, then a giant smoke trail shot through the English squadron. Was I successful? As a matter of fact, yes! An English pilot put his biplane into a dive and landed on the nearest field. Throttling down, I dived after him, landing some 20m away. The Tommy did not try the trick of surrendering and then at the last minute taking-off to escape. The new weapon had frightened him to such an extent that he surrendered without a fight. Eight days later I was to discover that the stovepipes had more than a mere morale effect. During this mission I shot the airscrew off an enemy machine. It crashed on the ground.

 

A week later, the fiery exhaust of the rockets, now mounted on an Alb DIII, ignited the wings, but fortunately the slipstream extinguished the flames. Nebel was lucky to escape serious injury when his a/c crash-landed.

 

A second Halberstadt fighter-rocket combination was less successful. On October 16, 1916, a Raketentrupp equipped with one Halb DII armed with four stick-stabilised rockets mounted on the outer wing struts for attacking balloons (an idea that had been copied from the French) left Berlin for the First Armée on the Western Front. Two weeks later the Raketentrupp was back in Berlin due to 'difficulty with the rocket system.' ...In any event, rocket attacks on balloons appear to have been a totally useless exercise, spectacular to be sure but incendiary bullets proved far more accurate.

 

Cheers,

shredward

[Dej 17]

Some intersting snippets at the University of Birmingham (UK not AL USA) and the prospect of e-versions on old or out of print works on The Great War.

 

Centre for first World War Studies

Edited May 1, 2009 by Dej

[Pips 5]

One of my most treasured books is "Flying The Old Planes" by Frank Tallman. Published in 1973 Frank describes flying original WWI aircraft in marvellous detail. Given that not everyone would have read this book I thought I would reproduce sections that relate to our era of interest. This is the first of several posts.

 

Frank, who along with Paul Mantz fomed Tallmantz Aviation, was famous as a stunt pilot for Hollywood and a collector of rare and vintage aircraft. Paul was killed in 1965 on the film set for 'Flight of the Phoenix'. Frank died in 1978 while delivering a Piper Aztec. In bad weather, with a lowering ceiling and rain, he struck the side of Santiago Peak in the Santa Ana Mountains near Trabuco Canyon. RIP.

 

 

Certainly the loveliest racehorse lines of all the WWI aircraft belonged to the Nieuport 28, and like the beautiful thoroughbred it resembles, it also had real speed and agility.

 

Gustave Delage was the chief designer of the extensive series of Nieuport aircraft. Yet in spite of the efficient designs, many models had intrinsic weaknesses. The N.28 is no exception. The sewn cover seams on the wing lay so spanwise, approximately ten inches back on the upper surface of the wing. Even in those relatively early years of aviation the area’s of life on a wing were known, and this major error in manufacturing, tied to an airplane quite capable of exceeding two hundred miles per hour in a dive, culminated in many an accident. Consequently the ‘28’ series, good in so many other respects, was never as popular as the sturdy SPAD’s.

 

The ‘28’ was constructed with a real mix of materials; wood spars with built-up wood ribs, plywood leading edge, turn buckles by the barrowload, streamline tubing for the landing gear, ‘I’ beam steel tubing in the centresection, paired with light aluminum and wooden outer wing struts and a pressed-cardboard cover (tulip wood strips) from the engine cowling to the rear of the cockpit area.

 

After a general inspection we face the aircraft into the wind and chock it. The single lever controlling fuel air mixture is retarded while the gas is on and the propeller pulled through. The dual ignition switch is off, and the coupe (cut-out) button on the top of the stick is depressed for added safety. There is fair compression necessitating a strong mechanic to pull through the prop.

 

The 160h.p. Gnome starts without priming and with a real bark. With the appearance of spattered castor oil on the leading edge of the wing we know we re oiling and ready for takeoff. With the chocks pulled and the Gnome winding up it’s like a Clydesdale pulling, so strong is the old engines power.

 

I know of no other aircraft except the Boeing F4B that has such complete and instant response. The tail is up in 15 feet of forward roll, and the rudder is needed to overcome torque, though the actual torque is nothing like the hair-raising fables of WWI-type pulp magazines.

 

With its short wingspan, it bounces off the surface in about 220 feet. Wow! The climb is spectacular, and a steep-climbing turn gives not the tiniest evidence of payoff. In flight, the most noticeable fact of the N.28 is that the big Gnome gives off heat like a cast-iron stove in a New England country winter. Great of you were flying over cold Europe, but hot as hell over sunny Cal.

 

Climb is in the order of 1,200 feet a minute, and stalls are straightforward unless one uses full back elevator.

 

Given the dubious seamstress work on the top wing, and in recognition of the aircraft’s advanced age, most of my aerobatics are done with ‘G’ loads in the order of 2 to 3, and with some timidity on my part.

 

The N.28 loops beautifully, and with the exception of offset rudder at the top (to counteract torque), it might as well be on rails. I start the loop in a gentle dive of 120 mph, and there is an immense sense of thrust from the big Gnome as it pulls you up and over.

 

Slow rolls are smooth, and you don’t need forward stick to hold the nose up, just unshakable faith, for the engine quits and doesn’t come back again for about 15 seconds. With that short wingspan the N.28 excels in quick changes of direction, and that big positive rudder really swings the nose around in turns.

 

No other aerobatics were tried, but the plane picks up speed like a pig on a greased slope, and you can comfortably get 200 mph without too much of a dive.

 

Like almost all WWI planes a nose high forward slip with this plane can kill off speed and yet give you some idea of clearance in your landing area. In the N.28 this is even more necessary, because with the Vickers guns in the staggered position your vision on the port side in a standard field pattern is quite limited.

 

With it’s short wings the N.28 pays off fast, and you had better be close to the ground in nay three-point attitude. But thanks to the graceful and generous rudder, you don’t have to make the rudder correction on landing that you do with the SPAD and the Fokker D.VII. The apparent touchdown speed is between 48 and 50 mph. The skid takes hold quickly, and drags to a stop in about 300 feet.

 

===================================================================

STATS: From “French Aircraft Of World War One”, by Dr. James J. Davilla and Arthur M. Soltan.

 

Empty Weight: 456kg (1,005 lb)

Loaded Weight: 698kg (1,539 lb)

Max Speed: 198 km/h (123mph) @ 2,000m (6,560 feet)

Climb: 5.5 minutes to 2,000m (6,560 feet)

Ceiling: 5,180m (16,998 feet)

Endurance: 1 hour 30 minutes

Armament: two .303 Vickers mg’s

No’s Built: 310, of which 297 were delivered to the American Air Service.

[Pips 5]

Flying The Old Planes - Part 2: SPAD VII

 

Extract from the book "Flying The Old Planes" by Frank Tallman, 1973.

 

The tongue-twisting mouthful of Societe pour Aviation et Ses Derives were the manufacturers of the SPAD, and it was Louis Becherau, the designer of the pre-war Gordon Bennet winning Deperdussin monoplane, who carried his ideas for speed and ruggedness into this new concept of fighter.

 

The choice of the superb Hispano Suiza powerplant was an innovation for its day. Becherau had decided that the days of rotaries were numbered. Gyroscopic force and the unreliability of rotaries had combined to make the choice of a Hisso an imaginative but eminently proper one. Starting with the 140 hp Hispano-Suiza, Becherau gradually increased the horsepower with different engine models of 150, 180 and finally 200 hp.

 

The ruggedness of the SPAD was refreshing to the French squadrons, and it could readily make a tiger out of an Escadrille pilot who in flying Nieuports in combat often waited for the weakly designed wing to take leave. Early models had a weakness with unreliable carburettor’s and cooling problems, but once that was overcome the SPAD came to epitomise the word reliable.

 

One other fault, later to be corrected with the SPAD XIII, was the single Vickers gun.

 

The SPAD construction was, of course, predominately wood, and it never ceases to surprise me that in this First World War period such large quantities of spruce, veneers and ply’s were available to both the Allies and the Germans. The radiator, being brass, lead, aluminium and some steel, weighs enough to require a forklift or nine graduates of a Charles Atlas weightlifting class; and, of course, behind it is a water-cooled V8 which, while light for it’s day, weighs more than most modern-day air-cooled engines of a similar size.

 

Like most of the aircraft of the time the SPAD VII ha d a square longeron fuselage covered in the engine area with aluminium, and the oval-shaped fuselage was formed with light veneer and stringers. The tail surfaces were wooden and used a comfort making strut for additional rigidity on the fixed portion of the elevators.

 

In the 180 hp and the 200 hp SPAD VII’s, they used a rudder with an additional midsection bulge like the belt line of a beer salesman, and this was supposed to take care of the additional torque of the larger engines. I have always flown our SPAD with the smaller straight-sided surface, and have had no rudder problems in the air or on the ground.

 

The wings of the SPAD were a thin French wingspan made with two routed spars and built-up ribs. Wings and tail section all had a typical wire-formed scalloped trailing edge.

 

The SPAD has an airfoil that gives a good climb (but awful glide characteristics), while the Se.5, according to the historians, was better acrobatically. Having flown the SPAD and the SPAD XIII as well as the Se.5 extensively, if I were in combat I would choose the SPAD VII. With no dihedral and quite light control forces, I found that the SPAD did not require the high perspiration count to throw it about that the heavier Se.5 required.

 

SPAD’s had push-pull rod-controlled ailerons; this was a real innovation, and it contributes greatly to the light feel and quick response of the aircraft.

 

Before flight, we had to set the plane in level-flight position and fill the header tank first, then the radiator, to eliminate (as much as possible) the steam-provoking air bubbles due to operating the SPAD in a much warmer, and dryer, climate than what it was designed for.

 

Once in position for take-off I turned the fuel-on switch off, and we went through the procedure that is necessary to start a Hisso. It includes checking if the fuel pump is operative. We also rock the propeller until fuel spills from the carburettor; then with contact, the pilot madly spins the booster coil and the mechanic flips the prop backward. It kicks forward and catches, and the Hisso rumbles nicely as the pressure and temperature rise. Because of the long exhaust stacks the engine is extremely quiet, and it’s easy to hold a conversation by the cockpit without shouting.

 

Pointing the SPAD into the wind I pour the coal on. Instantly the tail is up, and I have complete rudder control. I am off the ground and climbing in about 150 feet. Best climb speed is around the 60 to 65 mph. The push-pull ailerons are delightful, and the response is equal to or exceeds that of any of the WWI aircraft I have flown, including the Fokker D.VII; which is the best of the rest.

 

The Hisso idles beautifully, and power-off stalls occur at 47 mph, with a positive and quick nose drop. Like all WWI aircraft the control throw of the joystick is long, and adds to the challenge of maintaining a smooth coordinated flight until one gets used to it.

 

Rarely do I spin the World War One airplanes. If they are out of rig and you can’t recover, having to leave them would be much like the skipper of the Lusitania saying goodbye to his pride and joy. But spinning the SPAD VII is pure delight. Of all the aircraft in our collection, the SPAD VII promotes the most confidence. It’s sheer ruggedness, it’s light positive controls, all contribute to make taking liberties with this aircraft absolute pleasure.

 

With fly-through manoeuvres like the loop, I start at 135 mph, and halfway up I can either quit or got through with ball-bearing facility. It goes over nicely, but you see the flying wires slightly bowing all the way around. Generally I take a ‘G’ meter along and try to stay within 2 to 2 ½ G’s in manoeuvres with the old girls. Slow rolls are a combination of slow roll and aileron roll and come through nicely at 110 mph without enough altitude loss to upset the most stringent FAA flight examiner.

 

Cuban 8’s are a combination of the above, Immelmann’s are effortless, as is quick changes of direction in the roll plane. It doesn’t turn as well as any of the Sopwith’s or Dr.1, but with lots of rudder and practice it can get round quite quickly.

 

With the water temperature again rising in the warm air I got back into the pattern. A speed of 55 to 65 mph was adequate for the approach, and I touched wheels first on the concrete at about 48 mph. Holding the tail up with just enough power, I rolled onto the grass, immediately sucking the stick back and digging in the tail skid, and stopping in about 250 feet.

 

Just flying these World War I airplanes straight and level isn’t enough, so when the opportunity arose to do a special film documentary, I got most of the WWI birds out for flight and evaluation. In limited combat I found the SPAD noticeably more manoeuvrable than the Se.5, better than the Pfalz D.XII and better in some respects than the Camel or Nieuport. With a height advantage the Dr.1 could even get close. The only serious contender was the Fokker D.VII. The SPAD is more limber than anything except the Camel, Triplane or Dr.1 and the engine is pure reliability. And with its high speed it will run away from anything except perhaps the Se.5, and loops and rolls are positive and comfortable.

 

=========================================================================

 

 

STATS: From “French Aircraft of the First World War” by Dr. James J/ Davilla and Arthur M. Soltan

 

Empty Weight: 500kg (1102 lb)

Loaded Weight: 705kg (1554 lb)

Engine: 180 hp Hispano Suiza 8Ab

Max Speed: 212 km/h (132mph) @ 2000m (6,561 feet); 204 km/h (127 mph) @ 3000m (9,842 feet); 200km/h (124 mph) @ 4000m (13,123 feet); 187 km/h (116 mph) @ 5000m (16,404 feet).

Climb Rates: 4 minutes 40 seconds to 2000m (6,561 feet); 8 minutes 10 seconds to 3000m (9,842 feet); 12 minutes 49 seconds to 4000m (13,123 feet).

Ceiling: 6,553m (21,499 feet)

Endurance: 1 hour 30 minutes

Armament: one 7.7mm Vickers mg

No’s Built: Approx 3,500 SPAD VII’s of all versions

[Pips 5]

Flying The Old Planes - Part 3: SE 5

 

Extract from the book "Flying The Old Planes" by Frank Tallman, 1973.

 

Have you ever looked at the lines of a plane and from experience known instinctively that it will be all you expect? Such a plane is the British Se.5. It’s appearance reminds one of the British bulldog: sturdy, short, not beautiful but honest and dependable.

 

As you take it from the hanger the first thing to check is the radiator. It is adequate under most normal conditions, but it should be full. Next pull the undercowl by releasing the piano hinges, reach in, and with a wrench unscrew the oil plugs in the case. Staring from the top plug, to check the oil. Check your fuel tanks – the main tank is in front of the pilot. Then the leader tank, which is actually the leading edge of the centre section. Now walk around the Se, paying particular attention to the exhaust stacks, the shock cord, and the landing gear fittings, your dual set of flying and landing wires and, most particularly, the tail surfaces, with their bracing wires underneath and above.

 

On your way to the flight line you would notice that in manually lifting the tail of the Se.5, it is light in comparison with many other WWI aircraft. This is primarily due to the landing gear being set rearward, almost even with the leading edge of the wing. This was a source of embarrassment to some, occasionally causing nose-overs when landing and taking off.

 

Climbing in to the Se.5 make sure to swing you leg well clear of the exhaust pipe, which extends past the cockpit coaming. Your hand falls easily to the circular spade joystick. The rudder bar is set off the floor and has a top for your foot so that it cannot slip off when the plane is inverted. Oddly the throttle and mixture are set on the right on a little shelf (rather than the left as in almost all other aircraft), and the mixture control when full open is to the rear when your throttle at the same time goes forward!

 

All Hisso engines have to be loaded up with throttle back and switch off and the propeller moved back and forth until you get some fuel overflow. Check carefully to see your gas valve is on. When ‘contact’ is called and the prop is swung “clear”, rotate the booster mag handle, and the engine will catch and start easily with a nice gentle rumble. It idles nicely below 500 rpm. After allowing the water temperature to rise and checking oil pressure mags, you’re clear to go.

 

The heart-lifting thrill of shoving the throttle forward is never lost, at least to me, and it was there as I pushed forward the control of the Se.5. The tail levelled almost instantly. Because the propeller is slow-turning (about 1500 rpm on take-off), you have no appreciable torque and very little engine noise. The Se.5 was airborne in 246 feet, and could have gotten off somewhat sooner if required. You have a nice positive feel, and you are climbing out at about 75 to 80 mph with a rate of climb approaching 900 feet per minute.

 

Straight and level at 3,000 feet, I noticed slight tail heaviness, even with the trim tab wheel forward. The cockpit is roomy by WWI standards; comfortable, with fine visibility and very little wind flow.

 

Wide open I was indicating 127 mph and 1650 rpm at 3,000 feet. Settling back to cruise, I locked my belt and brought the stick back for a stall. It pays off gently, but with a sharp right wing drop at an indicated 52 mph. Invariably, in a stall, the right wing dropped. I tried a spin – one turn nicely, cleanly to the right; unfortunately, it would only spiral to the left and, I believe sensibly, I did not try to force it in. with any aircraft over fifty years old I eat a little raw heart with aerobatics, for no matter how careful you check it, anything can fatigue in this length of time.

 

Being careful to keep heavy stick pressures out of my work, I pulled up into vertical reverses in both directions, an it held on nicely and reversed well with rudder. Looping at 135 mph went well but got slightly soft at the top, where I was indicating 60 mph, but it came through without my hanging on the belt. Cuban 8’s went well, but the engine spewed fuel out on my descending half roll and cut out for a period of four seconds. It slow rolls nicely to the left, but you need 115 mph to carry you through for the time the engine cuts out. Unfortunately, in rolling to the right it resists strongly, and you get a roll that is impossible to do smoothly and takes much time. Flick rolls or snap rolls were nice to the right at 85 mph, but completely impossible to the left, for it stalls straight forward and will not snap with any combination of stick and rudder movements.

 

Controls are positive but slightly heavy, and even with low ‘G’ manoeuvres the stick force required makes one feel the effort. To throw the Se.5 around with abandon would require a fit young man with muscle. Especially for any length of time or at high altitude.

 

Entering the traffic pattern I circled as I waited for the green light. Once it flashed I started a gentle turn into my grass area, holding about 75 to 80 mph indicated. By now the strangeness of flying with my left hand and using the throttle with my right was gone. Like all early aircraft the Se.5 pays off very quickly, and in attempting to check my touchdown speed on the airspeed indicator I bounced but caught it with stick and a little rudder. It indicated about 54 mph. The rudder was quite positive and the steerable tailskid is one of the few WWI planes so equipped, making taxiing very easy.

 

==========================================================================

 

Here's another view of the ability of the SE 5 in a fight. Both are drawn from the classic book "Sagittarius Rising" by Cecil Lewis, and provide another perspective of the SE 5 performance - as well as the confidence that the aircraft engenders. Both are from when Lewis was serving with 56 Squadron, by which time he was a very experienced pilot on his second tour, and with several kills to his credit.

 

 

Extract 1

Rumours of the new SE 5 with a 200 hp engine had been prevalent for some weeks, and at last the machine arrived. I was detailed to take it up on the test. I found it faster, and it climbed so well that, since it was a beautiful evening, I decided to find it's ceiling.

 

At ten thousand feet the view was immense, England quartered on its northern perimeter. Oh to be home again. Just to be over England, even if one could not land! After all, why not? I turned north. At twenty thousand feet, Kent was below me. The faintest drift of blue smoke from the chimneys of some country houses. There would be the scent of a wood fire down there, far, far, far below.

 

The wing-tips of the planes, ten feet away, suddenly caught my eye, and for a second the amazing adventure of flight overwhelmed me. Nothing between me and oblivion but a pair of light linen-covered wings and the roar of a 200-h.p. engine! There was the fabric, bellying slightly in the suction above the plane, the streamlined wires, taut and quivering, holding the wing structure together, the three-ply body, the array of instruments, and the slight tremor of the whole aeroplane.

 

I looked long at the island below me, then shut off the engine, and in one long, unbroken glide swept back to France. I came over St. Omer at about five thousand feet and saw a back-staggered scout circling the aerodrome. I turned to have a look. When I came close, I saw it was one of the new Sopwith Dolphins. I plunged down on its tail as a challenge for a scrap. This new SE I was flying would be more than a match for anything in the sky.

 

The reader will not take it amiss if I say that by this time I was a fairly competent pilot. I could do every stunt then invented with ease and style. I admitted none to be my superior in the handling of an aeroplane. So I confess I dived on the Dolphin with the intention of showing him just how and aeroplane should be flown in a fight, sitting on his tail for a bit and then, when it was quite obvious I had killed him ten times over, coming up alongside, waving him a gracious good-bye and proceeding to my aerodrome.

 

But it didn't work out a bit like that. The Dolphin had a better performance than I realised. He was up in a climbing turn and on my tail in a flash. I half rolled out of the way, he was still there. I sat in a tight climbing spiral, he sat in a tighter one. I tried to climb above him, he climbed faster. Every dodge I had ever learnt I tried on him: but he just sat there on my tail, for all the world as if I had been towing him behind me. Who was the fellow anyway? What was it coming to when test pilots at Aircraft Depots could put it over a crack pilot of 56? The Dolphin shut off and dropped to the carpet. I followed. We jumped out of our machines. I seemed to recognise the spare figure crossing towards me. He lifted his goggles. It was Patrick!

 

"Well, Lewis," he said, as we shook hands, laughing, "I see your still learning to fly?"

 

(Patrick was the O.C of the testing and ferry pilots at Marquise in March 1916 when Lewis first arrived in France on his first tour).

 

 

Extract 2

A Wing of French machines had been sent up from the south to operate in the Dunkerque area. In order to familarise the French pilots with all types of British aircraft operating in the sector (so they might not shoot down friendlies by mistake), a machine from every British Squadron was sent over for the French pilots to see. I was detailed to take over an SE. The French flew SPADS, a neat low-winged biplane, and it's leader was the famous French ace, Guynemer. He had three aircraft, a standard SPAD VII, a high compression SPAD and a larger special machine (SPAD XII) made by the same firm with a 200-h.p. Hispano engine fitted with a cannon.

 

A race was held between the two special SPAD's and the SE 5. Their speeds were almost identical, but the high-compression SPAD climbed quicker. After the race was over, Guynemer and I held a demonstration combat over the aerodrome. Again I was badly worsted. Guynemer was all over me. In his hands the SPAD was a marvel of flexibility. In the first minute I should have been shot down a dozen times. Nothing I could do would shift that grim-looking French scout off my tail. Guynemer sat there, at about thirty yards range, perfectly master of the situation. In self-justification, I feel I must add that both the Sopwith Dolphin and the SPAD were more manoeuverable than the SE 5. So that, given equal flying ability, they would win. Given Guynemer's still greater skill, the SE 5 was right out of it. At last we came down, landed, shook hands, and went into the Mess to drink sweet wine and eat sugar cakes. Only a week later Guynemer was shot down and killed.

 

To be fair to the SE the above combats are not necessarily the way to fight the SE 5. And although they do portray a fairly accurate comparison in head to head combat, it would not have been the way Lewis would have fought in the real kill or be killed arena. The SE is not the sort of aircraft to get in close and dogfight with, unlike more nimble aeroplanes like the Tripe, Pup and Camel. As Lewis describes several times in his book combat was more a case of using height, climb rate and speed to out manoeuver your opponent, so as to drop on him when he was at a disadvantage. "A pilot would go down on the tail of a Hun, hoping to catch him in the first burst; but he would not be wise to stay there, for another Hun would almost certainly be on his tail hoping to gte him in the same way. Such fights were really a series of rushes, with momentary pauses to select the next opportunity - to catch the enemy at a disadvantage, or seperated from his friends."

 

The same approach is described several times in McCudden's marvellous book "Flying Fury". The SE's strength, like the SPAD, is better suited to the vertical than the horizontal, and woe betide anyone foolish enough to fight otherwise.

 

========================================================================

 

 

STATS: From “British Aeroplanes 1914 – 1918” by J. M. Bruce

 

Se.5

Empty Weight: 1,406 lbs (638 kg)

Loaded Weight: 1,940lbs (879 kg)

Engine: 150 hp Wolseley-built Hispano Suiza

Max Speed:

120 mph (193 km/h) @ 6,500 feet (1981m);

116 mph (187 km/h) @ 10,000 feet (3048m);

105 mph (169 km/h) @ 15,000 feet (4572m)

Climb Rates:

5 minutes 35 seconds to 5,000 feet ();

7 minutes 50 seconds to 6,500ft ( 1981m);

13 minutes 40 seconds to 10,000 feet (3048m);

29 minutes 10 seconds to 15,000 feet (4572m).

Ceiling: 17,000 feet (5182m)

Endurance: 2 ½ hours

Armament: one fixed Vickers mg, one Lewis mg on a Foster mounting

No’s Built: 5,205 of all types with 828 built in 1917 and 4,377 in 1918. In total 1,999 were sent to France.

 

Se.5a

Empty Weight: 1,580 lbs (716 kg)

Loaded Weight: 2,034 lbs (922 kg)

Engine: 200 hp Wolseley-built Hispano Suiza

Max Speed:

132 mph (212 km/h) @ 6,500 feet (1981m);

128 mph (205 km/h) @ 10,000 feet (3048m);

115 mph (185 km/h) @ 15,000 feet (4572m)

Climb Rates:

6 minutes 0 seconds to 6,500ft ( 1981m);

11 minutes 20 seconds to 10,000 feet (3048m); 2

2 minutes 55 seconds to 15,000 feet (4572m).

Ceiling: 19,000 feet (5791m)

Endurance: 2 1/4 hours

Armament: one fixed Vickers mg, one Lewis mg on a Foster mounting

No’s Built: 5,205 of all types with 828 built in 1917 and 4,377 in 1918. In total 1,999 were sent to France

[Pips 5]

Flying The Old Planes - Part 4: Sopwith Triplane

 

Extract from the book “Flying The Old Planes” by Frank Tallman, 1973.

 

The father of the Sopwith Triplane was the Sopwith Pup, and according to Oliver Stewart, one of the most romantic chroniclers of World War One flying, these were two of the finest and most widely loved and respected Allied aircraft of that conflict.

 

Sopwith sensibly decided to use the Clerget Rotary engine which, among other qualities, had dual ignition and was an advanced design over the 110 hp Type 9J Le Rhone.

 

Like the Pup, the Tripe used the single Vickers gun for armament, with the padded porthole-like windscreen on the back of the gun. Clearing a jam on this little dude must have involved a frozen face and fingers over the snow-covered western Front, and the pilot must have needed a high-wire artists lack of acrophobia to stand up and play armourer on the jammed Vickers. Several Tripes were fitted with twin Vickers, but the performance hit of the extra weight was noticeable and, with the Sopwith Camel beginning to be delivered in large numbers, the Triplane was relegated to second-line status.

 

Through the history of this unusual airplane runs an aura of very strange dealings and decisions. At the same time that the Sopwith Triplane had been ordered by the RFC, the Admiralty had ordered SPAD VII’s for it’s RNAS. Due to reasons never adequately explained, the Services did a swap and, except for one in the Near East, and another fighting the White Russians in 1919, the RFC never flew the type. The area of doubt that still remains is why this fine aircraft was never placed into quantity production, when it was so evidently superior to anything the Germans (or Allies) had at the time.

 

Like the later Fokker Dr.1, the Tripe used a single I bracing-type strut, although in the case of the Tripe flying and landing wires were also utilised. Time was to prove it a strong basic design which, except for early rigging problems, gave little reason for structural worries.

 

The Sopwith Triplane’s fuselage, gear, and tail surfaces are almost dead ringers of the Pup’s, so they are simplicity with a capital S, and the Sopwith Triplanes wings have two solid spars fifteen inches apart. Although not apparent in most photo’s, there are flying and standing wires, as well as drag wires from the cowling to the wings, and additional wires from aft of the pilots seat forward to the wing structure.

 

The struts, which are of spruce and go through the wings as well as the fuselage in the cockpit area, are of a size and shape of a plank from a hundred-gun ship of the line. Interestingly enough, the trim wheel for the adjustable tail plane is bolted to the centre section strut that goes through the cockpit and fastens to the bottom longeron.

 

The Triplane I flew was built by Lou Stolp for Earl Tavan, a Californian rancher who dreamed of Tripes instead of cattle. Lou is a master builder of the Experimental Aircraft Association. With the valuable assistance of the Hawker Siddeley Group detailed original plans were provided to Lou and his team as well as much needed assistance. Some modernisation changes were made for modern convenience that did not spoil the appearance. For power, instead of the cranky and rare rotaries, a Warner 165 hp radial (with the same frontal dimensions) was substituted. A battery, starter, and generator were included as well. Wire wheels of the proper size and weight were designed and beautifully built, with a brake inside the hub and completely unseen.

 

The basic fuselage was constructed of square steel tubing of the same dimensions and of greater strength than the original wood. The cockpit layout was faithfully identical to the original, as were the wings, controls and all wires. The bracing wires were all of the streamlined type (as were those on original Tripes) and purchased from MacWhyte Company in Milwaukee, which is the only firm in the USA which makes such.

 

Because of it’s height, the Tripe appears rather larger than it is, when it actuality it is only a foot higher than the Dr.1.

 

It was brutally hot on the day I flew the tripe, with a ground temperature of 100 degrees. The Warner started easily, and visibility while taxing out was a pure pleasure after the truly blind Dr.1.

 

I taxied out to the end of the runway, and after running up the Warner, turned into the wind. Pouring on the coal, I left the tail on the ground for about 100 feet, then raised it instantly. I got an unexpected torque swing to the left and went off the narrow grass runway, clipping the growth like a McCormick reaper. Full opposite rudder and aileron brought me slowly back along with a sudden wetness in my palms, and I was airborne with no wind in about 480 feet. Obviously the triplane is heavier than the original (by about 300 pounds) and without the slow, big propped rotary, the performance suffers.

 

Climbing out, I was struck by the typical rotary torque feel that had occurred on takeoff. Rate of climb was approximately 1,000 feet a minute at an indicated 58 mph. The three ailerons on each wing were pure delight and gave this machine a crisp response equal to that of a Stearman or Tiger Moth.

 

I climbed to the aerobatic area in slow circles, feeling out the rudder and elevators, which have somewhat lees positive ness than the ailerons. Stalling speed occurred at 44 mph, and the plane broke gently straight ahead.

 

Wide-open throttle gave an indicated airspeed at 3,000 feet of 92 mph, and, edging the throttle back, I dropped the nose gently for a loop. With 115 mph indicated, I pulled back gently and added full power over the top, where I had 30 mph. The Tripe followed through nicely, but with a loop considerably larger in diameter than the Dr.1. All the way through the flying wires sang like a demented peanut vendor.

 

In slow rolls without an inverted feed system, the Warner cut out at the inverted position, and it was necessary to finish dead stick. Normally you would pick something for a horizon line, but in a roll with the Triplane, you have the feeling of three artificial horizons bars, and you are not sure which one to pick.

 

Cuban 8’s are performed easily, as are climbing reverses, with the rudder proving to be adequate. Rolls and changes of direction are crisp and the aircraft quite agile due to those excellent ailerons. Sustained turns on the other hand leave something to be desired. A turn is not the manoeuvre to use with someone on your tail. The strong point of the Triplane is its rate of climb. It goes up like the proverbial monkey, and when speed drops to around 45 mph if you level out quickly it’ll just sit at that height, without dropping off into a stall or spin. Speed quickly returns and the Triplane is once again responsive and light on the controls.

 

In a mock combat with an extremely able pilot, ex-Major James Appleby flying the Fokker Dr.1, I would have the edge flying the Triplane due to the stiff and slow ailerons on the D.1; but both aircraft have their limitations. The skill and experience of the pilots are more important than the actual physical differences between the two planes.

 

Coming into land, I sensibly chose the grass area and not the narrow surfaced runway. I touched down faster and sooner than anticipated at about 52 mhp. Still I managed to roll to a stop straight ahead, and wiped nineteen gallons of salty water off my forehead.

 

Reflecting on the differences between the Dr.1 and the Triplane I feel that the tripe is infinitely superior. It is more controllable, lovelier on the ailerons, climbs faster, and the roll out on landing is easier. It would have been nice to have flown a Tripe with the Clerget rotary, and see how it performed without the extra 300 lb penalty imposed by the Warner engine. Then again, the Dr.1 was also equipped with the Warner, so perhaps the comparisons are valid.

 

=========================================================================

 

STATS: From “British Aeroplanes 1914 - 18” by J. M. Bruce.

Empty Weight: 1,101 lb (335 kg)

Loaded Weight: 1,541 lb (698 kg)

Engine: 130 hp Clerget

Max Speed:

117 mph (188 km/h) @ 5,000 feet (1524m);

112 mph (180 km/h) @ 7,000 feet (2133m);

109 mph (175 km/h) @ 9,000 feet (2743m);

107 mph (172 km/h) @ 11,000 feet (3352m);

104 mph (167 km/h) @ 13,000 feet (3962m);

98 mph (158 km/h) @ 15,000 feet (4572m).

Climb:

1 minute 45 seconds to 2,000 feet (609m)

2 minutes 30 seconds to 3,000 feet (914m)

4 minutes 35 to 5,000 feet (1524m)

7 minutes 15 seconds to 7,000 feet (2133m)

11 minutes 50 seconds to 10,000 feet (3048m)

17 minutes 30 seconds to 13,000 feet (3962m)

22 minutes 22 seconds to 15,000 feet (4572m)

26 minutes 30 seconds to 16,400 feet (4998m)

Ceiling: 20,500 feet (6248m)

Endurance: 2 hours 45 minutes

Armament: One fixed .303 Vickers mg

No’s Built: 178, of which 10 were delivered to the Aviation Militaire

[Pips 5]

As a balance to Frank Tallman's view of the Sopwith Triplane I thought I would add some other first-hand accounts by those who have flown it. Most are drawn from the books "Sopwith Triplane Aces of World War 1" by Norman Franks or "Sopwith Aircraft" by Mick Davis.

 

Wing Commander Paul Hartman, RCAF (Rtd) - commenting on the Carl Swanson reproduction Triplane in 1968 at the International Air Conference about flying vintage aircraft.

Of all the vintage aircraft I have flown, this is undoubtedly the most pleasant to fly. It possessed stability and control response so good as to be unique, not only for aircraft of that era but also in comparison with many of todays machines. It's positive stability about all three axes, plus the horizontal stabliser that was adjustable by the pilot during flight, resulted in an aircraft that coudl be flown with a minimum of concentration and effort. Indeed, when the aeroplane was properly rigged and correctly trimmed in flight, it could be flown hands-off. The controls were light, powerful and well-harmonised and the aircraft's response to the controls was excellent.

 

As I settled into the seat for my first flight I was again stuck by the simplicity of the cockpit and the paucity of instruments. Airspeed indicator, tachometer and pulsometer; throttle, Tampier lever, fuel cock and 'blip' switch plus stick and rudder was the sum total.

 

The seat of the Triplane is much lower than in other aircraft, and my initial impression on sitting in it was one of very limited visibility forward through an arc of 30 degrees either side of the centre line. However a gap between the wing root of the centre mainplane and the fuselage enabled the pilot to see forward and downward for approach and landing. Moreover once airborne the thin wings offered almost no restriction to overall visibility.

 

The engine was primed, throttle and Tampier levers set, switch on. Contact! The Clerget fired immediately and settled into a rhythmic rattle typical of the rotary and idled smoothly at about 700rpm. I had no intention of allowing this aircraft to become airborne in a three-point attitude, as happened during my first flight in the Nieuport 17. Thus the control stick was held about one inch forward of centre as I opened the throttle. The Tripe accelerated quickly as the power was increased to approximately 1150rpm, and the tail rose at about 20 knots. There was almost no tendency for the aircraft to swing to the left due either to torque or the gyroscopic effects of the engine, and very little rudder was required to keep the aircraft straight during the take-off run.

 

With the tail up and the aircraft in almost level flight attitude, visibility over the nose during the take-off run was excellent. At 38 to 40 knots, the aircraft left the ground and accelerated rapidly to 60 knots. I eased the climb, holding the speed constant at 60. The altimeter indicated 650 to 700 feet as the aircraft boundary was crossed - a distance of approximately 5,000 feet from the take-off point. I had been airborne less than a minute at that instant, so the aircraft has a fair rate of climb. Those watching on the ground told me later it appeared to be climbing like a homesick angel. It certainly felt so to me. I continued the climb to 900 feet, where I levelled off and made a left hand return to the field.

 

During the turn, with an angle of bank of 40 degrees, I became aware that a coordinated entry into the turn had been made without my being aware of it. There was no slip or skid, and no gyroscopic precession was apparent from the engine. The wind blasting squarely in my face confirmed the former, and the necessity to hold a very light top rudder force during the turn attested to the latter. At 1,500 feet above the aerodrome a stall check was made. The throttle was closed and the engine idled at approximately 700rpm at an indicated airspeed of 40 knots. The control stick was fully back. The aircraft was hanging on the properller in a 12 to 13 degree nose high attitude, refusing to stall. I depressed the blip switch, the rpm decreased, and the nose dropped. The ailerons were fully effective immediately prior to either wing drop. As the nose dropped, the blip switch was released and the engine picked up to idle rpm. The height lost during recovery from the stall was 75 feet.

 

After recovery the aircraft as trimmed to glide at 50 knots. The glide was continued to 1,000 feet, where the engine power was set at 1100rpm and a level speed run made. Subsequent corrections for air temperature showed the aircraft achieved a true airspeed of 111 mph.The speed run also enabled a last check to be made of the effectiveness of the adjustable horizontal stabliser as a trimming device. It was a positive and poweful trimming device.

 

A speed of 105 knots indicated was the maximum to which the aircraft was flown. It displayed a slight tendancy to yaw to the left as speed increased in a dive, then yaw to the right as speed was reduced. The yaw is easily overcome with rudder. The landing was straightforward and easy. The aircraft was glided at 50 knots to a height about 15 feet above the ground, at which point the blip switch was depressed and held. The control stick was eased slowly backward to flare the aircraft. It slowly lost height as the speed decreased during the flare, until the aircraft was about one foot off the ground at a speed of about 40 knots. Stick fully back at this pont - a slight sinking feeling as the air speed needle touched 37 to 38 knots - and we're on the ground!

 

Captain Foster Herbert Martin Maynard, who served with 'Naval 1' in the Great War.

The Triplane was an excellent machine for fighting purposes, for although somewhat leisurely in manoeuvre, it's extra-ordinarily good climbing powers generally enabled a good pilot to get the better of his opponent in an individual contest.

About the middle of July (1917) I was given a two-gun Triplane to try out. The extra firepower afforded was, of course, extremely valuable. Unfortunately, the extra weight took off so much performance that the machine was of no use in a formation of ordinary one-gun Tripes.

 

A report by a British Third Army AA position, which witnessed Robert Little (Naval 8) attack eleven Albatross near Arras om 7th April, 1917.

At 1845hrs on the 7/4/17 a Sopwith Triplane, working alone, attached 11 hostile machines, almost all Albatross scouts, north-east of Arras. He completely outclassed the whole patrol of hostile machines, diving through them and then climbing above them. One Albatross scout, which was particulary aggressive, dived on him and passed him. The Sopwith then dived on him and then easliy climbed again above the whole patrol, drawing them all the time towards the anti-aircraft guns. As soon as they were within range, the anti-aircraft guns opened fire on the patrol, which turned eastwards, and the Sopwith returned safely. The officers who witnessed the combat report that the manoeuvering of the Sopwith completely outclassed that of the Albatross scouts.

 

Captain Robert Alexander Little, The great Australian ace, Naval 8.

(he has dived into a mixed fight involving several FE's and Albatross scouts on 30 April at 0645hrs, east of Arras).

An Albatross dived on me from out of the sun. My gun jammed and I tried to break off the engagement, but the HA kept pace with me and opened fire, shooting away my pump and hitting the planes, so then I stopped and stunted. I then got under the HA and stayed there. I turned when he turned and dived when he dived. The HA pilot could not find me.

 

I got my jam clear and fired on the HA, which was about 20 feet in front of me and about 10 feet above. Half the fuselage and engine was all I could see through my sight. I saw tracers hit it. It started to climb, then stalled and went down in a dive, turning slowly. I last saw him at 1000 feet when I lost him in the mist.

 

Flight Commander Raymond Collishaw, Naval 10.

The Triplane I found to be a delightful machine - in my estimation much preferable to the Pup. The machine was a private venture by the Sopwiith Company, and the prototype made it's appearance in mid 1916.

 

The three-wing design was adopted to permit the pilot the widest possible field of vision, and also as a means of ensuring manoeuverability. The middle wing was at the pilot's eye level, and interfered very little with his vision. All three wings had a narow chord, and because of this the top and bottom wings blocked off less from the pilot's view than in the case of biplanes. The standard Triplane was fitted with the Clerget 130 hp engine. This powerful motor gave it a speed of nearly 100mph at 15,000 feet, and it could climb to 10,000 feet in just under 12 minutes and had a service ceiling approaching 20,000 feet.

 

Apart from it's good manoverability and rapid rate of climb, which was very good for it's day, the Triplane's main virtue was the extreme altitude that it could attain, and its performance at these heights. Like all aircraft the Triplane had its weaknesses. It was not quite as fast as it could have been, and it could not match a machine such as the Albatross D.III in a dive. Its main failing though was its armament. Like the Pup it only had one Vickers. The German fighters it was pitted against during 1917 had twin guns, and given comparable performance, it is hard to find a substitute for firepower.

 

Six experimental models were in fact fitted with twin Vickers, and I was fortunate enough to obtain one prior to leaving Naval 10. Some of the pilots considered the added firepower would be more than offset by a drop in speed and climb performance at height as a result of the extra weight. Others, including myself, felt that a certain loss of performance would be acceptable in exchange for the extra gun. I found, in fact, that although there was a definite loss in performance over 10,000 feet, it was relatively slight, and having twice the firepower at my command made a big difference.

[Pips 5]

Flying The Old Planes - Part 6: Sopwith Camel

 

Extract from the book "Flying The Old Planes" by Frank Tallman, 1973.

 

 

My Sopwith Camel is, as far as I’m aware, the only original World War 1 Camel ever brought back to flying condition. It was originally owned by Colonel Jarrett of the Jarrett War Museum located on the old Steel Pier in Atlantic City; who in the 1930’s had the best museum of WWI equipment ever assembled, including the Belgian War Museum in Brussels. The Jarrett Museum fell on hard times following WWII and, with time and money on my side after my service period, and a lifelong ambition of owning a WWI aircraft, I purchased for a small sum (by today’s standards) several antique aircraft including the Camel, a Nieuport 28, a Pfalz D.XII, a Fokker D.VII and a SPAD VII.

 

The Camel was the first WWI aircraft I brought back to flying condition and required some major rebuilding, which took several years, many thousands of dollars and a whole host of experts including Paul Poberzney of the Experimental Aircraft Association, the gifted master craftsman Ned Kensinger, the Hawker Siddeley Group and a number of very dedicated volunteer’s.

 

(NB: There is quite a bit on the rebuilding process in the Chapter but I have left it out of this extract for the sake of space).

 

When the day finally came to fly the air was filled with great anticipation. On arrival at the airport though I was dismayed to hear from my team that they had been trying to get the temperamental 110 h.p. Le Rhone started since 8.00am that morning, without success. The lack of knowledge amongst us regarding the Le Rhone was appalling. Did we have spark? Yes. Was the mag set? Yes. Had the commutator ring been wiped off? Yes. Had we primed it? Only every other cylinder.

 

With only a vague notion of what I was doing I clambered into the cockpit (a very tight fit) and reviewed the cord-wrapped Spade stick, the Block tube, carburettors next to one’s knees, the flexible air intake to the outside air scoops, the wood wire brace longerons, the instrument panel with it’s clutter and the duel control cables to the wooden rudder bar. At my request, the crew forced open the intake valves as the engine was pushed through (switch off) and shot a charge of fuel in each cylinder, as the cylinder came in front of the hole in the cowling. By accident, rather than by knowledge, I advanced the long lever controlling the air, and in pushing the manet (a small wheel knob on the miniature control quadrant) forward and then returning it, I had hit on the correct starting procedure. Wonder of wonders, as I flipped the porcelain-mounted switch up and called for contact, the Le Rhone started with a full-throated bellow, scaring both me and the crew!

 

By shoving the fuel-controlling lever forward and using the coupe (cut-out) button on the stick, I was able to keep the engine running. Soon the never-to-be-forgotten smell of castor oil infused our area, and the sight of oil splattering the leading edge of the low wings indicated that the engine was lubricating properly. Taxiing practice ended ignominiously a hundred feet from the starting point, when my newfound knowledge wasn’t equal to the delicate adjustment of fuel and air, and the Le Rhone quit.

 

The revitalised ground crew hauled the 900 pound airplane over the grass and faced me into the wind. For safety sake we changed the plugs, and the Le Rhone started first try. I headed down the field with the throttle wide open. The tail came up almost instantly, and visibility was good, except for the Aldis sight and the twin Vickers. Not having planned on flight it came as something of a shock to find the Camel airborne at about 35 mph after a ground run of just 150 feet. Being afraid of jockeying with my ticklish fuel and air controls I stayed low and just got used to the Camel’s sensitive ailerons, elevators and rudder.

 

I circled the field once, got into position for landing, shut fuel air and switch off, and made a light forward slip, touching down gently on three points. Total landing couldn’t have been much longer than the initial take-off run.

 

So much for my first (unintentional) flight in the Camel.

 

Since then I’ve spent more time flying the Camel than any of the other historical aircraft in our collection. I’ve also had more forced landings in it than all the rest of the WWI aircraft combined. It’s that temperamental Le Rhone. Cylinders have blown, magneto’s have failed, even fouled spark plugs have brought me down unceremoniously, with sweating hands and my heart in my mouth, desperately seeking a patch of open ground on which to land. Yet for all that it’s the one I turn to first for any show or exhibition, as the Camel gets my blood going like no other. This is an aircraft that is a joy to fly.

 

With the Le Rhone 9J, you cannot adjust either the fuel or air intake without running the risk of a dead-stick landing. You must leave them alone and use you Coupe (cut-out) button for all fight handling.

 

The take-off run is easy. In a wind of 10 to 15 knots you are airborne in a couple of plane lengths at 35 mph and climbing out at 60 mph, with a rate of climb of almost 1,000 feet a minute. The elevators are sensitive, as is the rudder. Consequently, when fling for any distance I often put the heels of my shoes on the floor tie wires, because the vibration of the Le Rhone through the rudder bar exaggerates the rudder movements.

 

In level flight at 100 mph indicated, the Camel is delightful, with just a hint of rudder being required for straight flight. The structure is rugged enough to feel comfortable in loops, and being slightly tail-heavy it goes up and over in an incredibly small circle in the sky, and faster than any other WWI aircraft I have flown. Sneeze and your halfway through a loop before your aware of what’s happened. 110 mph is enough to carry you through, and as you slow down over the top you must feed in rudder against the torque.

 

In military shows I have ground strafed, and as soon as the airspeed reaches 130 to 140 mph the nose begins to hunt up and down, and the elevator becomes extremely sensitive. I feel this action is due largely to the square windshield between the two Vickers guns, causing a substantial burble over the tail surfaces.

 

Turns are what the Camel is all about. Turning to the right with the torque requires the top rudder to hold the nose up, and the speed with which you can complete a 360-degree turn is breathtaking. Left turns are slower, with the nose wanting to rise during the turn. But small rudder input easily keeps the nose level with the horizon. In stalls at 35 to 40 mph the nose drops frighteningly fast and hard to the right, but you also get control back quickly, although a surprising amount of altitude has been lost. I have had the pleasure of limited dog fighting with other WWI fighters, and there are none that can stay with a Camel in a turn.

 

With the Le Rhone being temperamental as it is, flying the Camel is best done at times when there are few other aircraft in the sky, leaving easy access to the airport in cases of emergency. The Camel touches down easily but runs out of rudder control almost instantly, and if you bounce your landing at all, you are likely to find yourself in a hairy ground loop looking at a rapidly bending aileron dragging in the grass.

 

For a wide variety of reasons, the Camel is a fascinating airplane, flight-wise as well as historically. But don’t think I ever got out of the Camel after being airborne even in the coldest weather without buckets of perspiration and considerable gratitude that I had gotten the little girl home again without breaking her into splinters!

=======================================================================

 

 

STATS: From “British Aeroplanes 1914 - 18” by J. M. Bruce.

 

 

130 hp Clerget

Empty Weight: 929 lb (421 kg)

Loaded Weight: 1,453 lb (659 kg)

Max Speed:

115 mph (185 km/h) @ 6,500 feet (1981m);

113 mph (181 km/h) @ 10,000 feet (3352m);

106 mph (170 km/h) @ 15,000 feet (4572m).

Climb:

6 minutes 0 seconds to 6,500 feet (1981m)

13 minutes 35 seconds to 10,000 feet (3048m)

20 minutes 40 seconds to 15,000 feet (4572m)

Ceiling: 19,000 feet (5791m)

Endurance: 2 hours 30 minutes

Armament: Two fixed .303 Vickers mg

No’s Built: 5,490; of which 1,325 were built in 1917 and 4,165 in 1918. Of the 4,188 machines distributed to the RFC/RAF, 2,116 went to Squadrons with the B.E.F. in France

 

 

150 hp B.R.1, standard induction, compression 5.5 to 1

Empty Weight: 931lb (422 kg)

Loaded Weight: 1,471 lb (667 kg)

Max Speed:

121 mph (195 km/h) @ 6,500 feet (1981m);

117.5 mph (189 km/h) @ 10,000 feet (3352m);

111.5 mph (179 km/h) @ 15,000 feet (4572m).

Climb:

5 minutes 05 seconds to 6,500 feet (1981m)

8 minutes 50 seconds to 10,000 feet (3048m)

16 minutes 30 seconds to 15,000 feet (4572m)

Ceiling: 22,000 feet (6705m)

Endurance: 2 hours 30 minutes

Armament: Two fixed .303 Vickers mg

No’s Built: 5,490; of which 1,325 were built in 1917 and 4,165 in 1918. Of the 4,188 machines distributed to the RFC/RAF, 2,116 went to Squadrons with the B.E.F. in France

[Pips 5]

Flying The Old Planes - Part 6: Fokker DR.1 Triplane

 

Extract from the book "Flying The Old Planes" by Frank Tallman.

 

 

Because of its step-on-step appearance, the Fokker DR1 Triplane at first glance has all the grace of a blacksmith lifting an anvil. But in its short-lived time of combat over the Western front, its awkward appearance belied flight characteristics as nimble as a nervous hummingbird.

 

A unique machine from Sopwith’s house of wonders provided the inspiration for Mr. Fokker’s flying Venetian blind. The inability of the Albatross and Pfalz fighters to dogfight with this startling innovation forced the German High Command into a reappraisal of it’s own fighter aircraft.

 

The Flugzengmeisterei sent a letter to the German manufacturers on the 27th July 1917 requesting that they submit bid for a triplane, and AEG, Brandenberg Pfalz, Roland and others built prototypes. Yet months before the competition and bids at Adlershof, Fokker had in his usual tour of the front visited Jasta 11 to find only one thing on their minds: the sparkling performance and outstanding fighting characteristics of the Sopwith Triplane. In one instance an extremely courageous and foolhardy pilot of the RNAS Naval 8 (the great Australian ace Robert Little) had attacked eleven Albatross D.III’s and had outmanoeuvred the entire German Group.

 

NB: The battle is described in the Sopwith Triplane thread.

 

Because of Fokker’s Dutch nationality and enviable business success, he was resented by the German manufacturers and got little support from them. He waged a constant war of supply and demand, and from necessity developed material sources that were undesirable or unavailable to the other German firms. With the full production of the reliable Mercedes and BMW water-cooled engines swallowed up by the manufacturers Albatross, Roland etc, Fokker had to look elsewhere for a power plant. Fokker located seven hundred superb Swedish Thulin copies of the French 110-hp Le Rhone stored at Adlershof, where they had been written off by the Germans as out of date.

 

With the rotary engine as the base, Fokker quickly came out with a triplane design that in no way resembled the Sopwith craft, other than for it’s three wings. All three wings were full cantilever, with the lower two bolted directly to the fuselage, while the upper stood on two vees and was wire-braced. At a time when most spars were routed sections, Platz came out with a built-up box spar joined to another box spar with a top and bottom plywood web. The double spar thus joined is light, but large enough in appearance and strength to be the ridgepole in a Jacobean manor house. The fuselage was typical Fokker, with light welded tubing, wire-braced. The gear was streamlined tubing, with ball sockets pinned for security (like the fittings on the Pfalz D.XII) and with the small wing airfoil between the gear, which created enough lift in itself to carry more than the weight of the gear and wheels.

 

Fokker flew the first triplane and promptly sent it back for Platz to balance the tail surfaces and ailerons. After the Adlershof trials, where the test pilots rejected the safe but birdlike flexing of the wings, Fokker wisely added an outboard jury strut that attached to the wings rather than go through them as in the Sopwith Triplane.

 

Ordered into production the first two triplanes in August 1917 became the pet loves of Werner Voss and Manfred von Richthofen. Voss was to achieve immortal fame in the Triplane in his epic battle with some of the best pilots of 56 Squadron RFC, including James McCudden.

 

Shortly, two accidents put an instant hold on production. Heinrich Gontermann, the renowned ‘sausage busting’ leader of Jasta 15 and victor over seventeen balloons and twenty-two aircraft, was killed in full view of his Jasta when the top wing of the DR1 came off in aerobatics directly over his airfield. Two days later a pilot in Jasta 11 dies in the same way. Richthofen grounded his airplanes before the investigating committee arrived, and on opening the wing structure they were appalled to find workmanship on the spars so slipshod as to be almost sabotage, and other spars so badly affected by moisture as to have the strength of a wet cigarette. Months were to go by before the modifications had been completed and the DR1 was again in full production.

 

Although several DR1’s were captured and tested at Farnborough, no truly accurate plans or figures have been discovered. And none of the captured DR1’s survived long after war’s end.

 

With Hitler’s rise to power the Richthofen squadron was reactivated in the mid 1930’s. With the commissioning ceremony just days away, a real Fokker DR1 was found languishing in a barn, and another shortly after. The experts who saw it felt both aircraft were genuine Fokker built triplanes. To inspire the revived Luftwaffe, Hitler commissioned a motion picture on World War One, unblushingly filled with propaganda about a German squadron flying triplanes. There are some lovely flying shots of the Triplanes that can be seen in this film. They are in death-defying combat, with modern Bucker Jungmans thinly disguised as Allied SE5’s. Sadly both resurrected triplanes were destroyed in the bombing of Germany in World War Two.

 

Although there are no genuine DR1’s left, there are at this time at least five replica’s flying, one even with a rotary engine. I have seen most of them, but so far have only flown ours. Reports vary considerably on their characteristics, and at least one owner admitted to me that he enjoyed flying it about as much as if he had climbed into a hive of bees in a bathing suit.

 

Two gentlemen with the dreams of Richthofen and the patience and dedication of Christian martyrs, Tony Bright and Dutch Durringer, were responsible for the original construction of the DR1 now in our Movie of the Air Museum at Orange County in Santa Ana, California. The construction took several years.

 

Facing all builders of replica aeroplanes of this period is the inescapable fact that original engines for WWI are very scarce. Even if you find a modern engine that can be squeezed into the traditional cowling and that has the same rated power, you still do not have the necessary slow-turning propeller with the horsepower developed at 1200 – 1400 rpm (instead of 2500 – 3500rpm), which give all WWI aircraft their unique characteristics.

 

The only American engine that has a rotary facial area and sufficient horsepower was the 165-hp Warner engine, and they are getting exceedingly scarce, but we found one. Basic construction of our DR1 followed closely the original in all detail, with welded steel tubing, wire bracing and box spars.

Before I bought the DR1 from Tony and Dutch I had occasion to rent it for a major air show we were doing. We wanted a World War 1 combat act. Arriving to pick it up I found it painted a dull barn door red, with the wrong type of crosses for Richthofen’s aircraft. Otherwise, it looked every inch like the original. I was eager to fly it, and began my pre-flight checks.

 

Because of the cantilever construction, the most important points to check are the centre section struts, the gear shock cord, and the bracing struts on the underside of the tail. Swinging into the cockpit past the cut out in the middle plane, one wonders what happened to the world ahead, for you can only see to the sides and rear. Controls are straightforward.

 

The Warner is a lovely engine, and it started on the first pull, but because of the limited visibility taxiing was a chore. Checking controls for freedom of movement and checking mags, I turned onto the runway. My rudder became effective in about fifty feet of take-off roll and the elevators brought the nose onto the horizon, so that I could see ahead for a change. The Triplane is airborne in about three hundred feet (with a true rotary it would do that in half the distance). The climb out was at 55 mph, and as I begin a climbing turn I felt ailerons as stiff as a boiled shirt. You very nearly need both hands for the ailerons.

 

Climbing up to altitude and settling down for an hour cross-country, I was struck again by the in-flight appearance of the upper wing so far above and so lightly hung on. I was cruising at a pleasant 98 mph. Getting used to everything except the Mach truck-like ailerons, I stalled the plane, and it fell through at about 50 mph, usually dropping the right wing. Recovery was easy and loss of height slight. Putting the bird in a Lufberry circle, I could see how you could cut the circle small enough to nearly chew your own tail off. The ailerons may be stiff to use, but they do bite the air, and the rudder virtually whips the aeroplane around. In a climbing vertical reverse, the three-wing concept worked well.

 

In a fit of daring equal to grabbing a leopard by the tail, I decided to try a loop. Picking up to 120 mph, I pulled up, but because of the placement of the wings it was hard to orient with the horizon. It was a most uncomfortable feeling. Unfortunately I was a little slow and did not pull tight enough at the top, and barely managed to get over. As the Triplane fell through, I wondered whether the whole stack of wings might not collapse like a club sandwich being sat on by a fat lady. My nerves took longer than the DR1 to recover, but vowed to try again once I had gained my breath. Second time I was more forceful, again entering at 120 mph but this time really hauling on the stick. Almost before I knew it the DR1 had whipped up and over in a very tight loop, with almost no rudder required. This is an airplane that needs to be flown forcefully, no tiptoeing around.

 

Having had enough for one day I let down into the traffic pattern for landing. Choosing to land on a dirt strip, I glided in, and nose down had good enough visibility so that I didn’t feel I was conning a nuclear sub. Flaring out, the DR1 loses speed fast, levelling down at about 45 mph with a rather wobbly feel, and blanking out almost completely of the tail surfaces, so much so that as you are rolling along you might as well have a broomstick for company in the cockpit.

 

Several years went by before I climbed into its cockpit again, now as its owner. The DR1 has gone through a painstaking development process equal to the Saturn rocket and looks infinitely better in correctness of colour and markings. Moreover it now has infinitely better aileron control than it had originally, due to replacing the wrongly routed control cable and the aileron hinges. It’s now a fun aircraft to fly, with beautifully light ailerons that are so positive that to change direction one simply has to look in that direction for the DR1 to go. The rudder is as powerful as ever, and in even gentle turns you can feel the planes gripping the air and wanting to turn more steeply. The roll rate is good, but the fun thing to do is the flat turn just using full rudder. Loops, Cuban 8’s, Lufberry’s, wingovers all are easily performed.

 

Flying the DR1 for any length of time though can get tiring, as there is no tail fin. A large powerful rudder on the end of a short fuselage makes for continual concentration to keep the aircraft from yawing one way or the other. Even so if it wasn’t for the poor(ish) visibility it would be as good as the Sopwith Triplane, although that aircraft is just that much easier to fly, especially in landing. But one adapts. I now make all DR1 landing wheels first, dropping the tail only late in the landing run, with a prayer each time to Icarus or other flying gods to keep me straight.

==========================================================================

 

STATS: From "German Aircraft Of The First World War" by Peter Gray and Owen Thetford; and "Fighter Aircraft Of The 1914 - 1918 War" by W.M. Lamberton and E.F. Cheesman.

 

Empty Weight: 406kg (893 lb)

Loaded Weight: 586kg (1,289 lb)

Engine: 110-hp Swedish Thulin (Le Rhone copy)

Max Speed:

185 km/h (115 mph) @ 1,000m (3,280 feet)

165 km/h (103 mph) @ 4,000m (13,120 feet)

128 km/h (80 mph) @ 5,000m (16,404 feet)

Climb:

2.9 minutes to 1,000m (3,280 feet)

5.5 minutes to 2,000m (6,561 feet)

9.3 minutes to 3,000m (9,842 feet)

13.9 minutes to 4,000m (13,121 feet)

21.9 minutes to 5,000m (16,404 feet)

Ceiling: 6,100m (20,013 feet)

Endurance: 1 hour 30 minutes

Armament: Two 7.92mm Spandau LMG 08/15

No’s Built: 320

Edited July 16, 2009 by Pips

[Pips 5]

Flying The Old Planes - Part 7: Fokker D.VII

 

Extract from "Flying The Old Planes" by Frank Tallman.

 

Our original Fokker D.VII had stayed in storage following the movie 'Hell’s Angels', and was located at the same time as our original SPAD VII – and both were found in nearly flyable condition!

 

“What a sweetheart”: This is my Number one thought every time the candy-stripped Fokker breaks ground. By any pilot’s standards it is a delightful, exciting aeroplane to fly. Although I often do not have a chance to fly it, there is always a brand new excitement each time I get airborne in it.

 

The D.VII is the greatest of Fokker’s WWI designs, and for reliability, strength and smooth, easy flight characteristics, it was arguably equalled by no other aircraft in either the Imperial German Air Service or the combined Allied air forces. It is without doubt the easiest World War One aircraft I have ever flown. It fills one with immediate confidence, and has no vices worth mentioning.

 

The D.VII was one of some twenty odd Fokker designs made in Germany and under licence in Austria and Hungary in WWI. But because of his financially large aircraft and gun contracts and his Dutch nationality, Fokker was looked upon with ill-disguised jealousy by other German aircraft manufacturers. Background machinations and politics, the failure of the DR.1 to win large production contracts as well as the growth of such firms as Roland, Pfalz, Albatross and others had reduced Fokker by 1918 almost to the role of a subcontractor. When the Johannisthal fighter trials came up in January 1918 the D.VII, which was in its early developmental stage, was flown to the base by Fokker himself. On the trip to Johannisthal he found directional control poor, and against every military and trial regulation he hired outside welders and spliced in several more feet of fuselage the night before the trials began. The D.VII was an instant success. It led every flight category and was put immediately into quantity production. Now the German firms that had given Fokker such a hard time suddenly found the roles reversed, with their factories being pushed into producing the D.VII instead of their own aircraft.

 

Unfortunately, in our D.VII we had a 180-hp Hispano Suiza for power instead of the regulation Mercedes. The change goes back many years to “Men with Wings”; a picture Paul Mantz did using the Fokker D.VII. By that year (1937) the WWI Mercedes was beginning to show definite signs of age, and because Hisso’s were readily available, one was used with no basic structural changes to the aircraft.

 

As you walk out to the D,VII it impresses you as being larger than it actually is. Possibly that’s due to it’s coffin like nose and because of the thick high-lift wings. The pre-flight inspection is simpler by far with the D.VII than with any other Allied or German aircraft because of the lack of bracing wires. Both wings are fully cantilevered, and the outer N struts were added only as a sop to the German pilots, for these struts serve no structural purpose.

 

Apart from the engine, the gear will stand a look. Tightness of the streamlined landing gear is important, as is the condition of the shock cord. The trailing edges of the wings, because they are of wire, sometimes work through the fabric. This must be checked, as well as the integrity of tail bolts and the structure of the tail.

 

Like all German aircraft the first step up is along one. Once settled in the cockpit with a couple of Spandaus six inches from your moustache, you realise this is a war plane, and in case of accident and no shoulder straps, you might very easily, and permanently, shift your appearance.

 

In taking off, the tail comes up immediately, with complete rudder control. We were airborne in 383 feet. What a completely responsive aeroplane! The ailerons are sheer delight, and the climb is a revelation after flying other Allied and German aircraft of WWI vintage.

 

Levelling out at 3,000 feet, the D.VII indicates 110 mph, and trues out at 118mph. Stalls are straightforward and hang on until 49 mph on the clock and then fall straight ahead. Loops cover about 800 feet of sky, and when started at 120 mph carry through beautifully, with no tendency to fall out at the top. Strangely, to the vertical point, the ailerons of the D.VII are all anyone could ask for. Following through the inverted phase, the roll slows down. A full slow roll is on the order of nine seconds. But make no mistake; this aircraft is not a slouch. If you want to hustle through rolls it will whip from side to side faster than almost any other WWI aircraft. Changes of direction, either vertically or horizontally, as performed with ease.

 

Spins of one turn are smooth and precise in either direction. And yes, the Fokker will hang vertically on its prop for several seconds before a gentle tail slide initiates. Once that occurs a light tap of rudder and the Fokker flips over to direction you want without the slightest hiccup. Wingovers are a real joy, as are vertical banks. This aircraft is solid as a rock in all manoeuvres.

 

Landings with the D.VII as with many other aircraft of that period, are much different than with their WWII counterparts. As you come in on your grass or dirt strip, you’ll find the D.VII moving quite a bit faster than you anticipated and touching three points hot and skittish at about 55 mph. The only directional control is throttle, and a real blast over the rudder is necessary to stop any turning on landing.

 

It’s said that the Fokker D.VII can make the most mediocre pilot look good, and a good pilot great. Given it is such a vice-free aeroplane to fly it’s easily understandable why it was so well thought of by the Germans, and feared so much by the Allies.

===========================================================================

 

STATS: From "German Aircraft Of The First World War" by Peter Gray and Owen Thetford; and "Fighter Aircraft Of The 1914 - 1918 War" by W.M. Lamberton and E.F. Cheesman.

 

Engine: 180 hp Mercedes D III

Empty Weight: 700kg (1,540 lb)

Loaded Weight: kg (1,936 lb)

Max Speed:

186 km/h (116 mph) @ 1,000m (3,280 feet)

182 km/h (114 mph) @ 2,000m (6,560 Feet)

175 km/h (109 mph) @ 3,000m (9,843 feet)

165 km/h (103 mph) @ 4,000m (13,124 feet)

152 km/h (95 mph) @ 5,000m (16,405 feet)

Climb:

3.30 minutes to 1,000m (3,280 feet)

6.48 minutes to 2,000m (6,560 Feet)

12.0 minutes to 3,000m (9,843 feet)

18.30 minutes to 4,000m (13,124 feet)

31.30 minutes to 5,000m (16,405 feet)

Ceiling: 5,974m (19,600 feet)

Endurance: 2 hours

Armament: Two 7.92mm Spandau LMG 08/15

No’s Built: Approximately 1,700

 

 

Engine: 185 hp B.M.W. III

Empty Weight: 700kg (1,540 lb)

Loaded Weight: kg (1,993 lb)

Max Speed:

193 km/h (120 mph) @ 1,000m (3,280 feet)

188 km/h (117 mph) @ 2,000m (6,560 Feet)

183 km/h (114 mph) @ 3,000m (9,843 feet)

175 km/h (109 mph) @ 4,000m (13,124 feet)

168km/h (105 mph) @ 5,000m (16,405 feet)

Climb:

2.50 minutes to 1,000m (3,280 Feet)

8.30 minutes to 3,000m (9,843 feet)

11.40 minutes to 4,000m (13,124 feet)

16.0 minutes to 5,000m (16,405 feet)

21.15 minutes to 6,000m (19,685 feet)

Ceiling: 6,979m (22,900 feet)

Endurance: 2 hours

Armament: Two 7.92mm Spandau LMG 08/15

No’s Built: Approximately 1,700

 

Speed wise the BMW powered DVII has a slight advantage at all altitudes. But the big difference is in climb rate. Here the BMW engine has a significant advantage over the Mercedes.

Edited July 18, 2009 by Pips

[Pips 5]

Flying The Old Planes - Part 8: Pfalz D.XII

 

Extract from the book "Flying The Old Planes" by Frank Tallman.

This is the last article in this series.

 

 

The father of the Pfalz was the Pfalz D.III, an elegant-looking airplane that was certainly more graceful than it’s predecessor, the Pfalz E series. The plywood semimonocoque fuselage, with its light spruce longerons and oval formers, was both graceful and strong. The clean streamlined lines of the Pfalz were not uncommon to the German Jastas, and manufacturers such as Pfalz, Albatross and Roland made some of their slab-sided counterpart fighter aircraft on the Allied side look about as graceful as a barn door.

 

The layout of the Pfalz D.III was standard: The wings were of unequal span and cord with the radiator mounted in the upper right wing. The reliable Mercedes was the powerplant, and the D.III entered Jasta service primarily with Bavarian units, side by side with the Albatrosses, where they sometimes suffered an unfavourable comparison. The British reported a captured D.III as having excellent visibility, a slow rate of roll, outstanding dive speed, good manoeuvrability, and better all-round handling than an a captured Albatross D.V.

 

However no model of Pfalz was ever truly embraced by the German Air Force, even the D.XII. The 'E' Series, the D.III and the D.XII were always considered less capable (unfair as that may be) than their equivalents.

 

The successful birth of the Pfalz D.XII was accomplished at the Adlershof fighter trials in June of 1918, and thanks to the aircrafts basic virtues and the company’s ‘favourite son’ status, it was put into quantity production for the Bavarian Jastas.

 

My first introduction to even the name Pfalz was when I purchased the remaining two aircraft from Colonel Jarrett’s World War One collection, a SPAD VII and the Pfalz D.XII. Due to WWII storage problems both aircraft had fallen on hard times, and the plywood of the Pfalz had taken more water punishment than some of the towels in a Turkish bath. Because of the wet and dry rot, the interior of the fuselage had been braced with two-by-fours to make it displayable. The wings were badly deteriorated, though the landing gear, the distinctive M struts, and the dual bay wing struts were fortunately in good condition.

 

Once the aeroplanes were stored in a rented barn in Delaware, a period of ennui settled on yours truly as the enormity of the task of rebuilding the Pfalz finally penetrated my concrete dome.

 

Most fortunately I was able to make contact with a soft-spoken mechanical genius by the name of Robert Rust, who allowed that he would like to take on the task of rebuilding the Pfalz. He arrived with a trailer from Atlanta in the rain (I seem to have made most of my important antique aircraft acquisitions in the rain), and as he quietly walked around the Pfalz in the dimly lit hangar I edges out of his way. Figuring he was going to make a dash for his car. “Well” he said “its bad, but not hopeless”.

 

NB: The description of the rebuild has been left out owing to space – but it is fascinating! The only departure from the original was including brakes as a safety feature. Even the Mercedes was restored to its former glory.

 

Finally one November day I was airborne on my way to Atlanta to try my shaking hands on the only German aircraft of World War 1 that I ever thought I would be lucky enough to fly. Bob picked me up at the airport and drove me to an outlying airfield, where the Pfalz sat gleaming in her camouflage paint. The strange colours of the Pfalz were researched as carefully as was the rest of the reconstruction, and the information came from a scholarly series published by the English magazine ‘Flight” following WWI.

 

Unlike the Fokker DR.1 and D.VII, with their cantilever construction, the Pfalz is a maze of wires and includes double bays on each wing. The maintenance of this maze of wires was about as eagerly looked forward to by the German mechanics as a bath in a tub of live eels. Inspecting the wires and then the fittings; the gear and its ball sockets; the aileron elevators and the rudder attach points; the glass window in the Mercedes crankcase, which tells you whether you have sufficient oil; and the radiator are all part of a somewhat unfamiliar pre-flight to our derring-do aviators of today.

 

Like most German aircraft of the period, to get into the cockpit you have to have been sired by giraffes or have a ladder. Once in the nice battleship grey cockpit, your nose is assailed by the strong fuel smell until you find the tank in the floor directly under you. With incendiary ammunition aboard, what a lovely location for a sausage sizzle.

 

A little-known fact is that the German Air Force of this first global conflict actually flew instrument missions with their giant series of aircraft. They were using reliable artificial horizons as early as 1915 on night operations into Russia. The Pfalz does not suffer from an oversupply of instruments, and there is no panel as we know today. Instruments are stuck around as haphazardly as a modern artists paint strokes.

 

Along with the inverted ram’s horn on the stick, there is a radiator control shutter, a mag switch, and a fuel valve. There is no firewall in these machines, and it was a distinctly unpleasant feeling to see the rear of the Mercedes engine block. With six cylinders, each with the bore of a butter plate, a compression release is provided. The cockpit is not deep, and seated on my ever-present parachute, I felt like a penthouse dweller.

 

With my feet in the stirrup-equipped control bar, gas on, radiator shutters closed, motorcycle throttle on stick cracked, and an athlete standing on the wheel with his hand on the compression release, the Mercedes fired on the first pull and ran unevenly until the compression release was locked. The Mercedes idles a bit unevenly, with the valve springs rattling like castanets.

 

Taxiing to the takeoff point with runners on the wingtips, I got no real rudder response. I checked to clear myself and was on my way, with the intention of getting the feel of the aircraft on a straight high-speed taxi run. While the acceleration of the Mercedes seemed slow, the tail was up in just fifty feet, and the rudder response was positive and good. The only problem was a wide-open throttle I couldn’t close, the throttle being a motorcycle-type design fitted to the top of the joystick. In the space of the telling, I was up and flying. General balance and feel seemed good, so I climbed out around the field with the stuck throttle.

 

The flight was fast, and I ran away from am accompanying PT-19 as if it were moored. Windblast was severe, for the only protection was the German tachometer mounted between the twin Spandaus. Control response in the air was very precise, and fast on the elevators and rudders, but as in some of the spade-grip British aircraft, the aileron movement was restricted, and the inverted ram’s horn kept hitting my thigh.

 

Visibility was excellent, and wide-open the aircraft seemed to be doing in the vicinity of 120 mph, if other aircraft were a guide. The climb, as with many other WWI aircraft, seemed flat but was actually better than a thousand feet a minute, and I easily climbed away from most civilian aircraft. Then landing approach was flat and fast, about 65 mph, and I moved with the alacrity of a mongoose to get the tail down as it settled. Fortunately the first landing was in a good headwind and mild, for the tailskid bit before I realised how little control the Pfalz has because of the blanking out of the tail surfaces by the lower wing in landing configuration. Not all flights with the Pfalz were to be even half as easy as this first one.

 

The D.XII was shipped out to the West Coast by truck, and with the aid of Bob’s excellent plans, the aircraft was rigged and ready to go in no time for a second flight. All went well until the throttle again stuck open, the twist grip on the joystick proving to be a less than reliable design. In fact on the first seven flights I had sticking problems with this arrangement, and finally got fed up enough to replace it was a standard arm throttle set on the left side of the cockpit. It may not have been historically accurate, but it did wonders for my blood pressure. Once that was solved the Pfalz did behave itself better. Although I should say that among the many aircraft I have been lucky enough to fly, this D.XII has no peer in pure cussedness, and each landing presents enough emergencies and handling problems to make an instant trip to the local pub not only desirable but an absolute necessity.

 

The problem lies in the last 50 feet of altitude of landing, when the speed drops and the nose rises slightly, thereby the lower wing blanks out the elevators and rudder controls. At that point the Pfalz pretty well drops to the ground. The only alternative is to come in hot and land on the front wheels, cutting throttle on touching ground. Or come in on a steep glide path and flare at the very last moment. Either way its sweaty palms all round.

 

Coming, as it did, late in the war, the Pflaz stacks up reasonably well when measured against other types I have flown, and flown against. Speed is better than most, but aerobatically it is larger and clumsier than opponents such as the SE.5, SPAD and Fokker D.VII. And with a slower roll rate its hard put to match turns or reverses. It’s best features are it elevators and rudder, which are very powerful; its rate of climb and breathtaking dive. This is definitely an aircraft that wants to manoeuvre more in the vertical plane that anywhere else. Immelmann’s and wingovers are its forte.

 

Stepping into the Fokker D.VII after flying the Pflaz really drives home just how good an aircraft, let alone fighting machine, the Fokker is. Where manoeuvres in the Fokker are as effortless and graceful as a butterfly, in the Pflaz they have to be planned and forced. The Fokker is as a gentle breeze when landing, the Pfalz makes you break out in a sweat. Not the sort of aircraft to come home in after a trying day at the office. Still, the Pfalz is not a bad aeroplane, indeed it is a good as most for the period. It’s just that the Fokker is so much better.

 

===========================================================================

 

STATS: From “Fighter Aircraft Of The 1914-1918 War” by W.M. Lamberton; and "German Aircraft Of The First World War" by Peter Gray and Owen Thetford.

 

Engine: 180-hp Mercedes DIIIa

Empty Weight: 716kg (1,566 lb)

Loaded Weight: 897kg (1,952 lb)

Max Speed:

193 km/h (120 mph) @ 1,000m (3,280 feet)

185 km/h (115 mph) @ 3,000m (9,843 feet)

148 km/h (92 mph) @ 5,000m (16,405 feet)

Climb:

3 minutes 25 seconds to 1,000m (3,280 feet)

7 minutes 0 seconds to 2,000m (6,560 feet)

17 minutes 30 seconds to 3,000m (9,843 feet)

29 minutes 50 seconds to 5,000m (16,405 feet)

Ceiling: 5,181 m (17,000 feet)

Endurance: 2 hour 30 minutes

Armament: two 7.92mm Spandaus

No’s Built: Approximately 800

[RAF_Louvert 101]

Last night I was again going through my WW1-related files and folders and ran across an outstanding article written by Tom Solinski, (about ten years ago now), on the alphanumeric designations of the many aircraft the Germans flew in WW1. It is very concise and clear, and dispels some commony held misconceptions about the system. Some of you may have already read this, for those who have not you may find it interesting. Enjoy.

 

 

German Aircraft Designations

By: Tom Solinski (tskio at cox dot net)

 

 

As we approach the new millenium and the subsequent Centennial of powered flight I have noticed several aviation myths that should remain in this century

 

This short paper started off after I read an article on flying the Fokker D-VII at old Rhinebeck aerodrome. The author, the late Jeff Ethell frankly states that "D" designation of German WW-I era fighter aircraft, such as the Fokker D-VII, the Pfalz D-III the Albatros D-V, stood for "Doppledecker" or bi-plane. Looking at these examples it is easy to see how this could be accepted, because all of these aircraft were in fact bi-planes. Other Imperial German Army's aircraft designations go on to support this statement, i.e. the Fokker E-III Einedecker, (one-wing) for a monoplane and the Dr, or Dridecker (three wing) designation for the famous Fokker Dr-I of Von Richtoffen the "Red Baron".

 

But other designations make this "D" designation confusing. What about all of the biplanes that had "B, C, G, & W" designations? Why isn't there a "D" in these titles to identify them as Doppledeckers?

 

Another contradiction to this designation is found in the usually clear, specific Teutonic thinking. If they called a ONE wing airplane by the numeric title of Eine (one) and a THREE wing airplane by the numeric of Dri (three) why break convention by calling a TWO wing airplane Dopple instead of the logical, numeric Zwie (two)? After all, this Prussian logic was followed in identifying one, and two-bay rigging on bi-planes as "einstielig" and "zwiestielig" respectively.

 

I have come to believe that the correct answer to all of this is that under the Imperial German Army designation system the "D" designation of German WW-I aircraft DOES NOT stand for "Doppledecker". It stands for "Type D" aircraft, in a very organized, logical, system.

 

My research has revealed that the Inspektion der Fliegertruppen (Inspectorate of the Flying Troops) i.e.: Idflieg had an aircraft mission identification system in place as early as the fall of 1915. The system consisted of identifying the designing manufacturer by name; followed by an alphabetical mission designation (i.e. A through W) followed by a Roman numeral sequence number of that mission type from that manufacturer. This system continued to evolve throughout World War One and it eventually consisted of:

 

"Type A" A single place unarmed monoplane scout of less than 150 horsepower. Example the Pfalz A-I, & A-II.

 

"Type B" A two place unarmed biplane scout or trainer of less than 150 Hp. Example the Albatros B-I.

 

"Type C" A two place armed biplane scout of 150 Hp or more. Example the Albatros C-III.

 

"Type CL" This was a subset of the "C" type indicating "light" weight. They were developed for a new mission; to be an armed escort, or two-seat fighter. Example the Hannover Cl-III.

 

"Type D" A single place armed biplane scout of 150 Hp or more. Example the Pfalz D-III, and D-XII. However, this designation was later applied to monoplane fighters as well, i.e. the Fokker D-VIII.

 

" Type E" A single place armed monoplane scout of less than 150 horsepower. Example the Fokker E-III. Note: the Pfalz A-II became the Pfalz E-III when armed! The Fokker D-VIII was originally the Fokker E-V

 

"Type F" A single place armed triplane scout of less than 150 horsepower. The original designation for the Fokker Dr-I, was Fokker F-I.

 

"Type G" A multi place armed biplane bomber with two or more engines. Example the Gotha G-IV. This designation was originally "K" for Kampf flugzeug or battle-plane. The "G" apparently lent itself to "Grosse" or large

 

The sequence breaks down after G, skipping through the alphabet, sometimes using the first letter of the name of the mission type.

 

"Type J" A two-place, armed, and armored biplane specifically designed for the trench-strafing mission. Example the Junkers J-I

 

"Type N" A two-place, armed biplane scout of 150 Hp or more specifically designed for night bombing. Very few were produced. Example the Friedrichshafen N I

 

"Type R" "Riesenflugzeug", "Giant aircraft". A multi place armed biplane bomber with four or more engines. Example the Zeppelin-Staaken R-I.

 

"Type W" "Wasser"? A designation for all float equipped land planes or flying boats regardless of number of wings, seats, or horsepower.

 

I have two other items to support this position, of "D" being "Type D" and not "Doppeldecker". In 1918 the IDFLIEG held two "Type D" aircraft competitions. The aircraft evaluated and eventually winning werent always biplanes, but they ended up being Type D aircraft.

 

On page 19 in the book "Aircraft versus Aircraft by Norman Franks" there is a contemporary German photo of an L.V.G. B-II training aircraft. The caption printed on the negative in German reads "LVG Doppledecker, System Schneider, Schulemachine" this is clearly a distinction between the training mission and the biplane configuration of the aircraft.

 

Please note that this list applies to the official Imperial German Army designation for these airplanes once they were accepted for service. Many of the German and Austrian manufacturers had their own internal designation systems.

 

Take the case of Anthony Fokker who initially used a designation of "M" and a series number, so his companies M5K became the Fokker E-III in service. Later in the war Fokker used the designation "V". It is not clear weather this stood for Versuchflugzeug or "test aircraft" (i.e. prototype) or Verspannungsloser for "wing without bracing" as found on the Fokker D-VI and subsequent.

 

The Junkers company identified all of their prototypes with "J" not to be confused with the in service "J". Their J-4 became the operational J-I.

 

And finally, to confuse the whole issue the Brandenburg Company of Austria built an armed biplane designated "KD" for "Kampf Doppledecker" or "Battle bi-plane"

 

Some of you are probably saying to yourself, "this guy has too much time on his hands", and normally I'd agree with you on an article such as this covering this type of minutia. But, as one popular radio talk show host says, "words mean things". Aviation has always been an art and science of exacting words. If we care about aviation as our hobby, or for some of us, as our living, then we owe both the founders and our future followers a clear accurate history of aviation stomping out half truths and myths whenever possible.

 

 

Cheers!

 

Lou

[shredward 12]

Flying and Fighting the Sopwith Camel

from "Sopwith Camel, King of Combat", Chaz Bowyer

[Bletchley 8]

Allies: Floating to Victory on a Tide of Oil

 

At a meeting of the Inter-Allied Petroleum Conference after the end of the war, in December 1918, British Cabinet member Lord Curzon claimed that the Allies had "floated to victory on a tide of oil." Although Germany and the Central Powers had struggled to find adequate supplies of fuel oil and gasoline throughout the war for an increasingly mechanised army and expanding air force, the British and French forces opposing them on the Western Front had never been in any serious danger of running short of either, quantitatively or qualitatively, despite German U-boat sinkings in the Atlantic and elsewhere. It is true that tanker ship sinkings, together with a huge rise in military mechanisation and demand for gasoline led to a temporary hiatus in Entente distribution capacity at the end of 1916, which in turn led to some domestic restrictions and much political concern (particularly amongst the French, who were the least prepared to meet this sudden increase in demand) that strategic sources of oil might become insufficient. But the US entry into the war, domestic restrictions, and a re-organisation of the Allied supply and distribution system meant that, by the signing of the Armistice, Curzon could claim that the stocks of oil in Allied countries had been "brought up to a point of absolute safety", an achievement that "reflected the greatest credit on the Petroleum Council and on the great oil companies that had subordinated their own interests to the Allied cause."

 

French problems in mid to late 1917 stemmed largely from a lack of mechanisation before the war, a corresponding lack of an oil producing or refining infrastructure, and a consequent failure to grasp the importance of gasoline supply and distribution to an increasingly mechanised army and a hugely expanding air force until it was almost too late. Whilst American, German, English and Dutch oil companies established a series of port installations, refineries, and depots before the war for the import of fuel from company owned oil fields, France, sheltering behind its tarif barriers, had only a loose association of small distributing companies that imported refined or semi-refined oil, mostly from the US, in foreign owned tankers for onward distribution by barge through the French river network. At the outbreak of the war, total French oil consumption was some 400,000 tons annually, the bulk of this being heavy fuel oil for industrial and naval use. By comparison the French air force alone, by 1918, was consuming 110,000 tons of aviation gasoline a year. By early 1917 the French army and air force was entirely dependent on the British Shell company for 100% of its aviation fuel and much of its motor gasoline, and whilst the British flying corps laid claim to the best grade of fuel from Sumatra, the French had to make up for any shortfall with a suposedly second-grade 'Light Borneo' gasoline from the Kalimantan oil fields. In May 1917 Henri Berenger, Rapporteur to the French Senate Army Committee, warned of a looming transportation crisis due to difficiencies in the French distribution system, and the French Government responded in July of 1917 by forming a Comite Generale du Petrole, with Berenger as Chairman, to negotiate a better deal with Britain through the new Inter-Allied Petroleum Conference. French aviation fuel needs were by now being estimated at 10,000 tons a month, and the French Chambre Syndicale de l'Industrie du Petrole claimed, rather dramatically, that they would run out within the next three months unless something was done. When this failed to impress their British allies, the French Premier Clemenceau sent an appeal to the US in December 1917, warning of an impending paralysis of the French armed forces and requesting immediate shipment of 100,000 tons of gasoline in US tankers directly to French ports (thus bypassing the 'pool' system, controlled by Shell and the other British oil companies). This request was met, and with the entry of the US into the war supplies of US aviation gasoline now made inroads into the Shell company's monopoly of the supply and distribution of Allied aviation fuel - although the US "X" (or Export) grade aviation fuel, although it was light enough to meet all aviation fuel specifications, was paraffinic and low in aromatics, and therefore had a tendancy to detonate and produce slightly less power in the higher compression Allied aero engines then coming into use. Whilst the British continued to use their more aromatic Shell aviation fuels from the Dutch East Indies, a fuel that would support these higher compression ratios, the French air force was forced by distribution difficulties and politics into an ever greater dependence on US supplies of this 'inferior' "X" Grade 'Export' and 'Fighter' grade fuel that the US forces were themselves now using in France.

 

The British supply of aviation fuel was dominated and controlled largely by one company throughout the war - the Anglo-Dutch Shell group of companies, which was 60% Dutch and 40% British. Within this group of companies, the British owned Shell Transportation company controlled the distribution of fuel (and owned abput 50% of the world's tanker fleet), whilst the Royal Dutch Shell company exploited the Shell oil fields in the Dutch East Indies and had a controlling interest in the Romanian oil fields via a majority share-holding in the Romanian 'Astra' Oil Company. The Shell group also had substantial holdings in Russian oil production. In 1914 the Group faced some minor competition from two other British companies: the Burmah oil company, a Scottish oil company established originally to exploit the Scottish shale oil resources but then expanded into Burma; and the Anglo-Persian oil company established to exploit the newly discovered oil resources of Persia (Iran), Turkey (Iraq) and the Near East. Both these latter companies had, by 1914, contracts with the Admiralty to supply heavy fuel oil to new British oil-fired naval cruisers, but were not a serious competitor at that time in the British or European motor gasoline and aviation fuel markets. The best aviation fuels at this time were regarded as the light gasoline fractions from straight-run distillations of crude oil, with quality measured by the specific gravity and volatility of the fuel, and some of the best oil fields for this 'light' gasoline were to be found in Sumatra (in the Dutch East Indies), and in the oil fields of Romania. These were all owned or controlled by the Shell group, although in quantitative terms the Group accounted for little more than 5% or 6% of world oil production. The US was by far the largest world oil producer, accounting for about 65% of world production, but it exported mostly heavy fuel oil and kerosene for industrial and domestic use, and gasoline for motor vehicles. Russia, the second largest world producer (16% of world production in 1914) exported predominantly heavy fuel oil, whilst the Austro-Hungarian oil fields in Galicia (around 2% of world production) were mostly producing fuel oil, kerosene and heavier gasoline for themselves and for export to Germany. The US gasoline exports to Europe were controlled largely by the giant US Standard Oil (New Jersey) company, and were the main competitors to Shell in the pre-war European motor gasoline market. There was also some minor competition to Shell from a small association of companies promoting benzol, an alternative motor fuel produced from coal as a by-product of the coking process used in steel manufacturing.

 

Before the war, British oil policy had been dominated by the requirement to obtain a strategic and secure supply of fuel oil for their new oil fired naval warships. The Burmah oil company was contracted first to supply heavy fuel oil to the Admiralty, but as the naval demand increased the British government went so far as to acquire a controlling interest in the Anglo-Persian oil company (later re-named British Petroleum) to secure further supplies. The British Shell Transportation Company could also supply some heavy fuel oil from the Borneo oil fields controlled by Royal Dutch Shell, but as the wartime naval demand grew until it started to outpace supply from these sources in 1916, the Shell company realised that it could use crude oil resources from its new oil fields in South and Central Americal (Mexico and Venezuela) to give it leverage into the British motor gasoline market and, more importantly perhaps, secure influence over British policy on the supply and distribution of gasoline to Entente military forces in Europe. They arrived at an agreement to supply the Admiralty with as much fuel oil as the Navy needed from Shell oil fields in the Americas, offering the tankers to transport it directly to naval bases, thereby regaining much of the influence on British oil policy that had been lost by an earlier decision of the Royal Dutch Shell to use its Dutch neutrality to continue supplying Germany with light gasoline via the Astra company in Romania. Astra, a local company controlled by Royal Dutch Shell, continued to supply both the Allies and the Germans with light gasoline until Romania then entered the war in 1916. In a subsequent move to ensure the loyalty of the Shell group, the British attempted to gain a controlling share in the British company by the purchase of British shares in Shell, but failed, and, largely due to Admiralty opposition, had to pull back from further moves to interfere in or 'nationalise' the company. Threats by the Shell executive that it would be "quite useless to disguise that the position of this Group might become so intolerable that they would withdraw the administration of their business from the United Kingdom" also threatened the supply of toluene (an essential ingredient of TNT, or Trinitrotoluene, used in many British and French munitions) which was being extracted by Shell from their aromatic-rich Borneo crude at a refinery in Portishead. This accounted for about 50% of the wartime toluene consumption of the British armed forces. Shell agreed instead to increase production of toluene in return for a much less interventionist government policy on oil, and they offered the Group's technical expertise to help improve the quality and distribution of motor gasoline and aviation fuel to the British forces in Europe.

 

By early 1917 the British Shell company had a complete monopoly on the supply of aviation fuel to both the British and French armed forces, and also controlled the distribution of gasoline in France via the 'pool' system in which petrol companies 'pooled' their gasoline in Britain for transport by Shell tankers to ports across the channel in France, where the Shell company then established canning centres for the onward supply of gasoline in jerry cans to British and French military forces. They maintained this monopoly until the end of 1917, when the arrival of the US forces brought their own gasoline supply network and (a novelty!) gasoline pumps to replace cans. But Shell aviation fuel was so ubiquitous by this time that contemporary British references to aviation fuel of this period are often made just to "Shell A" (the 'A', presumably, for 'Aviation' or 'Aircraft'). The French, though, continued to make a distinction between "Sumatra" and "Light Borneo" (both of them, however, supplied exclusively by Shell). Not only was the Shell company involved in the direct supply and distribution of fuel to forces in France, but by 1917 it also effectively controlled government policy on issues regarding the quality and use of the different grades of fuel. Shell chemists and research scientists provided the armed forces with technical advice (there is very little evidence for independent military research into fuel by organisations such as the RAE at Farnborough until after the war) whilst Sir Robert Waley Cohen, the Managing Director of Shell Transport, was Chairman of the influential Petroleum Committee responsible for making day to day decisions on the distribution of fuel to the different branches of the armed forces. Harry Ricardo records having to present himself before this committee in the spring of 1917, in an attempt to get a better grade of fuel for the new Mk.V Tank then under development. By this period the lightest gasoline (60 octane plus, according to Ricardo) was reserved for the flying corps, the middle grade (50 to 60 octane) for 'fast staff cars', whilst the lowest grade (around 45 octane) was allocated to heavy vehicles, tractors and tanks. Ricardo knew that if he could obtain the Committee's permission to use the readily available commercial benzol, or add benzol to the low-octane fuel allocated to Tank engines, he would be able to raise the compression ratio of these engines. He also knew that the same could be done for the aero engines then under development, including his own, but his request was turned down flat by the Committee, chaired by Robert Waley Cohen. This is, perhaps, not surprising. Although it was well known before the war that benzole would suppress detonation in engines and could be used to support a higher compression ratio (a statement by the British Petrol Substitutes Joint Committee in October 1913 advised that "the use of benzol will stop knocking in practically all cases where engines are inclined to knock on petrol...[and]... benzol permits of higher compression without causing preignition or knocking"), the British had a plentiful supply of light high quality gasoline from Shell's Sumatra oilfields, an aviation fuel that would support a compression ratio up to around 5.25:1, and this fuel was actively promoted by Shell, both before and after the war, as both the best and the 'purest' aviation fuel then available. To the Shell executives such as Waley Cohen it would have been commercially unthinkable that this 'pure' fuel should be 'diluted' by the addition of any fuel additive that was controlled by a direct competitor in the form of the National Benzole Association. A similar resistance much later, to the use of the TEL anti-knock additive,patented by the US General Motors and Standard Oil companies, meant that the Group spent a great deal of time and money on an unsuccessful search for TEL alternatives in the 1920s and 1930s, and was the last major fuel producer to adopt it as an anti-knock additive in the inter-war period.

 

Nevertheless, Waley Cohen must have recognised that benzol was a potential threat to the company's post-war share of the European motor gasoline market, and must also have known that the aromatic rich East India crude (already being exploited for its toluene content) could be the key to maintaining the company's position against the small but growing competion from benzol-petrol blends, such as that being promoted by the National Benzole Association (later to compete directly at petrol stations with their National Benzole brand). In order, one suspects, to keep Ricardo quiet, but also to gain a technical lead on their commercial rivals, Waley Cohen then approached Ricardo with a proposition - to test a sample of the Shell gasolines for their 'highest usable compression ratio', using equipment that Ricardo already had, but closely watched and assisted by Shell's own research chemist, Kewley. This produced a surprising result for both Shell and Ricardo. As expected, perhaps, most of the Shell samples were very similar to one another in the compression ratio supported - but one sample of 'heavy' Borneo gasoline indicated a very high 'usable compression ratio', or suitability for use in high compression engines. At this time, the straight run Borneo gasoline fraction from the Kalimantam oil fields was being further refined into at least two distinct narrow cuts by distillation - a benzol-rich 'Light Borneo', with approximately twice the aromatic content of Sumatra straight run gasoline but less favoured as an aviation fuel, and a 'heavy' Borneo from which toluene was extracted to leave a heavy gasoline very rich in naphthenes. This 'heavy' Borneo gasoline was too heavy, and distilled at too high a temperature to meet any existing specification for gasoline, and was being burned off at the refinery as commercialy unusable. When Ricardo discovered the value of this fuel, however, Waley Cohen immediately sent a message to the refinery telling them to stop burning this fraction and to blend it back into the other Shell gasolines. It is unlikely, however, that the resulting blends would have been used as an aviation fuel in 1917/18, as the resulting blends would have been too heavy to meet the current specifications for aviation fuel, and there would have been no commercial advantage to Shell, at that time, in promoting a higher octane blend against their own Sumatra fuel that was available in much greater quantities. Between 1917 and 1918 Ricardo and Kewley did, however, refine the Borneo fraction further to produce a small quantity of some very highly aromatic 'super' Borneo, and sent this away for testing by Rolls Royce. The Rolls Royce company discovered that with this new fuel they could then raise the compression ratio of their Eagle aero engines to 6:1 without detonation, and went on to recommend in their Eagle engine manuals that, although the engines would run satisfactorily on existing aviation gasolines, they would run better on a fuel later known as "F12 Spirit", a 20/80 blend of benzole and aviation gasoline. Although only a very small quantity of 'super' Borneo was ever refined by Shell, it was this fuel that was used in the RR Eagle engines that powered the first post-war transatlantic flight by Alcock and Brown.

 

Due largely to the commercial interests of the Shell company, the Entente therefore lost the opportunity in early 1917 to produce an aromatic rich or benzol-petrol blend of aviation fuel that would have supported the development of much higher compression aero engines, effectively condemning Allied aero-engine designers to a maximum compression ratio of no more than 5.3:1. It is known, for example, that the compression ratio of the SE5a's Wolseley 'Viper', originally raised to 5.68:1, had to be reduced back to 5.3:1 (Bruce). The Shell company ensured Ricardo's silence by offering him a very generous contract, funding an extensive period of research into the chemical nature and anti-knock potential of a wide range of gasolines and hydro-carbon fuels supplied by them, with the proviso that he would not publicise or publish the results of this research until 18 months after the completed report and conclusions had been handed to them. The results of this ground-breaking research project were eventually released for publication in 1921, in the Automobile Engineer, and had a huge impact on the post-war development of aviation fuels and aero engine design. As most of the reference fuels examined by Ricardo were from the war-time period, and appear to have been supplied by Shell, or were of US origin, these results also include a valuable snap-shot of the aviation fuels in use at the end of the war.

 

Although Ricardo did not identify his 'reference fuels' by name, only by identification letter, in the published report of his investigations into the properties of the various fuels supplied to him, most of them are readily identifiable by their chemical composition and distillation curves, and from close comparison with the features of named fuels in other contemporary sources. The four lightest of these reference fuels can be identified as the standard WWI aviation fuels - Shell "Sumatra" ©, Shell "Light Borneo" (B), German "Flugbenzin" (E) and US "X" or Export Grade (F). There are also reference fuels that appear to match the published descriptions for Shell 'Super' Borneo (A), Shell 'Heavy' Borneo (H), and a straight run Borneo (D), with a probable but unidentifiable motor gasoline (G) included for purposes of comparison.

 

Sumatra © is listed with a specific gravity of 0.727: 61% paraffins, 8.5% aromatics, 30.5% naphthenes and a 'highest useful compression ratio' of 5.25:1. Distillation curve: 11.5% by 80 deg. C; 47% by 100 deg. C; 79% by 120 deg. C; 92% by 140 deg. C; 98.5% by 160 deg. C. A straight run distillation, the relatively high aromatic content ensured that it would have supported the highest compression ratio used by the Allies (5.3:1) without fear of detonation, but no higher. This was the dominant aviation fuel used by both the British and the French, at least up to early 1918 when the French, in particular, started to supplement this with US "X" grade 'Export' and 'Fighter' grade fuels.

 

Light Borneo (B) is listed with a specific gravity of 0.723: 62% paraffins, 14.9% aromatics, 23% naphthenes and a 'highest useful compression ratio' of 5.7:1. The distillation curve identifies it as a close-cut fraction: 4% by 60 deg. C; 37.5% by 80 deg. C; 79% by 100 deg. C; 99% by 120 deg. C. Available, apparently, in only relatively small quantities (as compared to the more abundant Sumatra), the very high aromatic content meant that it provided slightly less power (about 1% or 2% less), probably due to a slightly lower calorific value, than Sumatra (above) in all engines with a compression ratio of 5.3:1 or less. It appears to have therefore been regarded as a 'second-grade' aviation fuel, although with a much higher aromatic content it could have been used to support a significantly higher compression aero engine without risk of detonation.

 

US "X" Grade (F) is listed with a specific gravity of 0.704: 80% Paraffins, 4.3% aromatics, 15.2% naphthenes and a 'highest useful compression ratio' of 5.05:1. Distillation range: 1% by 60 deg. C; 27% by 80 deg. C; 65% by 100 deg. C; 86.5% by 120 deg. C; 94.5 by 140 deg. C (final at 153 deg. C). This paraffinic, very light gasoline is characteristic of the standard US "X" grade 'Export' and 'Fighting' gasolines that were derived mostly from Pennsylvania crude, complying with Specification no.3512 (Export) or no.3513 (Fighting) of the Bureau of Aircraft Production for export aviation gasoline used by the French and the AEF in 1918. The exact chemical composition of this straight run US "X" grade aviation gasoline varied somewhat, depending on the source of the crude oil and distillation, with the 'Fighting' grade being very slightly lighter and having a slightly narrower range of distillation but otherwise being very similar to that of the 'Export' in terms of performance. Tests run by the US Bureau of Standards indicated that, in an engine with a compression ratio of 5.3:1, the US "X" grade aviation gasolines were slightly inferior in their power output to the Shell 'Sumatra', but slightly better than Shell 'Light Borneo' (but only by a difference of 1% or 2%, either way). This can probably be accounted for by the tendency of the US fuels (with a HUCR of just over 5:1) to mild detonation in the highest compression (5.3:1) aero engines then in use by the French and British.

 

Of the remaining 'reference' fuels detailed by Ricardo, 'H' is a very close match for the 'Heavy' Borneo described by L.J. Simon in the French comparative analysis of Allied and German fuels quoted in NACA Report no.47 Part II. This appears to be a close cut distillation of Borneo crude from Kalimantan, specific gravity 0.767: 10-28% paraffins, 2%-4% aromatics, 70%-85% naphthenes and a 'highest useful compression ratio' of 5.9:1. Distillation range: 7% by 100 deg. C; 55% by 120 deg. C; 83% by 140 deg. C; 94% by 160 deg. C (final at 176 deg. C). This may have been the sample that was tested by Ricardo in 1917, and is probably the heavy, very naphthenic gasoline fraction of the .Borneo crude remaining after the toluene content had been extracted by the Shell refinery in Portishead. From late 1917 onwards this was blended back into other Shell gasolines, although because of the high specific gravity it is very unlikely that it would have been blended back into either the 'Sumatra' or the 'Light Borneo' fractions supplied as aviation fuel. The 'reference' fuel 'A' is very close to the description of the 'Super' Borneo refined by Kewley and Ricardo in 1918, from a straight-run Kalimantan Borneo, a heavy gasoline fraction with a very high aromatic content (39%) and a 'Highest Useful Compression Ratio' of 6:1, whilst 'reference' fuel 'D' , similar but with a much lower aromatic content (14.6%) and HUCR of 5.35:1 is likely to be the straight-run Kalimantan Borneo gasoline fraction that probably forms the base for the close-cut gasolines 'A', 'B', and 'H'. The 'reference' fuel 'E' is a close match for the standard German 'Flugbenzin', and will be examined later, whilst 'reference' fuel 'G' with specific gravity of 0.750 and a 'Highest Useful Compression Ratio' of 4.55:1 is probably a commercial motor gasoline.

 

Research by Tizard and Pye into the chemical characteristics of these fuels showed that they were all, when used in a carburettor adjusted to give maximum power for each fuel, and in the absence of detonation or distribution problems, producing the same amount of power to within 1% or 2% either way (an experimental result largely confirmed by the tests run by the US Bureau of Standards) stating that "there is no consistent difference in the maximum power obtainable with any hydrocarbon fuel, provided the conditions... are the same in each case" and "all reports to the effect of greatly increased power caused by a change in fuel are due either to one fuel being on the point of 'detonation' ... or, in the case of multi-cylinder engines, to bad distribution in one case... provided the initial temperature of the change is the same (i.e the volumetric efficiency is constant)." It seems very likely, therefore, that the problems encountered with US aviation fuels were due not to any 'inferiority' in the fuel, as such, but by a lower resistance to knock that led to mild detonation and slight loss of power in the higher compression French and British aero engines designed to run on more aromatic fuels from the Dutch East Indies. The Compression ratio that could, potentially, be supported by the 'Light Borneo' fraction and refined straight-run Borneo also indicate that there was the potential for the Allies to exploit the anti-knock capacity of these aromatic fuels, or of British (and then US) benzol resources (Britain was the largest world producer of benzol after Germany, at this time, and had enough benzol to make up for any short-fall in the naturally aromatic gasolines of the East Indies) to produce the higher compression engines that could have competed more successfully with the very high compression German aero engines of 1918. This potential was however knocked on the head, as early as the spring of 1917, by the influence and the commercial priorites of the Shell group, who not only supplied the German refineries with large quantities of high quality light petroleum, via their 'Astra' subsidiary until the entry of Romania into the war, but also very effectively blocked any attempt to upset their control of the Entente military aviation fuel market by 'diluting' their fuel with benzol obtained from commercial rivals. Far from "subordinating their own interests to the Allied cause" they appear to have used the war to firstly consolidate and then to extend their share of the European gasoline market, and gain leverage over government policy.

 

 

References:-

 

'Floated to victory on a wave of oil: Earl Curzon tells how Allied ingenuity overcame petroleum crisis of 1916', New York Times, 23 November 1918.

 

'A substitute for gasoline described', New York Times, 5 October 1913.

 

Bruce, J.M. Fighters, vol.2 (War Planes of the First World War). Macdonald, 1968.

 

Dickinson, H.C. (and others). 'Power characteristics of fuels for aircraft engines', NACA Report no.47.

 

Ferrier, R.W. 'French oil policy, 1917-30: the interaction between state and private interests', in: Coleman, D.C. and Mathias, Peter (eds.). Enterprise and history. Cambridge University Press, 1984.

 

Ferrier, R.W. The history of the British Petroleum Company, vol.1: the developing years 1901-1932. Cambridge University Press, 1982.

 

Friedensburg, Ferdinand. Das Erdol im Weltkrieg. Enke, 1939.

 

Hoffert, W.H and Claxton, C. Motor Benzole: its production and use. The National Benzole Association, 1938.

 

Howarth, Stephen. A century in oil: the "Shell" Transport and Trading Company, 1897-1997. Weidenfeld & Nicolson, 1997.

 

Jonker, Joost and Luiten van Zanden, Jan. A history of Royal Dutch Shell, vol.1: from challenge to joint industry leader, 1890-1939. Oxford University Press, 2007.

 

McBeth, B.S. British oil policy, 1919-1939. Frank Cass, 1985.

 

Ricardo, H.R. 'The influence of various fuels on the performance of internal combustion engines: an experimental investigation into their behaviour', in The Automobile Engineer. (Part 1, February 1921, pp.51-54; Part 2, March 1921, pp.92-97; Part 3, April 1921, pp.130-133; Part 4, May 1921; Part 5, June 1921, pp.201-205; Part 6, July 1921, pp.242-247).

 

Ricardo, Harry R. Memories and machines: the pattern of my life. Constable, 1968.

 

Tizard, H.T. and Pye, D.R. 'The character of various fuels for internal combustion engines: the influences of specific heat and dissociation of the working fluid', Part 1, in The Automobile Engineer, February 1921, pp.55-59.

 

 

Central Powers, 'Making a little go a long way ?'

 

At the otbreak of war in 1914 Austria-Hungary was producing 890, 000 tons of crude oil a year, or 1.6% or world production - 875,000 tons of which was from a large number of small producers in Galicia. Of this 400,000 tons was exported, over 50% of it to Germany. Germany produced only 110,000 tons from within its own borders, 0.2% of world production - ten times as much as France (10,000 tons), but less than half as much as Britain (290,000 tons, mostly from Scottish shale). With stocks of only 340,000 tons (around 85,000 tons of this in the form of gasoline and lubricants, 50,000 tons of which was allocated as aviation fuel), and consumption running at 1,400,000 tons per year in 1914, Germany (even with Galician oil from Austria-Hungary) was not prepared for a long war of industrial attrition. Germany required a further one million tons of oil a year, from other countries through or around the Allied blockade, just to maintain pre-war levels of consumption. Of this, between 127,00 and 155,000 tons a year were being imported from Romania up to the middle of 1916. This still left a huge shortfall in the early to mid part of the war, particularly when the Galician oilfields were briefly occupied by the Russian army (Galician consumption fell to 677,000 tons in 1915, recovering to 928,000 in 1916 but declining thereafter to 900,000 tons in 1917, and then 840,000 tons in 1918), whilst the crude oil from Romanian oil fields was also blocked briefly when Serbia closed the Danube to oil barges in 1914. Most of this oil was for domestic lighting and heating and for industrial use, but the Army was consuming around 25% of all gasoline imported into the country. Gasoline for both the army and an expanding air force was an immediate priority, and in the early spring of 1915 very severe restrictions were imposed. on private motorists, including on order from the Bundesrat on March 15th 1915 to take 25,000 automobiles off the roads.

 

Despite this shortfall in the supply of crude oil, there is nevertheless little evidence that the German army or air force went short of fuel in this first period of the war, up to the spring of 1917. Domestic restrictions, and the use of alternative fuels in the form of benzol petrol or of benzol petrol alcohol mixtures in motor vehicles, ensured that the lighter gasoline fractions in particular, from the German refineries, could be diverted to meet the expanding needs of the air force. At the outbreak of war Germany, unlike France, had some extremely good oil refineries, probably amongst the best at that time in Europe, if not the world, and was quite capable of taking any crude oil from any source to refine and blend into fuels that could match the Entente's straight run gasoline fractions from the East Indies. In the early years of the war, however, with access to good quality light crude from Romania, and with existing pre-war stocks to draw from, the German refineries appear to have been producing just two basic grades of gasoline for aviation use - a 'Leichtbenzin' or 'light gasoline', a close cut distillation with a specific gravity of 0.68 - 0.70 and distillation range: 20% by 60 deg. C, 60% by 80 deg. C, approx. 98% by 100 deg. C (final, 115 deg. C); and a 'Schwerbenzin' or 'heavy gasoline', another close cut distillation but with a specific gravity of 0.70 - 0.75 and a distillation range: 10% by 100 deg. C, 40% by 120 deg. C, 60% by 130 deg. C, 80% by 140 deg. C, 90% by 150 deg. C (final 170 deg. C) (Reinhardt). The Leichtbenzin appears to have been reserved for front-line units and aircraft industry, whilst the heavier 'Schwerbenzin' appears to have been allocated to training and home defence (AchimEngels). Although apparently low in aromatic content, this Leichtbenzin would have supported most of the low compression aero engines then in use without much danger of detonation.

 

By the spring of 1915, therefore, reports filtering through to the Allies indicate that, despite the blockade, there was little sign of fuel shortages amongst German military units on the Western Front, either on the ground or in the air. United States neutrality at this time meant that the US reporters and diplomats in Germany were in a good position to feedback information on the situation in Germany, and in an interview between Lord Kitchener and Irvin S Cobb, published in a London newspaper and reported in the New York Times on 10th January 1915, Kitchener asked Cobb: "Is there any shortage of the supply of available petrol in the field ?" Cobb replied that "there is no actual shortage of fuel, as distinct from petrol" as "the Germans have been using large quantities of a benzine product... commonly known as benzol" The report goes on to add that "More light is daily being shed on the subject through the examination of captured or destroyed transports. To eke out their petrol supplies German military cars and wagons are making considerable use of a benzol-alcohol mixture" in such quantities that, according to other reports, "except for her aerial fleet, Germany could almost dispense with petrol, and still continue her warlike activities", as German industry was able to "manufacture all the benzol and alcohol neccessary for the military motors." This, the report states, at least in part: "solves the problem which has been baffling many on this side: Where is Germany getting her fuel from ?" ("Germany using substitute fuel"). Between the spring of 1915 and the summer of 1916 there were similar press reports, confirming in detail that Germany was using a variety of heavy gasoline-benzol and benzol-gasoline-alcohol or benzol-alcohol mixtures both domestically and on the ground at the Front to substitue for gasoline ("25,000 Berlin autos stop", "Use gasoline mixture", "Tells Germany;s motor mixture"). There is no indication, however, from any of these reports that benzol or alcohol mixtures, with or without gasoline, were being used before the end of 1916 in aviation fuel.

 

Benzole is not the same as benzene, although benzene is the main constituent of benzol. A typical refined benzol (or benzole) of this period, suitable for use as a fuel, typically had a 90% aromatic content (and so was sometimes referred to as "90s benzole", the remaining 10% being heavy gasoline or kerosene, and the aromatic content was about 75% benzene, 20% toluene and 5% xylenes (Hoffert). The ratio of constituents could vary, though, and the aromatic content of the German refined benzole used in fuel mixtures has been listed as 84% benzene, 13% toluene and 3% xylenes (Reinhardt). By 1910 Germany was using half of German benzol production, a byproduct from coke ovens and gas works, for motor fuel and the German producers had joined together in the 'Westdeutsche-Benzol-Verkaufsvereinigung' (later it was renamed the Benzol-Verband, still exists today as Aral AG & Co.), and formed a distribution network for motor benzol in Germany, even importing large quantities from Britain and the US. By 1913 it was receiving government support, with a new state-funded benzol plant producing 6 million gallons a year on goverment property, and even royal sponsorship in the form of Prince Henry of Prussia (Miller). But as benzol production was closely linked to the coking industry, it was relatively inelastic and could not be increased dramatically between 1914 and 1918, so total production in Germany rose from a pre-war level of 230,000 tons in 1913 to only 248,000 tons in 1918 (Friedensburg) - this was, however, much greater than the output in any other European country or the USA, and made a huge contribution to filling the gap left by the reduction in gasoline supplies from foreign oil imports. But even though it was known before the outbreak of war in 1914 that benzole could be used on its own, or in a mixture with either gasoline or alcohol (or in a combination of all three) to suppress the 'knocking' in petrol engines, and would support a higher compression ratio than any gasoline used on its own, it was also 'heavy' with a very high specific gravity of 0.87 to 0.885 and a slightly lower calorific value than gasoline. When used as an aviation fuel, benzole also had the severe disadvantage of a very high freezing point - when used on its own, it will start to freeze at +3 deg. C, and even in a mixture with gasoline it can raise the fuel's freezing point from the -50 to -55 deg. C of a gasoline to a figure as high as -20 deg. C or more, although the freezing point will depend on the proportion of benzol to gasoline and on the toluene content of the benzol, so that a fuel with a 20% or less of benzole content, or with an increased proportion of toluene, could nevertheless meet even a specification for fuels such as the British postwar DTD 224 Specification with the requirement that it would not freeze above -50 deg. C (Hoffert).

 

But something happened in August 1916 that changed everything - Romania entered the war on the Allied side, attacking Austro-Hungarian forces in Transylvania, and suddenly Germany (and Austria-Hungary) no longer had access to the light crude oil from the Romanian oilfields. German forces counter-attacked, and by mid November 1916 had captured the Romanian oilfields. Before they arrived, however, the Romanian engineers - with the urging and assistance of the British military mission to Romania, had comprehensively destroyed all of the above-ground stocks of petroleum and most of the equipment, pipelines, tanks, refineries and installations. It took the German engineers about six months to get the oil flowing again, leading to a hiatus in supply that lasted through until mid to late 1917. Total Romanian oil production dropped from 1,673,000 tons in 1915 to 1,244,000 tons in 1916, and then to just 517,000 tons in 1917. By the spring and summer of 1918, however, it was back up to 1916 levels at 1,214,000 tons, the bulk of which, 890,000 tons, was being sent to Germany with 231,000 tons to Austria-Hungary, 13,800 tons to Turkey and 5,900 tons to Bulgaria (Friedensburg). Between the autumn of 1916 and the end of 1917, however, the German refineries had to rely largely on their remaining stocks of the Romanian oil and the dwindling supply of somewhat heavier Galician oil. This was a severe blow to the German and Austro-Hungarian air forces as, up to this time, they appear to have been getting sufficient supplies of light gasoline to meet most of their front-line requirements, but now faced imminent shortages from the spring of 1917 when air activity would increase. A decision appears to have been made at this time to produce a new blended aviation fuel (possibly just for two-seater units, to start with), a 'Mittelbenzin' or 'Flugbenzin' that was not a straight-run distillate, but a blend of approximately 60% 'Leichtbenzin' and 40% 'Schwerbenzin' from a variety of sources (Reinhardt). The chemical composition of this blend, according to the analysis of two captured samples of this fuel by the French in the summer of 1917 (Dickinson), was very similar to that of the Shell East India gasolines and had, very strikingly, a relatively high aromatic similar to that of Sumatra and Borneo. It is known that the Germans had access to the Shell East India gasolines before the war, they had analysed the content of these fuels and were aware of their relatively high aromatic content (Reinhardt). It seems likely, therefore, that they were using these as 'reference fuels' in the creation of the blended 'Flugbenzin', and as neither Galician nor Romanian oil was noted for its high aromatic content (Hoffert), it seems probable that, from the winter of 1916, at least, they were adding some benzol to the blend to achieve a very similar aromatic content. This would help to explain the remarkable similarity in the chemical composition and distillation properties of the Flugbenzin and East India gasolines, noted by the French and the Americans. In Ricardo's immediate post-war analysis of the chemical and anti-knock properties of the gasolines then in use, one 'reference fuel' (E) stands out as a close match to the Reinhardt's distillation curve and the German Flugbenzin samples analysed by the French in 1917. This is listed with a specific gravity of 0.719: 68% paraffins, 11.3% aromatics, 20% naphthenes, and a 'highest useful compression ratio of 4.7:1, and is a close match to the chemical composition of the two different samples of Flugbenzin captured and analysed by the French: 68-78% methanes, 24-26% naphthenes, and 7-8% aromatics. As Flugbenzin was a blend of several very different gasolines, it is not surprising to find some variation, even between the French samples, and the resulting blends probably varied somewhat in their capacity to resist detonation - but appear to have been generally lower in this respect than the Allied Sumatra gasoline, at 4.7:1 according to Ricardo's analysis of Highest Useful Compression Ratio, or between 4 and 5 to 1 according to AchimEngels' source. It is notable that very few of the German aero engines of this early to mid period had a compression ratio higher than 4.7:1 (KACEY).

 

Despite the introduction of Flugbenzin, which appears to have largely replaced Leichtbenzin as the main aviation fuel by the end of 1917, this period between the winter of 1916 and the spring of 1918 was a difficult one for the Germans, as it coincided with a big increase in the front-line aircraft strength from 2,270 aircraft in the spring of 1917 to 3,600 aircraft in the spring of 1918 - but a corresponding fall from 11,000 tons of fuel a month from early 1917 to 7,000 tons a month at the time of the Spring Offensive in 1918. The response to this was to make even greater use of the benzol still available in very large quantities, and experiments with a variety of petrol-benzol and petrol-benzol-alcohol at Adlershoff and elsewhere led to the creation of a new petrol-benzol aviation fuel named 'Fliegerbenzin', in both a summer and a winter variety, that made use of this benzol. The summer variety was a mixture of 40% 'Leichtbenzin' and 60% benzol, and with a relatively high freezing point of -20 to -24 deg. C it was clearly not going to be suitable for the increasing altitudes at which air operations were being conducted by the German fighter and high-flying recon aircraft during the winter months. The 'winter benzin' that replaced this for the colder winter months was a 50/50 mixture of 'winter benzol' (77% benzol, 23% solentnaphtha) and 'Schwerebenzin', with a reduced aromatic content (to around 35%) that reduced the freezing point and allowed for high-altitude winter flying (Reinhardt; also Dechamps & Kutzbach). For home defence, a benzin benzol alcohol Spiritus-Benzol-Mischung was developed (Rammjaeger; also Dechamps & Kutzbach). Although the initial urgency to find these gasoline substitues was almost certainly generated by the developing fuel crisis of 1917, the introduction of benzolated fuel in increasing quantities and a gradually increasing aromatic contentalso enabled engine designers to increase compression ratios, cautiously at first in the spring and summer of 1917 (increasing the compression ratio of the Daimler Mercedes D.IIIa, for example), and then more dramatically from the winter/spring of 1917/1918 with some innovative 'Hohenmotoren' such as the BMW IIIa. British tests indicate that these very high compression late-war engines appear to have required the new Fliegerbenzin to support their very high compression ratios, but between them and the early to mid-war lower compression engine types there appear to have been a wide range of hybrid intermediate types, such as the overcompressed Mercedes and Benz, or the Maybach Mb.IVa, that seem to have functioned well on either Flugbenzin or Fliegerbenzin. According to British tests of a captured Maybach Mb.IVa, for example, this engine could be used as a high-powered low altitude engine when running on a rich mixture setting - but it could also function very well as one of the new Hohenmotoren when it was run, as intended, on a weak mixture of Fliegerbenzin in the high altitude recon aircraft or airships. Similarly, tests of the Daimler Mercedes D.IIIau by the British indicated that, when run on a Sumatra gasoline (or on a similar Flugbenzin) the engine would run well at low altitude or ground level when it was throttled back to 160 hp at 1400 rpm, but when unthrottled to 1500-1600 rpm (well within the mechanical limits of this engine) it appeared to loose power, probably from detonation (Piston aero engines of the Great War). German pilots, however, appear to have got 180 PS at ground level from this engine, presumably using the higher rpm range with non-detonating Fliegerbenzin, although it was still officially rated at 160 PS at 1400 rpm.

 

This was happening at a time, in the spring and summer of 1918, when supplies of light oil from Romania were arriving in great quantity, and there should have been no shortage of lighter Leichtbenzin coming out of German refineries from the spring of 1918 onwards. Despite this, the fuel shortage appears to have got worse. By June 1918 gasoline supplies to front-line units had fallen from 7,000 tons a month in 1917 to 5,000 tons a month in 1918, whilst their aviation fuel consumption had apparently risen from 7,000 tons to 9,000 tons a month in 1918 (a shortfall, presumably, being met by supplies of Fliegerbenzin), and restrictions were being placed on the number of sorties that could be flown from German airfields. It is likely that these shortages were not due to any real shortfall in the supply of a suitably light crude oil to German refineries - as Romanian oil was once again flowing into Germany and Austria-Hungary, and in much greater quantities than ever before - but to an increase in demand at the front combined with severe distribution difficulties on the home front, due to lack of spare parts and other industrial resources, disruption caused by civil disturbance and Allied strategic bombing, and the difficulties presented by the movement of fuel forwards from these refineries and rear areas to the front line units, particularly under the almost continuous low-level Allied bombing and strafing of German lines of communication from the spring of 1918 through to the end of the war.

 

Bletchley

 

References

 

'25,000 Berlin autos stop: government cuts down the use of gasoline and rubber', New York Times, 31st March 1915.

 

'Germany's new problems: substitutes for rubber and gasoline found perpexling', New York Times, 27th December 1914.

 

'Tells Germany's motor mixture: proportions in alcohol-benzol combustible used as economy substitute for gasoline', New York Times, 6th August 1916.

 

'Germans using substitute fuel: employment of benzol and alcohol may increase life of war motors', New York Times, 10th January 1915.

 

'Use gasoline mixture: Germans overcome shortage of fuel for motor vehicles', New York Times, 15th July 1916.

 

Brewer, Robert W. The motor car: a practical manual for the use of students and motor car owners. 1909.

 

AchimEngels. Aerodrome Forum, 29th July 2002.

 

Dechamps, H. and Kutzbach, K. Prufung, Werung und Weiterentwicklung von Flugmotoren. Richard Carl Schmidt, 1921.

 

Dickinson, H.C. (and others). 'Power characteristics of fuels for aircraft engines', NACA Report no.47.

 

Friedensburg, Ferdinand. Das Erdol im Weltkrieg. Enke, 1939.

 

Hoffert, W.H and Claxton, C. Motor Benzole: its production and use. The National Benzole Association, 1938.

 

Howarth, Stephen. A century in oil: the "Shell" Transport and Trading Company, 1897-1997. Weidenfeld & Nicolson, 1997.

 

Jonker, Joost and Luiten van Zanden, Jan. A history of Royal Dutch Shell, vol.1: from challenge to joint industry leader, 1890-1939. Oxford University Press, 2007.

 

KACEY. Aerodrome Forum.

 

Miller, J.C. Popular Mechanics, February 1913.

 

Piston aero-engines of the Great War. Hampshire County Library, 2009 (2 CD).

 

Rammjaeger. Aerodrome Forum, 3rd May 2003.

 

Reinhardt, Bruno. Vergaser, Brennstoffe und Brennstoffzufurung (Flugtechnische Bibliothek, Band 9), Richard Carl Schmidt, 1919.

 

Ricardo, H.R. 'The influence of various fuels on the performance of internal combustion engines: an experimental investigation into their behaviour', in The Automobile Engineer. (Part 1, February 1921, pp.51-54; Part 2, March 1921, pp.92-97; Part 3, April 1921, pp.130-133; Part 4, May 1921; Part 5, June 1921, pp.201-205; Part 6, July 1921, pp.242-247).

 

Riedler, A. 'Disturbing effect of free hydrogen on fuel combustion in internal combustion engines', Technische Berichte vol.III no.2, pp.25-26, 1918 (translated in NACA Technical Notes no.133, March 1923).

 

Bletchley

[Bletchley 8]

Rounds Carried

 

In arriving at a figure for bullet load I think we have to draw a distinction between the maximum number of rounds that an aircraft could carry; the weight of ammunition (from which we can infer the number of rounds) included as 'military weight' in official flight tests (from which we get the standard parameters on an aircraft's performance); and the number of rounds that an individual pilot might specify as his loadout.

 

The first of these, at least for belt-fed machine guns (Vickers and LMG 08 or 08/15) must be limited by the capacity of the ammunition boxes, and then by the capacity of the belts used. From the evidence that I have come across so far, I think that a standard 500 round capacity box was used by the Allies (a box capable of holding a 500 round belt) for each belt-fed machine gun, and a standard 600 round capacity box by the Germans. Fabric belts appear to have been made in standard sizes, and I have come across no evidence so far to indicate that pilots would cut these down or stitch them together to form shorter or longer belts: the Germans probably used 250 or 500 round Maxim belta in the LMG 08 and 500, 250 or 100 round Parabellum belts in the LMG 08/15, whilst the British used either the 500 or 250 round fabric Vickers belts, up to mid 1917, but variable length belts using either metal links or Prideaux metal links thereafter.

 

Both sides, in the early years, used stripped-down versions of the machine guns used by the ground forces - the French predominantly used the Hotchkiss, which had either a 25 round clip or a 100 round belt (the former being used on aircraft), until they acquired enough Lewis and Vickers guns to replace them; the British used the Lewis (a 47 round drum, and then mostly the 97 round drum from mid 1916) until they developed effective synchronising gears for the Vickers: a single synchronised Vickers with a fabric belt (250 rounds or 500 rounds) and then Prideaux links (400-500 rounds) followed by a twin Vickers with 2 x 250 round fabric belts or 2 x 200/250 or 2 x 400/500 round Prideaux linked belts (up to 750 rounds per gun, in some cases, where the aircraft was used in a ground-strafing role, and rising to 1000 rounds per gun at the end of the war); the Germans used Parabellum guns to begin with (100, 250 or 500 round fabric belts), then a stripped down LMG 08 (250 or 500 round fabric belts, or a 500 round metal linked belt) that was soon replaced by a lighter LMG 08/15 that used either 100, 250 or 500 round fabric Parabellum belts - 500 round fabric belts for all the twin-gun biplane and triplane types being the standard.

 

The weight of ammunition included as 'military weight' in British flight tests can be used to infer the number of rounds that were carried when assessing the performance of aircraft - the closest thing that we have, perhaps, to a 'standard' ammunition loadout. In general, this appears to be equivalent to 500 rounds, or sometimes 400 rounds with Prideaux links, for a single Vickers, and 250 rounds for each Vickers in the twin Vickers arrangement (400-500 rounds per gun for some of the later aircraft such as the Snipe and the Spad XIII, and probably 500 rounds per gun for the up-engined Sopwith Camels of 1918). There is some evidence that these 'standard' loads would be increased to the 'maximum load' of 500 rounds per gun when tasked for ground strafing.

 

Any individual pilot specification would therefore be constrained by the limits imposed by the capacity of the ammunition boxes (i.e. a maximum of 500-600 rounds per gun), the size of the available belts, and the effect on aircraft performance of increasing/decreasing the weight of ammunition carried forwards of the aircraft's centre of gravity. British memoirs that we have looked at indicate that 200 rounds per gun in a twin Vickers arrangement was regarded as a minimum useful load, and 500 rounds per gun as a maximum load for ground strafing. In a single Vickers arrangement either a 400 or 500 round loadout appears to have been the standard load. Evidence from the 'military weights' included in the British and US capture reports on German aircraft suggests that the 'standard' load for the early German single gun scouts (the early Fokker types, such as the E.III) was 500 rounds (25-30 lb weight), and 1000 rounds (55lb weight, or 500 per gun) for all twin gun types.

 

Woodman, Harry. Early aircraft armament: the aeroplane and the gun up to 1918. Arms & Armour Press, 1989.ISBN: 0853689903

 

Williams, Anthony G.; Gustin, Emmanuel. Flying guns: World War I and its aftermath, 1914-32. Airlife, 2003. ISBN: 1840373962

 

Clarke, R. Wallace. British aircraft armament, vol.2: RAF guns and gunsights from 1914 to the present day. Patrick Stephens, 1994. ISBN: 1852604026

 

Weyl, A.R. Fokker: the creative years. Putnam, 1965 (Ed. J.M. Bruce).

 

Bruce, J.M. War planes of the First World War: Fighters (vol.1-5). Macdonald, 1968.

 

Jane's fighting aircraft of World War I: a comprehensive encyclopedia. Studio, 2001 (reprint of 1919 ed.). ISBN: 1851703470

 

Profile publications (various), and books on individual aircraft.

 

Memoirs and diaries (various).

 

Air Board data for structure and stability calculation of aircraft. [british] Air Board, August 1917. (unpublished, UK National Archives).

 

Bowyer, Chaz. Sopwith Camel - King of Combat. Aston, 1988. ISBN: 0946627495.

 

Aerodrome Forum - various threads and posts.

 

Miller, James F. (JFM). Post in OFF Forum, quoting from Lothar and Manfred von Richthofen's combat reports.

[Bletchley 8]

WWI Anti-Aircraft Artillery Munitions

 

For some time I have been wondering why, when the British AA artillery units switched from using Shrapnel to HE rounds in 1916, they are still reported to have burst with a white/grey smoke, when German HE rounds burst with a black smoke.

 

Lyddite (Picric Acid) was used for British artillery shells up to and shortly after the outbreak of war in 1914 (black or dark grey smoke), and then they switched to TNT - but TNT was expensive and in short supply (at least until they started to extract toluene from aromatic Borneo heavy crude oil later in the war), and Amatol (initially 60:40, later 80:20 from around 1917) was much cheaper. The disadvantage, compared to TNT, is that it is hygroscopic and does not store as well as TNT. Even in dry conditions it will deteriorate after 5 years or so, becoming rather unstable, and it then 'sweats' corrosive and toxic residues. The Royal Navy continued to use TNT in their shells, I would guess for this reason, but the British artillery and AA units probably used up their stocks so fast that this would not have been a problem, despite the sometimes very damp conditions on the Western Front.

 

Up to mid or late 1916 the British AA artillery used Shrapnel in preference to HE, and this also burst with a white smoke (black powder bursting charge). It was not very effective as an AA weapon, as the shrapnel balls were discharged in the direction of travel of the shell (on an upwards trajectory), so unless a target aircraft was above and more or less directly in the path of the shell then the burst, even very close, would do relatively little damage (the blast effect was only about 1/3 or less that of an HE shell, I think). German AA units switched mainly to HE (TNT) shortly after the start of the war.

 

Digging into this a bit more I discovered that the British munitions manufacturers appear to have switched from filling HE shells with TNT to filling them with Amatol (80/20 TNT/Ammonium Nitrate from 1917, 60/40 before that) from around early to mid 1915 onwards, due to a perceived or actual shortage of toluene (an essential ingredient of TNT, or Tri-Nitro-Toluene), and this might account for the white smoke from this point onwards. The Germans had a much more plentiful supply of toluene (a by-product of their coking industry), and it therefore makes sense that they would continue to fill their shells with TNT. This burst with an oily black smudge of smoke, because it is not entirely consumed by the explosion (not enough oxygen in the air to burn the TNT completely). The Ammonium Nitrate in Amatol is less brisant than TNT (it burns more slowly, producing less of a blast), but also provides additional oxygen to fully consume the TNT in the explosion - the result is an equivalent blast to TNT (even slightly better, so long as the proportion of TNT to Ammonium Nitrate remains high), but it leaves a thick white or light grey smudge of smoke.

 

By comparison, WWII HE AA shells were filled with RDX, or possibly a mixture of RDX, TNT and aluminium powder, to produce a blast that was far more brisant, from 50% to 100% stronger than that produced by the WWI HE AA shells (either TNT or Amatol) of an equivalent size and weight.

 

Bletchley

Edited March 16, 2011 by Bletchley