Map 10: The Tank

[Hauksbee 103]

 The tank makes its debut

The tank, the brainchild of First Lord of the Admiralty (and future Prime Minister) Winston Churchill, was developed by the British during World War I. British officials were anxious not to tip the enemy off to what they hoped would be a powerful new weapon, so they decided to tell people that the strangely-shaped objects they had concealed under tarps were mobile water receptacles: "tanks." [for the desert campaign in Mesopotamia] The code name stuck, and we still call them tanks today. This image shows the design of a tank used by the British at the Battle of Cambrai in 1917. While tanks were developed and used in large numbers by the Allies (and to a much lesser extent by the Germans) they were too primitive to be a major factor in the outcome of the war. Tanks were slow and frequently broke down in the middle of battle. It would take further refinements to turn tanks into the formidable killing machines they would become later in the 20th century. ['love the crank starter handle.]

 

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          

Edited November 12, 2014 by Hauksbee

[Capitaine Vengeur 263]

The monument to the French tank crews of WW1 is located at Berry-au-Bac, North of Reims, on the place from where the French tanks were launched in action for the first time, on 16 April 1917. Some 250 slow and unreliable Schneider and St-Chamond machines, it turned into a slaughter. The commander, Cdt Bossut, having stated that this involvement was prematurate and doomed, had required to advance as the spearhead tank, to avoid facing the families of those lost; he was KIA as expected, like half of the crews involved. The French developped later the outstanding Renault FT.17, first tank with a rotative turret hosting either a MG or a 37mm gun able to blast fortified MG nests by direct fire. Quite reliable, acting in large swarms of small targets, overrunning the strongest German defenses, the FT.17 was a key in the final breakthroughs in the French and U.S. sectors of the Front.

 

What is interesting in the monument at Berry-au-Bac, is that it displays two quotes that summarize quite well the developmement and impact of this new weapon:

• "Victory shall belong to the first one who will design an armoured machine, able to advance on any ground, and armed with a cannon." (22 August 1914 - Colonel Estienne, then CO of the artillery of 6e D.I., he is considered as the father of the French tanks)
• "There is no more any chance to prevail, and the first decisive factor having led to this result, is the tank." (8 October 1918 - Deputy of the German High Command before the Reichstag)

[Hauksbee 103]

A 37mm on the FT-17? I am amazed. As amazed as I was when I first discovered they had mounted one on a SPAD. The Germans didn't mount a 37mm until 1936-37 when the launched the PzkwIII.

[+Gepard 11,147]

Caliber is not all. The gun of the FT had a length of 21 calibres. The gun had so a lenght of 78cm and was useless against other armored vehicles. The gun of the PIII had L/45. It was 1,67 m long and was able to penetrate the most armors at the begin of the WW2.

[Capitaine Vengeur 263]

Both the heavy tanks German A7V and British Mk.I to Mk.V ('male' version) had 57mm guns with a length over 40 calibers, but of limited use and aiming, as not mounted into a rotative turret. Same thing for the French Schneider and St-Chamond, with respectively a short-barrel Schneider 75mm gun and the powerful, long-barrel original version of the famous 75mm gun. Armor-piercing ammo were of little use, at least on the Allied side, as the Germans did not believe in those rolling monsters, favouring Stosstruppen for their own breakthroughs, and they never lined up over 150 tanks at their apex (mostly captured British tanks and a few dysfunctional home-made A7V). A lethal mistake that some junior officers like young Heinz Guderian never forgot. The Germans designed armor-piercing 'K' bullets, five of them theoretically provided to each infantryman, but mostly supplied to machine-gunners. The first AT rifles with extra-long barrel appeared during the year 1918 (13.2mm caliber). I do not know if the Germans designed during WW1 AP rounds specifically intended to be direct fired by guns against tanks.

 

The gun mounted into the SPAD XII was a slightly different model of 37mm weapon from the SA18 gun the FT.17 tank had, with lower muzzle velocity but alleged higher rate of fire, designed as well by Puteaux in 1916. The SPAD XII had little success, as the gun placed between the pilot's legs produced much smoke when fired, and had to be reloaded after each shot (these operations and faults in action can be seen in the excellent comics "Le pilote à l'Edelweiss", discussed about on this site, volume 2). It may have been the same mess into the FT.17's cramped turret. However, Guynemer, first user of the SPAD XII, seemed to have liked what he called his 'avion-canon'. French and U.S. infantry also made a large use of these 37mm guns during the breakthroughs of the last months (the French had one per battalion by 1917, attached to the battalion's MG company). This model, somewhat heavier to move than an MG (108 kgs, mounted either on wheels or tripod), was intended to fire HE or shrapnel rounds at sustained rate in direct fire, to eliminate the German fortified MG nests. It did quite well.

Edited November 19, 2014 by Capitaine Vengeur

[Hauksbee 103]

Both the heavy tanks German A7V and British Mk.I to Mk.V ('male' version) had 57mm guns with a length over 40 calibers,

I'm not understanding your use of the word 'caliber'. In the U.S., caliber refers to the diameter of the bullet measured in 1/100's of an inch, i.e., a .50 caliber MG fires a bullet 1/2" in diameter. Thus, it can only have one caliber. What does it mean when you say '40 calibers long'?

[33LIMA 972]

The 'calibre' can mean 'length in calibres' eg the German 7.5cm Pak 40 was  IIRC 'L/46' meaning barrel length was 46 times 7.5 cm while the tank mounted KwK derivatives were first L/43 later L/48.

[Hauksbee 103]

So that's it? Never heard of it before. Is it mainly a European thing?

[+Gepard 11,147]

So that's it? Never heard of it before. Is it mainly a European thing?

 

Its a german thing.

The lenght of the barrel is important for the penetration power of a projectile. The messurement is in Kaliberlängen (caliber lenght). As longer the barrel as faster the projectile, but there is a relation between thecaliber of the barrel and the lenght too. What does it mean? Take a 2,0cm gun with a 200 cm long barrel, so it is a L/100 gun. The muzzel velocity v0 is very high. A 10,0cm gun with a 200cm barrel has only L/20. It is a short gun with low muzzel velocity, which is used in a howitzer or so. (in comparision, the D10Ts gun of the T-55 tank is a L/56 with 5,60 meter long barrell which can reach with subcaliber darts a speed of ca. 1.400m/s)

The designation of a gun with Kaliberlänge was widely used during WW2, when german tanks had a lot of 7,5cm guns. There was a short L/24 in the first PzIV which was nearly useless against the soviet T-34. Later came the L/43, which gave the german tank a fair chance against the T-34 and finaly the L/48 which was very good to kill the T-34. For the PzV Panther a gun with L/70 was used and this had an outstanding performance. With a simple calculator you can find out how long the barrels of the different guns were.

[Hauksbee 103]

Very interesting. I shall view all artillery and tanks with new eyes.