Tanks

In the meantime the authorities in England who were respon sible for the production of tanks were becoming perturbed about the delay over a decision as to the design of tanks for the order of r,000 machines. For the original idea of fighting a surprise battle on a new front the existing design was suitable, hut to produce the ideal machine for traversing the shell torn ground of an old battlefield, a new and special design was necessary and this would mean a complete new series of experimental trials involving much delay. It was not till the end of March, involv ing the loss of five valuable months, that a decision was reached and it was then decided that the r,000 machines should be of a type known as the Mark IV. This type was again very similar to the Mark I., using the same engine and transmission and the same shape of hull. It included the minor improvements already incorporated in Marks II. and III. and in addition had sponsons which could swing into the body for travelling on a railway, and so saved the labour of detaching and remounting these heavy sponsons for every railway journey. Another feature of this tank was that it carried an unditching beam which could be fas tened when required on to the tracks to extricate the tank from a ditch. The Mark IV. tank was the main machine used through out 1917 and the early part of 1918.

The next action in which the tanks took part was the battle of Arras (q.v.) on April 9 in which the I., III. and V. Armies attacked with a view to penetrating the German defences and allowing an Army Corps and two cavalry divisions to break through. Only 6o tanks were available for this attack and they were again used in the minor role of assisting the infantry to "mop up" machine gun nests and small posts that had been passed over by the artil lery barrage and the assault of our leading troops. The tanks were of the Mark I., II. and III. pattern and some of them suffered heavily from armour-piercing bullets. In many cases the tanks rendered valuable assistance, overcoming enemy ma chine-guns and barbed wire with ease. The cavalry were prevented from breaking through owing to the usual obstacles—barbed wire and machine-guns—the tanks being far too few in numbers and too dispersed to be able to keep up the pressure and assist in further operations.

Messines.

The next attack was against the Messines-Wyt schaete ridge on June 7 in which 76 Mark IV. and 12 supply tanks were used. The latter were made from old converted Mark I. or II. tanks and were used to keep the fighting tanks supplied with petrol and ammunition—a need which had been much felt in former battles. The attack was in the nature of an assault in the old form of siege warfare. The result was a com plete success in which the tanks only played a small part, though in a few individual cases they rendered valuable help. The ground was completely pulverized by the preliminary bombardment but very few tanks became ditched, mainly owing to the fact that there had been no rain for many weeks and that there had been time to make a close reconnaissance of the ground and pick out the best lines of advance for the tanks. After this attack the

arm was renamed as the Tank Corps.

On July 31 the battle of Ypres (q.v.) was launched. As the preliminary bombardment had been so successful at Messines it was decided again to use a long preliminary bombardment lasting ten days. The danger of thus rendering the ground im passable to tanks, especially if it rained, was explained by those responsible for the action of tanks, but it was considered that the value of the bombardment more than balanced the possible loss of the use of tanks; this did not prove to be the case as the Germans adopted a defence distributed in depth which did much to discount the value of the bombardment. Unfortunately it rained on the first day of the battle and although the tanks rendered much assistance in individual cases during the early stages of the attack, the ground soon became quite impassable to tanks, and later it became impassable to infantry as well.

Success at Cambrai.—Although the failure of the tanks at the third battle of Ypres was through no fault of the officers and men and those who commanded them, it lead to much discussion as to whether tanks should be retained at all. The Germans formed the opinion that the tank was practically useless, and many British officers held the same view. Fortunately this view was not unanimous and on Nov. 20 permission was obtained to launch an attack at Cambrai, in which the tanks were to be used in the way in which their originators had intended that they should be used. This was the turning point in the history of the Tank Corps. The action as fought was in almost every detail the execution of the plan put forward officially for the employment of the tanks by Col. Swinton in Feb. 1916, seven months before the first tank action. The attack was to be a complete surprise and no preliminary bombardment was to be used. Three brigades of tanks (nine battalions) were to take part with a total of 378 Mark IV. tanks and 98 administrative machines (see CAMBRAI).

The attack was launched at 6.2o A.M. in a slight fog, Maj. Gen. Elles leading the attack in a vanguard tank with the centre division. The operation was a complete success; the enemy were taken absolutely by surprise and most of the infantry bolted or surrendered. Within 12 hours the infantry had advanced 12,000 yd. on a front of 13,00o with only 4,000 casualties. A similar penetration at Ypres had taken three months, with enormous loss of life and morale. The preliminary bombardment which had cost some £22,000,000 at Ypres was dispensed with and a further advantage was gained in that the roads had not been torn up with shell fire and were available for use almost at once. And this had been achieved by the Tank Corps using great mechanical power, but numbering only 4,000 of all ranks.