Tanks

As regards tank design three main lessons were learnt from the battle of Cambrai. First of all the tanks required to be handier, and controlled by one man, without the assistance of any gears men, and to meet this requirement the Mark V. tank was pro duced. This design had been suggested but not accepted almost a year previously. Outwardly the tank had the same appearance as Marks I. to IV., but the engine and transmission were much improved. The engine developed more power and the steering was effected by using epicyclic gears on the transmission to each track; this was the best tank produced during the War. Then the difficulty of crossing the wide trenches of the Hindenburg line had been considerable, and a certain number of special long tanks were ordered for this purpose. These were made from Mark V. tanks by adding a section in the centre to obtain the required length, and were known as Mark V.* tanks. Later an improved type was made with a more powerful engine known as the Mark V.** The third lesson was the necessity at times for a much more mobile tank for use beyond the main trench systems. These tanks would not need to cross wide trenches and hence they could be shorter and lighter and more mobile. One type, known as the whippet, had already been constructed ex perimentally. These lighter tanks became known as "medium" tanks, and the whippet was named the Medium Mark A.

German Offensive of March 1918.

The Tank Corps was now expanded to five brigades of 13 battalions with 32o Mark IV. machines and 5o Medium A. machines. During the winter of 1917-18 all units were training and being equipped with new tanks. No further offensive operations were in view and there ensued a period of preparation for the expected German attack in the spring of 1918. To assist in repelling such an attack the Tank Corps was distributed in detachments on a front of some 6o miles.

The attack was launched on March 21 (see ST. QUENTIN, BATTLE OF), and the Germans advanced rapidly. The tanks took part in many improvised attacks in attempting to stem the German advance. Some of these met with fair success and caused heavy casualties but the tanks were too few and too dispersed to make their real weight felt. It was during this retreat that the Medium A. tanks were first engaged in action and they met with considerable success, their additional mobility being of great assistance in this type of warfare. The attack fought itself to a standstill within a month, immobility being caused more by the difficulties of transport than by the resistance offered by the Allies. The supply of ammunition and food to the advanced Ger man troops, especially where the lines of supply crossed the old battlefields, became exceedingly difficult, and it was at this stage that the necessity for some form of cross-country transport to enable an army to pursue across the devastated country left behind by the opposing force, began to be realized. The Tank

Corps had already foreseen its own requirements by the pro vision of supply tanks and sledges drawn by tanks, and later by moving signalling equipment in special signal tanks.

In the meantime a reaction had set in as regards the estimated value of fighting tanks. The critics asserted that the battle of Cambrai could never be repeated and pointed to the lack of decisive results achieved by the tanks during the German ad vance. The proposed expansion of the Tank Corps was post poned and the existence of the corps seriously threatened. For tunately the Mark V. tanks were now arriving at the rate of about 6o machines per week, and on July 4 one brigade of tanks equipped with these machines carried out a surprise attack on the Germans at Hamel in conjunction with the Australians. The attack was a complete success. The extra handiness and mobility of this machine enabled it to be used very effectively against machine-guns, many of which were crushed and rolled into the ground.

The Triumph of the Tank.

The great French victory of Soissons on July 18, 1918 (see MARNE, SECOND BATTLE OF THE), marked the turning point of the War; the victory was largely due to the use of French tanks employed in much the same way as the British had used their tanks at Cambrai. This was followed by the opening of the British strategic offensive on Aug. 8 with the battle of Amiens (q.v.). In this attack the tank tactics were those of Cambrai modified by recent experience and adapted to the improved machines available. The attack was carried out by three army corps, a cavalry corps and I 1 tank battalions ; nine battalions were equipped with Mark V. tanks and the remainder with Medium A. tanks. For the first time since tanks had been used for an offensive it was possible to keep some in reserve and 42 tanks were kept in hand. The attack was a complete success, the greatest penetration of the tanks being miles. The tanks continued in action till Aug. 11.

From that date until the Armistice tanks took part in every main attack and in no case, where tanks were properly employed in conjunction with the other arms, did the attack fail. During this period the tanks co-operated in the battles of Bapaume, Epehy, Cambrai, St. Quentin, the Selle and Maubeuge. Tanks came to be looked upon as essential to the success of any attack, and in his final dispatch the commander-in-chief stated that the successful attacks which won great victories at Amiens and afterwards would have been impossible without tanks. The Germans also confessed that it was the tanks that had caused the downfall of their armies in the field. An expansion of the Tank Corps to 34 battalions had been sanctioned if the War con tinued into 1919, and the Ministry of Munitions in England had hoped to produce a total of 6,000 machines in 1919.