Progress in Tank Design

PROGRESS IN TANK DESIGN With the exception of the Germans, who are prohibited by the Peace Treaty from doing so, all great nations now employ tanks as part of their military force. The French have retained the Renault tank as the main armament of their tank corps and although they have carried out much experimental work, no models have been considered sufficiently advanced to standardize and construct in any large numbers. The Americans have also constructed many experimental patterns, and after for long retaining the Mark VIII. or Allied tank as the heavy tank with which their tank units are equipped, are now superseding it by a 23 ton tank with a crew of four, a speed of 12 m.p.h., a protection of an inch of armour and an armament of one 6-pounder and two machine-guns. The Renault has also been replaced by a light tank with a speed of 18 m.p.h. and a cruising radius of 8o miles. It has a crew of two and an armament of one 37 mm. gun and one machine-gun.

The British, as the originators of the tank, have sought to main tain their lead. Some months before the conclusion of the World War, when preparations were being considered for a great of fensive in 1919, the specification was drawn up for a tank which was to be a great advance on the existing patterns. It was to have a speed of 20 m.p.h. and be capable of floating and propelling itself across water. Enough petrol was to be carried to travel 200 m. cross country, and the tank was to be long enough to cross a trench 12 ft. wide. This tank was to be used for attacking the enemy communications and headquarters while the more con ventional tanks were attacking the main armies in front. The first experimental model was actually completed just after the Armistice. The tank used a system of spring suspension on a cable and hydraulic power for control. Although the machine attained a speed of 28 m.p.h. and swam successfully across a nar row river on several occasions, it proved to be unreliable owing to the many new devices which it contained and which required further development. The problem of steering has been found to present many mechanical difficulties and, although much work has been done, no satisfactory solution has yet been found.

The Vickers Tank.

In the meantime the British Tank Corps which was reduced to four battalions after the War, was armed with the Mark V. tank and the Medium C. The Medium B.

replaced the Medium A. at the end of the War, but very few of this model were made and the units were equipped with an im proved type in the Medium C. This machine had a maximum speed of 12 m.p.h. and a radius of action of 7o m. and would have been a very useful tank in France. But by 192o-21 these machines were becoming worn out, and, although much knowledge had been gained, the experimental machines aiming at far higher achievements, and which have already been referred to, were not yet in a satisfactory state for production. A tank was therefore designed which was constructed on conventional lines and aimed at obtaining a high degree of mobility, if necessary at the expense of trench spanning capacity. The machine was known as the Vickers light tank. It is 18 ft. in length and weighs 1 o tons and is armed with one 3-pdr. gun and two machine-guns. It can attain a speed of over 20 m.p.h. and travel 15o m. on the petrol that it carries.

One Man Tanks.

In 1925 a new line of development was started by the British and the first one man tank' was constructed. The essence of the idea was to produce a small cheap fighting machine which could be used in large numbers, either instead of or in addition to the much larger and more expensive fighting tanks. The anti-tank weapons have become a serious threat to 'The idea was initiated and the first tank constructed as a private experiment by Major G. le Q. Martel, D.S.O., M.C., R.E.

the large tanks used in the small numbers that peace time financial stringency dictates, but if they can be split up into 20 times as many small tanks, the casualties can be reduced by the use of dispersion. Furthermore, small cheap tanks provide a means of sending out scouts and a protective screen which the tanks did not formerly possess. It was with these ideas in mind that the first of these small tanks was made. The original idea was that one man should both drive and fight the machine, and practical trials showed that this was not impossible. The advantage of hav ing only one man was that for the same charge on army funds, a larger number of machines could be manned and maintained than if two men were used in each machine. After due consideration it was, however, decided that these small tanks should be made to take two men each, the one to drive and the other to fire the machine gun.