Tank
Most modern tanks most often have four crew members, or three if an auto-loader is installed. These are the:
Historically, crews have varied from just two members to a dozen. For example, pre-World War II French tanks were noted for having a two-man crew, in which the overworked commander had to load and fire the gun in addition to commanding the tank. First World War tanks were developed with immature technologies; in addition to the crew needed to man the multiple guns and machine guns, up to four crewmen were needed to drive the tank: the driver, acting as the vehicle commander and manning the brakes, drove via orders to his gears-men; a co-driver operated the gearbox and throttle; and two gears-men, one on each track, steered by setting one side or the other to idle, allowing the track on the other side to slew the tank to one side.
Tanks in the German Army
After British tanks went into action on 15 September 1916, the German Army immediately demanded their own landships. Following the appearance of the first British tanks on the Western Front, the War Ministry formed a committee of experts from leading engineering companies, answerable to the "Allgemeines Kriegsdepartement, Abteilung 7, Verkehrswesen" ("General War Department, 7th Branch, Transportation"), The project to design and build the first German tank was placed under the direction of Joseph Vollmer, a leading German automobile designer and manufacturer. He was chosen to design the World War I German tanks A7V, and the "Großkampfwagen" or K-Wagen. The K-Wagen was a German super-heavy tank, two prototypes of which were almost completed by the end of World War I. The A7V tank which actually got into the war, was known as the Sturmpanzerwagen A7V, named after the committee that oversaw its development. It was to weigh around 30 tons, capable of crossing ditches up to 1.5 metres wide, have armaments including cannon at front and rear as well as several machine-guns, and reach a top speed of at least 12 km/h. The running gear was based on the Holt tractor, parts for which were copied from examples borrowed from the Austrian army. After initial plans were shared with the Army in December 1917, the design was extended to be a universal chassis which could be used as a base for both a tank and unarmoured "Überlandwagen" ("Over-land vehicle") cargo carriers. Powered by two Daimler engines, the tank was first demonstrated in the Spring Offensive of 1918. Internally, the Sturmpanzerwagen was cramped, smelly and noisy. No fewer than 18 men were called upon to man the machine to full potential. With the 57 mm main gun at front, internal operators had access to two 7.92 mm machine guns at the rear along with a further four along the sides of the steel beast - two to a side. Each machine gun would need to be addressed by a further two personnel per gun - a firer and an ammunition re-supplier. The engine sat in the lower-middle of the design with the main gear components resting under the rear. A crew of two would man the front 57 mm main gun, one firing whilst the other loading the weapon. Two drivers sat in the upper center budge area operating a steering wheel and lever controls. Stowage was allotted for individual crew weapons in the form of rifles. During final design the rear-facing cannon was removed and the number of machine-guns was increased to six. Grab ropes were provided throughout as the design had plenty of headroom space for the average soldier, though travel made for an uneasy and overall bumpy ride.
In theory, the idea of an armored box bristling with all types of deadly hardware seemed sound. In practice, however, the large design was far from perfect. The vehicle was top-heavy, making it impractical to be used on uneven terrain. The system was slow as well, often meaning that it could be outpaced by the very infantry it was to assist. The short tracks of the tractor system also made the vehicle relatively unsafe and uncontrollable in some cases. If the A7V has one saving grace, it was that the all-around armor protection for the crew was second to none - even when compared to the British designs - over an inch in some areas. Twenty of these tanks were produced, and the first of these were ready in October 1917. The A7V was first used at St Quentin on 21 March 1918. Although some of its features, such as the sprung tracks and the thicker armour, made it better than British tanks at that time, the A7V was less successful as a battle vehicle. The main problems concerned its mechanical reliability and the difficulty it encountered crossing enemy trenches.
By the time of the arrival of the Sturmpanzerwagen, the Germans had already successfully developed their own brand of armor-piercing projectile as well. Near the end of the First World War it was clear that the A7V was a failure, being too slow and clumsy in action and slow to build. Therefore, it was decided that a lighter tank was required which could spearhead assaults and which could be mass-produced, and was called the Sturmpanzerwagen Oberschlesien.