by two Daimler engines, the tank was first demonstrated in the German spring offensive of 1918. Internally, the Sturmpanzerwagen was cramped, smelly and noisy. it required a crew of 18 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 - two to a side. Each machine gun needed 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 operated the front 57 mm main gun, one to aim and fire while the other loaded it. 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, a 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 with a lot of weapons 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. It 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. Three of the five tanks committed broke down at St Quentin. At the Second Battle of