The A7V was a tank introduced by Germany in 1918, near the end of World War I. One hundred vehicles were ordered during the spring of 1918, but only 21 were delivered. It was nicknamed "The Moving Fortress" by the British because of the shape of the hull. They saw action from March to October of that year, and were the only tanks produced by Germany in World War I to see operational use The tank's name was derived from that of its parent organization, Allgemeines Kriegsdepartement, 7. Abteilung, Verkehrswesen. In German the tank was called Sturmpanzer-Kraftwagen (roughly "assault armoured motor vehicle"). The A7V was 7.34 metres (24.1 ft) long, 3 metres (9.8 ft) wide, and the maximum height was 3.3 metres (11 ft). The tank had 20 mm of steel plate at the sides and 30 mm at the front; however the steel was not hardened armour plate, which reduced its effectiveness. It was thick enough to stop machine gun and rifle fire, but not larger calibres. This offered protection comparable to the thinner armour of other tanks of the period, which used hardened steel. The crew normally consisted of up to sixteen soldiers and two officers[clarification needed]: commander, driver, mechanic, mechanic/signaller, twelve infantrymen (six machine gunners, six loaders), and two artillerymen (main gunner and loader). The A7V was armed with six 7.92 mm MG08 machine guns and a 5.7 cm Cockerill-Nordenfelt fortification gun mounted at the front. Between forty and sixty cartridge-belts, each of 250 rounds, were carried as well as 180 shells for the main gun, split 90:54:36 between canister, antitank, and explosive. These were the official figures, up to 300 rounds for the main gun were actually stowed. The "female" variant had two more machine guns in place of the main gun. It is not entirely clear how many started this way or were converted. Some sources say only chassis number 501 saw combat as a female.