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.
Second Battle of Gaza
The tanks which arrived in Palestine in January 1917 had been used for instruction and were not of the latest type, however during a trial attack they proved themselves in the sandy conditions. "[T]he sand though fairly heavy, did not interfere with them in the least. They buzzed along most satisfactorily." They worked well in sand so long as the treads were not greased, which was the normal practice. The tank, "War Baby" was powered by a 105-horsepower engine. It had a revolver, loop holes, periscopes, dynamos and differentiator, and was armed with four Hotchkiss machine guns and two auxiliary guns. This tank was manned by one officer sitting beside the driver, four gunners on bike seats and two greasers.