Tank
A tank normally has 3-5 crew members with at least a driver, commander and gunner.  There may also be a loader, who handles the ammunition for the main gun (so the gunner doesn't have to take eyes off the target).  Some WWII tanks also had a separate soldier responsible for the radio.  Since then, tank crews have evolved to have each person do one of these things, but in their early stages, the commander was often the loader and radio operator, and in a few tanks was also the driver.