Tanks are Armored Fighting Vehicles characterized by thick armor
and heavy weapons. They are designed as mobile weapon platforms,
so they have no space to carry troops other than their required
crews (although their have been instances in which soldiers have
ridden on the outside of a tank). A typical crew consists of a
driver, one or two gun crew, and a commander. Modern tanks are
tracked vehicles used primarily for line-of-sight combat, armed
with cannons and machine guns. The first tanks were built during
the Great War by the British as a means of overcoming German
trench lines. While they did have some success, they were slow,
cumbersome, temperamental, difficult to produce, and
inefficiently used. Proper design and strategy for using tanks
would not develop until World War II. Several subclasses of
tanks have been employed, including light tanks, amphibious
tanks, and main battle tanks (MBTs). Several defunct classes
have been used but are no longer in service, including
Tankettes, Cruiser Tanks, Infantr