I.

Introduction

Tank, heavily armored military vehicle with cross-country mobility and road speeds up to 97 km/h (60 mph). Tanks travel on tracks or treads, rather than wheels. Tanks are classified as light, medium, and heavy. They range in weight from approximately 14 to 69 metric tons, have at least 15 cm (6 in) of armor plate, and mount cannons ranging from 75 mm to 122 mm in the tank's turret.

The turret is a structure on top of the tank that can rotate 360 degrees, enabling the tank to fire in any direction. In addition, tanks often have both light and heavy machine guns. Light tanks are used for reconnaissance; heavier tanks are used primarily to penetrate or flank enemy defenses.

The concept of armor protection dates from antiquity. By the 5th century bc Greek warriors, and sometimes their horses, wore armor. Florentine artist and scientist Leonardo da Vinci designed a crank-operated covered chariot in 1482, but development of an effective, track-laying armored vehicle was only possible after the invention of the internal-combustion engine.