Army Tanks
USA and British

Mark VIII Heavy Tank

Active: 1918
Crew: 8
Weight: 37 tons (37,593kg)
Length: 34ft 2in (10.41m)
Height: 10ft 3in (3.12m)
Width: 12ft 4in (3.76m)
Weapons: Main - 2 x 6 pounder 2.24in (57mm) guns, Secondary - 7 x 0.303in (7.7mm) machineguns
Armor Maximum - 0.63in (16mm)
Engine: Ricardo V12 gasoline, 300hp or Liberty V12 gasoline, 300hp
Speed: 6mph (9.7kph)
Range: 55 miles (88 km)

The production of the Mark VIII heavy tank, also known as the International, was supposed to have been a joint venture between Britain and the United States. Together, the two countries planned to build 4,450 Mark VIIIs as well as 2,000 Mark Xs. The design of the Mark X was never finished.

Of all the British World War I tanks, the Mark VIII was the largest and the most powerful. It weighed 9 tons (9,144kg) more than the Mark I heavy tank.  The Mark VIII's engine generated 300 horsepower at 1,250 rpm.  This gave it a power to weight ratio that was about two times that of the Mark I.

The Mark VIII's armament consisted of two six pounders as well as seven machine guns.  It was the first heavy tank to have a separate engine compartment.

The British were able to produce only five Mark VIII heavy tanks before World War I ended. Only three of these ever went into service.

One Mark VIII was sent to the United States, so that the Americans could copy it.

Mark VIII Heavy TankAmerica built about 100 Mark VIII's after the war.  In the American version of the Mark VIII, the British Ricardo V12 engine was replaced by an American Liberty V12 engine which also produced 300 horsepower.

The United States Army sent some Mark VIIIs, along with some Ford 6 Ton versions of the Renault-FT17, to Canada in 1940. These tanks were used for training Canadian armored units.

The Mark IX was the last of the British armored fighting vehicles to be used during World War I.  It was the first armored personnel carrier, and was designed to carry troops or cargo, rather than function as a conventional tank. The Mark IX could carry 30 fully equipped infantrymen or 10 tons of stores.  Instead of gun sponsons, it had two large oval doors on each side.

One version of the Mark IX, which was being tested on Armistice Day, had huge air drums attached to its sides in order to make it amphibious.