Vickers A1E1 Independent

Vickers A1E1 "Independent"
The Vickers A1E1 in 1925
Type	Tank
Place of origin	United Kingdom
Production history
Manufacturer	Vickers
No. built	1
Specifications
Weight	33 long tons (34 t)
Length	24 ft 11 in (7.59 m)
Width	8 ft 9 in (2.67 m)
Height	8 ft 11 in (2.72 m)
Crew	8
Armour	13–28 mm
Main armament	QF 3 pounder gun (47 mm)
Secondary armament	4 × 0.303 Vickers machine gun
Engine	Armstrong Siddeley V12 petrol 370 hp (280 kW)
Transmission	4 forward, 1 reverse
Suspension	coil spring bogies
Operational range	95 miles
Speed	20 mph (32 km/h)

The Independent A1E1 is a multi-turreted tank that was designed by the British armaments manufacturer Vickers between the First and Second World Wars. Although it only ever reached the prototype stage and only a single example was built, it influenced many other tank designs.

The A1E1 design can be seen as a possible influence on the Soviet T-100 and T-28 tanks, the German Neubaufahrzeug tanks, and the British Medium Mk III and Cruiser Mk I (triple turret) tank designs. The Soviet T-35 tank was heavily influenced by its design.

The Independent was a multi-turret design, having a central gun turret armed with the 3 pounder (47 mm) gun, and four subsidiary turrets each armed with a 0.303 inch Vickers machine gun. The subsidiary turrets were mounted two at the front and two to the rear of the turret (about halfway along the hull). The gun of the left rear turret was able to elevate to engage aircraft. The tank was designed to have heavy firepower, self-defence capability, and superiority to enemy weapons. It had a crew of eight men, the commander communicating with the crew through an intercom system. The Independent was never used in combat, but other armies studied it and a few adopted designs derived from it.

In 1924 the General Staff of the British Army ordered the prototype of a heavy tank, which became known as the Independent. Largely designed by Walter Gordon Wilson, its 35.8 litre V12 air-cooled engine was designed by Armstrong Siddeley. It also incorporated a new hydraulic braking system which had to be specially developed due to its weight and speed. The prototype was delivered to the War Office in 1926, and displayed to the premiers of the Dominions that year.