Cruiser MkI A9
Weight: 12 tons
Length: 19 ft 3 in
Width: 8 ft 4 in
Height: 8 ft 4 in;
Armour: 14 mm -l6 mm
Main Armament: 2-pdr (3.7-in howitzer in Mark 1CS),
Supplementary Armament: 3 Vickers machine guns 1 co-axial with the Main gun;
Engine: 150-hp AEC
Crew 6: Driver, gunner, loader, Commander and 2 machine gunners
Speed: 25 mph
Range: 100 miles.
When the A9 was first conceived in 1934 the intention was to produce a close support tank. With this in mind the intended main armament was to be a 3.7 inch mortar. When the Medium MkIII (A6, A7 & A8) programme was abandoned in 1937 it was decided that the role of the A9 should be that of battle tank and the main armament was changed to a 2 pounder. British tank doctrine at the time called for three classes of tank, Light for reconnaissance, Cruiser: for the exploitation of breakthroughs and Infantry intended for infantry support. The A9 became the first designated Cruiser, a naval term derived from the concept that tanks could be treated as ‘land ships’. When you look at the A9, bristling with gun turrets and with a boat shaped hull, the term Cruiser seems quite fitting.
The two forward machine gun turrets, apparently included at the personal insistence of Sir John Carden, were an inheritance from the A6 experimental tanks. These turrets proved to be extremely cramped internally with the ammunition belts often impairing the traverse mechanism. They also had the unfortunate effect of obscuring the driver’s vision and it is reported that it was almost impossible to fire the guns in long bursts due to the fumes generated within the small turrets. The turrets also had the most undesirable effect of creating lethal shot traps.
The A9 did however incorporate some very interesting technical developments. It was the first British Tank with a hull shaped to offer ballistic protection from mines and also employed periscopes rather than direct vision blocks. The A9 was also the first tank to provide a powered turret traverse which was provided by an adaptation of the hydraulic traverse system used in aircraft gun turrets. The suspension became something of a trademark for the early war British tanks and consisted of two triple wheel bogies on each side of the hull. The front and rear wheels on each side were larger at 24 inch diameter than the remaining 4 wheels which were of 19.5 inch diameter. The two smaller wheels on each bogie were sprung against the larger in an arrangement that included an enclosed hydraulic shock absorber. This suspension system became known as the Vickers ‘slow motion’ suspension.
The A9 has the distinction of being the first vehicle to perform deep wading. Deep wading basically consists of waterproofing the vehicle, fitting it with a breathing tube (for the engine) and then driving along the sea bed/ river bed. Unfortunately as with many British ‘bright’ ideas the concept was not pursued and the Germans are credited with being the first tactical use of snorkelling tanks.
The A9 saw service in France until the retreat at Dunkirk and later with the 7th Armoured Division in North Africa until the end of 1941. A total of 125 A9s were built.
© 1998 Chris