The AC4 (Australian Cruiser Tank Mk. 4) was a
cruiser tank
The cruiser tank (sometimes called cavalry tank or fast tank) was a British tank concept of the interwar period for tanks designed as modernised armoured and mechanised cavalry, as distinguished from infantry tanks. Cruiser tanks were develop ...
designed in Australia in World War II as the intended successor to the
AC3 Thunderbolt. Like its predecessors the AC4 was to have a one piece cast hull and turret. The AC4's most important characteristic would be the use of a
17 pounder
The Ordnance Quick-Firing 17-pounder (or just 17-pdr)Under the British standard ordnance weights and measurements the gun's approximate projectile weight is used to denote different guns of the same calibre. Hence this was a 3-inch gun, of which ...
tank gun.
History
Reservations about the utility of the
25 pounder
The Ordnance QF 25-pounder, or more simply 25-pounder or 25-pdr, was the major British field gun and howitzer during the Second World War. Its calibre is 3.45-inch (87.6 mm). It was introduced into service just before the war started, combin ...
in the AC3, and the 25 pounder's limited ability to pierce armour led to experimentation with a 17 pounder mounted on an Australian cruiser.
A turret was built and mounted on one of the earlier development vehicles to assess the vehicle's ability to mount the foremost
Allied
An alliance is a relationship among people, groups, or states that have joined together for mutual benefit or to achieve some common purpose, whether or not explicit agreement has been worked out among them. Members of an alliance are called ...
anti-tank gun of the day – the British 17 pounder (76 mm, 3 in). This was achieved by mounting two 25 pounder gun-howitzers which when fired together would significantly exceed the recoil of a 17 pounder. In this configuration the tank was tested on 2 November 1942. It fitted with a 17 pounder and after successful gunnery trials on 17 November 1942 the 17 pounder was selected for the AC4 design. For the AC4 the 17 pounder was to be mounted in a new and larger turret, attached by a 70-inch (1778 mm) diameter turret ring, the space for which was accommodated by changes to the upper hull permitted by the compact nature of the "Perrier-Cadillac".
A design for the tank had been established, however it was subject to a redesign to alter the internal stowage, and include new features not previously considered such as removal of the turret basket, addition of a gyro-stabiliser, and swapping a hydraulic traverse for the electrical system, and torsion bar suspension for the volute spring used up until that point.
The programme was authorised to build a total of 510 AC4 tanks.
Of these 510 tanks, 110 were to be the "A" variant fitted with a 25 pounder tank gun instead of the 17 pounder.
While the AC4 did not receive a formal name the Director of AFV Production, Alfred Code, had the name "
Woomera" in mind for the tank.
The design was not yet finalised when the programme was terminated in July 1943.
Variants
*AC4A
**one 25 pounder gun
**one
Vickers machine gun
See also
;Tanks of comparable role, performance, and era
* Australia
Thunderbolt
* British
Cromwell
* Canadian
Grizzly I
* German
Panzer IV
* Hungarian
Turán III
* Italian
Carro Armato P 40
* Japanese
Type 3 Chi-Nu
* Soviet
T-34
* Swedish
Stridsvagn m/42
Stridsvagn m/42 (Strv m/42) was a Swedish medium tank in service in the World War II period. Known by its manufacturer AB Landsverk as Lago II-III-IV, it fielded a 75 mm L/31 gun, the first of its size in a Swedish tank. It entered service ...
* United States
M4 Sherman
Notes
;Footnotes
;Citations
References
*
*
{{DEFAULTSORT:Australian Cruiser tank Mk IV
Cruiser tanks of Australia
World War II tanks of Australia
Military vehicles introduced from 1940 to 1944