A cruiser tank, or cavalry tank, was designed to move fast and exploit penetrations of the enemy front.
(The 18th Australian Infantry Brigade had arrived from Egypt by sea, after the dispatch of the 7th Australian Division to Greece had been cancelled.) A small force held El Adem, south of Tobruk to observe the approaches from the south and south-west and at Mechili, Gambier-Parry had the 2nd Armoured Division headquarters soft-skinned vehicles and a cruiser tank, most of the 3rd Indian Motor Brigade, M Battery 1st Royal Horse Artillery, part of the 2/3rd Australian Anti-tank Regiment and elements of other units.
The development team tried to match the lower weight of a cruiser tank, allowing the suspension and transmission parts of the A10 heavy cruiser to be used, with the greater armour of an infantry tank.
The AC1 Sentinel was a cruiser tank designed in Australia in World War II in response to the war in Europe, and to the threat of Japan expanding the war to the Pacific or even a feared Japanese invasion of Australia.