The first version of the vehicle was built in 1940 by Standard Motor Company at the instigation of Lord Beaverbrook, then Minister of Aircraft Production (hence the name Beaverette).

It was based on commercial car chassis, on which a simple riveted armoured hull was mounted.

The armament consisted of a Bren light machine gun, which could be fired through a slot in the casemate armour.

Describing the vehicle in 1941, a correspondent for The Light Car magazine reported "touching the 60-mark [60 mph (97 km/h)]" while following one along a road.

Restricted vision meant the Beaverette driver had to rely on an observer to relay information about other road traffic and also to consider situations well in advance, for example, when making a turn, the driver had to base his steering on "observations made something like ten yards [30.00 ft (9.14 m)] back".