[3] Weighing around 4 long tons (4.1 t) these vehicles were fitted with armoured plates 8 mm (0.31 in) thick that covered the sides and top of the engine and extending along the sides at dashboard height; they had an open rear fighting compartment in which crew members remained dangerously exposed to enemy fire unless they chose to lie on the floor, the driver being the only member of the crew completely protected, sitting under a box shaped armoured hood.

[4] The Clément-Talbot company of North Kensington was originally formed to import French Clément cars into the United Kingdom, although the Talbot 25/50 hp of 1914 was entirely British designed and built.

[3] The first Admiralty pattern armour scheme was a design by Lord Wimbourne and the Admiralty Air Department, a full sized wooden mockup was created on a Rolls-Royce chassis and testing of all three chassis types was conducted with equivalent weights to the proposed armour and a 30 hundredweight (1.5 t) load, the modifications deemed necessary were the fitting of new wheels and twin wheels at the rear.

[1][3][4] By the time they came into service in the first week of November 1914 most of the Western Front had descended into trench warfare and the opportunities for their employment were almost gone, so they were sent to the still open La Bassée area to be trialled in combat.

[1][3][4] The first three Rolls-Royce Admiralty turreted pattern armoured cars were ready in December 1914 and in early 1915 three Talbot 25/50 hp chassis were fitted to virtually the same design.