Originally, these lorry-mounted guns were provided by the Navy. At the end of May 1940, the Admiralty informed the War Office (telegram dated 30.5 in file WO 199/523) that lorry-mounted gun batteries with over a hundred guns in all were being formed, as follows:
- Three Royal Marine batteries (R.M.1, R.M.2, R.M.3) with 8 x 12pdrs each
- Six batteries each in the ports of Chatham, Portsmouth and Devonport, numbered C.1 to C.6, P.1 to P.6 etc. In all three cases the first four batteries would have 2 x 3pdrs and 2 x 12pdrs, and the batteries numbered 5 and 6 four 4in guns.
According to various sources, the total number of lorry-mounted 4in guns was between 40 and 50, and it does seem that some more batteries were added later. The 69th Anti-tank Regiment (45th Inf Division, defending the southern Kent/eastern Sussex coast) had the RM battery designated C.7 and equipped with 7 x 4in guns attached in July; at some point in Aug. the Marines left and handed over their guns to 273 Bty of that regiment (which was at that time still very short of “real” anti-tank guns).