Dear Ministry of Defence,
I'm looking for records relating to a series of proposed battleship designs from the 1920s. The vast majority of these battleship designs never came to fruition due to the Washington Naval Treaty. The designs I am interested in are the following;

"The 'L Twin' was further refined to become the L2. The major change was the introduction of the transom stern. Possibly D'Encourt himself suggested that since the long stern was only kissing the water, that there might not be a severe penalty if they were cut off square. Already in March 1920, Haslar had tested models with transoms for the 'AR' battlecruiser design. Four alternatives were tried; the stern cut off at 30ft abaft the aft perpendicular (the rudder stock), that at 15ft abaft, 7ft 6in abaft and finally at the rudder. The resistance curves for all but the last configuration were identical to the original. The loss of efficiency at moderate speeds was noted however. Superintendent S. Payne began introducing transoms and the Ls benefited from this. The broad transom aided stability in damaged condition and gave the performance of a hull form some 20ft longer.
L2 was 860ft (oa) (850ft wl) x 106 x 33.5ft and displaced 52,100tons with 70,000shp for a speed of 25kts. Armament was 4x2 18in, 8x2 6in, 6x1 4.7in HA, 4x10 2pdr and two underwater 24.5in torpedo tubes. The 15in thick main belt was mounted internally at an angle of 25 degrees, it was 470ft long and all the armour weighed 18,850 tons (37.1% of the displacement). This thinner belt was probably as effective as the 18in thick belt inclined at 10 degrees of the original design."

Following on from the L2 and L3 designs came M2 and M3. M2 was 805 (wl) x 106 x 33ft and displaced 48,750 tons with 56,000shp for a speed of 23kts. Armament was 4x2 18in, 8x2 6in, 5x1 4.7in HA, 4x10 2pdr and two underwater 24.5in torpedo tubes. The 15in thick main belt was mounted internally at an angle of 25 degrees. The belt was 440ft long and the deck armour was 8-9in thick. The armour's total weight was 17,310 tons. The M designs introduced a novel layout, the aft engine layout reduced the length of the citadel to save weight (1,540 tons saved over the L2 for the belt alone). The engine rooms were ahead of the boiler rooms to reduce the rake of the shafts and possibly because the gearing would not have fitted aft. The firing arcs of the rear turrets were restricted to 60 degrees off the bow to 75 degrees forward of the stern. The blast effects from the 18in guns were expected to be severe. The unarmoured ends also posed problems as if they were riddled with gunfire the loss of stability would be severe. Both M2 and M3 were submitted in December 1920, but it would be M3 with triple turrets that would be selected for further design work to become the N3.

I'm looking for specifically for any proposed drawings, technical reports on construction and weapons and costing reports.

Yours faithfully,

Eli Hayes

DBS KI-RR FOI (MULTIUSER), Ministry of Defence

1 Attachment

Dear Eli Hayes,


Please find attached a response to your request for information reference



Defence Business Services

Knowledge and Information

Records Review Freedom of Information Team




Thank you very much for your prompt reply and helpful clarification.

Yours sincerely,

Eli Hayes