In 1912 false reports of German cruisers with guns larger than 170mm (6.8in) for commerce raiding led the First Lord, Churchill, to ask for a counter in case the information was true. The DNC, d'Enycourt drew up three studies during 1912 (Brown cites the head of cruiser design, William Berry, having designed these but the designs all feature in d'Enycourt' workbooks, Berry's have not been found so there is no conclusive proof of his input and influence) followed by two more in July/August 1913. Details are sketchy, information here comes from D.K. Brown’s
The Grand Fleet and Norman Friedman’s
British Cruisers. Friedman cites a slightly different genesis, namely d’Enycourt’s 1912 report on replacing the armoured cruisers currently on foreign stations, Germany’s 1912 Naval Law planned ten foreign service cruisers so the Admiralty should build twenty new ships to counter on a two-to-one basis. Friedman cites B3 as the response to the rumoured German 170mm armed cruisers. The designs were entitled ‘Light Cruiser for Atlantic Service’.
Design A
6,150 tons (deep); 500ft long; 40,000shp for 28kts, oil fired boilers; 2x1 7.5in (Mk V?) and 8x1 6in Mk XI (50cal) and 8x1 12pdr, 2x 21in TT (uw); armour 4in main belt tapering to 2in aft and to 3/2/1in forward; estimated cost £550,000.
This design was probably rejected because the armament was too light. The 7.5in was probably fitted to counter the German 170mm gun and its sustained rate of fire would have been about 3rpm, the turret was a lighter version fitted to armoured cruisers with 4in armour and barbette. Without fire-control equipment Brown estimates these ships would have been unlikely to have scored hits at ranges over 6,000yds.
Design B1
8,150 tons (deep); 540ft long; 40,000shp for 28kts, oil fired boilers; 4x1 7.5in and 8x1 6in and 8x1 12pdr, 2x21in TT (uw); armour 6in main belt tapering to 2in aft and to 3/2/1in forward, upper belt 4in and 3in over casemates; estimated cost £750,000. Unusually the bulk of the 6in battery was located in casemates. This design was probably rejected because it was too expensive but it did combine heavy armament, armour and high speed.
Design B2
8,000 tons (deep); 540ft long; 40,000shp for 28kts, oil fired boilers; 4x1 7.5in and 8x1 6in and 8x1 12pdr, 2x 21in TT (uw); armour 6in main belt tapering to 2in aft and to 3/2/1in forward and upper belt 4in; estimated cost £740,000. This design was also rejected because it was too expensive. The casemated 6in of B1 were replaced by a single 7.5in turret and the 6in moved forwards in the usual shielded mounts except for two casemates aft (these are missing on Brown's sketches but are obvious on the original sketch plan).
Design B3
7,400 tons (deep); 540ft long; 30,000shp for 26kts, oil fired boilers; 8x1 7.5in and 4x1 12pdr, 4x 21in TT (uw); armour 4in main belt tapering to 3in aft and to 3/1.5in forward, upper belt 3in; estimated cost £700,000. In July 1913 d’Enycourt submitted a new design with all-oil fuel, a uniform battery of 7.5in guns, the turret being slightly lighter than A, B1 and B2 with 3in armour. Unlike the earlier designs, this design had four underwater torpedo tubes, fore and aft of the machinery spaces. Although the armament was much more powerful, reducing speed by 2kts cut the costs by £40-50,000. The Third Sea Lord liked the design, comparing very favourably with the County Class armoured cruisers despite being smaller and lighter. Churchill however felt it was too big and expensive and disliked the ‘Atlantic’ title.
Design B4
Design B4 with straight funnels and masts as requested by the Board
Figures in parentheses [] are for a mixed-fuel version: 6,500 tons (deep) [7,000 tons]; 510ft long; 30,000shp for 27.5kts [28,000shp for 26.5kts], oil fired boilers [coal-oil]; 2x1 7.5in , 6x1 6in, 4x 21in TT (uw); armour 4in main belt tapering to 3in aft and to 3/1.5in forward, upper belt 3in; estimated cost £548,000 [£588,000]. Developed in response to Churchill’s criticisms of B3, B4 was offered in both oil-only and mixed firing versions and was smaller and cheaper and was closer to the scout cruiser origins of these designs with centreline 6in armament and a superfiring 6in in B position, pre-dating that of the later Ceres Class by three years. Once the reports of German cruisers were realised to be incorrect these ships were soon dropped, although the design work was approved. A few years later the same requirements in wartime would bring the ‘Improved Birmingham’, the Hawkins Class into existence.
Drawing Notes: these are all drawn from sketches of original plans in D.K. Brown’s
The Grand Fleet and Norman Friedman’s
British Cruisers and copies of the original sketches. The sketches of B1 and B2 had least details regarding locations of funnel and masts so these have been estimated based on location of boiler rooms etc.
Many thanks to Smurf for much additional information on these ships to clarify certain errors and omissions in Brown and Freidman's accounts.