Changes in the programme left little time to design the 1906–7 ships. Unsurprisingly, they were largely repeat Dreadnoughts (Bellerophon class). The choice to repeat the previous design seems to have been taken about May 1906; an early Folio in the Cover is a 21 May 1906 memo on an invitation to tender for 12in/45 mountings for two repeat Dreadnoughts to be built in the Royal Dockyards. The third ship was built by Elswick (Armstrong). Outline sketches were apparently sent to the Board on 1 June 1906. The repeat ship showed some features of the abandoned ‘fusion’ design: a 4in anti-torpedo battery and two tripod masts (with boats handled from the mainmast).
A Legend dated 1 June showed 10in to 5in rather than 11in to 4in side armour, with 10in rather than 11in gun shields. Sixteen 4in guns replaced the previous twenty-seven 12pdr. The new ship would have the same dimensions as Dreadnought, but she would displace somewhat more (18,400 tons rather than 17,900 tons). On 16 June DNC ordered a revised Legend in which 11in armour was substituted for 10in on side and barbettes. This change was expected to cost 100 tons. Another change was to continue the inner bottom up to the slope of the protective deck, the torpedo bulkhead being moved inboard. DNC seems to have submitted the modified design to the Board on 11 July 1906. At that point displacement was 18,500 tons, dimensions matched those of Dreadnought and the extra displacement had been obtained by deepening the ship 6in. By this time the heaviest armour had been reduced back to 10in, but the belt was of uniform thickness instead of tapering to 7in at the bottom. Also, it was carried to 3ft 6in above load waterline, rather than 2ft as in Dreadnought. Gun shields were maintained at Dreadnought thickness, 11in. Side armour at the ends was thickened. About half the forward 6in armour was increased to 7in and the whole of the 4in armour aft was increased to 5in. The whole protective deck was now the same thickness (1¾in); in the past, the slopes had been 2¾in thick. As partial compensation, the torpedo bulkhead was reduced.
Bellerophon is shown in December 1915, with her distinctive enlarged angled compass platform. The most evident war modification is the anti-aircraft gun on the stub structure between the two centreline turrets aft. (John Roberts)
Bellerophon in Scapa Flow, 1917–18, shows post-Jutland modifications (‘coffee box’ searchlight towers around the after funnel) and a 4in gun atop ‘Y’ turret rather than right aft (it was moved in 1918). In 1917 most of the earlier dreadnoughts had their secondary batteries reduced to thirteen 4in guns to release weapons to arm small craft. Two empty casemates are visible here, one just abaft ‘P’ turret and one just forward of it (one was not removed on the other side). The St Vincent class was similarly modified. Stern torpedo tubes were removed from this class in April 1917. The identification is based on the details of the searchlight towers around the after funnel (Superb and Temeraire had three searchlights on each side in a single wrap-around structure). (Photo by Commander H L Pencew USN via US Naval History and Heritage Command)
The most obvious changes were an entirely new rig (two tripods, both keeping fire-control tops clear of funnel smoke) and the substitution of 4in/50 QF guns for the 12pdr (3in) anti-torpedo (boat) guns of HMS Dreadnought. The latter was ordered after tests against the old destroyer Skate raised questions about the lethality of the 12pdr. It seems likely, too, that the more powerful anti-destroyer gun was wanted in view of increasing torpedo ranges.
A revised Legend dated 6 August 1906 received the Board Stamp on 7 August.7 It showed a displacement of 18,600 tons. In the usual accompanying memo, Watts pointed out that in view of recent experiments, the ship had been given torpedo bulkheads throughout the length of the machinery and magazine spaces, whereas in HMS Dreadnought they covered only the magazines. These bulkheads had been kept at least 11ft from the ship’s side, in some cases further.8 Thickness varied from 1in to 3in according to distance from the ship’s side. On the grounds that shells hitting the upper deck would probably explode before reaching the barbettes, there was no particular reason to vary the barbette thickness; instead barbettes would be of uniform thickness, at least 8in, below the upper deck. It was desirable to make barbettes thicker above the upper deck, but the width involved (2½ft) was so narrow that this would be impractical. Barbettes would therefore be of uniform thickness from the main deck up. ‘B’ and ‘C’ barbettes (waist mountings) were made thicker (10in) on the grounds that they might be hit directly. For all the barbettes, armour below the main deck was 5in thick. The design received the Board Stamp on 7 August 1906; ships were to be built in two years from 1 January 1907, one at Portsmouth, one at Devonport and one under contract.
The Hague Conference failed to agree on naval arms control. The British naval attaché in Berlin reported that the Germans refused to contemplate any change in their Navy Laws, claiming that any agreement would freeze them in a position of gross inferiority. Their press published claims that the British had a preposterously large margin of superiority. That was true of bare numbers of capital ships. However, if indeed Dreadnought and Invincible had made all existing capital ships obsolete, the British had given up their previous margin. If the Germans built aggressively enough, they might, it seemed, achieve superiority in this key type of ship. The 1907–8 programme was kept to the previously agreed three ships per year, the only question being which types to build.
For 1907–8 the Board proposed an armoured cruiser and battleships, both conceived as leaps beyond their 1905–6 predecessors. The two new possibilities were a more powerful 12in gun (12in/50 rather than 12in/45) and a triple turret. Slightly further off was a more powerful gun, a 13.5in/50 (not the 13.5in/45 later adopted). It offered a much heavier shell (1250lb compared to 850lb for a 12in) and a higher muzzle velocity than the existing 12in/45 (2850ft/sec rather than 2735ft/sec). The new 12in/50 Mk XI offered the same muzzle velocity as the 13.5in, as understood at this stage. A twin 13.5in turret was expected to weigh about as much (revolving weight) as a triple 12in/45 and somewhat less than a triple 12in/50. Both new designs incorporated 12in/50 guns.
There was interest in a more powerful anti-torpedo gun. DNO (Jellicoe) obtained designs of 5in guns from Coventry Ordnance (COW).9 This gun could easily be mounted on turret tops, but any positions in the superstructure would be cramped due to its size. Jellicoe decided that the 4in gun was quite adequate to deal with future destroyers, but he wanted the number increased to twenty to provide four ‘re-inforcing guns’ to any group which might have to deal with more than one attacking destroyer.
The battleship began as a series of alternative Design Js (soon redesignated Design F, to show a relationship with battlecruiser Design E described below); J indicated a relationship with Dreadnought (Design H).10 Both it and the battlecruiser were to have roughly the turret arrangement of the Invincibles. In Battleship F (J4) the twin end turrets were replaced by triples, to give a total of ten 12in/50 guns. Armour was the same as that of the Bellerophons. An alternative J6 had three triple turrets on the centreline; J7 had four. The additional turret cost about 1000 tons. Conversely, the reduction to three turrets in J6 saved about 1800 tons compared to F (17,800 tons). All the other alternatives had about the same displacement as F(J4). The battleship designs all had the same protection and speed as the ‘New Dreadnought’ (Bellerophon). Compared to Battlecruiser E, the hull of Design F was shorter (500ft × 83ft 6in × 27ft, 19,800 tons excluding Board Margin) and power was reduced to 25,000 IHP equivalent to give the usual battleship speed of