Similar stripped-down bridge structures were installed in the ‘large light cruisers’. HMS Courageous is shown. As in the Royal Sovereigns as built, the ship was always steered from inside the conning tower, which made the conning tower platform (protected by splinter mattresses) an important conning position, the alternative being the compass platform further aloft. Note the extra protection applied to her lower bridge level and to her stabilised rangefinder (atop the conning tower) and the splinter mattresses around the compass platform and the conning tower (steel splinter protection to the front of the conning tower is less visible). Both directors were on the centreline, the main-battery director above the secondary-battery director. The foretop supported a 12ft rangefinder (added well after completion), visible here and the steel casting atop the conning tower (director/rangefinder) housed the standard 15ft instrument. The turrets had 15ft rangefinders, which were due for replacement by 30ft instruments after the war. The forebridge carried two 12ft rangefinders for secondary battery control, which are not visible here. A separate torpedo control top carried another rangefinder and the ship also had a 2m high-angle rangefinder, probably aft.
Viewed from aft in March 1918, HMS Glorious shows the 9ft rangefinder (later replaced by 15ft) atop her torpedo-control tower (visible just forward of her after triple 4in gun) and her after secondary-battery director. The framework atop ‘X’ turret is for a flying-off platform. The objects visible on deck near ‘X’ turret are fixed torpedo tubes.
On 6 September 1938 the new First Sea Lord Admiral Backhouse, who had supported elimination of conning towers during the run-up to the 1935 battleship designs, reviewed the King George V and Lion class designs. He wanted enough protection to keep out a 5in destroyer shell at short range (both the Japanese and the Germans were using this calibre). King George V was too far along to change, but he wanted Lion modified. Her steering position already had 4½in C on its sides, 3in on front and rear and 2in floor and roof, to meet the 1935 requirement against 6in fire at 12,000 yds. Now sides had to be thickened to 5in, the front to 3½in and the rear to 2½in, at a total cost of 6 tons. The overall shape of the bridge structure was unaltered from that of King George V. CNS also wanted 2in rather than 1in protection for cable trunking.
Initially the bridge planned for Vanguard would have duplicated that of Lion. Controller wanted the protected steering position moved up a deck, incorporating the Admiral’s bridge. DNC had already said that the conning tower should be nearer the compass platform. In March 1940, Assistant Controller proposed reducing the compass platform to a walkway around the conning tower, the latter slightly above the level of ‘B’ turret – something like the old lower bridge in Canada and Royal Sovereign (DNC asked for papers explaining why that earlier idea had failed). In an echo of Captain Nicholson a quarter-century before, Assistant Controller claimed that this arrangement gave a better view at night. Bridge arrangements in French and German capital ships were similar. In October 1940 Home Fleet wanted the opposite; it thought the compass platform too low and too drafty, as it would have the vertical wall of the conning tower immediately abaft it. C-in-C Home Fleet wanted two independent conning positions and two steering positions forward. DNC asked whether adjacent compass platform and conning tower would be considered as two independent conning positions.
Completing at John Brown in 1916, HMS Repulse shows her simplified bridge structure, with only the after part of the compass platform in place. The central part was extended forward and upward. The foremast shows a main-battery director above a secondary-battery director and she has the usual director/rangefinder in a steel casting above her conning tower. The turrets show ridges housing 15ft rangefinders (after the war Repulse had a 30ft rangefinder in ‘A’ turret and both had 30ft instruments in ‘Y’ turret).
In 1943 Vanguard’s superstructure was redesigned to provide a large open bridge above the admiral’s bridge. Behind it would be an armoured bridge looking out over it. Wind tunnel experiments showed that the open bridge had to be at least partly roofed to protect personnel against downwinds and that the entire structure should be square in planform. C-in-C Home Fleet wanted the signal bridge raised to the top platform of the superstructure, the separate armoured bridge eliminated and the entire structure armoured. By this time internal requirements had changed, as radar plotting (Action Information Organisation) evolved. A small open bridge (called first a manoeuvring bridge and then a compass platform) was placed atop the armoured bridge. Its after end was the ADO position with the air lookouts in its wings. The armoured bridge (later called the conning tower) was the alternative conn. The compass platform had a viewing glass through which the plot on the Admiral’s bridge could be seen. The clifflike bridge structure was intended to direct air up past the compass platform, keeping it draft-free.
Photographed by the US Navy while passing through the Gatun Locks of the Panama Canal on 25 January 1927, the newly-modernised HMS Renown shows much of her wartime bridge arrangement, the most prominent change being the roof and windows over the fore part of the compass platform. Note the bulges on either side for chart tables. The ship has a 30ft rangefinder supplementing the earlier 15ft one on the director/rangefinder atop her conning tower and a 9ft rangefinder (for secondary battery control) is visible in an open position on the bridge wing below the compass platform. Atop the foretop is a 12ft rangefinder. The unusually massive foretop was characteristic of this class. Note the extensive wiring connecting the director platforms to the transmitting station below via the legs of the foremast and also the wiring coming down from the foretop. Both forward turrets still have 15ft rangefinders.
HMS Hood was photographed by the US Navy in Gatun Lake (Panama Canal Zone) during her 1924 round-the-world cruise. Her design reflected wartime experience in fleet operations under North Sea conditions. Consistent with the 30° elevation of her 15in guns, she had 30ft rangefinders in her turrets and in the cast steel director/rangefinder atop her conning tower. Her large foretop carried a similar director/rangefinder, in this case equipped with a 15ft rangefinder. Unlike the foretops of earlier ships, it included control positions for the 5.5in battery, in its rear port and starboard areas. Each such position included the 9ft rangefinder which in earlier ships was lower in the bridge structure. The enclosed level below the foretop was for torpedo lookouts. It was flanked by range (concentration) dials, one of which is visible (it was sometimes designated a concentration control position). Below that was a searchlight platform. It carried a torpedo rangefinder (removed during the ship’s 1927 refit) on its forward part, with two searchlights on the parts visible between the tripod legs. The bridge structure below that was similar in principle to earlier ones, but it was plated in to form a simpler structure. As in the past, the upper level, which was roofed over, was the compass platform, from which the ship was conned. Barely visible at the after end of the roof is a 9ft rangefinder. At its after end was the charthouse, which had to be adjacent to the compass platform because it housed the tactical plot. The level below, with bridge wings, was the admiral’s bridge and signal bridge – Hood was conceived as a flagship. The windowed level below