With the increasing importance of long-range torpedo fire after Jutland, many ships were given small enclosed torpedo lookout positions either bracketed to the foremast or atop the foretop. Another wartime requirement was a plotting space near the charthouse and the compass platform. Ships maintained plots so that they could report to a master plot on board the fleet flagship, the master plot providing the fleet commander with a tactical picture he could use to make tactical decisions. Plotting meant indicating where various ships were in terms of both range and bearing, hence a dedicated rangefinder.
Modernisation of the Queen Elizabeth class in the 1920s replaced the 15in director atop the foretop with a high-angle control system, the director being relocated to a new platform below the top (some ships had an interim high-angle system in the position atop the foremast). The forepart of the foretop was for main-battery control (spotting); the high-angle position was flanked by 6in control positions. A new level built atop the bridge structure carried a principal torpedo-control position topped, at its fore end, by a 9ft or 12ft torpedo-control rangefinder. A new structure at the after end of the compass platform below this level carried plotting spaces abaft the charthouse. The level below (searchlight and charthouse platform) carried the admiral’s charthouse and the W/T office abaft it, in some cases with a 9ft rangefinder for secondary-battery control and to serve the plot. The level below (lower searchlight platform) carried the captain’s sea cabin and below that, on the shelter deck level (conning tower platform), were the chief of staff’s sea cabin and the admiral’s sea cabin.
The minimal bridges of the Royal Sovereigns seem to have attracted little attention until the Royal Navy began to embrace night action (as opposed to defence against night torpedo attacks) in the 1930s. Night action required remote searchlight control, so that searchlights could be trained on targets whose position was indicated by the ship’s tactical plot (alternatively, they could be illuminated by starshell controlled on the basis of the plot or by other ships’ searchlights controlled on the basis of a flagship’s plot). Ideally plot and remote control should be adjacent and both should be adjacent to the compass platform so that the CO could use the tactical plot.
As the Mediterranean Fleet began to practice night combat from about 1932 on, ships’ COs found their bridges less than perfect.2 After various experiments, an arrangement adopted in the cruiser Suffolk was pronounced ideal.3 At night targets had to be found and tracked despite limited illumination. The Principal (Fire) Control Officer (PCO) moved from the director to the compass platform. During a day action his main function was to get the ship’s guns onto an indicated target. At night everything changed: the great problem was merely finding and tracking the target. When both were on the compass platform at night, CO could easily communicate the bearing of a target to PCO, who could pass it to the Evershed Bearing Indicators (EBIs). This simplicity was disrupted by the sheer number of individuals who together might occupy the small compass platform.
The compass platform was particularly inadequate and it was soon extended forward, as in HMS Conqueror, shown here.
The new arrangement was barely adequate for low-powered battleships, but it was impossible in a high-powered battlecruiser. HMS Lion was completed with the new type of bridge, as shown here, but the fire-control platform aloft was so badly smoked on trial that she had to be rebuilt and her sister-ship HMS Princess Royal altered before completion. Note the bulge at the after end of ‘B’ turret, covering the standard 9ft rangefinder. Another rangefinder was installed in the foretop.
Lion’s bridge structure was completely rebuilt. Her heavy tripod was replaced by the pole foremast and her conning tower enlarged, with a revolving armoured hood on top carrying a standard 9ft rangefinder in a stabilised Argo mounting. The new foretop was hardly rigid nor capacious enough to take a rangefinder. Two bridge levels were provided, a charthouse and searchlight platform and, below it, a lower searchlight platform. Note the double 24in searchlights on both. The new bridge structure provided facilities such as sea cabins. Note the additional rangefinder (9ft, later 12ft) atop the much-enlarged compass platform. Note the rangefinder hood atop ‘B’ turret, carrying a 9ft rangefinder. Note, too, that the shelter deck 4in gun, originally an open mount, has been protected by a casemate. In wartime longer-base rangefinders were needed because ranges were greater than had been envisaged. A separate 15ft instrument was mounted atop the conning tower, forward of the armoured hood, in an unstabilised mounting, and a second one was mounted atop the torpedo-control tower, not visible here.
In 1934 CO of Royal Sovereign reported that her bridge was unsatisfactory both for night cruising and night fighting.4 At night he wanted a good all-round view, easy and sure means of communication between CO and PCO, comfort (space to move freely and protection from wind and rain), quiet and no glare from within.
Due to these reports Ramillies had her bridge modified. Instead of matching that of Royal Sovereign as intended, it was enlarged by moving the plotting office down a deck to space formerly occupied by the remote control office, which in turn was moved another deck down. The wings of the upper bridge were extended. Ramillies’ CO found the result much superior to that of Royal Sovereign. However, the Vice Admiral of the Battle Squadron considered that the bridge still lacked the essential features of a navigational and fighting position: a good all-round and overhead view (it had a bulletproof roof over its central part and canvas wings to the roof). The view aft was too limited, the severe draft caused fatigue and the limited open space was too crowded.
Princess Royal is shown in wartime, with anti-range finding baffles set up to frustrate any attempt to ‘cut’ her foremast using a coincidence rangefinder (which was futile, since the Germans used stereo instruments). Once she was fitted for director control, it became essential to stiffen her foremast, in this case with a substantial reinforcing leg. In contrast to many other ships, she had her main-battery director on a platform well below her spotting top. Her compass platform was protected with splinter mattresses. Atop it was a 12ft rangefinder. Like Lion, she had a steel casting protecting the 9ft rangefinder atop her conning tower. She also had a 9ft rangefinder in her foretop. Aft she had a 15ft rangefinder on her torpedo-control tower and a 2m (6.56ft) high-angle rangefinder, neither of which is visible here. This photograph seems to have been taken before the range dial was installed on the fore face of the foretop and also before deflection scales were painted on the forward turrets. Note the ‘PR’ recognition letters painted on ‘A’ turret and the 4in high-angle gun visible between the first and second funnels.
During her last large repair, Royal Oak received an entirely new ‘citadel style’ bridge. The new compass platform was much larger and squarer, with two somewhat lower squared-off lower wings, all with prominent wind baffles to keep them reasonably dry without roofs. Below this level was an upper bridge with two more large and more or less rectangular wings. Installation of this ‘citadel’ bridge in other ships of the class was precluded by the outbreak of the Second World War. In a wind off Portland in 1936, Royal Oak showed just how much of an improvement the new bridge was.5 In a Force 4 wind, the nearby HMS Ramillies had her funnel smoke ‘as usual’ drawn into her control top before blowing aft, but that of Royal Oak blew aft without rising into the