page_title: Colossus-class battleship (1910)
section_title: Background and design
hierarchical_section_title: Colossus-class battleship (1910) / Background and design
caption_attribution_description: English: The battleships Revenge (left) and Hercules (right) en route to the Battle of Jutland
context_page_description: The Colossus-class battleships were a pair of dreadnought battleships built for the Royal Navy at the end of the first decade of the 20th century, the last 12-inch-gunned battleships built for the RN. The sister ships spent their whole careers assigned to the Home and Grand Fleets, often serving as flagships. Aside from participating in the Battle of Jutland in May 1916, and the inconclusive Action of 19 August several months later, their service during the First World War generally consisted of routine patrols and training in the North Sea.
  The Colossus class were deemed obsolete by the end of the war in 1918 and were reduced to reserve the following year. Hercules was sold for scrap in 1921, although Colossus was briefly used as a training ship. She was hulked in 1923 and sold for scrap five years later.
context_section_description: The initial 1909–1910 Naval Programme included two dreadnoughts and a battlecruiser, but was later increased to six dreadnoughts and two battlecruisers as a result of public pressure on the government due to the Anglo-German naval arms race. The original pair of battleships became the Colossus class and were improved versions of the preceding battleship, HMS Neptune. On 19 November 1908, Rear-Admiral Sir John Jellicoe, the Third Sea Lord and Controller of the Navy, proposed the changes that he would like to make to the Neptune's design. He wanted to redistribute the armour from locations not exposed to enemy fire to those that were and to fit 21-inch (533 mm) torpedoes in lieu of the 18-inch (450 mm) weapons used in the earlier ship; the number of spare torpedoes were to be increased as well. Likely prompted by an earlier memo from Admiral Francis Bridgeman, commander-in-chief of the Home Fleet, Jellicoe wanted to eliminate the mainmast and transfer most of the functions of its spotting top to an armoured spotting tower atop the conning tower in the superstructure. The Director of Naval Ordnance (DNO), Rear-Admiral Reginald Bacon, argued that the spotting top in the foremast should be retained. Jellicoe was willing to slightly increase the new design's displacement over Neptune, but it could not cost any more, which placed major constraints on the Director of Naval Construction (DNC), Sir Philip Watts.
  The DNC objected to the loss of the mainmast as he believed that it was needed to support a boat-handling derrick, but was overruled by the Admiralty, which preferred to position the tripod foremast behind the forward funnel with the tripod legs facing forward to allow the vertical leg to be used to support the derrick. This all but guaranteed that the hot funnel gases could render the spotting top uninhabitable. The short height of the funnel also bedevilled the bridge with smoke until it was raised in 1912, although this exacerbated the problem for the spotting top. The decision to space the wing turrets more closely together also made the smoke problem worse; because it reduced the space available to the aft boiler room which meant that the forward funnel had to accommodate the exhausts of a dozen boilers compared to the aft funnel's six, further increasing the smoke from the forward funnel.
  All eight capital ships of the 1909–1910 Naval Programme had the same arrangement of masts and funnels; only the two battlecruisers had their foremast and forward funnel positions exchanged at considerable expense. David K. Brown, naval architect and historian, commented on the whole fiasco: "It is amazing that it took so long to attain a satisfactory arrangement, which was caused by the DNO's insistence on sighting hoods in the roofs of turrets and Jellicoe's obsession with boat-handling arrangements. These unsatisfactory layouts reduced firepower, prejudiced torpedo protection and probably added to cost. As DNO and then as Controller, Jellicoe must accept much of the blame for the unsatisfactory layout of the earlier ships."
  Like Neptune, the wing turrets of the Colossus-class ships were staggered "en echelon" so that all five turrets could shoot on the broadside, although in practice the blast damage to the superstructure and boats made this impractical except in an emergency. The design also perpetuated siting the ship's boats on girders over the two wing turrets to reduce the length of the vessel. However, if the girders were damaged during combat, they could fall onto the turrets, immobilising them. The bridge and its associated compass platform was also situated above the conning tower, which similarly risked being obscured if the bridge collapsed.
caption: Revenge (left) and Hercules (right) en route to the Battle of Jutland, 31 May 1916, showing how the latter's spotting top could be totally enveloped by funnel smoke
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