Neptune class battleship

The "Neptune" class battleships were dreadnoughts of the British Royal Navy. There were originally going to be three ships in the class, but the second and third had slightly thicker main belt armour and other differences, and are usually characterised as "Colossus"-class vessels.

Design

The "Neptune" class was the first attempt by the Royal Navy to get a full ten-gun broadside from its dreadnoughts. This innovation was required to match competing foreign designs, such as the [http://www.scientificamericanpast.com/Scientific%20American%201900%20to%201909/7/lg/sci12121908.htm Brazilian "Minas Geraes"] and the American "Delaware"-class battleships. In previous classes, of the ten guns mounted only 8 could face either broadside. In the "Neptune"s, the wing turrets were staggered so that each could fire cross-deck past the other.

However, the staggering of the wing turrets was achieved in only convert|10|ft|m greater hull length and convert|1|ft|m|1 greater beam, resulting in an increase in displacement of 650 tons compared to the preceding "St. Vincent" class which had wing turrets which were not staggered.

To achieve the staggering with such a small increase in hull length, the designers moved the mid-ship "X" turret and place it just in front of the aft turret and superfire over it. She was first Royal Navy ship to have superfiring main armament (the American battleship class South Carolina class battleship, launched in 1908, was the first battleship anywhere to have superfiring main turrets). However, the upper of the two turrets could not fire within 30 degrees of the stern without the lower turret being damaged by blast through its sighting hoods.cite book | author= DK Brown | title= "The Grand Fleet, warship design and development 1906–1922" |id = ISBN 1-84067-531-4 | year=2003 | publisher= Caxton Editions | page 38-40 ] The superfiring disposition was placed aft because this made for a better sea boat than putting the huge weight of a pair of turrets towards the bow.

A further saving in length was achieved by siting the ship's boats on a flying deck over the two en-echelon turrets. However, had the flying deck been damaged during action, they may have fallen onto the turrets, immobilising them. The bridge was also situated above the conning tower, which risked similarly being obscured if the bridge collapsed.cite book | author= DK Brown | title= "The Grand Fleet, warship design and development 1906–1922" |id = ISBN 1-84067-531-4 | year=2003 | publisher= Caxton Editions | page 38-40 ]

The main innovation in armour was the fitting of strakes protecting the funnel uptakes. Previously these were very vulnerable to damage that would have resulted in the lower decks being smoked out. Otherwise, the increasingly inadequate 10 inch main belt was retained, and this and the other strakes were repositioned in detail.

The power plant provided an additional 500 hp over previous classes to offset the greater displacement. The troublesome cruising turbines of previous classes were finally suppressed.
Secondary armament was slightly reduced.

Criticisms

* The 10-gun broadside layout was powerful, but only had a narrow arc.
* Cross-deck firing of the main armaments damaged the ship so badly that it was not allowed except in an emergency.
* Battle damage to the flying deck and bridge seriously risked putting wing turrets and the conning tower out of action.
* The layout of the guns complicated internal arrangements. As a result, the magazines competed for space with the ship's other machinery.
* The magazines were also located very close to major heat sources. They were also placed close to the sides of the ship, making them particularly vulnerable to enemy attacks and fire.

References

* Robert Gardiner, ed., "Conway's All the World's Fighting Ships 1906 - 1921", (Conway Maritime Press, London, 1982)