HMS Neptune

HMS Neptune was the first British dreadnought to deviate significantly from the original layout of HMS Dreadnought. The biggest problem with that layout was that only eight of the Dreadnought’s ten guns could fire on the broadside. This was perfectly acceptable while the rest of the world’s navy depended on pre-dreadnoughts, with their four gun broadside, but the appearance of designs such as the American Delaware class of 1909, or the upcoming German Kaiser class ships, both with ten gun broadsides, made it clear that the British design would have to be updated.

HMS Neptune leads line of Dreadnoughts
HMS Neptune
leads line of
Dreadnoughts

Superfiring Turrets on HMS Neptune
Superfiring Turrets on
HMS Neptune

HMS Neptune under construction
HMS Neptune
under construction

Side view of HMS Neptune
Side view of HMS Neptune

The American design adopted what would become the standard layout for battleships, with all of their big guns on the centreline of the ship, and one superfiring turret at each end of the ship to keep her length under control. The resulting Delaware class ships were 519ft long.

In contrast both the German Kaiser class ships and HMS Neptune adopted a design with a pair of superfiring turrets at the rear, a single turret at the front and a pair of echeloned turrets amidships. In this design the two central turrets were arranged diagonally across the ship – on HMS Neptune one was forward and left, the other back and right. The superstructure was designed with big gaps to allow each of the central guns to rotate clockwise to fire across the ship, allowing HMS Neptune to fire a ten gun broadside. As first built she had a very distinctive profile, carrying her ships boats on a “flying bridge” above the central guns (removed at the start of the First World War).

The design was not a great success. Her fore and aft firepower was very limited. The rear superfiring turret was not adequately protected against blast from the upper turret, and so that upper turret could only be fired on the broadside. The two central guns couldn’t be fired directly fore or aft either, as their blast damaged the superstructure. Even the cross-deck firing wasn’t as useful as expected, placing too much strain on the hull close to the cross-firing turret. 

Plans of HMS Neptune
Plans of HMS Neptune

At the start of the First World War, HMS Neptune was part of the First Battle Squadron of the Grand Fleet, remaining with that squadron until 1917, when she was transferred to the 4th Battle Squadron to make way for the more modern Revenge class ships. On 18 March 1915 she was involved in the incident that led to the only occasion where a battleship sank a submarine by ramming. The Grand Fleet was returning from exercises east of Scapa Flow when U 29 fired a torpedo at the Neptune. This torpedo passed behind the ship, and U 29 then became the target of the Dreadnought. After a ten minute chase the Dreadnought crashed into the submarine, sinking her. HMS Neptune was part of the main battleship fleet at Jutland, taking part in the short battleship actions. She was sold off in 1922.

Displacement (loaded)

22,720t

Top Speed

21kts

Range

6,440 nautical miles at 10kts

Armour – deck

3in-0.75in

 - belt

10in-2.5in

 - bulkheads

8in-4in

 - barbettes

9in-5in

 - turret faces

11in

 - conning tower

11in

Length

546ft

Armaments

Ten 12in Mk XI guns
Sixteen 4in Mk VIII guns
Four 3pdr guns
Three 18in torpedo tubes

Crew complement

759

Launched

30 September 1909

Completed

January 1911

Captains

A. T. Hunt (1914)
T. D. L. Sheppard

Sold for break up

1922

Books on the First World War | Subject Index: First World War

How to cite this article: Rickard, J (8 November 2007), HMS Neptune , http://www.historyofwar.org/articles/weapons_HMS_Neptune.html

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