Orion class battleships

The Orion class battleships were the first British dreadnoughts to carry all of their guns on the centre line, allowing them to fire a full ten-gun broadside without putting excessive stress on the ship’s hull. The five turrets were arranged in two superfiring pairs fore and aft, with one turret amidships. The only weakness with the turret layout was that the lower turrets were not adequately protected against the blast from the upper turrets, meaning that only the lower turrets could fire directly fore and aft.

Super-dreadnought HMS Orion
HMS Orion

The Orion class ships were significantly larger than the previous Colossus class ships, coming in 35 feet longer and 3,000 tons heavier. The extra weight was used for the heavier guns and to provide thicker armour. Engine power was also increased, to maintain the now standard 21kts top speed.

The 13.5in guns had a number of advantages over the 12in guns used on earlier ships. They fired heavier shells – 1,250lb and then 1,400lb (compared to 850lb in the 12in guns), fired at a lower muzzle velocity. This reduced barrel wear and improved long range accuracy. Their maximum elevation was increased from 15 degrees to 20 degrees, giving them a range of 24,000 yards.

HMS Monarch firing broadside
HMS Monarch
firing broadside

Plans of Orion Class Battleships
Plans of Orion Class Battleships

The main flaw with the design was the location of the tripod mast, with the all important fire control platform. This was placed immediately behind the forward funnel, where the view was often obscured by smoke.

The Orion class served together in the 2nd Battle Squadron of the Grand Fleet during the First World War, together with the ships of the King George V class and after the loss of HMS Audacious the ex-Turkish battleship HMS Erin. They fought at Jutland, where none suffered any casualties.

Displacement (loaded)


Top Speed



6,730 nautical miles at 10kts

Armour – deck


 - belt


 - bulkheads


 - barbettes


 - turret faces


 - conning tower





Ten 13.5in Mk V guns
Sixteen 4in Mk VII guns
Four 3pdr guns
Three 21in submerged torpedo tubes

Crew complement






Ships in class

HMS Conqueror
HMS Monarch
HMS Orion
HMS Thunderer

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

How to cite this article: Rickard, J (8 November 2007), Orion class battleships , http://www.historyofwar.org/articles/weapons_orion_class_battleships.html

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