Devastation Turret Class Ship

The Devastation Turret Class warship was designed in 1868 by Sir Edward J. Reed. The Reed concept was to produce short, handy ships of medium size as heavily armed as possible with a good turn of speed. His concept also included warships that could attack and destroy an opponent without much risk in being damaged during the process. During his studies of the American low-freeboard monitors, he developed his idea which he called the breastwork monitor. The First Lord of the Admiralty, Admiral Sir Hugh Childers and Admiral Sir Robert Spencer Robinson (Comptroller of the Royal Navy) in discussions with the Chief Constructor of the Royal Navy, Sir Edward Reed of the need for a large breastwork monitor capable of steaming from Queenstown (now Cobh, Ireland) on the south-east coast of Ireland to Halifax, Nova Scotia on the east coast of Canada.

HMS Devastation and a second vessel (HMS Thunderer) were ordered for the Royal Navy under the 1869 – 1870 Naval Estimates. A third vessel (HMS Fury) would be ordered the following year to a modified design. The vessels were assailed in the British Press as absolute failures even before either were launched. From their commissioning to 1888 they were the most formidable British battleships in the Royal Navy.

Design and development
The Admiralty Design Board set forth the requirements for the oceangoing monitors. These included the requirement of two twin 12-inch gun turrets capable of firing 600-pound shells with a 280-degree firing arc. The turrets would require 14-inch armour protection, with the machinery spaces and shell rooms protected by 12-inch-thick armour. Further, to reduce the interference with the main guns, no masts or sails were needed. The ships would need two steam engines for security and a minimum 12-knot speed. The trans-Atlantic concept was changed to a coastal defence ship, so a very low freeboard of 4 ft was specified.

The loss of HMS Captain (1869) in September 1871 led to concerns about the stability of turret ships, and a special committee was set up to determine the safety of turret ships. Changes to the design were recommended. The freeboard of the design was increased to 10 ft. Another change was to extend the armoured breastwork with unarmoured structure to the sides of the ship and carried aft to improve the stability at large angles of heel. This greatly improved the crew comfort by adding extra accommodation and especially latrines, but since it was not armoured would have been riddled in a battle, reducing the stability of the vessel.

In 1871 a 9 ft model of Devastation was tested in a water tank, and subsequently with an 18 ft version. Once Devastation was completed, tests could be carried out with the real ship. This included building up a roll of 7 degrees by having 400 men run back and forth across the deck 18 times. Other tests involved taking it to sea to look for rough weather, in one trial waves of 20–26 feet (6–8 m) were encountered which gave the ship a 14-degree roll either way.

In 1872 the armour protection of the turret was subjected to a series of tests. A replica of the proposed turret was constructed and tested at Shoeburyness in May 1872. The 11 in armour plate backed by 15 in of teak and a 1.25 in metal skin resisted hits from a 25-ton 12-inch gun firing at a range of 200 yd, although one shot hit a joint between plates and opened a gap 7 in wide but did not penetrate. A second test involved HMS Hotspur firing three shots at the turret of HMS Glatton from a 25-ton gun at a range of 200 yards. The first shot missed, however the second and third shot struck the turret. The turret was not appreciably damaged, though theoretically it should have been penetrated.

Construction and specifications
Both vessels were laid down in 1869 at Portsmouth and at Pembroke. The Portsmouth ship was launched in 1870. Construction on the Pembroke ship was suspended following the loss of HMS Captain and not launched until 1872. They were 285 ft in length between the perpendiculars with an overall length of 307 ft. They had a beam of 62 ft and a maximum draught of 26 ft. They displaced 9330 t. HMS Devastation was completed in 1873 and after a series of stability tests, HMS Thunderer was not completed until 1877 awaiting stability tests on HMS Devastation and a boiler explosion in 1876.

The machinery was initially supplied by Penn for the Portsmouth ship and Humphry’s, Tennant & Company of Depford for the Pembroke ship. The ships were equipped with eight rectangular boilers powering two 2-cylinder trunk direct acting steam engines turning two shafts producing 6,650 indicated horsepower (IHP) under a natural draught (ND) for a designed speed of 13.75 knots. The ships carried 1,800 tons of coal giving a cruising range of 5,980 nautical miles at a nominal speed of 10 knots. They could remain at sea for approximately 12 days with fuel available to steam at full speed for a short duration.

HMS Devastation shipped four 12-inch rifled muzzle-loading (RML) 35-ton Mark I naval guns on sliding carriages and HMS Thunderer shipped two 12.5-inch RML 38-ton Mark I or II naval guns (fore turret) and two 12-inch rifled muzzle-loading (RML) 35-ton Mark I naval guns on sliding carriages (aft turret). The guns were housed in two round turrets shipped fore and aft on the centreline. The guns would be reloaded under the cover of the turret thereby not exposing the gun crew to enemy fire. To load the guns the guns would be trained to approximately 140 degrees on either side of the centreline then moved to the end of their recoil. The muzzles would be lowered towards the deck; the shell and powder track would be raised from the deck below. On HMS Devastation they would be manually raised whereas on HMS Thunderer they would be raised hydraulically. A rammer would ram first the powder then the shell into the gun. The gun then would be raise and moved to the firing position. The angle of the guns during reloading would be at an angle that in the event of a premature firing, the shell would exit the hull above the waterline rather than below it. No secondary armament or anti-torpedo boat armament was fitted. In 1879 she was fitted with two Whitehead 14-inch (36 cm) torpedo tubes in fixed mounts, one per broadside below the waterline.

For armour protection the ships were provided with wrought iron plating backed with 18 to 19 inches of teak. The sides of the breastwork were plated with 14 inches of armour. This armour extended below the waterline. It was pierced with square portholes to provide ventilation for the crew spaces. The turrets were protected with 14 inches of plate armour on the front and 12 inches on the sides and rear. Ships built previous to the HMS Devastation only had deck armour as part of the structure. HMS Devastation and the ships that followed her were given increasing weight of desk armour. The armoured deck was 3 inches, tapering to 2 inches at the lower edge. The armour plating only applied to the breastwork portion of the ship, and the bow and stern sections were basically unprotected.

1890/92 reconstruction
After the investigation into the boiler explosion on HMS Thunderer revealed the hazards of the rectangular boilers, they were ‘taken in hand’ for a boiler upgrade and armament change in 1890. Their replacement machinery was supplied by Maudslay, Son & Field of Lambeth. The ships had their boilers replaced with eight cylindrical locomotive type boilers powering two Maudslay 3-cylinder vertical triple expansion (VTE) steam engines turning 2 shafts producing 7,000 IHP under a forced draught (FD) for an increase in speed to 14 knots. The 35 and 38 ton MLRs were replaced with four 10-inch 32-calibre (25.4 cm) breech-loading (BL) naval guns mounted in twin Mark II Turrets. With the advent of torpedo boats, a secondary armament was fitted consisting of six 6-pounder 8-hundredweight (cwt) [2.244-inch 40-calibre (57 mm)] quick-firiing (QF) Mark I naval guns on Mark I* low-angle single mounts and twelve Hotchkiss 3-pounder (1.4 kg) (1.85-inch 40-calibre (47 mm)) QF Mark I naval gun on single Mark I* low-angle mounts. Seven (Devastation) and five (Thunderer) Nordenfelt 1-inch multi-barrel guns were installed on single-pedestal mounts was also fitted, and she carried two Gardener light machine guns

Service and disposition
The ships originally conceived as oceangoing breastwork monitors were redesignated as 2nd Class Turret ships in 1886 and finally as 2nd Class Battleships by the 1900s. Both ships served in Home Waters and the Mediterranean during their careers. The concept of the ships was openly assailed by the British press and cost Sir Edward Reed his position as Chief Constructor. However, the ships were excellent sea boats and well thought of by their crews. Both were modernized in 1891 and spent the next ten years as guard ships or in reserve being activated only for the annual summer manoeuvres. Their age (Devastation was 32 years and Thunderer was 28 years in service) condemned them to being removed from the effective list in 1905. HMS Devastation went to the breakers in 1908, followed by HMS Thunderer in 1909. As the first major British warships built without sails, thereby relying solely on steam power, they were the start of modern British battleship design