The King George V-class battleships were the most modern British battleships in commission during the Second World War. Five ships of this class were built: HMS King George V (commissioned 1940), HMS Prince of Wales (1941), HMS Duke of York (1941), HMS Anson (1942) and HMS Howe (1942). The names honoured King George V, and his sons, Edward VIII, who had been Prince of Wales, and George VI who was Duke of York before ascending to the throne; the final two ships of the class were named after prominent 18th century admirals of the Royal Navy.
The Washington Naval Treaty of 1922 limited all of the number, displacement, and armament of warships built following its ratification, and this was extended by the First London Naval Treaty but these treaties were due to expire in 1936. With increased tension between Britain, the United States, Japan, France and Italy, it was supposed by the designers of these battleships that the treaty might not be renewed and the ships of the King George V class were designed with this possibility in mind.
All five ships saw combat during World War II, with King George V and Prince of Wales being involved in the action on 24 May to 27 May 1941 that resulted in the German battleship Bismarck being sunk. Following this, on 25 October 1941, Prince of Wales was sent to Singapore, arriving on 2 December and becoming the flagship of Force Z. On 10 December, Prince of Wales was attacked by Japanese bombers and sank with the loss of 327 of its men. In the aftermath of the sinking, King George V, Duke of York, Howe and Anson provided escort duty to convoys bound for Soviet Union. On 1 May 1942, King George V collided with the destroyer HMS Punjabi, resulting in King George V being sent to Gladstone docks for repairs on 9 May, before returning to escort duty on 1 July 1942. In October 1942 Duke of York was sent to Gibraltar as the new flagship of Force H and supported the Allied landings in North Africa in November. Anson and Howe would also provide cover for multiple convoys bound for Soviet Union from late 1942 until 1 March 1943, when Howe provided convoy cover for the last time. In May 1943 King George V and Howe were moved to Gibraltar in preparation for Operation Husky. The two ships bombarded Trapani naval base and Favignana on 11–12 July and also provided cover for Operation Avalanche on 7 to 14 September. During this time, Duke of York and Anson participated in Operation Gearbox, which was designed to draw attention away from Operation Husky. Duke of York was also instrumental in sinking the German battleship Scharnhorst on 26 December 1943. This battle was also the last time that British and German capital ships fought each other.
In late March 1945, King George V and Howe were sent to the Pacific with other Royal Navy vessels as a separate group to function with the U.S. Navy's Task Force 57. On 4 May 1945, King George V and Howe led a forty-five-minute bombardment of Japanese air facilities in the Ryukyu Islands. King George V fired her guns in anger for the last time in a night bombardment of Hamamatsu on 29 and 30 July 1945. Duke of York and Anson were also dispatched to the Pacific, but arrived too late to participate in hostilities. On 15 August Duke of York and Anson accepted the surrender of Japanese forces occupying Hong Kong and, along with King George V, were present for the official Japanese surrender in Tokyo Bay. Following the end of World War II, the ships were phased out of service and by 1957 all of the ships had been sold off for scrap, a process that was completed by 1958.
The King George V class was the result of a design process that began in 1928. Under the terms of the Washington Naval Treaty of 1922, a "holiday" from building capital ships was in force through to 1931. The battleships of the British Navy consisted of only those old battleships that had been kept after the end of World War I, plus the two new, but slow Nelson-class battleships. In 1928, the Royal Navy started considering the requirements for the warships that it expected to start building in 1931.[1]
The First London Naval Treaty of 1930 extended the "shipbuilding holiday" through to 1937. Planning began again in 1935, drawing on previous design work. The new class would be built up to the Treaty maximum displacement of 35,000 tons. Alternatives with 16-inch, 15-inch and 14-inch main guns were considered, and at that time the 15-inch armament was chosen. Most designs were intended to steam at 27 knots with full power, and it was decided that the likely decisive range in a battle would be from 12,000 to 16,000 yards. Armour and torpedo protection formed a much greater portion of the design than that of the previous Royal Navy battleships.[2]
In October 1935, the decision was made to use 14-inch guns. At the time, the United Kingdom was negotiating for a continuation of the Naval Treaties with the other parties of the London Treaty. The British Government favoured a reduction in the maximum calibre of battleship gun to 14 inches and in early October, the government learned that the United States would support this position if the Japanese could also be persuaded to do so. Since the large naval guns needed to be ordered by the end of the year, the British Admiralty decided on 14-inch guns for the King George V class.[2] The Second London Naval Treaty, a result of the Second London Naval Conference begun in December 1935, was signed in March 1936 by the United States, France and Britain and this set a main battery of 14-inch naval guns as the limit.[3]
The King George Vs were the first British battleships to alternate engine rooms and boilers in the machinery spaces, which reduced the likelihood of one hit causing the loss of all power.[4] The machinery was arranged in four engine (turbine) rooms and four boiler rooms, with the eight machinery compartments alternating in pairs of engine or boiler rooms. Each pair of boiler rooms formed a unit with a pair of engine rooms. Nominal full power was 110,000 shaft horsepower (82,000 kW) with 400-pound-per-square-inch (28 kg/cm2; 2,800 kPa) steam at 700 °F (371 °C).[5] The machinery was designed to operate at an overload power of 125,000 shp (93,000 kW) and Prince of Wales' "...main machinery steamed at overload powers of 128,000 to 134,000 shp (95,000 to 100,000 kW) with no difficulties..."[6] during the hunt for the Bismarck. The Admiralty 3-drum boilers operated very efficiently, and similar boilers of nearly identical power, fitted to the older battleship Warspite during her rebuilding in 1937 achieved a full-power specific fuel consumption [a] of 0.748 lb per shp on trials which compared favourably with contemporary battleships.[7][8] During her full-power trials on 10 December 1940, King George V at 41,630 long tons (42,300 t) displacement achieved 28 knots with 111,700 shp at 230 rpm and a specific fuel consumption of 0.715 lb per shp.[9]King George V had her paravanes streamed during her full power trials, which caused an estimated .7 knot loss of speed.[10] The Duke of York at her trials, on 1 November 1941, displacing 42,970 tons (sea slight, wind moderate), attained a speed of 20.6 knots at 115 rpm and 28,720 shp and 28.6 knots at 232 rpm and 111,200 shp.[11] After 1942 the Royal Navy was forced to use fuel oils with considerably higher viscosity and greater seawater content than these boilers could efficiently use.[12] The poor quality of the oil fuel combined with the seawater contamination reduced the efficiency of the steam power plant and increased the maintenance required.[13] By 1944 the specific full-power fuel consumption had increased to 0.8 lb per shp, and boiler maintenance was becoming increasingly difficult.[14] The Admiralty had been aware of this problem and were designing new types of oil sprayers and burners that could burn the available fuel oil much more efficiently, and sometime after 1944,[15] Duke of York and Anson were fitted with new, higher-pressure oil sprayers and burners that restored the boilers to full efficiency.[14] These same oil sprayers and burners were used in HMS Vanguard along with other detail improvements so that Vanguard achieved a full-power specific fuel consumption of 0.63 lb per shp[16] while using the same steam pressures and temperatures as used on the King George V class.[17]
The armour protection of the King George V-class battleships was designed after consideration of the Royal Navy's experience of World War I and upon testing between the wars.[18] The design of this class was dominated by the provision of protection.[19] Magazine protection was given priority[20] through the provision of a thick belt and deck armour and by placing the magazines at the lowest levels of the ship.[21]
The horizontal protection over the magazines consisted of three layers with a total thickness of 9.13 in (232 mm); the weather deck consisted of 1.25 inches of Ducol (D) steel,[b] the main armoured deck was of non-cemented steel armour 5.88 in (149 mm) thick over a 0.5-inch D[22] steel deck and above the shell rooms there was another 1.5-inch splinter deck.[23][24] The powder magazines were below the shell rooms for added protection, a practice that was begun with the Nelson-class battleships.[21] The weatherdeck thickness was the same over the machinery spaces but there the main armoured deck was reduced to 4.88 in (124 mm) over a 0.5-inch D steel deck. The main armoured deck was continued forward of the forward armoured bulkhead and gradually reduced from full thickness to 2.5 inches, while aft of the after magazines an armoured turtle-back deck covered the steering gear with 4.5–5 inches of armour whilst also providing protection along the waterline.[23]
The main armour belt was 23.5 feet (7.2 m) high and covered the hull side from the main armoured deck to finish 15 feet (4.6 m)[20] below the deep waterline.[25] Post-World War I studies had indicated that it was possible for delayed-action AP shells to dive under a shallow belt and penetrate into vital areas of the ship and therefore the main belt was made to extend as far below the waterline as possible.[26] Along the ship, the belt started just forward of the forward turret and finished just aft of the aft turret. The armour consisted of three equal-depth strakes. The strakes were tongue-and-grooved together, and each individual plate in a strake was keyed into neighbouring plates.[27][28] The belt was at its thickest above and at the waterline. Most secondary and some primary sources describe the maximum thickness of the belt armour varying between 14 and 15 inches (possibly due to rounding to the nearest inch).[27][29][30] Some sources give more detail: along the magazines, the belt was 14.7 inches thick (373 mm) cemented armour, laminated onto 1 inch (25.4 mm) of "composition material" (cement) and an additional 0.875 inch (22.2 mm) of Ducol steel hull plating (this steel was also effective as armour),[22][31] over the machinery spaces, the belt was 13.7 inches (349 mm). The lower section of belt tapered to a thickness of between 4.5 in and 5.5 in.[2][32] Armour protection was even better than the thickness of armour would indicate due to the improved qualities of the British cemented[c] armour which provided excellent resistance.[33][34] The armoured belt, together with armoured bulkheads fore and aft and the armoured main deck, formed an "armoured citadel" protecting magazines and machinery. The armoured bulkhead was 12 in (305 mm) thick forward and 10 in (254 mm) thick at the after end of the citadel[23] The main armoured belt extended forward and aft of the main armoured bulkheads with reduced height to protect the waterline and gradually reduced in thickness from 13 to 5.5 inches.[23] Immune zone calculations vary widely from source to source.[35][36][37][38] The armour provision was designed to offer protection from guns of a greater calibre than the class mounted themselves, and was on a scale second to none at the time the ships were designed. Indeed, the armour protection of these vessels was to be subsequently exceeded only by the Japanese battleships of theYamato class.[39]
The main gun turrets were relatively lightly protected in comparison to contemporary battleships.[24] Extensive levels of flash protection were employed. Maximum turret and barbette armour was reduced to 12.75 inches in this class from the 16 inches of the Nelson class. The turret faces had 12.75 in (324 mm) of armour at the front; 8.84 inches (225 mm) sides (at the gun chamber); 6.86 inches (284–174 mm) on the sides and rear; the roof plate was 5.88 in (149 mm) thick. The main armament barbettes were of varying thickness: 12.75 in (324 mm) thick on the sides, 11.76 in (298 mm) forward and 10.82 in (275 mm) aft of the turret. To some extent the higher quality of the armour minimized the loss of protection and the turret's flat face improved ballistic resistance at long ranges, while the low profile of the turret minimized target area at closer ranges. The reduction in turret and barbette armour was a compromise in favour of the thickest possible protection for the magazines.[20] The extensive anti-flash protection in the turrets and barbettes was designed to ensure that the magazines would remain safe even if the turrets and/or barbettes were penetrated.[21] The secondary gun mounts, casements and handling rooms received only light plating of 0.98 in (25 mm) to protect against splinters.[23][24]
Unlike contemporary foreign battleships and the preceding Nelson-class battleships, the King George V class had comparatively light conning tower protection with 4-inch (102 mm) sides, 3 in (75 mm) forward and aft and a 1.47 in (38 mm) roof plate.[23][40][41] The RN's analysis of World War I revealed that command personnel were unlikely to use an armoured conning tower, preferring the superior visibility of unarmoured bridge positions[20][42] Stability and weight considerations clearly played an important part in the British decision to limit superstructure armour. The conning tower armour was sufficient to protect against smaller ship guns and shell fragments.[43]
The hull below the waterline, along the main armour belt, formed the side protection system (SPS). It was subdivided into a series of longitudinal compartments in a void-liquid-void layout; the outer and inner were filled with air, and the middle compartment with liquid (fuel or water). The outer hull plating in the region of the SPS was thin to reduce potential splinter damage from a torpedo. The outer compartment of the SPS was normally an empty or 'void' space (containing only air) and this allowed the initial explosion from a torpedo to expand while minimizing damage to the ship. The centre compartment was filled with oil or seawater and this spread the pressure pulse over a larger area while the liquid contained any metal splinters that were created from the torpedo explosion. The inboard compartment was another void space and served to contain any liquid leaking from the liquid layer and any remaining pressure pulse from the torpedo explosion. Inboard of the final void space was an armoured bulkhead which varied in thickness from 1.5 in (37 mm) over the machinery spaces to 1.75 inch (44 mm) abreast of the magazines. This bulkhead formed the "holding bulkhead" and it was designed to resist the residual blast effects from the torpedo hit. If this final inner bulkhead was penetrated a further set of subdivided compartments would contain any leaks; inboard of the holding bulkhead the ship was highly subdivided into small compartments containing auxiliary machinery spaces. The SPS void-liquid-void layer was generally about 13 feet wide, and the auxiliary machinery spaces added approximately another 8 feet of space from the outer hull plating to the major machinery spaces. The only exception to this was abreast A and B Engine Rooms, where the auxiliary machinery spaces were omitted, but another void space, about three feet wide was substituted in its place.[44]Above the SPS, and directly behind the armour belt, was a series of compartments, typically used for washrooms or storage spaces, which were designed to allow for upward venting of overpressure from a torpedo hit. This scheme was designed to protect against a 1000 lb warhead, and had been tested and found effective in full-scale trials.[45] The SPS was also a key component of the ship's damage control system, as lists resulting from flooding could be corrected by counterflooding empty void spaces, and/or draining normally liquid filled compartments. In the case of the loss of the Prince of Wales these spaces were used for counterflooding to reduce list.[46]
HMS Prince of Wales was sunk on 10 December 1941, from what was believed to have been hits by six aerial launched torpedoes[47] and a 500 kg bomb. However, an extensive 2007 survey by divers of the wreck of Prince of Wales determined definitively that there had been only 4 torpedo hits.[48] Three of these four hits had struck the hull outside the area protected by the SPS. In the case of the fourth, the SPS holding bulkhead appeared intact abreast the area where the hull was hit.[49] The conclusion of the subsequent 2009 paper and analysis[50] was that the primary cause of the sinking was uncontained flooding along "B" propeller shaft.[d] The propeller shaft external shaft bracket failed, and the movement of the unsupported shaft then tore up the bulkheads all the way from the external propeller shaft gland through to B Engine Room itself. This allowed flooding into the primary machinery spaces. The damage and flooding was exacerbated by poor damage control and the premature abandonment of the after magazines and a telephone communications switchboard.[51] "B" propeller shaft had been stopped, and then restarted several minutes after being struck by a torpedo.[52] Subsequent inquiries into her loss at the time[53] identified the need for a number of design improvements, which were implemented to a lesser or greater degree on the other four ships of the class.[54] Ventilation and the watertightness of the ventilation system were improved, while internal passageways within the machinery spaces were redesigned and the communications system made more robust.[55] Improved propeller shaft glands and shaft locking gear were introduced.[43] Some of the supposed failures of the ship were