G3 battlecruiser
A 1:96 scale model of a G3 battlecruiser
| |
Class overview | |
---|---|
Name | G3 |
Operators | Royal Navy |
Preceded by | Admiral class |
Succeeded by | None |
Planned | 4 |
Completed | 0 |
Cancelled | 4 |
General characteristics (as of November 1921) | |
Type | Battlecruiser |
Displacement | |
Length | 856 ft (260.9 m) |
Beam | 106 ft (32.3 m) |
Draught | 35 ft 8 in (10.9 m) (at deep load) |
Installed power |
|
Propulsion | 4 shafts; 4 geared steam turbines |
Speed | 32 knots (59 km/h; 37 mph) |
Range | 7,000 nautical miles (13,000 km; 8,100 mi) at 16 knots (30 km/h; 18 mph) |
Complement | 1,716 |
Armament |
|
Armour |
The G3 class was a class of battlecruisers planned by the Royal Navy after the end of World War I in response to naval expansion programmes by the United States and Japan. The four ships of this class would have been larger, faster and more heavily armed than any existing battleship (although several projected foreign ships would be larger). The G3s have been considered to be proper "fast battleships" since they were well-balanced designs with adequate protection. Nonetheless the class was officially designated as a "battlecruiser" due to their higher speed and lesser firepower and armour relative to the planned N3-class battleship design. The G3s would have carried nine 16-inch (406 mm) guns and were expected to achieve 32 knots (59 km/h; 37 mph), while the N3s would carry nine 18-inch (457 mm) guns on the same displacement at the expense of speed.[1]
The G3 design was approved by the Board of Admiralty on 12 August 1921. Orders were placed in October, but were suspended in mid-November shortly after the beginning of the Washington Naval Conference which limited battleship sizes. The orders were cancelled in February 1922 with the ratification of the Washington Naval Treaty which limited construction to ships of no more than 35,000 long tons (36,000 t) displacement.
Background
In 1916 the US had declared its intention to create a Navy "second to none"; the United States Congress had authorized the building of a large number of battleships and battlecruisers. In the aftermath of the First World War, the Japanese government were also embarking on a large programme of warship building. Meanwhile, in Great Britain, the
The US plan had been delayed by the wartime need to build smaller vessels. Nevertheless, estimates by the Admiralty were that by the early 1920s the UK would be behind in ships. The British did have access to German technology through ships such as the battleship
The first two design proposals, 'K2' and 'K3', had a general layout similar to Hood, but were armed with either eight or nine 18-inch guns, in four twin or three triple
This design was accepted at the end of 1920, but changes were made as the plans were finalized in early 1921, including the reduction of the ship's horsepower from 180,000 to 160,000 and the reduction of the main armament from 16.5 in to 16 in (406 mm).[5]
Design and description
The G3s incorporated several novel features for
General characteristics
The G3 battlecruisers were significantly larger than their predecessors of the Admiral class. They had an
Propulsion
The G3 battlecruisers would have had four geared
The ships had a maximum capacity of 5,000 long tons (5,100 t) of fuel oil. Using the 22,000-shaft-horsepower (16,000 kW) cruising turbines, they had an estimated maximum range of 7,000 nautical miles (13,000 km; 8,100 mi) at 16 knots (30 km/h; 18 mph). They had six turbo-driven 250-kilowatt (335 hp) dynamos and two 300-kilowatt (402 hp) diesel generators.[9]
Armament
Housing the main armament in triple turrets was new to the Royal Navy though British companies had been involved in the production of triple gun turret designs for other navies.
The G3 design mounted nine
An
Like previous classes of British battlecruisers, a pair of submerged, broadside-firing
Fire-control
The main guns of the G3 battlecruisers could be controlled from any of the three
Armour
A first for any British
The waterline belt of the G3 had a maximum thickness of 14 inches (356 mm) with the top of the armour angled 18° outwards. This angle increased the armor's relative thickness to horizontal, close-range fire, albeit at the cost of reducing its relative height which increased the chance of plunging shellfire going over or under it. It ran some 522 feet (159.1 m), from the forward edge of 'A' barbette to the rear of the after 6-inch magazine. The belt had a height of 14 feet 3 inches (4.3 m), of which 4 feet 6 inches (1.4 m) was below the designed waterline. Only the forward 259 feet (78.9 m) of the belt had the maximum thickness, it thinned to 12 inches (305 mm) for the rest of its length. The lower edge of the belt abreast the magazines was continued down another 3 feet (0.9 m) by a 4 inches (100 mm) thickness of high-tensile steel inclined at 36° to prevent a shell from reaching the magazines via a wave trough at high speed. The forward and rear ends of the belt terminated in 12-inch and 10-inch (254 mm) transverse bulkheads respectively. The waterline belt extended forward 46 feet (14.0 m) at a thickness of 6 inches that reduced to 2.25 inches (57 mm) in two steps.[21]
The funnel and boiler room ventilation shafts were surrounded by an armoured box 116 feet (35.4 m) long intended to prevent shells fired from behind the ship reaching 'X' magazine. The box narrowed at an angle of 21° as it rose and had a maximum thickness of 12 inches nearest to the magazine. Aft it reduced in a series of steps to 9 inches (229 mm), 6 inches, 5 inches (127 mm) and 4 inches (102 mm). The armoured deck matched the length of the waterline belt and sloped down 2.5° to meet the upper edge of the belt. It had a maximum thickness of 8 inches (203 mm) from the 'A' barbette to partway over the mid-boiler rooms and thinned to a minimum of 4 inches over the rear engine and boiler rooms. The deck's thickness increased to 7 inches (180 mm) partway over the rear engine room and covered the aft 6-inch magazines. The armoured deck extended forward 46 feet over the torpedo compartment with a maximum thickness of 8 inches, thinning to 6 inches. The armoured deck's rear extension was 106 feet 9 inches (32.5 m) long and was 5 inches thick until the last 27 feet 4 inches (8.3 m) when it thinned to 3 inches (76 mm).[22]
The turret faces were 17.5 inches (444 mm) thick while their sides ranged from 9 to 13 inches (229 to 330 mm) in thickness, and the roof was 8 inches thick. The armour of the barbettes ranged from 11 to 14 inches (279 to 356 mm) in thickness and it was carefully arranged to minimize the likely risk. The conning tower armour was 9 to 12 inches thick and its communications tube to the upper deck was 8 inches thick. The fire-control director atop the conning tower was protected by an armoured hood 3 to 5 inches thick.[23]
The
Orders and cancellation
At the end of the tendering process, the four G3 battlecruisers were ordered on 24 October 1921, without names, from John Brown, Swan Hunter, William Beardmore and Fairfield. Following the visit of an Admiralty delegation, detailed constructional drawings were sent to John Brown on 3 November with a request that copies be urgently circulated to the other successful contractors.[25] Work at John Brown progressed on the keel blocks and hull plates for the subsequent two weeks. Notwithstanding other events, instructions and amendments continued to arrive from various departments within the Admiralty until 25 November.[26]
The
Many of the aspects of their design ultimately were incorporated into the two Nelson-class battleships, and they are often described as being a cut-down G3. The Nelsons received the design designation 'O3', marking them as next in the design sequence from the 'N3' battleship design although they used the guns intended for the G3 class for cost reasons and to comply with the Treaty's 16-inch limitation on main armament.[28]
See also
- Lexington-class battlecruiser – a contemporary U.S. design also cancelled as a result of the Washington Treaty
- Eight-eight fleet", cancelled as a result of the Washington Treaty
Notes
- ^ Raven and Roberts, p. 90
- ^ Campbell, Part 1, p. 4
- ^ Campbell, Part 2, p. 13
- ^ Raven and Roberts, pp. 93–94
- ^ Raven and Roberts, p. 95
- ^ This arrangement of the main armament was later used in the French Navy's Dunkerque- and Richelieu class. As both French designs had only two turrets these were given as wide a separation as allowed by the other design constraints.
- ^ Raven and Roberts, p. 127
- ^ a b Raven and Roberts, p. 101
- ^ a b Campbell, pt. 4, p. 44
- ^ Campbell, Part 1, p. 9
- ^ Campbell, Part 1, p. 7
- ^ Raven and Roberts, pp. 98, 100
- ^ "British 16"/45 (40.6 cm) Mark I". Navweaps.com. 7 January 2009. Retrieved 26 July 2010.
- ^ a b c Raven and Roberts, p. 100
- ^ "British 6"/50 (15.2 cm) BL Mark XXII". Navweaps.com. 7 January 2007. Retrieved 26 July 2010.
- ^ a b c d e Campbell, Part 3, p. 42
- ^ "British 4.7"/43 (12 cm) QF Mark VII 4.7"/40 (12 cm) QF Mark VIII 4.7"/40 (12 cm) QF Mark X". Navweaps.com. 31 December 2006. Retrieved 26 July 2010.
- ^ "Britain 2-pdr [4 cm/39 (1.575")] Mark VIII". navweaps.com. 20 February 2008. Archived from the original on 26 June 2015. Retrieved 7 June 2010.
- ^ "British Torpedoes Pre-World War II: 24.5" (62.2 cm) Mark I". navweaps.com. 12 January 2009. Retrieved 7 March 2010.
- ^ Raven and Roberts, p. 92
- ^ Campbell, Part 3, pp. 42–43
- ^ Campbell, Part 3, pp. 41, 43
- ^ a b c Campbell, Part 3, p. 43
- ^ Raven and Roberts, p. 93
- ^ Johnston, p. 178
- ^ a b Johnston, p. 179
- ^ Campbell, Part 3, p. 44
- ^ Burt, p. 328
Bibliography
- ISBN 1-55750-315-X.
- Burt, R. A. (1993). British Battleships, 1919–1939. London: Arms and Armour Press. ISBN 1-85409-068-2.
- Campbell, John (1985). Naval Weapons of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-459-4.
- Johnston, Ian (2011). Clydebank Battlecruisers: Forgotten Photographs from John Brown's Shipyard. Barnsley, Yorkshire: Seaforth Publishing. ISBN 978-1-84832-113-7.
- Campbell, N. J. M. (1977). "Washington's Cherry Trees, Part 1". Warship. I (1). London: Conway Maritime Press: 2–12. ISBN 0-87021-975-8.
- Campbell, N. J. M. (1977). "Washington's Cherry Trees, Part 2". Warship. I (2). London: Conway Maritime Press: 12–19. ISBN 0-87021-975-8.
- Campbell, N. J. M. (1977). "Washington's Cherry Trees, Part 3". Warship. I (3). London: Conway Maritime Press: 38–45. ISBN 0-87021-975-8.
- Raven, Alan & Roberts, John (1976). British Battleships of World War Two: The Development and Technical History of the Royal Navy's Battleship and Battlecruisers from 1911 to 1946. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-817-4.