Post by Diarist on Jul 22, 2014 22:53:00 GMT 1
The Hawkins class is a class of five heavy cruisers of the Royal Navy designed in 1915 and constructed throughout the Great War. All ships were named after Elizabethan sea captains. HMS Vindictive, though no longer a cruiser, also served throughout the War. This class formed the basis for the definition of the maximum cruiser type under the Washington Naval Treaty of 1922.
Design
Although the Hawkins class were the first heavy cruisers built for the Royal Navy, they were designed as improved versions of the Birmingham sub-class of the "Town" class light cruisers, thus they were initially known as the "Improved Birmingham" type. Their lineage descended through an intermediate sketch design of 1912 known as the "Atlantic Cruiser", armed with a combination of 7.5 and 6 inch (190 and 152 mm) guns, designed to counter reported large German cruisers armed with 170 mm (6.8 inch) guns.
In 1915, a new design of cruiser was prepared for trade protection on distant waters, for which a heavy armament, long range and high speed was required; meaning a large ship. Previous large cruisers had been of the armoured cruiser or protected cruiser type. These ships had been made obsolete by the adoption of oil-firing and the steam turbine engine and had been superseded by the battlecruiser and the light cruiser. The Hawkins design was basically a light cruiser enlarged sufficiently to increase their range and armament as required. A mixed armament of 9.2 and 6 inch was rejected after wartime experience illustrated the difficulty of controlling a mixed battery as shell splashes could not be differentiated. Thus, a uniform battery of 7.5 inch calibre was adopted, controlled by the innovation of director firing.
The development of director firing made the planned armament obsolete, as director control relies on "straddles" in which some shells in a given salvo are seen to fall short of the target and some long. As long as straddles are maintained, some percentage of the shots will be hits. With a main battery consisting of only two guns, a straddle of one shell falling short and one long mathematically eliminates the possibility of a hit, while a uniform six-gun broadside allows the possibility of up to four hits out of a straddle.
The boilers were initially a combination of coal and oil firing to ensure a supply of fuel on distant stations; coal being more available and the ships could cruise on coal firing alone. The installed power was 60,000 shp for 30 knots (56 km/h). However, only Hawkins and Vindictive were completed as such. The other ships were not constructed with much haste and were completed post-war with oil-firing only, increasing power to 70,000 shp for 31 knots (57 km/h).
These ships did not suit the Royal Navy's post-War needs well, as Britain needed numbers of cruisers, rather than individually powerful ships. As breaking them up on the slips would have been an unwarranted waste of money, they were completed anyway. At just under 10,000 tons and armed with 7.5-inch guns, they became the prototype of the heavy cruiser designs based on limitations set by the Washington Naval Treaty in 1922.
HMS Vindicative
The fifth and last ship of the class - laid down as Cavendish - was altered to an aircraft carrier while building, renamed HMS Vindictive to perpetuate the name of the cruiser sunk at the Second Ostend Raid and her construction was rushed to bring her into service before her cruiser sisters. She had a 100-foot (30 m) flying-off platform forwards and a 215-foot (66 m) landing deck aft and a hangar for up to eight aircraft. She was armed with four 7.5 inch and six 12 pounder guns. In 1923 she reverted to a cruiser, but retained the hangar forwards and did not carry a 'B' gun; a crane and catapult being carried instead for seaplanes.
Ships
HMS Hawkins, named after John Hawkins, built by HM Dockyard Chatham, laid down 3 June 1916, launched 1 October 1917, completed 19 July 1919.
HMS Raleigh, named after Walter Raleigh, built by William Beardmore & Company, Dalmuir, laid down 4 October 1916, launched 28 August 1919, completed July 1921. Wrecked Point Amour, Forteau Bay, Labrador 8 August 1922, stripped and wreck demolished September 1926.
HMS Frobisher, named after Martin Frobisher, built by HM Dockyard Devonport, laid down 2 August 1916, launched 20 March 1920, completed 3 October 1924.
HMS Effingham, named after Charles Howard, Lord Effingham, built by HM Dockyard Portsmouth, laid down 2 April 1917, launched 8 June 1921, completed 9 July 1925.
HMS Cavendish, named after Thomas Cavendish, built by Harland & Wolff, Belfast, laid down July 1916, redesigned as an aircraft carrier, launched on 17 January 1918, renamed Vindictive on 29 June 1918 and completed October 1918. Converted back to a cruiser 1923–1925.
Source: Wikipedia - en.wikipedia.org/wiki/Hawkins-class_cruiser
Design
Although the Hawkins class were the first heavy cruisers built for the Royal Navy, they were designed as improved versions of the Birmingham sub-class of the "Town" class light cruisers, thus they were initially known as the "Improved Birmingham" type. Their lineage descended through an intermediate sketch design of 1912 known as the "Atlantic Cruiser", armed with a combination of 7.5 and 6 inch (190 and 152 mm) guns, designed to counter reported large German cruisers armed with 170 mm (6.8 inch) guns.
In 1915, a new design of cruiser was prepared for trade protection on distant waters, for which a heavy armament, long range and high speed was required; meaning a large ship. Previous large cruisers had been of the armoured cruiser or protected cruiser type. These ships had been made obsolete by the adoption of oil-firing and the steam turbine engine and had been superseded by the battlecruiser and the light cruiser. The Hawkins design was basically a light cruiser enlarged sufficiently to increase their range and armament as required. A mixed armament of 9.2 and 6 inch was rejected after wartime experience illustrated the difficulty of controlling a mixed battery as shell splashes could not be differentiated. Thus, a uniform battery of 7.5 inch calibre was adopted, controlled by the innovation of director firing.
The development of director firing made the planned armament obsolete, as director control relies on "straddles" in which some shells in a given salvo are seen to fall short of the target and some long. As long as straddles are maintained, some percentage of the shots will be hits. With a main battery consisting of only two guns, a straddle of one shell falling short and one long mathematically eliminates the possibility of a hit, while a uniform six-gun broadside allows the possibility of up to four hits out of a straddle.
The boilers were initially a combination of coal and oil firing to ensure a supply of fuel on distant stations; coal being more available and the ships could cruise on coal firing alone. The installed power was 60,000 shp for 30 knots (56 km/h). However, only Hawkins and Vindictive were completed as such. The other ships were not constructed with much haste and were completed post-war with oil-firing only, increasing power to 70,000 shp for 31 knots (57 km/h).
These ships did not suit the Royal Navy's post-War needs well, as Britain needed numbers of cruisers, rather than individually powerful ships. As breaking them up on the slips would have been an unwarranted waste of money, they were completed anyway. At just under 10,000 tons and armed with 7.5-inch guns, they became the prototype of the heavy cruiser designs based on limitations set by the Washington Naval Treaty in 1922.
HMS Vindicative
The fifth and last ship of the class - laid down as Cavendish - was altered to an aircraft carrier while building, renamed HMS Vindictive to perpetuate the name of the cruiser sunk at the Second Ostend Raid and her construction was rushed to bring her into service before her cruiser sisters. She had a 100-foot (30 m) flying-off platform forwards and a 215-foot (66 m) landing deck aft and a hangar for up to eight aircraft. She was armed with four 7.5 inch and six 12 pounder guns. In 1923 she reverted to a cruiser, but retained the hangar forwards and did not carry a 'B' gun; a crane and catapult being carried instead for seaplanes.
Ships
HMS Hawkins, named after John Hawkins, built by HM Dockyard Chatham, laid down 3 June 1916, launched 1 October 1917, completed 19 July 1919.
HMS Raleigh, named after Walter Raleigh, built by William Beardmore & Company, Dalmuir, laid down 4 October 1916, launched 28 August 1919, completed July 1921. Wrecked Point Amour, Forteau Bay, Labrador 8 August 1922, stripped and wreck demolished September 1926.
HMS Frobisher, named after Martin Frobisher, built by HM Dockyard Devonport, laid down 2 August 1916, launched 20 March 1920, completed 3 October 1924.
HMS Effingham, named after Charles Howard, Lord Effingham, built by HM Dockyard Portsmouth, laid down 2 April 1917, launched 8 June 1921, completed 9 July 1925.
HMS Cavendish, named after Thomas Cavendish, built by Harland & Wolff, Belfast, laid down July 1916, redesigned as an aircraft carrier, launched on 17 January 1918, renamed Vindictive on 29 June 1918 and completed October 1918. Converted back to a cruiser 1923–1925.
Source: Wikipedia - en.wikipedia.org/wiki/Hawkins-class_cruiser