L and M class destroyer
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 Legion |
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| Class overview | |
|---|---|
| Operators: |  Royal Navy Polish Navy Turkish Navy |
| Preceded by: | J, K and N class |
| Succeeded by: | O and P class |
| Subclasses: | L, M |
| Completed: | 16 |
| Lost: | 9 |
| Retired: | 7 |
| General characteristics as designed & per Lenton[1] | |
| Type: | L and M class destroyer |
| Displacement: | 1,935 tons (standard), 2,840 tons (full) |
| Length: | 362 ft (110 m) o/a |
| Beam: | 36 ft 9 in (11.2 m) |
| Draught: | 10 ft (3.0 m) mean |
| Propulsion: | 3 x Admiralty 3-drum water-tube boilers, Parsons geared steam turbines, 48,000 shp (36,000 kW) on 2 shafts |
| Speed: | 36 kn (67 km/h) |
| Range: | 5,500 nmi (10,200 km) at 15 knots (28 km/h) |
| Complement: | 221 |
| Armament: |
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| General characteristics (4-inch armed N class) | |
| Armament: |
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| Notes: | Other characteristics as per above |
| General characteristics (wartime modifications) | |
| Armament: |
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| Notes: | Other characteristics as per above |
The L and M class was a class of sixteen destroyers which served in the British Royal Navy during World War II. The ships of the class were launched between 1939 and 1942.
Contents |
[edit] Design Details
The armament of the class was subject of considerable debate, as the proponents of heavier anti-aircraft armaments for such vessels were at last beginning to be listened to by the Admiralty. This came mainly as a result of the lessons learned during the Spanish Civil War - i.e., that military aircraft were now sufficiently advanced to pose a major threat to land and sea targets.
The ships of the L and M class had single funnels as per the J class, a tripod foremast and a short mainmast just aft of amidships. One feature of note was the bridge design. From the I class to the Weapon class, all Royal Navy destroyers shared a distinctive wedge-shaped face to the bridge, incorporating an armoured wheelhouse, raised in order that the helmsman could see over the guns. The increased height of the new gunhouses of the L class meant that the wheelhouse was raised further, and the sloped roof of the wheelhouse (to direct the airflow over the compass platform) was almost flat. This feature was unique to the L and M's.
As ordered, the class comprised a leader and 7 destroyers. Each ship was to mount 6 x 4.7-inch (120 mm) guns and 8 torpedo tubes. Close range armament had still to be decided, with the expected time of delivery being a crucial factor.
They were the first British destroyers to have their guns in fully enclosed mountings. They also continued the practice (first introduced in the Js) of making the leader Laforey almost indistinguishable from the rest of the class, having only more extensive cabin accommodation and better W/T (wireless telegraph a.k.a. radio) equipment.
[edit] Main Armament
As ordered the ships were to have six QF Mark XI 4.7-inch (120 mm) guns in Mark XX twin mountings. They were to be in 'A', 'B', and 'X' positions. The 'X' mount was especially interesting in that it gave an arc of fire of around 320 degrees at low elevations and 360 degrees at elevations above around 20 degrees (estimated figures). The Mark XI gun itself was a major improvement on the previous version in that it threw a 62 lb (28 kg) shell (as opposed to the 50 lb (23 kg) in the preceding 'J's). The Mark XX mount was fully enclosed and supposedly weatherproof; however crews found that they were not. It also allowed the guns to be elevated independently. The Mark XX is not technically a turret, as the ammunition feed system was distinct from the weapon mounting, and did not train with the revolving mass. This meant that ammunition supply when the guns were at the limit of training was somewhat difficult. This also meant that the ammunition hoists had to be located between the guns. As a result, the axes of the guns were very widely spaced, a feature instantly obvious with the mounting Mark XX.
The Mark XX mounting permitted an increased elevation to 50 degrees (compared to 40 for previous marks). However, even this was to prove totally inadequate for dealing with the threats posed by enemy aircraft, particularly dive bombers. The Imperial Japanese Navy had already introduced a 5-inch (127 mm) gun with 70 degree elevation into service, while the United States Navy's 5"/38 cal Mark 32 mount count elevate to 85 degrees, why British designers had so much trouble has never been made clear. The 4.5-inch (114 mm) guns fitted to Ark Royal were already in service and capable of elevations of 70 degrees plus, although the mountings were not suitable for a ships of destroyer size. Coupled with the lack of powered elevation, the Mark XX mounting was compromised in its chosen anti-aircraft use.
Another development regarding the main armament was the adoption of a combined High Angle / Low Angle director tower, the HA/LA Mk.IV (TP). Unfortunately this was never entirely satisfactory in the HA mode, and was at least a ton overweight. It was later reworked, somewhat unsuccessfully again, as the Mk.I "K tower" of the Z class.
As originally ordered they had no close-range armament at all as the various departments could not agree on what to fit. Arguments as to one or two 4-barrelled 2 pdr "pom poms", one pom-pom and one of the 0.661-inch (16.8 mm) multiple machine guns then in development, one pom-pom and the traditional 0.5-inch (12.7 mm) machine gun raged, stoked by the manufacturing schedules (a second pom-pom per ship would not be available until 1942), the poor performance of the development models of the 0.661 and the campaign by a number of younger officers (led by Lord Louis Mountbatten) as to the effectiveness of all three weapons. Eventually, development of the 0.661 was dropped as it clearly would not be available and effective in a sensible timescale, this simplified the arguments somewhat.
The outbreak of war focussed minds somewhat. Apart from the AA armament issue concerns started to be raised about progress generally. By February 1940 the two factors led to a proposal to change the design of four of the 'L's and fit a main armament of 4-inch (102 mm) Mark XVI* guns in Mark XIX High Angle/Low Angle (HA/LA) twin mounts as used as secondary armament in the Southampton-class cruisers already in service and main armament in the Black Swan class of sloops then under construction. Associated changes were dropping of the pom-poms altogether and provision of two quad 0.5-inch (12.7 mm) machine guns.
The lessons of the Norwegian campaign and Dunkirk drove home the need for this change and it was agreed in July 1940, there were also to be four of the twin mounts instead of the originally proposed three. The fourth was to be at the forward end of the after superstructure which cut down on the fire arcs of both mounts but ensured the fourth would still be available for use in heavy weather.
Not all senior officers were in favour, and some openly expressed opinions that it would mean the ships could not successfully fight their foreign equivalents. Experience in the Mediterranean, especially that of Force K which contained two of the 4-inch (102 mm) 'L's, made a mockery of the idea, with the reduced weight of each shell being compensated for by the much higher rate of fire.
Review of AA armament continued, and in October a decision was taken to remove the after bank of four torpedo tubes and fit a single 4-inch (102 mm) HA gun instead, and that is how the 4.7-inch (120 mm) gunned ships eventually got to sea.
[edit] Ships
[edit] L class
- Laforey, flotilla leader, built by Yarrow & Company, Scotstoun, (lost on 30 March 1944)
- Gurkha, was originally named Larne but renamed after the loss of Gurkha (F20) on 1940-04-09, built by Cammell Laird & Company, Birkenhead (lost on 17 January 1942)
- Lance, built by Yarrow, (lost on 9 April 1942)
- Legion, built by Hawthorn Leslie & Company, Hebburn, (lost on 26 March 1942)
- Lightning, built by Hawthorn Leslie, (lost on 12 March 1943)
- Lively , built by Cammell Laird, (lost on 11 May 1942)
- Lookout built by Scotts Shipbuilding & Engineering Company, Greenock, BU 1948
- Loyal, built by Scotts, BU 1948
The L class (also known as the Laforeys) were approved under the 1937 Naval Estimates. Lance, Lively, Legion and Larne were built with 4-inch (100 mm) armament
[edit] M class
- Mahratta built by Scotts, (lost on 25 February 1944)
- Marne built by Vickers-Armstrongs, Walker, sold to Turkey 1959
- Martin built by Vickers-Armstrongs, (lost on 10 November 1942)
- Matchless built by Alexander Stephen & Sons, Linthouse, sold to Turkey 1959
- Meteor, built by Stephen, sold to Turkey 1959
- Milne, built by Scotts, sold to Turkey 1959
- Musketeer built by Fairfield Shipbuilding & Engineering Company, Govan, BU 1955
- Myrmidon built by Fairfield, (Became the Polish destroyer ORP Orkan) (lost on 8 October 1943)
[edit] References
- ^ British and Empire Warships of the Second World War, H. T. Lenton, Greenhill Books, ISBN 1-85367-277-7
[edit] See also
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