View source for L and M-class destroyer

{{Short description|Class of destroyers for Britain}}
{{Use dmy dates|date=January 2017}}
{{Use British English|date=January 2017}}
{{More footnotes needed|date=March 2010}}
{|{{Infobox ship begin|sclass=2}}
{{Infobox ship image
|Ship image=HMS Legion.jpg
|Ship caption=HMS ''Legion'' with her [[Type 285 radar]] aerials visible on her HA DCT
}}
{{Infobox ship class overview
|Builders=
|Operators=*{{navy|United Kingdom}}
* {{navy|Poland}}
* {{navy|Turkey}}
|Class before={{sclass2|J, K and N|destroyer|4}}
|Class after={{sclass2|O and P|destroyer|4}}
|Subclasses=L, M
|Built range=1938–42
|In commission range=
|Total ships building=
|Total ships planned=
|Total ships completed=16
|Total ships cancelled=
|Total ships active=
|Total ships laid up=
|Total ships lost=9
|Total ships scrapped=7
|Total ships preserved=
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=as completed
|Ship type=[[Destroyer]]
|Ship displacement=*{{convert|1920|LT|t|0|abbr=on}} (standard)
* {{convert|2660|LT|t|0|abbr=on}} (deep)
|Ship length={{convert|362|ft|3|in|m|1|abbr=on}} [[Length overall|o/a]]
|Ship beam={{convert|37|ft|m|1|abbr=on}}
|Ship draught={{convert|10|ft|m|1|abbr=on}}
|Ship power={{convert|48000|shp|kW|lk=in|abbr=on}}
|Ship propulsion=*2 × shafts
* 2 × [[Parsons Marine Steam Turbine Company|Parsons]] geared [[steam turbine]]s
* 2 × Admiralty 3-drum [[boiler]]s
|Ship speed={{convert|36|kn|lk=in}}
|Ship range={{convert|5500|nmi|lk=in|abbr=on}} at {{convert|15|kn}}
|Ship complement=190
|Ship sensors=*[[ASDIC]]
* [[Type 285 radar|Type 285]] [[Anti-aircraft warfare|anti-aircraft]] (AA) [[radar]]
* [[List of World War II British naval radar#Type 286|Type 286M]] air warning radar
|Ship armament=*3 × 2 - [[QF 4.7 inch Mark XI gun|QF 4.7-inch Mk XI]] [[dual purpose gun]]s  '''Or'''
* 4 × 2 - [[QF 4 inch Mk XVI naval gun|QF 4-inch Mk XVI dual purpose guns]]
* 1 × 1 - [[QF 4 inch Mk V naval gun|QF 4-inch Mk V anti-aircraft gun]]
* 1 × 4 - [[QF 2 pounder naval gun|QF 2-pounder Mk VIII anti-aircraft guns]]
* 2 × 4 - [[Vickers .50 machine gun|QF .5-inch Vickers Mk III anti-aircraft machine guns]]
* 2 × 4 - [[British 21 inch torpedo|{{convert|21|inch|mm|adj=on|0}}]] [[torpedo tube]]s
* 42 × [[Depth charge]]s, 2 rails and 2 throwers
}}
|}

The '''L and M class''' was a [[ship class|class]] of sixteen [[destroyer]]s which served in the [[United Kingdom|British]] [[Royal Navy]] during [[World War II]]. The ships of the class were launched between 1939 and 1942.

The L class (also known as the ''Laforeys'') were approved under the 1937 Naval Estimates. Four of these ships (''Lance'', ''Lively'', ''Legion'' and ''Larne'') were built with {{convert|4|in|mm|adj=on}} armament instead of 4.7 inch. Six of the eight were war losses, with the surviving pair being broken up in 1948.

The M Class were built under the 1939 Naval Estimates.  They served in the Home Fleet until 1944 and then went to the Mediterranean. Three were wartime losses; of the five survivors, the ''Musketeer'' was broken up in 1955 and the other four sold to Turkey in 1958.

==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 [[British Admiralty|Admiralty]]. This came mainly as a result of the lessons learned during the [[Spanish Civil War]]{{Citation needed|date=March 2010}} – ''i.e''., [[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, like the previous [[J, K and N-class destroyer|J class]], a tripod foremast and a short mainmast just aft of amidships. One feature of note was the bridge design. From the {{sclass2|I|destroyer|4}} to the {{sclass2|Weapon|destroyer|4}}, all Royal Navy destroyers shared a distinctive wedge-shaped face to the bridge, incorporating a bulletproof<ref>March, British Destroyers. March fails to note armour plating on any RN destroyer.</ref> wheelhouse, raised for the helmsman to 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 Ls and Ms.

The class comprised a leader and seven destroyers. Each ship was to mount six {{convert|4.7|in|mm|adj=on}} guns and eight [[torpedo tube]]s. 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 {{HMS|Laforey|G99|2}} almost indistinguishable from the rest of the class, having only more extensive cabin accommodation and better [[radio]] (wireless telegraph, W/T) equipment.

=== Main armament ===
The ships were to have six QF Mark XI {{convert|4.7|in|mm|adj=on}} guns in Mark XX twin mountings in 'A', 'B', and 'X' positions. The 'X' mount gave an estimated [[arc of fire]] of 320 degrees at low elevations and 360 degrees at elevations above around 20 degrees. The Mark XI gun was a big improvement on the previous version in that it threw a {{convert|62|lb|abbr=on}} shell (compared to the {{cvt|50|lb}} shell in the preceding J class). The Mark XX mount was fully enclosed and supposedly weatherproof; in service, crews found otherwise. It also allowed the guns to be elevated independently. The Mark XX was 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 just as in the USN [[5"/38 caliber gun|5" guns]].<ref name="ReferenceA">Destroyer Weapons of WW2, Hodges/Friedman, {{ISBN|0-85177-137-8}}</ref> The axes of the guns were very widely spaced, a feature instantly obvious with the Mark XX mounting.

The Mark XX mounting permitted an increased elevation to 50 degrees (compared to 40 for previous marks) but this still limited the engagement time against enemy aircraft, although medium calibre guns posed little threat to [[dive bomber]]s prior to the use of radar proximity fuzed ammunition.<ref>Hodges, ''Tribal Class Destroyers'', p32: Diagram of High Level Bomber Attack: A 240mph target, at 12 thousand feet altitude could expect to be under for fire about 75 seconds, from the time it enters the effective range of the HACS until it flies to within the minimum range of a 5.25 gun elevated to 70 degrees. A Tribal class destroyer with 40-degree elevation guns would be able to engage the same target for about 37 seconds.</ref><ref>Friedman, ''US Destroyers-An Illustrated Design History'', p203:"In theory, the 5in gun could counter either horizontal or torpedo bombers; it could not fire nearly fast enough to present any threat to dive bombers, which, ironically, were probably the most lethal threat to fast manoeuvrable craft such as destroyers."</ref> The [[Imperial Japanese Navy]] had already introduced a 5-inch (127&nbsp;mm) gun with 70-degree elevation into service which had very poor performance as an anti-aircraft weapon, while the [[United States Navy]]'s 5"/38 cal Mark 32 mount could elevate to 85 degrees.<ref>[http://www.navweaps.com/Weapons/WNJAP_5-50_3ns.htm 12.7 cm/50 (5") 3rd Year Type]: "''However, the very slow training speeds and lack of power ramming made these mountings almost useless against the fast-moving aircraft of World War II''"</ref> The 4.5-inch (114&nbsp;mm) guns fitted to {{HMS|Ark Royal|91|6}} were already in service and capable of elevations of 80 degrees, although the mountings were not suitable for a destroyer-sized ship. Coupled with the lack of powered elevation, the Mark XX mounting was compromised in its chosen anti-aircraft role, although it compared favourably with similar Axis weapons.

Another development regarding the main armament was the adoption of a combined high-angle/low-angle director tower, the HA/LA Mk.IV (TP). This was never entirely satisfactory in the HA mode, and was at least a ton overweight.<ref>Whitley 2000, p. 121.</ref> It was later reworked, somewhat unsuccessfully again, as the Mk.I "K tower" of the [[W and Z-class destroyer|Z class]]. These ships used the [[Fuze Keeping Clock]] HA Fire Control Computer.<ref name="ReferenceA"/> Despite its problems, the L and M class' director tower and its [[Type 285 radar]] provided better high-angle fire control than any similar Axis destroyer, the vast majority of which did not have any high-angle fire control system, much less a specialised AA fire control radar.<ref>Campbell, Naval Weapons of WW2. Campbell notes that no German or Italian destroyer had a high-angle (anti-aircraft) fire control system, and that the Japanese system was very rudimentary.</ref>

As originally ordered, the class had no close-range armament as the various departments could not agree on what to fit. Arguments raged as to the effectiveness of mounting one or two four-barrelled [[QF 2 pounder naval gun|2-pounder "pom poms"]], one pom-pom and one of the {{convert|0.661|in|mm|adj=on}} multiple machine guns then in development, one pom-pom and the traditional 0.5-inch (12.7&nbsp;mm) Vickers machine gun. The argument was exacerbated 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 a number of younger officers (led by [[Lord Louis Mountbatten]]) dissatisfied with anti-aircraft weaponry. Eventually, development of the 0.661 was dropped as it clearly would not be available quickly enough and this simplified the arguments somewhat.

The outbreak of war focused minds. 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&nbsp;mm) Mark XVI* guns in Mark XIX High Angle/Low Angle (HA/LA) twin mounts as used as secondary armament in the {{sclass|Southampton|cruiser|1}}s already in service and main armament in the {{sclass|Black Swan|sloop|4}} of [[Sloop-of-war|sloops]] under construction. Associated changes were provision of two quadruple 0.5-inch (12.7&nbsp;mm) machine guns. All ships of this class except ''Lightning'' and ''Laforey'' carried a four-barrel 2-pounder pom-pom.<ref>March, British Destroyers, p358.</ref>

The lessons of the [[Norwegian campaign]] and the [[Battle of Dunkirk]] drove home the need for this change and it was agreed in July 1940 that 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 said that it would mean the ships could not fight their foreign equivalents. Experience in the [[Mediterranean]], especially that of [[Force K]] which contained two of the 4-inch (102&nbsp;mm) 'L's, showed that the loss of gun power against surface targets was balanced against a higher rate of fire.

Review of AA armament continued and in October a decision was taken to remove the after bank of torpedo tubes and fit a 4-inch (102&nbsp;mm) HA gun instead and that is how the {{convert|4.7|in|mm|adj=on}} gunned ships eventually went to sea, although some surviving ships, including ''Matchless'' and ''Marne'', had the after tubes replaced later in the war.<ref>March, British Destroyers, p371</ref>

==Proposed conversion==
In the early 1950s, it was proposed to convert the five remaining ships of the M class, together with seven [[War Emergency Programme destroyers]] to Type 62 Air Direction Frigates. The conversion would have involved replacement of the ships' armament and sensors. The initial proposal would have armed the ships with a twin 4-inch gun mount, a twin [[Bofors 40 mm Automatic Gun L/60|40 mm Bofors gun]] and a [[Squid (weapon)|Squid]] anti-submarine mortar. Type 982 and 983 air direction radars would be fitted, as would Type 162 and 166 [[sonar]]s. In March 1952, the programme was reduced, as the War Emergency Destroyers were too small to accommodate the heavy radars. Later that year, it was decided to substitute a US twin [[3"/50 caliber gun]] mount for the 4-inch guns. The project was finally abandoned in May 1954, partly owing to the condition of the ships and poor shock-resistance.<ref name="English p115">English 2001, p. 115</ref><ref name="conways47 p516">Lyon & Chumbley 1995, p. 516</ref>

==Ships==

===L class===
The '''L class''' (also known as the '''''Laforey''s''') were approved under the 1937 Naval Estimates. Four of these ships (''Lance'', ''Lively'', ''Legion'' and ''Larne'') were built with {{convert|4|in|mm|adj=on|0}} armament. Six of the eight were war losses, with the surviving pair being broken up in 1948.

{|class="wikitable plainrowheaders"
|+ Construction data
|-
! scope="col"|Ship
! scope="col"|Builder
! scope="col"|[[Laid down]]
! scope="col"|[[Ceremonial ship launching|Launched]]
! scope="col"|[[Ship commissioning|Commissioned]]
! scope="col"|Fate
|-
! scope="row"|{{HMS|Laforey|G99|2}} ([[flotilla leader]])
| rowspan=2|[[Yarrow & Company]], [[Scotstoun]]
| 1 March 1939
| 15 February 1941
| 26 August 1941
| Sunk, 30 March 1944
|-
! scope="row"|{{HMS|Lance|G87|2}}
| 1 March 1939
| 28 November 1940
| 13 May 1941
| Sunk, 9 April 1942
|-
! scope="row"|{{HMS|Gurkha|G63|2}} (ex-''Larne'')
| rowspan=2|[[Cammell Laird & Company]], [[Birkenhead]]
| 18 October 1938
| 28 July 1940
| 18 February 1941
| Sunk, 17 January 1942
|-
! scope="row"|{{HMS|Lively|G40|2}}
| 20 December 1938
| 28 January 1941
| 20 July 1941
| Sunk, 11 May 1942
|-
! scope="row"|{{HMS|Legion|G74|2}}
| rowspan=2|[[Hawthorn Leslie & Company]], [[Hebburn]]
| 1 November 1938
| 26 December 1939
| 19 December 1940
| Sunk, 26 March 1942
|-
! scope="row"|{{HMS|Lightning|G55|2}}
| 15 November 1938
| 22 April 1940
| 28 May 1941
| Sunk, 12 March 1943
|-
! scope="row"|{{HMS|Lookout|G32|2}}
| rowspan=2|[[Scotts Shipbuilding & Engineering Company]], [[Greenock]]
| 23 November 1938
| 4 November 1940
| 30 January 1942
| Broken up, 1948
|-
! scope="row"|{{HMS|Loyal|G15|2}}
| 23 November 1938
| 8 October 1941
| 31 October 1942
| Broken up, 1948
|}

===M class===

The '''M Class''' were built under the 1939 Naval Estimates.  They served in the Home Fleet until 1944 and then went to the Mediterranean. Three were wartime losses; of the five survivors, the ''Musketeer'' was broken up in 1955 and the other four sold to Turkey in 1958.

{|class="wikitable plainrowheaders"
|+ Construction data
|-
! scope="col"|Ship
! scope="col"|Builder
! scope="col"|Laid down
! scope="col"|Launched
! scope="col"|Commissioned
! scope="col"|Fate
|-
! scope="row"|{{HMS|Milne|G14|2}}
| rowspan=2|[[Scotts Shipbuilding & Engineering Company]], [[Greenock]]
| 24 January 1940
| 30 December 1941
| 6 August 1942
| Transferred to Turkey, 1959, as ''Alp Arslan''
|-
! scope="row"|{{HMS|Mahratta|G23|2}} (ex-''Marksman'')
| 7 July 1939
| 28 July 1942
| 8 April 1943
| Sunk by the {{GS|U-990||6}}, 25 February 1944
|-
! scope="row"|{{HMS|Musketeer|G86|2}}
| rowspan=2|[[Fairfield Shipbuilding & Engineering Company]], [[Govan]]
| 7 December 1939
| 2 December 1941
| 5 December 1942
| Broken up, 6 December 1955
|-
! scope="row"|{{HMS|Myrmidon|G90|2}}
| 7 December 1939
| 2 March 1942
| 5 December 1942
| Loaned to the Polish Navy and renamed [[ORP Orkan (G90)|ORP ''Orkan'']]. Sunk by submarine, 8 October 1943
|-
! scope="row"|{{HMS|Matchless|G52|2}}
| rowspan=2|[[Alexander Stephen & Sons]], [[Linthouse]]
| 14 September 1940
| 4 September 1941
| 26 February 1942
| Transferred to Turkey, 1959, as ''Kilicali Pasha''
|-
! scope="row"|{{HMS|Meteor|G74|2}}
| 14 September 1940
| 3 November 1941
| 12 August 1942
| Transferred to Turkey, 1959, as ''Piyale Pasha''
|-
! scope="row"|{{HMS|Marne|G35|2}}
| rowspan=2|[[Vickers-Armstrongs]], [[Walker, Newcastle upon Tyne|Walker]]
| 23 October 1939
| 30 October 1940
| 2 December 1941
| Transferred to Turkey, 1959, as ''Maresal Fevzi Cakmak''
|-
! scope="row"|{{HMS|Martin|G44|2}}
| 23 October 1939
| 12 December 1940
| 4 August 1942
| Sunk by submarine, 10 November 1942
|}

==References==
===Citations===
{{Reflist|2}}

===Bibliography===
* {{cite book|last=English|first=John|title=Afridi to Nizam: British Fleet Destroyers 1937–43|year=2001|publisher=World Ship Society|location=Gravesend, UK|oclc=248419884}} <!-- (Note: The book was printed with invalid {{Listed Invalid ISBN|0-905617-95-0}}) -->
* {{cite book|last=Friedman|first=Norman|title=British Destroyers & Frigates: The Second World War and After |publisher=Naval Institute Press|location=Annapolis, Maryland|year=2006|isbn=1-86176-137-6|author-link=Norman Friedman}}
* {{cite book|last=Lenton|first=H. T.|title=British & Empire Warships of the Second World War|publisher=Naval Institute Press|location=Annapolis, Maryland|year=1998|isbn=1-55750-048-7|author-link=Henry Trevor Lenton}}
* {{cite book|editor1-last=Chumbley|editor1-first=Stephen|title=Conway's All the World's Fighting Ships 1947–1995 |year=1995 |publisher=Naval Institute Press|location=Annapolis, Maryland|isbn=1-55750-132-7|author1-last=Lyon|author1-first=Hugh|author2-first=Stephen|author2-last=Chumbley|chapter=Turkey|name-list-style=amp}}
* {{cite book|last=March|first=Edgar J.|title=British Destroyers: A History of Development, 1892–1953; Drawn by Admiralty Permission From Official Records & Returns, Ships' Covers & Building Plans|year=1966|publisher=Seeley Service |location=London |oclc=164893555}}
* {{cite book|last=Rohwer|first=Jürgen|title=Chronology of the War at Sea 1939–1945: The Naval History of World War Two|publisher=Naval Institute Press|location=Annapolis, Maryland|year=2005|edition=Third Revised|isbn=1-59114-119-2 |author-link=Jürgen Rohwer}}
* {{cite book|last=Whitley|first=M. J.|title=Destroyers of World War 2: An International Encyclopedia|publisher=Cassell & Co|year=2000 |isbn=1-85409-521-8 |location=London|author-link=Michael J. Whitley}}

==External links==
{{Commons category-inline|L and M class destroyer}}

{{L and M class destroyers}}
{{WWII British ships}}
{{Authority control}}

{{DEFAULTSORT:L And M Class Destroyer}}
[[Category:L and M-class destroyers| ]]
[[Category:Destroyer classes]]