Class of destroyers for Britain
|
Class overview
|
Operators
| |
Preceded by
| J, K and N class
|
Succeeded by
| O and P class
|
Subclasses
| L, M
|
Built
| 1938?42
|
Completed
| 16
|
Lost
| 9
|
Scrapped
| 7
|
General characteristics as completed
|
Type
| Destroyer
|
Displacement
|
- 1,920 long tons (1,951 t) (standard)
- 2,660 long tons (2,703 t) (deep)
|
Length
| 362 ft 3 in (110.4 m)
o/a
|
Beam
| 37 ft (11.3 m)
|
Draught
| 10 ft (3.0 m)
|
Installed power
| 48,000
shp
(36,000 kW)
|
Propulsion
| |
Speed
| 36
knots
(67 km/h; 41 mph)
|
Range
| 5,500
nmi
(10,200 km; 6,300 mi) at 15 knots (28 km/h; 17 mph)
|
Complement
| 190
|
Sensors and
processing systems
| |
Armament
| |
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.
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 4-inch (100 mm) 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
[
edit
]
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
[
citation needed
]
?
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 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 a bulletproof
[1]
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 Ls and Ms.
As ordered, the class comprised a leader and 7 destroyers. Each ship was to mount six 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
radio
(W/T ? "wireless telegraph") equipment
Main armament
[
edit
]
As ordered, the ships were to have six QF Mark XI 4.7-inch (120 mm) 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 itself was a major improvement on the previous version in that it threw a 62 lb (28 kg) shell (compared to the 50 lb (23 kg) 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" guns
.
[2]
As a result, 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). However, this still limited the engagement time against enemy aircraft,
[3]
although medium calibre guns posed little threat to
dive bombers
prior to the use of radar proximity fuzed ammunition.
[4]
The
Imperial Japanese Navy
had already introduced a 5-inch (127 mm) gun with 70-degree elevation into service which had very poor performance
[5]
as an anti-aircraft weapon, while the
United States Navy
's 5"/38 cal Mark 32 mount could elevate to 85 degrees. The 4.5-inch (114 mm) guns fitted to
Ark Royal
were already in service and capable of elevations of 80 degrees, although the mountings were not suitable for a destroyer-size 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 any similar weapon in the Axis inventory.
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.
[6]
It was later reworked, somewhat unsuccessfully again, as the Mk.I "K tower" of the
Z class
. These ships used the
Fuze Keeping Clock
HA Fire Control Computer.
[2]
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 dedicated AA fire control radar.
[7]
As originally ordered, the class had no close-range armament at all, as the various departments could not agree on what to fit. Arguments raged as to the effectiveness of mounting one or two four-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) Vickers machine gun. The argument was 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 a number of younger officers (led by
Lord Louis Mountbatten
) dissatisfied with available anti-aircraft weaponry. 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 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 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 provision of two quadruple 0.5-inch (12.7 mm) machine guns. All ships of this class except
Lightning
and
Laforey
carried a four-barrel 2 pdr pom-pom.
[8]
The lessons of the
Norwegian campaign
and
at 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 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, 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 single 4-inch (102 mm) HA gun instead and that is how the 4.7-inch (120 mm) gunned ships eventually went to sea, although some surviving ships, including
Matchless
and
Marne
, had the after tubes replaced later in the war.
[9]
Proposed conversion
[
edit
]
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
40 mm Bofors gun
and a
Squid
anti-submarine mortar. Type 982 and 983 air direction radars would be fitted, as would Type 162 and 166
sonars
. 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.
[10]
[11]
Ships
[
edit
]
L class
[
edit
]
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 4-inch (102 mm) armament. Six of the eight were war losses, with the surviving pair being broken up in 1948.
M class
[
edit
]
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.
References
[
edit
]
Citations
[
edit
]
- ^
March, British Destroyers. March fails to note armour plating on any RN destroyer.
- ^
a
b
Destroyer Weapons of WW2, Hodges/Friedman,
ISBN
0-85177-137-8
- ^
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.
- ^
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."
- ^
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
"
- ^
Whitley 2000, p. 121.
- ^
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.
- ^
March, British Destroyers, p358.
- ^
March, British Destroyers, p371
- ^
English 2001, p. 115
- ^
Lyon & Chumbley 1995, p. 516
Bibliography
[
edit
]
- English, John (2001).
Afridi to Nizam: British Fleet Destroyers 1937?43
. Gravesend, UK: World Ship Society.
OCLC
248419884
.
- Friedman, Norman
(2006).
British Destroyers & Frigates: The Second World War and After
. Annapolis, Maryland: Naval Institute Press.
ISBN
1-86176-137-6
.
- Lenton, H. T.
(1998).
British & Empire Warships of the Second World War
. Annapolis, Maryland: Naval Institute Press.
ISBN
1-55750-048-7
.
- Lyon, Hugh & Chumbley, Stephen (1995). "Turkey". In Chumbley, Stephen (ed.).
Conway's All the World's Fighting Ships 1947?1995
. Annapolis, Maryland: Naval Institute Press.
ISBN
1-55750-132-7
.
- March, Edgar J. (1966).
British Destroyers: A History of Development, 1892?1953; Drawn by Admiralty Permission From Official Records & Returns, Ships' Covers & Building Plans
. London: Seeley Service.
OCLC
164893555
.
- Rohwer, Jurgen
(2005).
Chronology of the War at Sea 1939?1945: The Naval History of World War Two
(Third Revised ed.). Annapolis, Maryland: Naval Institute Press.
ISBN
1-59114-119-2
.
- Whitley, M. J.
(2000).
Destroyers of World War 2: An International Encyclopedia
. London: Cassell & Co.
ISBN
1-85409-521-8
.
External links
[
edit
]
Media related to
L and M class destroyer
at Wikimedia Commons