L55 1918
| Name | No | Builder | Laid down | Launched | Comp | Fate |
| L50 | Cammell Laird, Birkenhead | 1917 | --- | --- | cancelled 1919 | |
| L51 | Cammell Laird, Birkenhead | 1917 | --- | --- | cancelled 1919 | |
| L52 | Armstrong, Elswick | 5/1917 | 18/12/1918 | 1/1921 | BU 9/1935 | |
| L53 | Armstrong, Elswick / Chatham DYd | 6/1917 | 12/8/1919 | 1/1925 | BU 1/1939 | |
| L54 | Denny, Dumbarton / Devonport DYd | 5/1917 | 20/8/1919 | 8/1924 | BU 2/1939 | |
| L55 | Fairfield, Govan | 5/1917 | 21/9/1918 | 12/1918 | sunk 9/6/1919, commissioned again by Soviet Union as Ë-55 (L-55) in 1931 | |
| L56 | Fairfield, Govan | 10/1917 | 29/5/1919 | 9/1919 | BU 3/1938 | |
| L57 | Fairfield, Govan | 1917 | --- | --- | cancelled 1919 | |
| L58 | Fairfield, Govan | 1917 | --- | --- | cancelled 1918 | |
| L59 | Beardmore, Dalmuir | 1918 | --- | --- | cancelled 1918 | |
| L60 | Cammell Laird, Birkenhead | 1918 | --- | --- | cancelled 1918 | |
| L61 | Cammell Laird, Birkenhead | 1918 | --- | --- | cancelled 1918 | |
| L62 | Fairfield, Govan | 1918 | --- | --- | cancelled 1918 | |
| L63 | Scotts, Greenock | 1918 | --- | --- | cancelled 1918 | |
| L64 | Scotts, Greenock | 1918 | --- | --- | cancelled 1918 | |
| L65 | Swan Hunter, Wallsend | 1918 | --- | --- | cancelled 1918 | |
| L66 | Swan Hunter, Wallsend | 1918 | --- | --- | cancelled 1918 | |
| L67 | Armstrong, Elswick | 1917 | --- | --- | cancelled 1919 | |
| L68 | Armstrong, Elswick | 1917 | --- | --- | cancelled 1919 | |
| L69 | Beardmore, Dalmuir / Devonport DYd | 7/1917 | 6/12/1918 | 4/1923 | BU 2/1939 | |
| L70 | Beardmore, Dalmuir | 1917 | --- | --- | cancelled 1919 | |
| L71 | Scotts, Greenock | 9/1917 | 17/5/1919 | 1/1920 | BU 3/1938 | |
| L72 | Scotts, Greenock | 1917 | --- | --- | cancelled 1919 | |
| L73 | Denny, Dumbarton | 1917 | --- | --- | cancelled 1919 | |
| L74 | Denny, Dumbarton | 1918 | --- | --- | cancelled 1918 |
|
Displacement standard, t |
|
|
Displacement normal, t |
960 / 1150 |
|
Length, m |
71.6 |
|
Breadth, m |
7.20 |
|
Draught, m |
4.00 |
|
No of shafts |
2 |
|
Machinery |
Vickers diesels / electric motors |
|
Power, h. p. |
2400 / 1600 |
|
Max speed, kn |
17 / 10.5 |
|
Fuel, t |
diesel oil 78 |
|
Endurance, nm(kts) |
4500(8) / 75(4) |
|
Armament |
6 - 533 TT (bow, 12), 2 x 1 - 102/40 QF Mk IV |
|
Complement |
44 |
| Diving depth operational, m | 50 |
Ship project history: Majority of these submarines become operational after the armistice. The design is developed on the basis of "E" class, which in 1916 were old and hard to "stretch" to accommodate further improvements. Admiralty experimented with double-hulled and partially double-hulled designs but eventually reverted to saddle-tank design with higher than "E" speeds. The first two submarines were intended as lengthened "E" and named originally E57 and E58 but showed very many improvements and later were chosen as new class prototypes L1 and L2. That pair was ordered in February 1916, later submarines in May 1916.
2nd series of "L" class was an attempt to increase bow torpedo salvo. These subs had 4 21`` bow TT instead of 4 18`` on predecessors but beam TTs calibre was retained to avoid to enlarge hull breadth. L12 and later ships had 102mm gun raised on bridge deck level. It was intended to permit the submarine to engage German submarine out of torpedo launch range with sub trimmed down. Bow tube compartment was separated from bow TT compartment by additional bulkhead. L18 onwards carried 78t of fuel, later all earlier "L" class submarines were so retro-fitted.
All 6 TT of 3rd series subs were placed in a bow and had heavier than predecessors gunnery armament. L50-55 were ordered in January-February 1917, L56-58 in April, L59-66 and L74 in April 1918.
Modernizations: 1925 - 1926, L54, 56, 69, 71; 1935, L53: - 1 x 1 - 102/40
Naval service: L55 was lost 4/6/1919 on a mine, she was salvaged in 1928 and since 1931 served in Soviet Navy under original name L-55.
L53 1930
© Ivan Gogin, 2008-10