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fighting ships of the world

ROYAL NAVY - UNITED KINGDOM

SUBMARINES

'J' submarines (1916-1917)

J2 1916

Name No Builder Laid down Launched Comp Fate
J1 (3/1919- RAN)   Portsmouth DYd 4/1915 6/11/1915 4/1916 sold 2/1924
J2 (3/1919- RAN)   Portsmouth DYd 5/1915 6/11/1915 7/1916 sold 2/1924
J3   Portsmouth DYd 1915 --- --- cancelled 4/1915
J4   Portsmouth DYd 1915 --- --- cancelled 4/1915
J3 (ex-J7) (3/1919- RAN)   Pembroke DYd 3/1915 4/12/1915 6/1916 sold 1/1926
J4 (ex-J8) (3/1919- RAN)   Pembroke DYd 3/1915 2/2/1916 8/1916 sold 2/1924
J5 (3/1919- RAN)   Devonport DYd 4/1915 9/9/1915 5/1916 sold 2/1924
J6   Devonport DYd 4/1915 9/9/1915 7/1916 sunk 15/10/1918
J7 (3/1919- RAN)   Devonport DYd 8/1916 21/2/1917 11/1917 sold 11/1929

 

Displacement standard, t

 

Displacement normal, t

J1 - 6: 1204 / 1820

J7: 1212 / 1820

Length, m

J1 - 6: 84.0

J7: 83.7

Breadth, m

7.02

Draught, m

4.27

No of shafts

3

Machinery

12-cyl Vickers diesels / electric motors

Power, h. p.

3600 / 1350

Max speed, kts

19.5 / 9.5

Fuel, t

diesel oil 91

Endurance, nm(kts) 5000(12.5)

Armament

J1 - 5: 1 x 1 - 76/30 10cwt QF Mk II, 1 x 1 - 76/28 12pdr 8cwt QF Mk I, 6 - 450 TT (4 bow, 2 beam, 12)

J6: 1 x 1 - 76/30 10cwt QF Mk II, 1 x 1 - 40/37 2pdr QF Mk III, 6 - 450 TT (4 bow, 2 beam, 12)

J7: 1 x 1 - 76/45 20cwt QF Mk II, 1 x 1 - 40/37 2pdr QF Mk III, 6 - 450 TT (4 bow, 2 beam, 12)

Complement

44

Diving depth operational, m 50

Ship project history: The continuing incorrect intelligence reports of 22kt U-boats so worried the C-in-C of the Grand Fleet that he lobbied successfully for yet another attempt at a fleet submarine, capable of keeping station with the battle fleet. Vickers, already wrestling with the engines for the Nautilus, did not propose to use the 1850hp diesel, and suggested instead that the standard 8-cyl engine could be enlarged to 12-cyl, but it would still take three, and although 20kts was the speed asked for, the records suggest that 19.5kts was the accepted design-speed. Given the haste with which the design was to be prepared the Admiralty had no choice, and approved its one and only triple-shaft design in January 1915. The design was another partial double-hull type, with the double hull occupying 56% of the length. As built the large free-flooding casing brought the bows down in a seaway, slowing the boat down, so it was sealed off. After some months in service all had their bows raised, and thereafter could make 17kts in the heaviest seas.

    Originally eight boats were approved, all from the Royal Dockyards, but two from Portsmouth DYd, J3 and J4, were cancelled and J7 and J8 were renumbered to fill the gap. A further boat was ordered for the RAN but she differed in important respects. The control room was moved from just forward of the beam TT to the motor room aft. The conning tower was therefore moved aft as well, but in other respects J7 was identical to her sisters.

Modernizations: about 1917, J1: + DC racks

1917-1918, J1: - 1 x 1 - 76/30, 1 x 1 - 76/28; + 1 x 1 - 102/40 BL Mk XI, 1 x 1 - 40/37 2pdr QF Mk III

1917-1918, J2, 4: - 1 x 1 - 76/30, 1 x 1 - 76/28; + 1 x 1 - 102/40 QF Mk IV, 1 x 1 - 40/37 QF Mk III

1917-1918, J5: - 1 x 1 - 76/30, 1 x 1 - 76/28; + 1 x 1 - 102/41 QF Mk VII, 1 x 1 - 40/37 QF Mk III

1917-1918, J6: - 1 x 1 - 76/30; + 1 x 1 - 102/41 QF Mk VII

1917-1918, J7: - 1 x 1 - 76/45; + 1 x 1 - 102/41 QF Mk VII

Naval service: J6 was sunk in error by British decoy ship Cymric 15/10/1918 off Blyth.

J4 1919

Ivan Gogin, 2008-13