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D 1 (I 71)

Built By: Vickers (Barrow)
Build Group: D
Fate: Used as a target and sunk on 23rd October 1918.

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Commanders
1909: Lieutenant Commander   C Little
1910: Lieutenant   Noel F Lawrence
1914: Lieutenant Commander   K Cochrane
1917: Lieutenant   William McKinstry Maitland-Dougall (RCN)

1914: 8th Flotilla Portsmouth, HMS Maidstone and Adamant

D1 was the first British submarine to be fitted with diesel instead of petrol engines.

The wreck of D1 has been given protected status. It was the forerunner to the Royal Navy's patrol submarines and was the secret prototype for the D class, the Royal Navy's first diesel-powered submarines.

D1 was assigned to protecting the coast of Dover from enemy invasion. In September 1917, joined the Portsmouth local defence flotilla and a year later it was relegated to training duties.

Weeks before the end of the war, it was decommissioned and scuttled off the Dartmouth coast. The submarine was later used as a target for Royal Navy training exercises involving the detection of enemy submarines.

The wreck, which sits upright and largely intact on the seabed, was identified by U-boat historian Michael Lowrey who was writing a book about First World War U-boat losses.

The submarine has now been granted protection by the Department for Digital, Culture, Media and Sport on the advice of Historic England. Lead diver, Steve Mortimer, said:

This is a fascinating survival which deserves protection as an important part of our seafaring history. Every diver dreams of identifying a historically important wreck.

Expecting to find the remains of a German U-boat, we were thrilled to discover a ground-breaking British submarine instead. It's tremendous that D1 is now protected but divers can still visit.

Events

 14-05-1907   Laid Down
 16-05-1908   Launched
 01-09-1909   Completed
 23-10-1918   Used as a target and sunk
D Specification
Length overall  164 ft
Beam  13 ft 10 7/8 inch
Depth  13 ft 11 1/8 inch
Displacement   Surface 495 tons
  Submerged 620 tons
Diving Depth  100 ft
Speed  Surface 14.5 knots (design)
  Surface 14.5 knots (service)
  Submerged 9 knots (design)
  Submerged 9+ knots (service)
No. of shafts  2
Propeller  3 blades, 5 ft diameter
Armament  2 x 18 inch bow tubes
  1 x 18 inch stern tube
  (6 torpedoes carried)
Endurance  Surface: 2500 miles at 10 knots (design)
  Surface: 2500 miles at 11.5 knots (service)
  Submerged: 70 miles at 5 knots (design)
Complement  3 officers and 22 ratings
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