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D-class (series) Ocean-Going Diesel-Electric Attack Submarine


 Updated: 9/28/2016; Authored By Staff Writer; Content ¬©www.MilitaryFactory.com

The British D-class attack submarines marked the first Royal Navy boats developed for ocean patrolling - they saw service in World War 1.


The D-class diesel-electric submarines were the first British deep water patrol boats taken into the Royal Navy inventory. This addition now provided warplanners with considerable tactical flexibility as the underwater force was no longer confined to coastal areas and could venture much further out in meeting the enemy. Compared to previous Royal Navy boats, the D-class offered up much more in the way of displacement, more powerful diesel engines and were outfitted with wireless sets for sending / receiving communications in-the-field. Eight such boats were laid down from the period of 1907 and 1910 (two more were planned but launched as E-class boats) and named rather appropriately as HMS D1 through HMS D8. Vickers Limited was involved in their construction.

The group superseded the earlier C-class and was itself succeeded by the E-class.

As built, the submarines were given a displacement of 483 tons when surfaced and 600 tons when submerged. Overall length was 163 feet with a beam of 13.6 feet and draught of 10.4 feet. Installed power (diesel engines for surface travel and electric motors for submerged work) drove 1,750 horsepower to 2 x screws at the stern to speeds of 10 knots and ranges out to 1,100 nautical miles. The crew numbered 25 men and armament centered on 3 x 18" (450mm) torpedo tubes with six reloads. Two of the tubes faced forward with the remaining one tube facing aft. 1 x 12-pounder (76mm) deck gun was carried for shorter-ranged surface work.

The boats were in active service when World War 1 (1914-1918) broke out in August of 1914. The force was assigned to convoy protection duty in Channel Waters as British ground forces made their way to France by ship for the fighting that lay ahead. There were also general patrols involving these boats in North Sea waters and around the Heligoland Bight (the bay located between Norway and Britain) in an effort to keep German forces contained. Before the cessation of hostilities, the boats were arranged as training platforms at Portsmouth for future submariners.

HMS D1 managed to survive the war but was sunk as a floating target in 1918. HMS D2, D3, D5 and D6 were all casualties of the war while HMS D4, D7 and D8 soldiered on for a time after the war.




D-class (series) Technical Specifications



Service Year: 1907
Type: Ocean-Going Diesel-Electric Attack Submarine
National Origin: United Kingdom
Ship Class: D-class




Structural (Crew Space, Dimensions and Weights)



Complement (Crew): 25
Length: 163 feet (49.68 meters)
Beam (Width): 13.6 feet (4.15 meters)
Draught (Height): 10.4 feet (3.17 meters)

Surface Displacement: 483 tons
Submerged Displacement: 600 tons

Installed Power and Base Performance



Engine(s): 2 x Diesel engines with Electric motors driving 1,750 horsepower to 2 x shafts.

Surface Speed: 14 knots (16 mph)
Submerged Speed: 9 knots (10 mph)
Operational Range: 2,520 nautical miles (2,900 miles, 4,667 km)

Armament / Air Wing



3 x 18" (450mm) torpedo tubes (two facing forward and one facing aft, six torpedo reloads).
1 x 12-pounder (76mm) deck gun

Aircraft: None.

Global Operators



United Kingdom

Ships-in-Class / Group (8)



HMS D1; HMS D2; HMS D3; HMS D4; HMS D5; HMS D6; HMS D7; HMS D8; HMS D9 (planned, finished as E-class boat); HMS D10 (planned, finished as E-class boat)