The D-class submarine was the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were foug ...

's first class of

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s capable of operating significantly beyond coastal waters. They were also the first boats to be fitted with wireless transmitters. Ten were laid down between 1907 and 1910, though only 8 were completed as D-class boats. The final two hulls were completed as British E-class submarine.

Design and description

The patrol submarines evolved from the C-class boats. They were designed to be propelled by diesel motors on the surface to avoid the problems with petrol engines experienced with the A class. These boats were designed for foreign service with an endurance of at on the surface and much improved living conditions for a larger crew. D-class boats were fitted with twin screws for greater manoeuvrability and were fitted with saddle tanks. The D class were the first submarines to be equipped with deck guns forward of the conning tower beginning with ''D6''. Also, reserve buoyancy was increased to 20.6%. Armament also included three

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed abo ...

s (2 vertically in the bow and 1 in the stern). The D class was also the first class of British submarines to have standard radio fitted. The aerial was attached to the mast of the conning tower that was lowered before diving. With their enlarged bridge structure the boat profile was recognisably that of the modern submarine. The D-class submarines were considered to be so innovative that the prototype, ''D1'', was built in utmost secrecy in a securely guarded building shed. She was launched at Barrow with equal secrecy, with only departmental heads and a few officers from the cruiser , that was currently in dock being present. Once moved to the fitting out berth, she was once again screened from view. The boats cost between £79,910 and £89,410 each excluding the deck gun.

Operations

The D class were based at

Harwich Harwich is a town in Essex, England, and one of the Haven ports on the North Sea coast. It is in the Tendring district. Nearby places include Felixstowe to the north-east, Ipswich to the north-west, Colchester to the south-west and Clacton- ...

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and

Dover Dover () is a town and major ferry port in Kent, South East England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies south-east of Canterbury and east of Maidstone ...

. Their wartime role was to sink German warships. In the latter stages of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

the D class were used for training crews based at

Portsmouth Portsmouth ( ) is a port and city status in the United Kingdom, city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a Unitary authorities of England, unitary authority since 1 April 1997 and is admi ...

. During World War I the boats patrolled the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

and the

Heligoland Bight The Heligoland Bight, also known as Helgoland Bight, (german: Helgoländer Bucht) is a bay which forms the southern part of the German Bight, itself a bay of the North Sea, located at the mouth of the Elbe river. The Heligoland Bight extends ...

, and protected cross channel troopships. During the war, four boats (''D2'', ''D3'', ''D5'', and ''D6'') were lost, and the remainder (''D4'', ''D7'', and ''D8'') were paid off in July 1919.

Boats

Eight D-class boats were built: * * * * * * * * There were plans for a further two, ''D9'' and ''D10'', but these were launched at Chatham Dockyard as and .

References

Works cited

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External links