British D-class submarine

	HMS D1
Class overview
Name	D-class
Builders	Vickers, Barrow; HM Dockyard, Chatham;
Operators	Royal Navy
Preceded by	C class
Succeeded by	E class
Completed	8
Lost	4
General characteristics
Type	Submarine
Displacement	483 tons surfaced / 595 tons submerged
Length	163.0 ft (49.7 m) (oa)
Beam	13.6 ft (4.1 m) (oa)
Propulsion	550 hp (410 kW) electric 1750 hp diesel twin screws
Speed	14.0 kn surfaced / 10.0 (design) 9.0 (service) submerged
Range	2500 nmi at 10 kn, surface / 45 nmi at 5 kn, submerged
Complement	25
Armament	3 × 18-inch (45-cm) torpedo tubes (2 forward, one aft, 6 torpedoes); 1 × 12-pounder (76 mm) QF gun;

The D-class submarine was the Royal Navy's first class of submarines 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.

^ Fitzsimons, Bernard. Illustrated Encyclopedia of 20th Century Weapons and Warfare (London: Phoebus, 1978), Volume 7, p.674, "D.1".
^ Fitzsimons, p.674.

[1] Fitzsimons, Bernard. Illustrated Encyclopedia of 20th Century Weapons and Warfare (London: Phoebus, 1978), Volume 7, p.674, "D.1".

[2] Fitzsimons, p.674.

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