C’s 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38.
This class of submarines is composed of vessels of the improved “B” type. They have a submerged displacement of 320 tons and are 135 feet long and 13 ½ feet broad. The petrol motors develop 600 H.-P. and give to these vessels a speed of 14 knots an hour on the surface. The power of the electric engines was increased to 300 H.-P., giving a submerged speed of just over 9 knots an hour. The surface cruising range is 2,000 knots at the most economical speed, and the submerged endurance 100 knots at 5 knots an hour. Their armament consists of two bow tubes with six 18-inch Whitehead torpedoes; and their complement sixteen officers and men.
In the later vessels of the “C” class heavy oil is used instead of petrol, giving a great increase in power without the comparative additional weight; enabling a wider radius of action. The vessels of both the “B” and “C” classes are fitted with air-traps and safety-helmets, giving the crew a possible means of escape in the event of disaster while submerged.
The distinguishing feature of the “C” class is the sloping bow. The C.11 collided with the steamer Eddystone in the North Sea in 1909 and was irretrievably lost.
“D” Class.
(Completed 1908–11.)
D’s 1, 2, 3, 4, 5, 6, 7, 8.
These are all modern vessels of the sea-going type, and are of considerable fighting value. They, however, differ slightly from each other: D.1 has a submerged displacement of 595 tons; D.2 of 600 tons; and the remaining vessels of this class of 620 tons. They have an approximate length of 150 feet and a beam of 15 feet. Heavy-oil engines of 1,200 H.-P. drive them at a maximum speed of 16 knots an hour on the surface, and electric motors of 550 H.-P. give them a submerged speed of just over 10 knots an hour. All these vessels have twin-screws situated below the centre line. Their cruising range on the surface is 4,000 miles, and when submerged 120 knots at 7 knots an hour. These vessels were the first to be fitted with a special and more efficient pattern of electric storage battery and a safer type of electric motor. The armament of the “D’s” consists of two bow and one stern tube with six 18-inch Whitehead torpedoes. D’s 4, 5, 6, 7, and 8 are also fitted with a small quick-firing, high-angle gun for defence against air-craft. This gun is fixed on a disappearing mounting, enabling it to be quickly and almost automatically lowered into a watertight cavity in the superstructure before the submarine dives below the surface. The complement of these vessels is twenty-one officers and men.
Photo, Cribb, Southsea.]