H Class

Coastal Defence Submarine

  • H Class Submarine
  • H5 through H10 with HMS Carnarvon
  • H5 view from bridge
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The first batch of ten of these Submarines were built by Vickers of Montreal, Canada. The parts being supplied by the Bethlehem Steel Company of the U.S.A. A second batch that had been ordered were impounded by the Americans until the end of the war. They were eventually released on the U.S. entry into the war in 1917.

These boats were single-hulled and suffered from a low reserve of buoyancy. H1 of this class crossed the Atlantic in 1915, this was a record length for any submarine of the time.

H11 and H12 were the only two boats of the second group to reach Britain and served with the 14th Flotilla stationed at Blyth. The remainder of Group2 were either ceded to Chile in exchange for ships which were being built in Britain at the outbreak of war or presented to the Royal Canadian Navy.

20 Built

H1 - H10
Vickers, Montreal, Canada.
1915 - 1915

H11 - H20
Fore River, Quincy, U.S.A.
1915 - 1915

Technical Information

364 sf
434 sm

Length (ft):

Breadth (ft):

Draught/Height (ft):

Nelseco diesel engines 480hp
2 Electric Motors 620hp

Speed (kts):
13 knots sf
11 knots sm

Oil Supply (tons):

4 x 18 inch tubes (bow).

1,600 nm at 10 kts sf
130 nm at 2 kts sm.

22 Officers and Ratings.