The B class was a short series of attack submarines launched between 1904 and 1906 for the Royal Navy. Equipped with a petrol engine, these
primitive submarines proved to be unreliable, and the lack of any internal bulkhead exposed the crew to the exhaust fumes of their petrol engines.
Ventilation was provided only for the electric batteries and not for the living area, which lacked the most minimal comfort. Due to
this, sea endurance was expected to be only four days during summer and three days during winter. With the exception of one unit sunk in 1912
because of a collision, the remaining vessels served during the First World War, albeit they were already becoming obsolescent.
The only successful war action was performed by the B11, which ventured into the Dardanelles in December 1914 after being upgraded with
new batteries and reinforced hydrofoils (to prevent submarine nets from damaging them). There the submarine sighted the old Turkish ironclad
Mesudiye (reconverted into a pre-dreadnought in 1903), which in that moment was idle. Lieutenant Holbrook approached the target and launched a
torpedo from a distance of 700 meters, which hit and quickly sank the ship. But despite this success, from that moment the bulk of operations in
the Sea of Marmara would be assigned to the more powerful submarines of the E class.
B class: 11 units (B1 to B11)
Type: Attack submarine
Length: 43.3 meters
Beam: 3.8 meters
Draught: 3.4 meters
Displacement (surfaced): 292 tonnes
Displacement (submerged): 321 tonnes
Propulsion: 1 x shaft, 1 x petrol engine 600 horsepower, 1 x electric motor 180 horsepower, 159 x battery cell
Speed (surfaced): 12 knots (22 kilometers/hour)
Speed (submerged): 6.5 knots (12 kilometers/hour)
Range (surfaced): 740 nautical miles (1370 kilometers) at 8.7 knots
Range (submerged): 25 nautical miles (46 kilometers) at 6.5 knots
Test depth: 30.5 meters
Armament: 2 x 457-millimeter torpedo tube (at prow), 4 x torpedo