HMS K1 was a First World War steam turbine-propelled K-class submarine of the Royal Navy. K1 was sunk to prevent it being captured after colliding with HMS K4 off the Danish coast. She had been patrolling on the surface as part of a flotilla of submarines operating in line ahead. The flotilla was led by the light cruiser HMS Blonde (1910), followed by K1, HMS K3, K4, and HMS K7. The crew survived and taken off by two cutters sent from HMS Blonde. The collision occurred at approx 17:35 and after consultation with the rescued submariner officers and concluding that the K1 could not be saved, Blonde opened fire with one of her 4 inch guns and sank the submarine with a few shells at 19:10 hours.

Design

K1 displaced 1800 LT when at the surface and 2600 LT while submerged. It had a total length of 338 ft, a beam of 26 ft, and a draught of 20 ft. The submarine was powered by two oil-fired Yarrow Shipbuilders boilers each supplying one geared Brown-Curtis or Parsons steam turbine; this developed 10,500 ship horsepower (7,800 kW) to drive two 7 ft screws. Submerged power came from four electric motors each producing 350 to 360 hp. It was also had an 800 hp diesel engine to be used when steam was being raised, or instead of raising steam. The submarine had a maximum surface speed of 24 kn and a submerged speed of 9 to 9.5 kn. It could operate at depths of 150 ft at 2 kn for 80 nmi. K1 was armed with ten 18 in torpedo tubes, two 4 in deck guns, and a 3 in anti-aircraft gun. Its torpedo tubes were four in the bows, four in the midship section firing to the sides, and two were mounted on the deck in rotating mountings. Its complement was fifty-nine crew members.