History 5: The Other A Class Submarines
The loss of A7 was one of a series of submarine accidents, often including fatalities. Between the launch of Holland 1 in 1901 and August 1914 there were 68 serious accidents in submarines in various navies, including 23 collisions, 7 battery (hydrogen gas) explosions, 12 gasoline explosions and 13 sinkings due to improperly shut hull openings. Technical developments and improved training reduced the risks considerably but submarines at this time were anything but safe (Compton Hall, 1983). Although the Hall-Rees submarine escape apparatus had been developed at the time of her loss the A7 was too small to carry this equipment.
Her sister ships also suffered their own catastrophes. The A1 was the first Royal Navy submarine to be lost in peace or war having been rammed and sunk by the SS Berwick Castle on 18 March 1904. She was salvaged and re-commissioned but sank again on trials in August 1911. Submarine A2 foundered in 1920 after grounding in Portsmouth Harbour, A3 sank off the Isle of Wight after colliding with HMS Hazard in 1912 and A4 sank after an explosion on board whilst under tow. A petrol explosion on board A6 in 1905 killed six of her crew and A8 sank in Plymouth Sound after water entered the main hatch whilst she was underway at speed. A10 sank in 1917 alongside in Ardrossan in Scotland but sustained no casualties.