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Davis, Sir Robert Henryfree

  • Richard Compton-Hall

Davis, Sir Robert Henry (1870–1965), inventor of diving and breathing apparatus, was born in London on 6 June 1870, the eldest son of Robert Davis, a detective in the City of London police force. In 1882, aged eleven, Davis entered the firm of Siebe, Gorman & Co. Ltd at Lambeth, manufacturers of diving equipment. His neat handwriting was noticed by Gorman, who placed him in the main office. He studied hard to complete his education out of office hours, and, still in his twenties, was promoted assistant manager. In 1900, when Davis married Margaret (d. 1952), daughter of William Tyrrell of Kildare, Gorman gave his gifted assistant a house and a gold watch as wedding presents. There were four sons and two daughters of this marriage. Davis rose successively to become general manager, managing director, governing director, and, in 1959, life president.

Siebe Gorman had long specialized in various types of diving and safety apparatus, but Davis vigorously developed and expanded the company's activities. In 1906 he perfected an oxygen breathing apparatus for mining rescue, and when, in April 1915, the German army launched its first gas attack on allied troops he immediately devised an emergency respirator, persuading friends, relations, and local families to manufacture it in great quantities, which were dispatched to France within 48 hours. Later Davis worked largely with the Royal Navy. He was a member, with Professor J. B. S. Haldane, Sir Leonard Hill, and Captain G. C. Damant, of the Admiralty deep sea diving committee which, in 1933, published decompression tables allowing safe ascents from depths down to 300 feet. Davis again co-operated with the Royal Navy on experiments which culminated in a record ‘hard hat’ dive to 540 feet in 1948. The submariners' escape method after 1929 was based on the Davis submerged escape apparatus, which incorporated a breathing bag with an oxygen supply from a small bottle and a chemical agent for absorbing carbon dioxide before exhaled breath was returned to the bag. The apparatus incorporated the hazard of breathing more or less pure oxygen under pressure. Siebe Gorman next proposed built-in breathing equipment for supplying a safe mixture of air to escapers—until the moment of exit—from large bottles attached to the submarine. In 1951 this equipment, used with immersion suits, started to replace the earlier apparatus for free ascent from submarines.

During the Second World War, Siebe Gorman, relocated at Chessington, Surrey, assisted in the development of ‘chariots’—the so-called human torpedoes, also X-craft, and other midget submarines, human mine clearance units, and anti-blast clothing. In 1951 the firm helped to pioneer the use of underwater television to investigate the sinking of the submarine Affray and the Comet aircraft disasters, and in 1953 it provided oxygen sets for the successful British climbing expedition to Mount Everest.

Davis devoted his life to the study of problems confronting those called on to work in unbreathable atmospheres. Among several publications his most important and comprehensive was Deep Diving and Submarine Operations (1920), which had run to six editions by 1955. His total absorption for sixty-two years with Siebe Gorman, in a field where his expertise was unrivalled, virtually precluded other interests. Knighted in 1932, and awarded an honorary DSc by Birmingham University, he attended the office regularly until 1964, although he had formally retired in 1960. He died at his home, San Toi, Jackson Close, Epsom, on 29 March 1965.


  • The Times (3 April 1965), 10g
  • personal knowledge (2004)
  • D. Young, The man in the helmet (1963)
  • d. cert.

Wealth at Death

£112,930: probate, 15 June 1965, CGPLA Eng. & Wales

Calendars of the grants of probate … made in … HM court of probate [England and Wales]