'BM' (i) was the designation of Allied convoys (together with a numerical suffix) plying the route from Bombay, India, or in one instance Colombo, Ceylon, to Ceylon and Singapore (September 1940/February 1942).
The first of these 16 convoys was BM.1 of 21/24 September 1940 with the 14,287-ton Polish Batory, 23,456-ton British Orcades and 23,722-ton British Stratheden escorted by the 8,108-ton Australian armed merchant cruiser Westralia. The convoy reached Colombo safely, and after a quick turnaround reached Colombo to become part of BM.1S. This departed Colombo on 28 September and reached Singapore on 1 October together with the 5,196-ton British Ellenga and additionally escorted by British light cruiser Capetown and 14,462-ton British armed merchant cruiser Arawa.
The last of these convoys was BM.12 of 23 January/4 February 1942 with the 11,2750-ton British Devonshire, carrying 1,673 troops, 16,909-ton Empress of Asia carrying 2,235 troops, 17,083-ton French Felix Roussel carrying 157 troops and 5,955-ton Dutch Plancius carrying 987 troops, escorted by the British heavy cruiser Exeter, British light cruisers Danae and Emerald, Dutch light cruiser Java, British destroyer Encounter, British sloop Falmouth, Indian sloop Sutlej and Australian sloop Yarra.