'CH' was the designation of Allied convoys (together with a numerical suffix) plying the route from Chittagong to Calcutta, India, and as such reciprocals of the 'HC' series (February 1944/January 1945).

The first of the series was CH.1 of 14/16 February 1944 with Bandra, 7,575-ton British Empire Rani, 5,574-ton British Ethiopia, 5,879-ton British Islami, 4,981-ton British Jalaganga, 4,991-ton British Jalakrishna, and 4,471-ton Norwegian Utsire, and the last was CH.63 of 13/15 January 1945 with the 7,203-ton Norwegian Belpareil.