There was one such ship in the 1959 Eastern Arctic Patrol Convoy that I took part in, she was the icebreaker "N.B. Maclean" (Call sign CGSN) and her radio house was at the stern. I was the 3rd Radio Officer on the Arctic resupply and hospital ship "C.D. Howe" (Call Sign CGSS.) Our radio room was on the bridge deck.