"Halcyon"s were pressed into service as anti-submarine escorts; this task slowly decreasing as the ships specifically designed for this task, such as s, came off the slips. "Halcyon"s accompanied most of the Arctic convoys, serving both as minesweepers and anti-submarine escorts. Several spent extended periods working out of Soviet naval bases in Northern Russia, such as Murmansk. Four "Halcyon"s were lost during this period.