	The depth-charge throwers were removed in 1936 and more 200-kilogram depth charges were carried in their place. The Navy reconsidered its anti-submarine warfare tactics after the war began in September and intended to reinstate the depth-charge throwers, although these were an older model than the one previously installed; "Tartu" had not received her as of early 1942. As an interim measure, a pair of rails were installed on the stern for depth charges. Each rail could accommodate three depth charges and ten more were stored in the magazine. During the ship's mid-1941 anti-aircraft refit, the mainmast was replaced by a platform for a single 37-millimeter twin-gun mount and two of her single 37-millimeter mounts were transferred to the platform while the other two single mounts were removed. The Hotchkiss machineguns were on new platforms between the funnels and a pair of Browning 13.2-millimeter AA machineguns were installed in front of the bridge. "Tartu" received a British Alpha 128 ASDIC system in October 1941 that had been taken from another ship.