another minefield of 170 magnetic mines was laid by "eckoldt", "ihn" and "steinbrinck" on the night of 6/7 january 1940 off the thames estuary. the destroyer and six merchant ships totalling 21,617 grt were lost to this minefield as well and another ship was damaged as well. commodore friedrich bonte led a minelaying sortie to the newcastle area with "heidkamp", "eckoldt", "anton schmitt", "richard beitzen", "galster", and "ihn". the latter ship suffered tube failures in her boilers that reduced her maximum speed to and she had to be escorted back to germany by "beitzen". this minefield only claimed one fishing trawler of 251 tons. "eckoldt", "beitzen" and "max schultz" laid 110 magnetic mines in the shipwash area, off harwich, on 9/10 february that sank six ships of 28,496 grt and damaged another. "eckoldt" was the flagship during operation wikinger, an attempt to capture british fishing trawlers operating off the dogger bank on 22 february, when two destroyers sank with heavy loss of life – one hit newly-laid british mines in a supposedly mine-free channel and the other was bombed in error by the luftwaffe.