Convoy RA 55B was however supported by a U-boat force of some thirteen boats in a patrol line, code-named Eisenbart, in the Norwegian Sea, which had  operated against all the December convoys, RA 55A sailed from Kola with its escort on 31 December 1943, accompanied by an eastern local escort of three minesweepers.
RA 55A was however threatened by a U-boat force of some thirteen boats in a patrol line, code-named Eisenbart, in the Norwegian Sea, which had operated against all the December convoys. RA 55A sailed from Kola with its escort on 31 December 1943, accompanied by an eastern local escort of three minesweepers. 
