5. In Northern Waters Germany's merchant shipping has been so reduced by sinkings and oil shortage that, despite increased assistance from Sweden, her imports of essential Swedish iron ore have fallen by more than one million tons a year. Allied attacks render shipping movements so dangerous that, for example, shipping is not used between Christiansand and Trondheim, cargoes being sent over land. The increasing scale of Allied attack has forced Germany to divert labour and material to the building of extra escort vessels.