The war industries in Britain depended upon resources shipped from North America. The main assembly areas for merchant shipping were the Nova Scotia ports of Halifax and Sydney. On 16 September 1939, the first transatlantic convoy, HX 1, sailed from Halifax for Britain. Two Royal Canadian Navy (RCN) destroyers, HMCS Saguenay and HMCS St. Laurent , escorted the convoy. In the mid- Atlantic, two Royal Navy cruisers, HMS Berwick and HMS York , assumed escort duties for the remainder of the voyage. After fulfilling their duties, the RCN destroyers returned to Halifax.