The HX convoys were a series of North Atlantic convoys which ran during the Battle of the Atlantic in World War II. They were east-bound convoys and originated in Halifax, Nova Scotia from where they sailed to ports in the United Kingdom. They absorbed the BHX convoys from Bermuda en route. Later, after the United States had entered the war the HX convoys began at New York.
They were designated fast convoys, that is, made up of ships that could make 9-13 knots. A parallel series of slow convoys, the SC series, was run for ships making 8 knots or less, while ships making more than 13 knots sailed independently, until 14-knot CU convoys were organized in late 1943.
HX convoys were organized at the beginning of the Atlantic campaign and ran without major changes until the end, the longest continuous series of the war. HX-1 set sail on September 16. 1939 and contained 18 merchant ships, escorted by HMCS St Laurent and HMCS Saguenay to an Atlantic rendezvous with Royal Navy ships HMS Berwick and HMS York. The HX designation also perpetuated a similar series that ran in World War I, between 1917 and 1918.
A total of 377 convoys ran during the campaign, conveying a total of approximately 20,000 ships. 38 convoys were attacked (about 10%), resulting in losses of 110 ships in convoy; a further 60 lost straggling, and 36 while detached or after dispersal, with loses from marine accident and other causes, for a total loss of 206 ships, or about 1% of the total.
The largest convoy of World War II was HX 300 which sailed for the UK via New York on 17 July 1944, with 167 merchant ships. It arrived in the UK, without incident, on 3 August 1944.
As fast convoys they were less vulnerable to U-boat attack than the slow convoys, but they still witnessed some of the great convoy battles of the war. Of the 40 convoys during the campaign which lost more than 6 ships, 5 were in the HX series.
Among the best known HX convoy battles were:
- HX 79 Attacked by a U-boat wolf pack in October 1940. 12 ships were lost, which, with the attack on Convoy SC 7 on the same day made the worst day's shipping losses of the entire Atlantic campaign.
- HX 84 Attacked on November 5, 1940, the German pocket battleship Admiral Scheer. 5 ships were quickly sunk, and only the sacrifice of the Armed Merchant Cruiser HMS Jervis Bay and failing light allowed the rest of the convoy to escape. The SS San Demetrio was also part of this convoy.
- HX 106 On 8 February, 1941 the two German small battleships, Scharnhorst and Gneisenau, appeared over the horizon. The presence of the escorting battleship HMS Ramillies was sufficient to deter the attack.
- HX 112 Attacked in March 1941 this battle was notable for seeing the loss to the German navy of two of its U-boat aces, Otto Kretschmer and Joachim Schepke.
- HX 156 was being escorted by the United States Navy in October, 1941, when U-552 torpedoed Reuben James. Reuben James was the first United States warship sunk during World War II.
- HX 212 suffered the heaviest loss of any HX convoy in 1942.
- HX 228 Was one of several convoys attacked sequentially in March 1943. Two U-boats were destroyed while sinking four merchant ships and the escort commander's destroyer.
- HX 229. Attacked in March 1943, this action, which converged with the action around SC 122, was the largest convoy battle of the Atlantic campaign.