| Conflict: | Convoy HX.300 |
| Partof: | World War II |
| Date: | 17 July – 3 August 1944 |
| Place: | North Sea |
| Combatant2: |  United Kingdom |
| Commander1: | Admiral Karl Dönitz |
| Commander2: | Rear-Admiral Sir A T Tillard KBE DSO |
| Strength1: | unknown |
| Strength2: | 159 merchant ships 32 escorts |
| Casualties1: | unknown |
| Casualties2: | none |
Convoy HX 300 was the 300th of the numbered series of World War II HX convoys of merchant ships from Halifax to Liverpool. It started its journey on 17 July 1944 and was the largest convoy of the war, comprising 166 ships.
These HX convoys had been established shortly after declaration of war; and the first sailed on 16 September 1939.[1] Ships in convoy were less vulnerable to submarine attack than ships sailing independently, but the Allies had difficulty providing an adequate number of escorting warships to establish a protective perimeter for detecting and defeating approaching submarines. British Admiralty operations research scientists evaluating convoy battles of 1941 and 1942 determined losses of ships in convoy were independent of convoy size, but varied with the number of attacking submarines and, when patrol aircraft were unavailable, with the number of escorting warships. They suggested convoy losses could be reduced by 64 percent by decreasing the frequency of convoys to increase the average number of merchant ships in each convoy from 32 to 54 and the number of escorting warships from 6 to 9.[2] Additional reduction of losses was theoretically possible with even larger convoys, but difficulties maneuvering large formations of ships and providing port services for simultaneous arrival of so many ships discouraged very large convoys until trade convoy escort warships were required to support the Invasion of Normandy. More than one hundred ships sailed in each of 7 ON convoys and 9 HX convoys during the summer of 1944. HX 300 was the largest of these with 166 merchant ships arranged in 19 parallel columns to produce a formation approximately 9miles wide and 4miles long.[3] Ships sailing from New York City on 17 July 1944 were joined by 30 merchant ships sailing from Halifax Harbour on 19 July, 24 sailing from Sydney, Nova Scotia on 20 July, and 3 from St. John's, Newfoundland and Labrador to form the largest trade convoy of the war.[4]
Ships sailing from New York were escorted by United States Navy submarine chasers SC 1338 and SC 1340, and by Western Local Escort Force (WLEF) and s, and . Ships sailing from Halifax were escorted by WLEF minesweeper and corvettes,, and . Rosthern and the escorts from New York were detached when the remaining ships from Halifax assumed responsibility for the convoy on 20 July. Ships sailing from Sydney were escorted by WLEF s and, and Norwegian . The escorting warships from Sydney detached from the convoy after the escorting warships from Halifax assumed responsibility for the ships from Sydney on 22 July. The four warships from Halifax were detached when Mid-Ocean Escort Force group C5 and corvettes,,,,, and assumed responsibility for the convoy on 24 July. The latter two corvettes had escorted the merchant ships sailing from St. Johns. Naval trawlers HMS Cape Mariato and HMS Southern Spray assumed responsibility for the convoy in the Western Approaches on 2 August. The convoy was not attacked by submarines and arrived in United Kingdom ports by 3 August 1944.[5]
After the seven Canadian warships of escort group C5 brought the largest convoy of the Battle of the Atlantic safely across the mid-ocean, many of the convoy's ships began offloading food, fuel, and materials to support the civilian population of the British Isles. One ship from the convoy waited in Loch Ewe to carry supplies to the United States garrison in Iceland; nine ships waited in the Firth of Clyde until convoy JW 59 formed to carry war materials to the Soviet Union; and 46 waited at Oban until channel ports were ready for them to offload food, fuel, and ammunition for Allied armies moving east from France, and trucks, jeeps, half-tracks, and locomotives to move those supplies to the front. HX 300 was one of six hundred World War II trade convoys from North America to the British Isles. The following list describes the British, American, Norwegian, Greek, Dutch, Panamanian, Polish, Yugoslavian, French, and Swedish ships of this convoy and the cargoes they were transporting.[4]
| Name | Flag | Destination | Tonnage (GRT) | Cargo | Notes | |
|---|---|---|---|---|---|---|
| Agia Marina (1912) |  | Avonmouth | 4,151 | Grain & armoured fighting vehicles | Joined from Sydney | |
| (1943) |  | Europe | 7,244 | General cargo | Liberty ship fitted with Anti-torpedo Net Device | |
| Aleksandar I (1927) | Liverpool | 5,948 | Sugar | |||
| (1942) | | Immingham | 7,181 | General cargo including explosives | Liberty ship joined from Halifax | |
| (1942) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| American Press (1920) | | Port of Hull | 5,131 | General cargo including explosives | Joined from Halifax | |
| Ancylus (1935) | Clyde | 8,017 | USN fuels | Merchant aircraft carrier tanker ferrying a deck-load of non-operational aircraft joined from St.John's, Newfoundland | ||
| (1944) | | Europe | 7,240 | General cargo including motor vehicles | Liberty ship | |
| Anna N Goulandris (1921) | | Thames | 4,358 | Grain | Joined from Sydney | |
| (1943) | | Europe | 7,176 | Explosives | Liberty ship | |
| (1942) | | Liverpool | 7,181 | Landing craft and locomotives | Liberty ship | |
| Athelduke (1929) | Bromborough | 8,966 | Molasses | |||
| Athelprince (1926) | Salt End | 8,782 | Molasses | Joined from Sydney | ||
| Athelregent (1930) | Greenock | 8,881 | Molasses | Carried 59 spare depth charges for escorting warships | ||
| (1944) | | Thames | 7,176 | General cargo | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo | Liberty ship | |
| Baxtergate (1925) | Thames | 5,531 | Wheat | Joined from Sydney | ||
| (1944) | | Europe | 7,182 | General cargo including motor vehicles | Liberty ship | |
| Bente Maersk (1928) | Firth of Clyde | 5,722 | Gas oil | Serving as escort oiler | ||
| Bernhard (1924) |  | Liverpool | 3,563 | Sugar | ||
| (1943) | | Europe | 7,176 | General cargo | Liberty ship | |
| Bonita (1918) |  | Thames | 4,929 | Lumber | Joined from Sydney | |
| British Colonel (1921) | Leith | 6,999 | Gas oil | Serving as escort oiler carrying 70 spare depth charges for escorting warships | ||
| British Promise (1942) | Soviet Union | 8,443 | Alcohol | Cargo loaded at Philadelphia | ||
| Cairnvalona (1918) | Tyne | 4,929 | Refrigerated general cargo | Joined from Sydney fitted with HF/DF | ||
| Calobre (1919) | | Belfast | 6,891 | Motor vehicles | ||
| Cataraqui Park (1944) | | Bristol | 2,877 | Lumber | Joined from Sydney | |
| (1942) | | Newport | 7,176 | Explosives and poison gas | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship fitted with Anti-torpedo Net Device | |
| (1944) | | Soviet Union | 7,176 | General cargo including locomotives | Liberty ship | |
| (1943) | | Immingham | 7,194 | General cargo including explosives | Liberty ship joined from Halifax | |
| Chesapeake (1928) | Firth of Clyde | 8,955 | Diesel oil and aircraft | Serving as escort oiler carrying 58 spare depth charges for escorting warships | ||
| Christine Marie (1919) | Rochester | 3,895 | Woodpulp | Joined from St.John's, Newfoundland | ||
| (1942) | | Europe | 7,177 | General cargo | Liberty ship joined from Halifax | |
| City of Lancaster (1924) | Thames | 3,041 | Asphalt, sugar & rum | |||
| City of Leicester (1926) | Manchester | 3,351 | Flour & general cargo | Joined from Sydney | ||
| Clan MacInnes (1920) | Avonmouth | 4,672 | Flour & general cargo | Joined from Halifax | ||
| (1944) | | Soviet Union | 7,198 | General cargo including locomotives | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo | Liberty ship | |
| Clydefield (1928) | Scapa Flow | 7,365 | Fuel oil | |||
| (1943) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| Dalhanna (1930) | Liverpool | 5,571 | Lard & general cargo | |||
| (1943) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| (1942) | | Liverpool | 7,181 | Explosives | Liberty ship | |
| Daylight (1931) | | Heysham | 9,180 | Petrol, oil & barges | ||
| Dimitrios Chandris (1910) | | Thames | 4,643 | General cargo | Joined form Sydney | |
| (1943) | | Europe | 7,176 | General cargo including explosives | Liberty ship | |
| Dramatist (1920) | Liverpool | 5,443 | General cargo | |||
| Eastern Guide (1918) | | Loch Ewe | 3,704 | General cargo including lumber and 300 depth charges bound for Iceland | ||
| (1944) | | Europe | 7,240 | General cargo including motor vehicles | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo | Liberty ship | |
| (1943) | | Soviet Union | 7,176 | General cargo including locomotives | Liberty ship | |
| Elg (1930) | | Greenock | 4,014 | Sugar & rum | ||
| (1944) | | Soviet Union | 7,176 | Locomotives & machinery | Liberty ship | |
| (1942) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo | Liberty ship joined from Halifax | |
| Elisabeth Dal (1910) | Manchester | 4,258 | Wheat | Joined from Sydney; constructive total loss following collision | ||
| (1943) | | Europe | 7,176 | General cargo including pontoons | Liberty ship | |
| (1943) | Liverpool | 8,252 | Grain | Merchant aircraft carrier joined from Halifax | ||
| (1941) | Avonmouth | 6,327 | Ore concentrates | |||
| (1921) | Hartlepool | 3,234 | General cargo including explosives | Joined from Sydney | ||
| (1942) | Liverpool | 7,046 | Refrigerated general cargo | Carried convoy commodore RADM Sir A T Tillard KBE DSO | ||
| (1943) | Liverpool | 7,022 | Meat, flour & general cargo | Joined from Halifax fitted with Anti-torpedo Net Device | ||
| Evanger (1920) | | Tyne | 3,869 | General cargo including barges | ||
| Exilona (1919) | | Europe | 4,971 | General cargo including motor vehicles | ||
| Ferncourt (1938) | | Manchester | 9,918 | Diesel oil & armoured fighting vehicles | Serving as escort oiler | |
| Fluor Spar (1919) | | Cardiff | 5,055 | General cargo including explosives | Joined from Halifax | |
| Fort Nipagon (1942) | Thames | 7,132 | General cargo | |||
| (1944) | | Europe | 7,210 | General cargo including motor vehicles | Liberty ship | |
| (1943) | | Europe | 7,176 | Explosives | Liberty ship fitted with Anti-torpedo Net Device | |
| (1943) | | Immingham | 7,176 | General cargo including explosives | Liberty ship | |
| Franka (1918) | Liverpool | 5,273 | Sugar | |||
| Frontenac (1928) | | Portsmouth | 7,350 | USN fuel | Serving as escort oiler carrying 10 spare depth charges for escorting warships | |
| (1942) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| Gatineau Park (1942) | Hull | 7,128 | General cargo including ammunition | Joined from Sydney fitted with Anti-torpedo Net Device | ||
| (1943) | | Europe | 7,244 | General cargo | Liberty ship joined from Halifax fitted with Anti-torpedo Net Device | |
| Georgian (1920) | | Europe | 5,825 | General cargo including motor vehicles | ||
| Gerard Dou (1941) |  | Thames | 7,242 | Sugar & general cargo | Carried convoy vice-commodore Vice-Admiral Sir R H O Lane-Poole KBE CB | |
| Gerassimos Vergottis (1920) | | Liverpool | 6,343 | Woodpulp | Joined from Halifax | |
| Glarona (1928) | | Manchester | 9,912 | Crude oil & aircraft | ||
| Gylfe (1930) | | Grangemouth | 6,129 | Diesel fuel | ||
| (1943) | | Europe | 7,180 | Military stores including motor vehicles | Liberty ship | |
| Hartlepool (1932) | Tyne | 5,500 | Lumber | Joined from Sydney | ||
| Helder (1920) | | Liverpool | 3,629 | Sugar & rum | Joined from Halifax | |
| Henrik Ibsen (1906) | | Ipswich | 4,671 | Grain | Joined from Sydney | |
| Hoegh Hood (1936) | | Liverpool | 9,351 | USN fuel & aircraft | ||
| (1943) | | Scapa Flow | 7,218 | USN fuel | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo including explosives & motor vehicles | Liberty ship | |
| (1943) | | Port of Hull | 7,176 | General cargo including explosives | Liberty ship joined from Halifax | |
| (1944) | | Immingham | 7,200 | Explosives & machinery | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo | Liberty ship joined from Halifax fitted with Anti-torpedo Net Device | |
| (1943) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| Jan Van Goyen (1919) | | Thames | 5,704 | Sugar & powdered milk | ||
| (1943) | | Firth of Clyde | 7,218 | USN fuel | Liberty ship | |
| (1944) | | Glasgow | 7,247 | General cargo including tractors & sulfur | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo including trailers | Liberty ship fitted with Anti-torpedo Net Device | |
| (1943) | | Firth of Clyde | 7,176 | Locomotives & building materials | Liberty ship | |
| (1942) | | Europe | 7,176 | General cargo | Liberty ship | |
| (1942) | | Europe | 7,191 | General cargo including motor vehicles | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo | Liberty ship | |
| Junior Van Noy (1919) | | Europe | 2,372 | Military stores & explosives | Army repair ship | |
| Kohistan (1933) | Glasgow | 5,884 | General cargo | |||
| Kronprinsessen Margareta (1914) |  | Swansea | 3,746 | General cargo | ||
| Lansdowne Park (1943) | Manchester | 2,861 | Woodpulp | Joined from Halifax | ||
| (1943) | | Soviet Union | 7,176 | General cargo including explosives and locomotives | Liberty ship | |
| Lista (1920) | | Manchester | 3,671 | General cargo including motor vehicles | ||
| Lucerna (1930) | Thames | 6,556 | Gas oil | Serving as escort oiler carrying 50 spare depth charges for escorting warships | ||
| Macoma (1936) | | Firth of Clyde | 8,069 | USN fuel | Merchant aircraft carrier joined from Halifax | |
| Maliakos (1912) | | Thames | 3,903 | Woodpulp | Joined from Sydney | |
| Margarita Chandris (1920) | | Thames | 5,401 | Grain | Joined from Sydney | |
| Maud (1930) | | Liverpool | 3,189 | Sugar | ||
| Merchant Royal (1928) | Manchester | 5,008 | Newsprint | Joined from Sydney | ||
| (1942) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship | |
| Mimosa (1905) | | Thames | 3,071 | Lumber | Joined from Sydney | |
| Minerva (1930) | | Liverpool | 5,883 | General cargo including landing craft | ||
| Mobile City (1920) | | Europe | 6,157 | General cargo | Joined from Halifax | |
| Morska Wola (1924) |  | Garston, Merseyside | 3,208 | General cargo including explosives | ||
| Mount Othrys (1919) | | Leith | 6,527 | Grain | Joined from Sydney | |
| Nacella (1943) | Soviet Union | 8,196 | Aviation gasoline | Fitted with Anti-torpedo Net Device | ||
| Nanceen (1929) |  | Thames | 2,895 | Woodpulp & motor vehicles | Joined from Halifax | |
| (1943) | | Europe | 7,200 | General cargo including motor vehicles | Liberty ship | |
| Nathaniel Matthews (1944) | Hartlepool | 2,437 | General cargo | |||
| (1944) | | Avonmouth | 7,240 | General cargo | Liberty ship | |
| Norma (1930) | | Liverpool | 4,487 | Sugar & general cargo | ||
| Norsk Tank (1928) | | Manchester | 9,720 | Fuel oil | ||
| Ocean Fame (1942) | Thames | 7,173 | Sugar | Fitted with Anti-torpedo Net Device | ||
| Odysseus (1913) | | Thames | 4,577 | Ammunition & general cargo | ||
| (1943) | | Europe | 7,244 | General cargo | Liberty ship joined from Halifax | |
| Ovula (1938) | | Southampton | 6,256 | Diesel fuel and aircraft | Serving as escort oiler | |
| Peik (1930) | | Derry | 6,099 | Furnace fuel oil | Joined from Halifax | |
| Pencarrow (1921) | Cardiff | 4,841 | Grain | Joined from Sydney | ||
| (1942) | | Europe | 7,176 | Explosives | Liberty ship | |
| (1943) | | Europe | 7,176 | General cargo including motor vehicles and explosives | Liberty ship | |
| Pomona (1920) | | Europe | 7,583 | General cargo | Joined from Halifax | |
| Prometheus (1925) | Liverpool | 6,095 | General cargo including motor vehicles | Joined from Halifax | ||
| Rapana (1935) | Firth of Clyde | 8,017 | USN fuel | Merchant aircraft carrier joined from Halifax | ||
| Riley (1936) | Manchester | 4,993 | Grain | Joined from Sydney | ||
| (1943) | | Europe | 7,191 | General cargo including motor vehicles | Liberty ship | |
| Rudby (1924) | River Tyne | 4,846 | Grain | Joined from Halifax | ||
| Saintonge (1936) | Thames | 9,386 | USN fuel | Serving as escort oiler carrying 60 spare depth charges for escorting warships | ||
| Salando (1920) | | Thames | 5,272 | General cargo including motor vehicles | ||
| Samfield (1943) | Manchester | 7,219 | Steel & lumber | Fitted with Anti-torpedo Net Device | ||
| Samsperrin (1944) | Liverpool | 7,219 | Grain | |||
| (1942) | | Europe | 7,177 | General cargo including motor vehicles | Liberty ship | |
| (1942) | | Europe | 7,191 | General cargo | Liberty ship | |
| (1942) | | Europe | 7,176 | Motor vehicles | Liberty ship | |
| (1942) | | Europe | 7,176 | General cargo | Liberty ship joined from Halifax | |
| San Valerio (1913) | Isle of Grain | 6,493 | Furnace fuel oil | Serving as escort oiler | ||
| Senga (1913) | Glasgow | 5,140 | Steel & woodpulp | Joined from Sydney | ||
| (1943) | | Firth of Clyde | 7,176 | Locomotives and explosives | Liberty ship fitted with Anti-torpedo Net Device | |
| Skeldergate (1930) | Manchester | 4,251 | Woodpulp | Joined from Sydney | ||
| Solstad (1927) | | Birkenhead | 5,952 | Lubricating oil | ||
| Stalowa Wola (1924) | | Sunderland | 3,133 | General cargo including explosives | ||
| Suerte (1910) | | 3,649 | ||||
| (1944) | | Soviet Union | 7,210 | General cargo including explosives | Liberty ship | |
| Thorshov (1935) | | London | 9,955 | Diesel fuel and aircraft | Serving as escort oiler carrying 60 spare depth charges for escorting warships | |
| Tilapa (1928) | Thames | 5,392 | Meat and general cargo | Joined from Halifax | ||
| Torr Head (1937) | Glasgow | 5,021 | Metal & general cargo | Veteran of convoy ON 67; joined from Halifax | ||
| Trocas (1927) | Thames | 7,406 | Furnace fuel oil | |||
| Tynebank (1922) | Liverpool | 4,651 | Sugar | |||
| Voco (1925) | Birkenhead | 5,090 | Lubricating oil | Carried 60 spare depth charges for escorting warships | ||
| (1944) | | Soviet Union | 7,210 | General cargo including locomotives | Liberty ship | |
| (1942) | | Liverpool | 7,177 | General cargo including explosives | Liberty ship | |
| Wind Rush (1918) | | Cardiff | 5,586 | Motor vehicles and explosives | Veteran of convoy JW 51A and convoy ON 166 | |
| Winona (1919) | | Liverpool | 6,197 | General cargo including ammunition and motor vehicles | Veteran of convoy SC 7 | |
| Wisla (1928) | | Bristol | 3,106 | General cargo | Veteran of convoy ON 154; joined from Halifax | |
| Zamalek (1921) | 1,567 | convoy rescue ship
| ||||
| (1943) | | Europe | 7,176 | General cargo including motor vehicles | Liberty ship |