ON convoys
Encyclopedia
The ON convoys were a series of North Atlantic trade convoy
s running Outbound from the British Isles
to North America during the Battle of the Atlantic (1939-1945).
, OB convoys sailed from Liverpool
south through St George's Channel
to the open Atlantic
. Off Land's End
the convoy would be joined by an OA convoy from London
on the River Thames
via the English Channel
. The combined OA/OB convoys were escorted for about four days to get beyond the range of U-boat
patrols before the ships dispersed to reach their individual destinations. After the fall of France in June 1940, OA and OB convoys sailed north to join in the Western Approaches
. As German aircraft, submarines, and surface ships reached further into the Atlantic, ships formerly assigned to OA/OB convoys were formed into ON convoys sailing from Liverpool via the North Channel
and escorted all the way to Halifax Harbour
. These convoys were sequentially numbered from ON 1 sailing on 26 July 1941 to ON 305 sailing on 27 May 1945.
From August 1942, the Mid-Ocean Escort Force
of British and Canadian ships (with a few United States Coast Guard
cutters) delivered ON convoys to the Royal Canadian Navy
Western Local Escort Force
(WLEF) off Halifax; and the WLEF escorted most convoys from ON 125 through ON 301 to New York City
.
Most ships in ON convoys were in ballast, although some carried coal or other export goods. A total of 14,864 ships sailed in 307 ON convoys. One ON convoy sailed in Fast and Slow sections and two others were cancelled. U-boats sank 81 of these ships, and another 23 were lost to marine accidents. These figures do not include stragglers; although the majority of casualties to U-boats were ships that had fallen out of convoys or were sailing independently. Ten warship
s on escort duty were also lost.
Convoy
A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support, though it may also be used in a non-military sense, for example when driving through remote areas.-Age of Sail:Naval...
s running Outbound from the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
to North America during the Battle of the Atlantic (1939-1945).
History
From 7 September 1939, shortly after the outbreak of World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, OB convoys sailed from Liverpool
Liverpool
Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...
south through St George's Channel
St George's Channel
St George's Channel is a sea channel connecting the Irish Sea to the north and the Celtic Sea to the southwest.Historically, the name "St Georges Channel" was used interchangeably with "Irish Sea" or "Irish Channel" to encompass all the waters between Ireland to the west and Great Britain to the...
to the open Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
. Off Land's End
Land's End
Land's End is a headland and small settlement in west Cornwall, England, within the United Kingdom. It is located on the Penwith peninsula approximately eight miles west-southwest of Penzance....
the convoy would be joined by an OA convoy from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
on the River Thames
River Thames
The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...
via the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
. The combined OA/OB convoys were escorted for about four days to get beyond the range of U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...
patrols before the ships dispersed to reach their individual destinations. After the fall of France in June 1940, OA and OB convoys sailed north to join in the Western Approaches
Western Approaches
The Western Approaches is a rectangular area of the Atlantic ocean lying on the western coast of Great Britain. The rectangle is higher than it is wide, the north and south boundaries defined by the north and south ends of the British Isles, the eastern boundary lying on the western coast, and the...
. As German aircraft, submarines, and surface ships reached further into the Atlantic, ships formerly assigned to OA/OB convoys were formed into ON convoys sailing from Liverpool via the North Channel
North Channel (Great Britain and Ireland)
The North Channel is the strait which separates eastern Northern Ireland from southwestern Scotland...
and escorted all the way to Halifax Harbour
Halifax Harbour
Halifax Harbour is a large natural harbour on the Atlantic coast of Nova Scotia, Canada, located in the Halifax Regional Municipality.-Harbour description:The harbour is called Jipugtug by the Mi'kmaq first nation, anglisized as Chebucto...
. These convoys were sequentially numbered from ON 1 sailing on 26 July 1941 to ON 305 sailing on 27 May 1945.
From August 1942, the Mid-Ocean Escort Force
Mid-Ocean Escort Force
Mid-Ocean Escort Force referred to the organization of anti-submarine escorts for World War II trade convoys between Canada and the British Isles...
of British and Canadian ships (with a few United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
cutters) delivered ON convoys to the Royal Canadian Navy
Royal Canadian Navy
The history of the Royal Canadian Navy goes back to 1910, when the naval force was created as the Naval Service of Canada and renamed a year later by King George V. The Royal Canadian Navy is one of the three environmental commands of the Canadian Forces...
Western Local Escort Force
Western Local Escort Force
Western Local Escort Force referred to the organization of anti-submarine escorts for World War II trade convoys from North American port cities to the Western Ocean Meeting Point near Newfoundland where ships of the Mid-Ocean Escort Force assumed responsibility for safely delivering the convoys...
(WLEF) off Halifax; and the WLEF escorted most convoys from ON 125 through ON 301 to New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
.
Most ships in ON convoys were in ballast, although some carried coal or other export goods. A total of 14,864 ships sailed in 307 ON convoys. One ON convoy sailed in Fast and Slow sections and two others were cancelled. U-boats sank 81 of these ships, and another 23 were lost to marine accidents. These figures do not include stragglers; although the majority of casualties to U-boats were ships that had fallen out of convoys or were sailing independently. Ten warship
Warship
A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...
s on escort duty were also lost.
Slow Convoys
Until April 1943, ships capable of speeds between 9 and 13 knots were assigned to odd-numbered (fast) convoys -- sometimes designated ON(F); while ships capable of speeds between 6 and 9 knots were assigned to even-numbered (slow) convoys -- sometimes designated ON(S) or (ambiguously) ONS. This situation, which has proved confusing to modern historians, prevailed until a new and separate series of ONS (Outbound North Slow) convoys was organized. These convoys were sequentially numbered from ONS 1 sailing on 4 April 1943 to ONS 51 sailing on 21 May 1945. ON 171 was a fast convoy, as were all subsequent ON convoys. The ONS series were suspended in the summer of 1944 as escort groups were diverted to cover the Normandy landings. A total of 1873 ships sailed in 51 ONS convoys. Only 5 of these were attacked (around 10%), though two of these battles were of major significance; ONS 5 is regarded as the turning point of the campaign, while ONS 18 was the last major convoy battle in the campaign. Nineteen ships were lost (around 1%) from ONS convoys.Notable Battles around ON and ONS Convoys
The Outbound Northern convoys saw some of the major convoy battles of the Atlantic campaign; of the 40 convoys which lost 6 or more ships, 8 were in the ON series (of which 5 were Slow, and 3 were Fast) and one was in the ONS series.- Convoy ON 67Convoy ON 67Convoy ON-67 was a trade convoy of merchant ships during the second World War. It was the 67th of the numbered series of ON convoys Outbound from the British Isles to North America...
was one of the few North Atlantic trade convoy of early 1942 to be attacked by multiple U-boats.
- Convoy ON 127 was the only North Atlantic trade convoy of 1942 or 1943 where all U-boats deployed against the convoy launched torpedoes.
- Convoy ON 154 included the last Q-shipQ-shipQ-ships, also known as Q-boats, Decoy Vessels, Special Service Ships, or Mystery Ships, were heavily armed merchant ships with concealed weaponry, designed to lure submarines into making surface attacks. This gave Q-ships the chance to open fire and sink them...
operation by the Royal NavyRoyal NavyThe Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
. Loss of 486 lives with 14 ships during the "Christmas Convoy" of December 1942 caused re-evaluation of Canadian convoy escorts.
- Convoy ON 166. Attacked in late February, 1943, ON 166 lost 13 merchant ships and the Convoy rescue shipConvoy rescue shipDuring the Second World War purpose built convoy rescue ships accompanied some Atlantic convoys to rescue survivors from ships which had been attacked. Rescue ships were typically small freighters with passenger accommodations. Conversion to rescue service involved enlarging galley and food...
Stockport. Three U-boatU-boatU-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...
s were destroyed and the USCG Treasury Class CutterUSCG Treasury Class CutterThe Treasury-class high endurance cutters were a group of seven ships launched by the United States Coast Guard between 1936 and 1937. The class were called the "Treasury-class" because they were each named for former Secretaries of the Treasury. These ships were also collectively known as the...
leading Escort Group A-3 was disabled.
- Convoy ONS 5. Attacked in April-May 1943, ONS 5 saw the loss of 12 ships, and the destruction of 6 U-boats, in a week long series of actions. It ushered in the period known as Black MayBlack May (1943)‘Black May’ refers to a period in the Battle of the Atlantic campaign during World War II, when the German U-boat arm suffered high casualties with fewer Allied ships sunk; it is considered a turning point in the Battle of the Atlantic.-Background:After February battles around convoys SC 118, ON...
and is widely regarded as the turning point in the Atlantic campaign.
- Convoys ONS 18/ON 202. Attacked in September 1943, these two convoys saw the loss of 6 ships and 3 escorts, for the destruction of 3 U-boats, in the first battle of KMKriegsmarineThe Kriegsmarine was the name of the German Navy during the Nazi regime . It superseded the Kaiserliche Marine of World War I and the post-war Reichsmarine. The Kriegsmarine was one of three official branches of the Wehrmacht, the unified armed forces of Nazi Germany.The Kriegsmarine grew rapidly...
's autumn offensive after Black May.