Convoy ONS-5
Encyclopedia
ONS 5 was a North Atlantic convoy
during the battle of the Atlantic in World War II; the battle surrounding it in May 1943 is regarded as the turning point of the Atlantic campaign.
The battle ebbed and flowed over a period of a week, and involved more than 50 Allied ships and their escorts, and over 30 U-boats. It saw heavy losses on both sides.
However it was almost the last Allied convoy to do so, while losses inflicted on attacking U-boats and U-boat groups became a besetting feature of the campaign;
As such it is seen as the point when the tactical and strategic advantage passed to the Allies
, and ushered in the period known to the German Navy
as Black May
.
to Halifax
, the ships either in ballast or carrying trade and export goods.
The convoy departed Liverpool on 21 April 1943, and would arrive in Halifax three weeks later on 12 May.
It was under the command of JK Brook RNR as Convoy Commodore, travelling in the Norwegian freighter Rena.
The escort was provided by Mid-Ocean Escort Force
group B7, 7 warships under Captain Peter Gretton, in the destroyer Duncan
. Also in the group were the destroyer
Vidette, frigate Tay, and corvettes Sunflower, Snowflake, Loosestrife, and Pink. The group also contained 2 trawlers, Northern Gem and Northern Spray as rescue ships, and the fleet oiler British Lady for mid-ocean re-fuelling. The convoy was joined by other escort vessels as the battle progressed.
ONS 5 was just one of the allied convoys at sea at the end of April; also in the Western Approaches were ON 180, just leaving, and HX 234, just arriving.
Approaching the Americas were ONS 4 and ON 179; departing was SC 128, while in mid-Atlantic, due to pass ONS 5 east of Greenland, was SC 127. Two other east-bound convoys, HX 235 and HX 236, were also in mid-Atlantic, following a southerly route.
This accounted for over 350 ships on the move in the north Atlantic at that time.
Ranged against them were 58 U-boats in 3 patrol lines; Specht (Woodpecker) with 17 boats south of Greenland
on the western side of the Air Gap; Meise (Bluetit) with 30 boats east of Greenland covering the northern route, and Amsel (Blackbird) with 11 boats, south of Meise covering the southern route.
Meise had been deployed to catch SC 127, which had been identified by B-Deinst, but on 26 April SC 127 had slipped through a gap in the line and escaped undetected. Realizing what had happened on 27 April,, and aware that a slow west-bound convoy was imminent,
Meise was re-configured; the easternmost boats (16 in all) formed the patrol line Star (Starling) to intercept it.
At 8am on 28 April U-650 sighted ONS 5, and group Star quickly gathered for the attack.
On the first night, the freighter Modlin had to turn back with engine trouble.
On the 24th, in a moderate gale, the air escort from Scotland, spotted and sank U-710 which was just 10 miles ahead of the convoy, though probably unaware of its proximity.
On 26th the freighter Penhale was storm-damaged, and detached to return to Reykjavík
escorted by Northern Gem, which re-joined the following day. Also on the same day Vidette joined with 3 merchant ships from Iceland
.
By nightfall she had been joined by 4 others ( U-375, U-386, U-528 and U-537), and at midnight they began their attack.
Warned by the radio chatter of their presence, Gretton mounted a vigorous defence; in the course of the night none of the ships were hit, while 2 of the U-boats, U-386 and U-532, were damaged and forced to return to base. (U-386 arrived safely at St Nazaire on 11 May, but U-532 was attacked in the Bay of Biscay
and sunk by aircraft on the same day). The assault continued into the day; at midday on the 29th one ship, McKeesport, was torpedoed and sunk. The attacker, U-258, was also damaged in the affair, and was also forced to return to base.
Also on 29th the Admiralty arranged reinforcements for ONS 5; HMS Oribi, detached from SC127 would arrive on the 30th, while 3rd Support Group, (the 4 destroyers Penn, Panther, Impulsive and Offa,under Capt. JA McCoy RN) would arrive on 1 May.
Later that night Impulsive also detached to Iceland, with Northern Gem carrying the survivors from McKeesport, while Penn and Panther detached for Newfoundland
.
Meanwhile the U-boats tried to maintain contact, though any attack was impossible. Only 6 of the Star boats had been able to make contact;of these 3 had been forced to return to base. Donitz decided that nothing could further be gained and on 1 May ordered boats from Star and Specht, with some newcomers to form a new patrol line to the west. This was group Finke (Finch) which was in place on 3 May numbering 27 boats, and tasked with intercepting westbound convoy SC128. This reorganization was also not without incident; on 1 May two of the newcomers were attacked by air patrol in separate incidents while joining Finke. One was thought to have been U-630, and sunk; but is now believed to have been U-209, which was damaged in the attack, succumbing later while attempting to return to base. The other, U-438, was only slightly damaged in the attack.
The rest were scattered and proceeding independently, including a group of 4 with Pink, trailing some 80 miles behind the main body.
On 4 May at local midday ships were sighted by U-628 of group Finke; not SC128, as they were expecting, but ONS 5. The boats of Finke started to gather, and by evening were ready to make their attack.
The assault started at nightfall and continued throughout the night; under the relentless pressure 5 ships were torpedoed while a number of U-boats were damaged.
The assault continued into the day, the U-boats switching to submerged attacks, and a further 4 ships were lost.
Several boats also found Pink’s party and made an attack; one ship, West Makadet, was sunk, while Pink mounted a spirited attack on a contact, and was credited with the destruction of U-192, though the recipient was more likely to have been U-358, which was damaged.
Determined to see results, Donitz ordered the assault to continue into the night; however with a thick fog forming, the advantage passed to the escorts. The U-boats lost visibility in the fog, while the escorts, equipped with radar, were able to strike un-hindered.
The assault was repulsed; no ships were lost, but 3 U-boats, (U-638, U-125 and U-531) were sunk.
On the morning of 6 May, reinforcement in the form of 1st Support Group arrived.
Led by Cdr GN Brewer in HMS Pelican, they announced their arrival by attacking and sinking U-438; while the cutter Sennen, sent to help Pink’s party, made an attack which was also credited as a kill, but was later found to have been unsuccessful. With the other members of 1st Support Group, the frigates Jed, Wear and Spey, the escort now stood at 13 warships.
Finke had already outlasted its usefulness, and faced mounting losses if the attack continued. Realizing his mistake, Donitz called off the assault on 6 May and ordered Finke to retire.
Although not home for another week, ONS 5 was not attacked again; this was as well, for Offa and Oribi detached on 6th through lack of fuel, while the ships of B7 group, low on fuel and ammunition, were in little shape for more action. Only the ships of 1st Support Group were in any state to fight.
With the loss of 13 ships totalling 63,000 tons, the escorts had inflicted the loss of 6 U-boats, and serious damage on 7 more.
This battle demonstrated that the convoy escorts had mastered the art of convoy protection; the weapon and expertise at their disposal meant that henceforth they would be able not only be able to protect their charges and repel attack, but they would also be able to inflict significant losses on the attacker.
ONS 5 marked the turning point in the battle of the Atlantic. Following this action, the Allies inflicted a series of defeats and heavy losses on the U-boat Arm, a period known as Black May
. This culminated in Donitz withdrawing his forces from the North Atlantic arena.
The official historian, Stephen Roskill
commented:
“This seven day battle, fought against thirty U-boats, is marked only by latitude and longitude, and has no name by which it will be remembered; but it was, in its own way, as decisive as Quiberon Bay
or the Nile
”.,,
Wolfpacks Star and Finke comprised 43 U-boats (though again, not all had been in contact throughout); 6 of these were 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...
during the battle of the Atlantic in World War II; the battle surrounding it in May 1943 is regarded as the turning point of the Atlantic campaign.
The battle ebbed and flowed over a period of a week, and involved more than 50 Allied ships and their escorts, and over 30 U-boats. It saw heavy losses on both sides.
However it was almost the last Allied convoy to do so, while losses inflicted on attacking U-boats and U-boat groups became a besetting feature of the campaign;
As such it is seen as the point when the tactical and strategic advantage passed to the Allies
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...
, and ushered in the period known to the German Navy
Kriegsmarine
The 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...
as Black May
Black 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...
.
The Protagonists
ONS 5 was a slow west-bound convoy of the ONS series organized and run during the Atlantic campaign. It consisted of 42 ships bound from LiverpoolLiverpool
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...
to Halifax
City of Halifax
Halifax is a city in Canada, which was the capital of the province of Nova Scotia and shire town of Halifax County. It was the largest city in Atlantic Canada until it was amalgamated into Halifax Regional Municipality in 1996...
, the ships either in ballast or carrying trade and export goods.
The convoy departed Liverpool on 21 April 1943, and would arrive in Halifax three weeks later on 12 May.
It was under the command of JK Brook RNR as Convoy Commodore, travelling in the Norwegian freighter Rena.
The escort was provided by 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...
group B7, 7 warships under Captain Peter Gretton, in the destroyer Duncan
HMS Duncan (D99)
HMS Duncan was a D-class destroyer leader built for the Royal Navy in the early 1930s. The ship was initially assigned to the Mediterranean Fleet before she was transferred to the China Station in early 1935 where she remained until mid-1939. Duncan returned to the Mediterranean Fleet just after...
. Also in the group were the destroyer
Destroyer
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from...
Vidette, frigate Tay, and corvettes Sunflower, Snowflake, Loosestrife, and Pink. The group also contained 2 trawlers, Northern Gem and Northern Spray as rescue ships, and the fleet oiler British Lady for mid-ocean re-fuelling. The convoy was joined by other escort vessels as the battle progressed.
ONS 5 was just one of the allied convoys at sea at the end of April; also in the Western Approaches were ON 180, just leaving, and HX 234, just arriving.
Approaching the Americas were ONS 4 and ON 179; departing was SC 128, while in mid-Atlantic, due to pass ONS 5 east of Greenland, was SC 127. Two other east-bound convoys, HX 235 and HX 236, were also in mid-Atlantic, following a southerly route.
This accounted for over 350 ships on the move in the north Atlantic at that time.
Ranged against them were 58 U-boats in 3 patrol lines; Specht (Woodpecker) with 17 boats south of Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
on the western side of the Air Gap; Meise (Bluetit) with 30 boats east of Greenland covering the northern route, and Amsel (Blackbird) with 11 boats, south of Meise covering the southern route.
Meise had been deployed to catch SC 127, which had been identified by B-Deinst, but on 26 April SC 127 had slipped through a gap in the line and escaped undetected. Realizing what had happened on 27 April,, and aware that a slow west-bound convoy was imminent,
Meise was re-configured; the easternmost boats (16 in all) formed the patrol line Star (Starling) to intercept it.
At 8am on 28 April U-650 sighted ONS 5, and group Star quickly gathered for the attack.
The Action
The convoy departed Liverpool on 21 April 1943, and was quickly involved in incident.On the first night, the freighter Modlin had to turn back with engine trouble.
On the 24th, in a moderate gale, the air escort from Scotland, spotted and sank U-710 which was just 10 miles ahead of the convoy, though probably unaware of its proximity.
On 26th the freighter Penhale was storm-damaged, and detached to return to Reykjavík
Reykjavík
Reykjavík is the capital and largest city in Iceland.Its latitude at 64°08' N makes it the world's northernmost capital of a sovereign state. It is located in southwestern Iceland, on the southern shore of Faxaflói Bay...
escorted by Northern Gem, which re-joined the following day. Also on the same day Vidette joined with 3 merchant ships from Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
.
The first battle
On the 28th ONS 5 arrived at the Star patrol area, and was sighted by U-650.By nightfall she had been joined by 4 others ( U-375, U-386, U-528 and U-537), and at midnight they began their attack.
Warned by the radio chatter of their presence, Gretton mounted a vigorous defence; in the course of the night none of the ships were hit, while 2 of the U-boats, U-386 and U-532, were damaged and forced to return to base. (U-386 arrived safely at St Nazaire on 11 May, but U-532 was attacked in the Bay of Biscay
Bay of Biscay
The Bay of Biscay is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Brest south to the Spanish border, and the northern coast of Spain west to Cape Ortegal, and is named in English after the province of Biscay, in the Spanish...
and sunk by aircraft on the same day). The assault continued into the day; at midday on the 29th one ship, McKeesport, was torpedoed and sunk. The attacker, U-258, was also damaged in the affair, and was also forced to return to base.
Also on 29th the Admiralty arranged reinforcements for ONS 5; HMS Oribi, detached from SC127 would arrive on the 30th, while 3rd Support Group, (the 4 destroyers Penn, Panther, Impulsive and Offa,under Capt. JA McCoy RN) would arrive on 1 May.
The storm
Over the next few days the action was dictated by the weather. In worsening conditions ONS 5 found itself making less than 3 knots headway into a Force 10 gale. The convoy started to be scattered, some ships ending up 30 miles from the convoy, and the escorts were kept busy rounding up stragglers. On 30th, and 1st reinforcements arrived, making the escorts' task easier. The weather made re-fuelling impossible, and a number of the destroyers became so low on fuel as to throw doubt on whether they could continue. On 3rd Gretton was forced to take Duncan to St John's at economical speed (8 knots); he arrived there with just hours to spare. In Gretton's absence command was assumed by Lt-Cdr RE Sherwood, of HMS Tay.Later that night Impulsive also detached to Iceland, with Northern Gem carrying the survivors from McKeesport, while Penn and Panther detached for Newfoundland
Dominion of Newfoundland
The Dominion of Newfoundland was a British Dominion from 1907 to 1949 . The Dominion of Newfoundland was situated in northeastern North America along the Atlantic coast and comprised the island of Newfoundland and Labrador on the continental mainland...
.
Meanwhile the U-boats tried to maintain contact, though any attack was impossible. Only 6 of the Star boats had been able to make contact;of these 3 had been forced to return to base. Donitz decided that nothing could further be gained and on 1 May ordered boats from Star and Specht, with some newcomers to form a new patrol line to the west. This was group Finke (Finch) which was in place on 3 May numbering 27 boats, and tasked with intercepting westbound convoy SC128. This reorganization was also not without incident; on 1 May two of the newcomers were attacked by air patrol in separate incidents while joining Finke. One was thought to have been U-630, and sunk; but is now believed to have been U-209, which was damaged in the attack, succumbing later while attempting to return to base. The other, U-438, was only slightly damaged in the attack.
The second battle
By 4 May the weather had abated to Force 6, and ONS 5 was now making up to 6 knots, though reduced to 30 ships and 7 escorts.The rest were scattered and proceeding independently, including a group of 4 with Pink, trailing some 80 miles behind the main body.
On 4 May at local midday ships were sighted by U-628 of group Finke; not SC128, as they were expecting, but ONS 5. The boats of Finke started to gather, and by evening were ready to make their attack.
The assault started at nightfall and continued throughout the night; under the relentless pressure 5 ships were torpedoed while a number of U-boats were damaged.
The assault continued into the day, the U-boats switching to submerged attacks, and a further 4 ships were lost.
Several boats also found Pink’s party and made an attack; one ship, West Makadet, was sunk, while Pink mounted a spirited attack on a contact, and was credited with the destruction of U-192, though the recipient was more likely to have been U-358, which was damaged.
Determined to see results, Donitz ordered the assault to continue into the night; however with a thick fog forming, the advantage passed to the escorts. The U-boats lost visibility in the fog, while the escorts, equipped with radar, were able to strike un-hindered.
The assault was repulsed; no ships were lost, but 3 U-boats, (U-638, U-125 and U-531) were sunk.
On the morning of 6 May, reinforcement in the form of 1st Support Group arrived.
Led by Cdr GN Brewer in HMS Pelican, they announced their arrival by attacking and sinking U-438; while the cutter Sennen, sent to help Pink’s party, made an attack which was also credited as a kill, but was later found to have been unsuccessful. With the other members of 1st Support Group, the frigates Jed, Wear and Spey, the escort now stood at 13 warships.
Finke had already outlasted its usefulness, and faced mounting losses if the attack continued. Realizing his mistake, Donitz called off the assault on 6 May and ordered Finke to retire.
Although not home for another week, ONS 5 was not attacked again; this was as well, for Offa and Oribi detached on 6th through lack of fuel, while the ships of B7 group, low on fuel and ammunition, were in little shape for more action. Only the ships of 1st Support Group were in any state to fight.
Conclusion
In the course of a week, ONS 5 had been the subject of attacks by a force of over 40 U-boats.With the loss of 13 ships totalling 63,000 tons, the escorts had inflicted the loss of 6 U-boats, and serious damage on 7 more.
This battle demonstrated that the convoy escorts had mastered the art of convoy protection; the weapon and expertise at their disposal meant that henceforth they would be able not only be able to protect their charges and repel attack, but they would also be able to inflict significant losses on the attacker.
ONS 5 marked the turning point in the battle of the Atlantic. Following this action, the Allies inflicted a series of defeats and heavy losses on the U-boat Arm, a period known as Black May
Black 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...
. This culminated in Donitz withdrawing his forces from the North Atlantic arena.
The official historian, Stephen Roskill
Stephen Roskill
Captain Stephen Wentworth Roskill, CBE, DSC, FBA, DLitt was a career officer in the Royal Navy, serving during the Second World War and, after his enforced medical retirement, served as the official historian of the Royal Navy from 1949 to 1960...
commented:
“This seven day battle, fought against thirty U-boats, is marked only by latitude and longitude, and has no name by which it will be remembered; but it was, in its own way, as decisive as Quiberon Bay
Battle of Quiberon Bay
The naval Battle of Quiberon Bay took place on 20 November 1759 during the Seven Years' War in Quiberon Bay, off the coast of France near St. Nazaire...
or the Nile
Battle of the Nile
The Battle of the Nile was a major naval battle fought between British and French fleets at Aboukir Bay on the Mediterranean coast of Egypt from 1–3 August 1798...
”.,,
Allied ships lost
| Date | Name | Nationality | Casualties | Tonnage | Sunk by… |
|---|---|---|---|---|---|
| 29 April 1943 | McKeesport | US | 11 | 6198 GRT | U-258 |
| 4/5 May | Lorient | British | ? | 4737 GRT | U-125 |
| 4/5 | North Britain | British | ? | 4635 GRT | U-707 |
| 4/5 | Harbury | British | 7 | 5081 GRT | U-628 |
| 4/5 | West Maximus | US | 5 | 5561 GRT | U-264 |
| 4/5 | Harpurley | British | 11 | 4586 GRT | U-264 |
| 4/5 | Bristol City | British | 15 | 2864 GRT | U-358 |
| 4/5 | Wentworth | British | 5 May | 5512 GRT | U-358 |
| 5 | Dolius | British | 4 | 5507 GRT | U-638 |
| 5 | West Makadet | US | nil | 5565 GRT | U-584 |
| 5/6 May | Selvistan | British | 6 | 5136 GRT | U-266 |
| 5/6 | Gharinda | British | nil | 5306 GRT | U-266 |
| 5/6 | Bonde | Norwegian | 5 | 1570 GRT | U-266 |
U-boats lost
| Date | Number | Type | Captain | Casualties | Sunk by… |
|---|---|---|---|---|---|
| 4.5.43 | U-630 | VIIC | Wachter | 47 | Canso PBY Catalina The Consolidated PBY Catalina was an American flying boat of the 1930s and 1940s produced by Consolidated Aircraft. It was one of the most widely used multi-role aircraft of World War II. PBYs served with every branch of the United States Armed Forces and in the air forces and navies of many other... 5 Sqdn RCAF |
| 5/6 | U-638 | VIIC | Straudinger | 44 | Loosestrife |
| 5/6 | U-125 | IXC | Folkers | 54 | Oribi, Snowflake |
| 5/6 | U-531 | IXC/40 | Neckel | 54 | Vidette |
| ?5.5.43 | U-192 | IXC/40 | Happe | 55 | Pink |
| 6.5.43 | U-438 | VIIC | Hensohn | 48 | Pelican |
Ships involved
ONS 5 comprised 42 ships and 16 escorts, (though not all were present at the same time); 13 ships were lost in the course of the 7 day engagement.Wolfpacks Star and Finke comprised 43 U-boats (though again, not all had been in contact throughout); 6 of these were lost.