Convoy ON 122 was a trade

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 and can help maintain cohesion within a unit. It may also be use ...

of merchant ships during the

second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. It was the 122nd of the numbered series of

ON convoys The ON convoys were a series of North Atlantic trade convoys running Outbound from the British Isles to North America during the Battle of the Atlantic. History From 7 September 1939, shortly after the outbreak of World War II, OB convoys sail ...

Outbound from the British Isles to North America. The ships departed

Liverpool Liverpool is a City status in the United Kingdom, city and metropolitan borough in Merseyside, England. With a population of in 2019, it is the List of English districts by population, 10th largest English district by population and its E ...

on 15 August 1942 and were joined on 17 August by

Escort Group B6 Escort Group B6 was a British convoy escort group of the Royal Navy which saw action during the Second World War, principally in the Battle of the Atlantic. Formation Escort Group B6 was one of seven British escort groups which served with th ...

of the

Mid-Ocean Escort Force Mid-Ocean Escort Force (MOEF) referred to the organisation of anti-submarine escorts for World War II trade convoys between Canada and Newfoundland, and the British Isles. The allocation of United States, British, and Canadian escorts to these c ...

.Milner pp.148-150

Background

As western Atlantic coastal convoys brought an end to the

second happy time The "Second Happy Time" (; officially Operation Paukenschlag ("Operation Drumbeat"), and also known among German submarine commanders as the "American Shooting Season") was a phase in the Battle of the Atlantic during which Axis submarines a ...

, Admiral

Karl Dönitz Karl Dönitz (sometimes spelled Doenitz; ; 16 September 1891 24 December 1980) was a Nazi Germany, German admiral who briefly succeeded Adolf Hitler as head of state in May 1945, holding the position until the dissolution of the Flensburg Gov ...

, the ''

Befehlshaber der U-Boote The ''Befehlshaber der Unterseeboote'' or BdU (Eng: "Commander of the U-boats") was the supreme commander of the German Navy's U-boat Arm (''Ubootwaffe'') during the First and Second World Wars. The term also referred to the Command HQ of the U-bo ...

'' (commander in chief of U-Boats), shifted focus to the mid-Atlantic to avoid aircraft patrols. Although convoy routing was less predictable in the mid-ocean, Dönitz anticipated that the increased numbers of U-boats being produced would be able to effectively search the area with the advantage of intelligence gained through ''

B-Dienst The ''B-Dienst'' (german: Beobachtungsdienst, observation service), also called x''B-Dienst'', X-''B-Dienst'' and χ''B-Dienst'', was a Department of the German Naval Intelligence Service (german: Marinenachrichtendienst, MND III) of the OKM, t ...

'' decryption of British Naval Cypher Number 3. However, of the 180 trans-Atlantic convoys sailing from the end of July 1942 until the end of April 1943, only 20 percent lost ships to U-boat attack. The Norwegian-manned corvettes of

fought three of these convoy battles in sequential voyages with convoys SC 104, ON 144, and HX 217.Hague pp.132, 137-138, 161-162, 164, 181

Discovery

''U-135'' discovered and reported the convoy on 22 August while patrolling a formerly assigned station after having missed the signal to change position. The initial report caused some confusion because of the unexpected position and a coding error, but after ''U-135'' sent two clarifying messages while shadowing the convoy, the wolf pack ''Lohs'' was ordered to converge on the convoy.Blair pp.662&663

Stalking

While the Norwegian corvettes investigated HF/DF bearings provided by ''Viscount'' and ''Stockport'' on 23 August, ''Viscount'' conserved fuel by declining to engage in long daylight stern chases with U-boats. ''Viscount'' and ''Potentilla'' attacked HF/DF contacts more aggressively through the hours of darkness, but were satisfied by simply forcing the U-boats to submerge rather than conducting sustained

depth charge A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive hydraulic shock. Most depth charges use ...

attacks.

Attack

Visibility was reduced to 7,000 yards with patchy squalls under overcast skies on 24 August. As dusk approached, the escort had located only four of the nine U-boats in contact with the convoy. The convoy's course was altered to 267° at 2300Z. ''U-605'' torpedoed ''Katvaldis'' and ''Sheaf Mount'' on the starboard side of the convoy an hour after the course alteration. ''Viscount'' obtained a RADAR contact and forced the submarine to submerge. As ''Viscount'' was dropping depth charges, ''U-176'' and ''U-438'' entered the front of the convoy to torpedo ''Trolla'' and ''Empire Breeze''.

Disengagement

The convoy escorts effectively intercepted attacks through the pre-dawn hours of 25 August. The calm sea conditions were favourable for the Type 271 centimeter-wavelength RADAR with which all the escorts were equipped, and prompt counter-attacks prevented the U-boats from reaching torpedo launch positions. A depth charge attack by ''Eglantine'' holed the conning tower of ''U-605''.Rohwer & Hummelchen p.157 ''U-135'', ''U-174'' and ''U-438'' were also damaged by depth charges. The shadowing U-boats lost contact after the convoy entered heavy fog after daybreak on 25 August, and discontinued pursuit on 26 August. ''U-256'' was under repair for more than a year after being bombed in the

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

on 31 August following depth charge damage from ''Viscount'' and ''Potentilla''. ''U-438'' aided ''U-256'' reaching port, and ''U-174'' refueled three ''Lohs'' U-boats before returning to France to repair damage. ''U-705'' suffered several casualties when hit by gunfire from the convoy escorts; and was sunk in the Bay of Biscay by

Armstrong Whitworth Whitley The Armstrong Whitworth A.W.38 Whitley was a British medium bomber aircraft of the 1930s. It was one of three twin-engined, front line medium bomber types that were in service with the Royal Air Force (RAF) at the outbreak of the World War II, ...

s of No. 77 Squadron RAF on 3 September. The ships in the convoy dispersed off

Cape Cod Cape Cod is a peninsula extending into the Atlantic Ocean from the southeastern corner of mainland Massachusetts, in the northeastern United States. Its historic, maritime character and ample beaches attract heavy tourism during the summer mon ...

on 3 September to proceed independently to North American ports.

Ships in the convoy

Allied merchant ships

A total of 37 merchant vessels joined the convoy, either in Liverpool or later in the voyage.

Convoy escorts

The armed military ships of

, from the

, escorted the convoy during much of its journey.

Notes

References

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