Operation Stonewall

Naval operation during the Second World War

Second World War

Part of Operation Stonewall of the Atlantic campaign

The Bay of Biscay
| Location|

Bay of Biscay

45°30′N 04°24′W﻿ / ﻿45.500°N 4.400°W﻿ / 45.500; -4.400

|

Result|  Allied victory

* v
* t
* e

Atlantic campaign

* Americas
* United States
* Caribbean
* St. Lawrence
* Northern Barrage
* Blockade of Germany
* Gibraltar

* * *

1939

* River Plate

1940

* HX 47
* HX 49
* 1st Happy Time
* HX 65
* SC 2
* HX 72
* SC 7
* HX 79
* HX 84
* Nordseetour
* HX 90

1941

* SC 19
* SC 20
* Berlin
* HX 106
* HG 53
* OB 293
* HX 112
* 4 April
* OB 318
* HX 126
* Rheinübung
* Denmark Strait
* Bismarck
* HX 133
* OG 69
* OG 71
* SC 42
* HG 73
* SC 48
* HX 156
* HG 76

1942

* Postmaster
* 2nd Happy Time
* Torpedo Alley
* SC 67
* Neuland
* ON 67
* 27 March
* OG 82
* ON 92
* 6 June
* HG 84
* SL 78
* QS 15
* ON 113
* ON 115
* SC 94
* ON 122
* Bell Island
* QS 33
* ON 127
* Laconia
* SQ 36
* SC 100
* SG 6/LN 6
* SC 104
* HX 212
* SL 125
* SC 107
* ON 144
* ON 153
* ON 154

1943

* TM 1
* SG 19
* SC 118
* ON 166
* UC 1
* SC 121
* HX 228
* UGS 6
* HX 229/SC 122
* HX 231
* Black May
* ONS 5
* HX 237
* SC 129
* SC 130
* Faith
* ONS 18/ON 202
* SC 143
* ONS 20/ON 206
* Sept-Îles
* ON 207
* SL 138/MKS 28
* SL 139/MKS 30
* SL 140/MKS 31
* Stonewall
* Bay of Biscay

1944

* Lyme Bay
* 26 April 1944
* Capture of U-505
* HX 300
* WEP 3
* BX 141

1945

* Teardrop
* Point Judith
* 5–6 May 1945
* 7–8 May 1945

Operation Stonewall was a naval operation in the Second World War from 26 to 27 December 1943 to intercept blockade-runners off the west coast of German-occupied France. It was an example of good inter-service and inter-Allied co-operation.

## Background[edit]

### Allied blockade of Germany[edit]

From the start of the war, the Allies had maintained a blockade of Germany to prevent the import of goods by Germany. Although rich in many basic industrial materials, Germany, like Britain, could not indigenously produce some essentials. These included rubber, oil, tin and tungsten. Until Operation Barbarossa the German invasion of the Soviet Union, it evaded the blockade via the Trans-Siberian Railway. Large quantities of materials were shipped by this route. After this was closed, German and Italian ships, stranded in Japan and Japanese-occupied Singapore, were used as blockade-runners to bring goods to ports in occupied France.[1]

### Ultra (cryptography)[edit]

Main article: Ultra (cryptography)

Locator map of the Azores

The defeat of the German U-boat offensive in the Battle of the Atlantic in 1943 was followed by the last attempt by the Germans to pass blockade-runners through the Bay of Biscay to and from the Japanese empire. From May 1943 decrypts of Japanese diplomatic wireless traffic revealed to the Allies that the losses of the 1942–1943 had not deterred the Axis from making another attempt in the autumn. Seven merchant ships were to sail from Europe carrying 50,000 long tons (51,000 t) of exports and that the Germans were building special U-boats to import 3,000 long tons (3,000 t) of goods from Japan in 1943. In July and August, photographic reconnaissance and agent reports from the French Atlantic ports that sailings for the far East were being prepared and by 6 September it was clear that seven ships were close to sailing.[2]

On 4 October, after the blockade-runner Kulmerland had been hit by bombers, a signal from the Japanese Ambassador in Berlin showed the Allies that the export programme had been cut to 35,000 long tons (36,000 t) because of the Allied bombing.[2] On 18 July the British and Portuguese reached a basing agreement for the Azores, which came into force on 8 October and which had the potential to deter the Axis from trying to run the blockade.[3] On 23 October, the Germans introduced new W/T methods for signalling between U-boats and blockade-runners in the Bay of Biscay and in early November Dresden, thought to be a blockade-runner, struck a mine. The British thought that five ships were preparing to leave the Bay and that four ships were preparing in the Far East. Later in November, another decrypt from the Japanese Ambassador revealed that the German export programme had been reduced again, to 29,000 long tons (29,000 t). US Navy patrols in the South Atlantic has been increased.[4]

Coastal Command prepared a force of Halifax and Liberator bombers to attack the blockade-runners as they crossed the Bay. Cruisers were put under the command of the naval Commander-in-Chief Plymouth (Admiral Ralph Leatham) for operations against the blockade runners.[5] The Shark cypher for U-boats was often being decrypted quickly; the U-boats were sailing in distant waters which required more signals from Befehlshaber der U-Boote (U-boat command HQ) about blockade-runners. The British Government Code and Cypher School (GC&CS) broke the Sunfish Enigma key used by the blockade-runners. Armed with this intelligence, the Allies were able to prevent any blockade-runner from escaping from the Bay from November 1943 to January 1944 when the Germans gave up.[4]

## Prelude[edit]

### Operations Barrier and Freecar[edit]

Map of the Bay of Biscay

Evidence that the new round of departures from the Far East had begun was found in an Ultra decrypt of 16 November prohibiting U-boat attacks west of a line in the south Atlantic. The Naval and air commanders were told that a northbound blockade-runner and possibly another eight were approaching, including Osorno and Alsterufer. Little was revealed by OP-20-G, the US Navy (USN) code-breaking organisation, until 26 November that on the day before the U-boat restrictions in the south Atlantic were imposed further north on 1 December.[6][a] Operation Barrier began with Task Force 41 (TF.41) with five task groups, each comprising a cruiser and a destroyer and USN aircraft patrols from Natal, Brazilian Air Force patrols from Recife and flights by USN patrol bombers from Ascension Island on 1 December.[6]

Operation Freecar began soon afterwards with the armed merchant cruisers HMS Corfu and Cilicia, the French cruiser Suffren and the Italian cruisers Abruzzi and d'Aosta.[6] The first blockade-runner en route to Europe was Osorno 6,951 GRT (Captain Hellmann) sailed from Kobe on 2 October, disguised as the British ship Prome, rounding the Cape of Good Hope on 15 November. The ship was spotted on 8 December by Liberator B-8 of VPB-107 from Ascension but TG.41.4 (the cruiser USS Marblehead and the destroyer Winslow) found only a Greek ship. Searches to the north-west failed but the ship was sighted by German submarine U-510 whose sighting report was decrypted by OP-20-G on 13 December and operations Barrier and Freecar were suspended, the refrigerated cargo ship (reefer) Alsterufer 2,170 GRT (Captain Piatek) passing unseen.[6]

More information was received by the Allies on 5 December that the restrictions were in force north of the equator from the next day. The Admiralty signalled the importance given to preventing the arrival of blockade-runners on 12 December and the Royal Navy light cruiser HMS Glasgow left on patrol from the Azores. On 18 December a Sunfish message to Osorno and Asterufer of 13 December was decrypted and on 22 December a decrypt of the U-boat Shark cypher showed that the U-boat restrictions were in force west of the Bay.[7] On 26 November the Italian ship Pietro Orseolo sailed from Bordeaux to Concarneau on the south Brittany coast and was attacked by aircraft on 1 December to no effect.[8]

### Hunt for Orsona[edit]

After the first blockade-runner managed to pass the Natal–Freetown narrows, Leatham began Operation Stonewall. The Royal New Zealand Navy (RNZN) light cruiser HMNZS Gambia and Glasgow sailed from Plymouth to Horta in the Azores taking turns to patrol, fuelling from a tanker at Horta. From 16 to 17 December, Osorno crossed the US to Gibraltar convoy route undetected.[9] Coastal Command assembled a force of Beaufighters and Torbeau torpedo bombers with an escort of Typhoon fighters, attacked the outbound Pietro Orseolo on 18 December, inflicting such damage that the ship later sank off Lorient.[8] On 19 December Osorno passed through the US–UK route near Convoy ON 215, following a day behind Convoy HX 270 and a day in front of Convoy SC 149. Alsterufer crossed the US–Gibraltar route on 20 December, not far from TG.21.16, which included the carrier USS Block Island and four destroyers.[10]

Alsterufer was behind the westbound Convoy GUS 23 and near the eastbound Convoy UGS 27.[10] From 21 to 22 December, Osorno turned east for the Bay of Biscay and crossed the paths of Convoy KMF 27 and Convoy MKS 33/SL 142. Wolfpack Borkum, was formed from the southernmost boats of Wolfpack Coronel to attack Convoy MKS 33/SL 142, which was accompanied by the Escort Group B4 and a support group based on HMS Fencer. The attack was to cover the return of Osorno[10][b] TG.21.15 comprising the escort carrier USS Core with four destroyers, detached from Convoy GUS 24 and TG.21.14 with the escort carrier Card and three destroyers, hunted Wolfpack Borkum, which was assisted by five FW 200 Kondor bombers flying by day, a BV 222 flying boat on the night of 20/21 December and more aircraft during the next day but no ships were sunk.[10]

German aircraft reported the escort carrier groups three times on 22 and 23 December.[10] Gambia and Glasgow were behind Osorno; Alsterufer was distant from Convoy CU 9 to the east, TG.21.16 to the south-east and Convoy SC 149 to the north.[9] On 23 December, a F4F fighter from Card sighted a suspect ship, which was Osorno about 500 nmi (930 km; 580 mi) south-west of Ushant but the aircraft lost track of the ship in bad weather.[10][c] During the evening of 24 December, Convoy OS 62/KMS 36 from the north with Escort Group B1 and the support group of the escort carrier HMS Striker ran into Wolfpack Borkum and German submarine U-415 sank HMS Hurricane with a T5 torpedo.[12]

### Unternehmen Bernau[edit]

At noon on 24 December, the 8. Zerstörerflotille (8th Destroyer Flotilla, Captain Erdmenger, Z 27, Z 23, Z 24, Z 32, Z 37 and ZH 1) with the 4. Torpedobootsflottille (4th Torpedo Boat Flotilla, Korvettenkapitän Franz Kohlauf) with T 22, T 23, T 24, T 25, T 26 and T 27 began Unternehmen Bernau by departing from the estuary of the Gironde to rendezvous with Osorno and escort it to port. From dawn on 25 December, Sunderland flying boats from 201 Squadron RAF, 422 Squadron RCAF and 461 Squadron RAAF were in contact with the German escort force but the rendezvous with Osorno was made after it shot down a Sunderland. Attacks by aircraft of 19 Group Coastal Command were thwarted by anti-aircraft fire from the ships and long-range Ju 88 fighters sent by Fliegerführer Atlantik. Osorno reached the Gironde estuary, then ran into the wreck of Seprrbrecher 21 and had to be beached.[12] Bomber Command sent twelve Stirling bombers on the night of 29/30 December to mine the waters around the ship to obstruct the unloading of its cargo of rubber but the Germans got most of it ashore.[13]

## Hunt for Alsterufer[edit]

### Unternehmen Trave[edit]

Map of the battle

The 8. Zerstörerflotille and the 4. Torpedobootsflottille, less ZH 1 which had engine-trouble, sailed into the Bay of Biscay again on 26 December to meet Alsterufer and escort it into the Gironde. Early on 27 December the ship was spotted by a Sunderland about 500 nmi (930 km; 580 mi) north-west of Cape Finisterre. From east of Alsterufer, the light cruiser Enterprise formed a cordon with Glasgow 300 nmi (560 km; 350 mi) to the west, to 300 nmi (560 km; 350 mi) north-west of Finisterre. Gambia (Captain William Powlett, also the flotilla commander), departed from Faial Island in the Azores. The light cruiser Penelope and the fast minelayer Ariadne sailed from Gibraltar and two Free French destroyers, Le Fantasque and Le Malin, were sent from the Azores.[14]

### Sinking of Alsterufer[edit]

Alsterufer under attack by a Czechoslovak-crewed RAF Liberator

On 27 December, at 4:15 p.m.} the Liberator GR Mk V "H" of 311 (Czech) Squadron, Coastal Command, sighted Alsterufer.[15][d] The Liberator made a diving attack with eight wing-mounted, semi-armour piercing (SAP60) rocket projectiles. Five of the rockets hit the cargo ship above the waterline and a 500 lb (230 kg) bomb and a 250 lb (110 kg) bomb were dropped, one hitting the ship aft of the funnel, setting the ship on fire.[15] Alsterufer had opened fire with anti-aircraft guns and parachute-and-cable rockets, hitting the Liberator's starboard outer engine but the aircraft returned to base at RAF Beaulieu in England. A force of Halifax bombers arrived at 6:00 p.m. to find the ship on fire and sinking; Alsterufer sank on the afternoon of 28 December. Four lifeboats with 74 survivors were picked up two days later by four Canadian corvettes.[16]

### Battle of the Bay of Biscay[edit]

Main article: Battle of the Bay of Biscay

A view from Z27 of T25 and T26 being shelled. A drawing by Hans Helmut Karsch, a German sailor, during internment at the Curragh Camp. (National Maritime Museum of Ireland)

Naval Group West did not find out about the loss of Alsterufer until morning on 28 December and cancelled Unternehmen Bernau ordering the ships to return. The flotilla was spotted by a Liberator of VPB-105 and attacked by fifteen more Liberators from the squadron and VPB-103, which enabled Glasgow and Enterprise to intercept them at noon. The eleven ships of the flotilla had twenty-five 150 mm and twenty-four 105 mm guns against the nineteen 6-inch and thirteen 4-inch guns of the cruisers and tried to attack them from both flanks but the stormy seas prevented the ships from sailing at their maximum speed.[14]

Z 27 (Captain Günther Schultz, with the flotilla commander, Captain Erdmenger, aboard), T 25 and T 26 were sunk. Z 24, T 23, T 24 and T 27 returned to Brest; Z 32, and Z 37 got to the Gironde and Z 23 with T 22, which had turned south, made port at St Jean de Luz. Sixty-four survivors were rescued by Royal Navy minesweepers, 168 by the Irish coaster, Kerlogue, six by Spanish destroyers and 55 by German submarine U-505 and German submarine U-618. Glasgow, Enterprise and Ariadne returned to Plymouth under glider-bomb attack and Penelope, Le Fantasque and Le Malin to Gibraltar. Gambia and Mauritius patrolled north of the Azores for blockade-runners until 1 January.[17]

## Aftermath[edit]

### Analysis[edit]

Morale in the Kriegsmarine was depressed further with the news that the battleship Scharnhorst had been sunk on 26 December at the Battle of the North Cape.[18] Osorno was the last blockade-runner to reach port, its cargo of rubber meeting German needs until November 1944.[19] In 1984, Harry Hinsley wrote in the official history of British intelligence in the war that the defeat of the German destroyer flotilla, like the sinking of Scharnhorst, could only have happened because the Admiralty was receiving decrypts of Enigma messages almost as quickly as their German addressees. The engagement also finally made the Admiralty admit that the German Type 1936A destroyers (Narvik-class to the British) carried 6 in (150 mm) guns.[20]

### Casualties[edit]

Of the 672 men on the three sunken ships, 93 were rescued from Z27, 100 from T25 and 90 from T26.[21] About 62 survivors were picked up by British minesweepers, 168 were rescued by a small Irish steamer, the MV Kerlogue, and four by Spanish destroyers.[22][18]

### Subsequent operations[edit]

The last three blockade-runners, Weserland, Burgenland and Rio Grande were known to the Allied through decrypts of their sailings from the Far East. US forces intercepted them in the south Atlantic from 3 to 5 January 1944. After another nine days, Sunfish decrypts revealed that the Germans did not know of the interceptions and had ordered two of their blockade-runners to prepare to sail. On 21 January it was discovered that all four blockade-runners preparing for the voyage top the Far East had been ordered to stand down because of the risk of interception.[20][e]

## Orders of battle[edit]

Ships: Canadian, French, New Zealand, United Kingdom, United States
Aircraft: United Kingdom (including one with Czechoslovak crew), United States

## Notes[edit]

1. ^ The sailing of five blockade runners had been revealed to US code-breakers by the Purple and Bertok/Barnacle cyphers.[6]
2. ^ Wolfpack Coronel was operating further north and Borkum comprised U-801, U-107, U-667, U-618, U-270, U-541, U-645, U-962, U-415, U-305, U-275, U-382 and U-641.[10]
3. ^ During the night of 23/24 December German submarine U-305 sighted TG.21.14 but was deterred by one of the destroyers, which detected it with HF/DF. German submarine U-415 fired three FATs (Flächenabsuchender Torpedo [area searching torpedo]) at Card but missed and also missed a destroyer with a G7es torpedo (T5). German submarine U-645 missed a destroyer with a T5 and was sunk by depth charges; German submarine U-275 hit the destroyer USS Leary with a T5 and it was sunk by a torpedo from German submarine U-382; TG.21.14 had to withdraw because of fuel shortage.[11]
4. ^ The Captain was Pilot Officer Oldřich Doležal with Sergeant Robert Prochazka, co-pilot, Flying Officer Zdeněk Hanuš, Navigator/Bomb Aimer, Warrant Officer Josef Kosek, Air Gunner, Flight Sergeant Jindřich Hahn, Radar Operator/Air Gunner, Flight Sergeant Marcel Ludikar, Wireless Operator/Air Gunner, Flight Sergeant Ivan Schwarz, Wireless Operator/Air Gunner and Sergeant František Veitl, Flight Engineer.[15]
5. ^ After the war it was found that Donitz had suggested to Hitler on 18 January 1944 that blockade-running be cancelled.[23]

## Footnotes[edit]

1. ^ Roskill 1957, p. 9, 43–44, 65, 551–552.
2. ^ a b Hinsley 1984, p. 247.
3. ^ Roskill 1960, pp. 46–47.
4. ^ a b Hinsley 1984, pp. 247–248.
5. ^ Roskill 1960, pp. 72–73.
6. ^ a b c d e Rohwer & Hümmelchen 2005, p. 290.
7. ^ Hinsley 1984, pp. 248–249.
8. ^ a b Roskill 1960, p. 74.
9. ^ a b Rohwer & Hümmelchen 2005, p. 292.
10. ^ a b c d e f g Rohwer & Hümmelchen 2005, p. 293.
11. ^ Rohwer & Hümmelchen 2005, pp. 293–294.
12. ^ a b Rohwer & Hümmelchen 2005, p. 294.
13. ^ Roskill 1960, pp. 73–74.
14. ^ a b Rohwer & Hümmelchen 2005, p. 295.
15. ^ a b c Vančata 2013, p. 64.
16. ^ Vančata 2013, p. 64; Rohwer & Hümmelchen 2005, p. 295.
17. ^ Waters 1956, p. 355; Rohwer & Hümmelchen 2005, p. 295.
18. ^ a b Whitley 1983, pp. 193–199.
19. ^ Müller 2003, p. 581.
20. ^ a b Hinsley 1984, p. 251.
21. ^ O'Hara 2004, pp. 277–279.
22. ^ Waters 1956, p. 355.
23. ^ Hinsley 1984, pp. 251–252.

## References[edit]

* Hinsley, F. H.; Thomas, E. E.; Ransom, C. F. G.; Knight, R. C. (1984). British Intelligence in the Second World War, Its Influence on Strategy and Operations (Part I). History of the Second World War. Vol. III (1st ed.). London: HMSO. ISBN 0-11-630935-0.
* Kroener, Bernhard R.; Müller, Rolf-Dieter; Umbreit, Hans (2003) [1999]. Organization and Mobilization of the German Sphere of Power: Part 2 Wartime administration, economy and manpower resources1942–1944/5. Germany and the Second World War. Vol. V. Translated by Cook-Radmore, Derry; Osers, Ewald; Smerin, Barry; Wilson, Barbara (Eng. trans. Clarendon Press, Oxford ed.). Stuttgart: Deutsche-Verlags-Anstalt GMBH for Militärgeschichtliches Forschungsamt (Research Institute for Military History) Potsdam, Germany. ISBN 0-19-820873-1.
* Müller, Rolf-Dieter. "Part II Albert Speer and Armaments Policy in Total War. III Basic Conditions of Wartime Production, and Civilian Factors. 4. Organization and Exploitation of 'Fortress Europe'. (c) The Decline in Wartime Foreign Trade (xiii) Japan". In Kroener, Müller & Umbreit (2003).
* O'Hara, Vincent P. (2004). The German Fleet at War, 1939–1945. Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-651-8.
* Rohwer, Jürgen; Hümmelchen, Gerhard (2005). Chronology of the War at Sea 1939–1945: The Naval History of World War Two (3rd rev. ed.). Annapolis, Maryland: Naval Institute Press. ISBN 1-59114-119-2.
* Roskill, S. W. (1957) [1954]. Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Defensive. History of the Second World War United Kingdom Military Series. Vol. I (4th impr. ed.). London: HMSO. OCLC 881709135. Archived from the original on 27 February 2022. Retrieved 14 January 2019.
* Roskill, Stephen (1960). Butler, J. R. M. (ed.). The War at Sea 1939–1945: The Offensive Part I 1st June 1943 – 31st May 1944. History of the Second World War United Kingdom Military Series. Vol. III. London: HMSO. OCLC 987392618.
* Vančata, Pavel (2013). 311 Squadron. Sandomierz: Stratus, for Mushroom Model Publications. ISBN 978-83-61421-43-6.
* Waters, S. D. (1956). "Chapter 23, The New Zealand Cruisers". Royal New Zealand Navy (online scan). The Official History of New Zealand in the Second World War 1939–1945 (New Zealand Electronic Text Collection ed.). Wellington: Historical Publications Branch. pp. 352–356. OCLC 173284131.
* Whitley, M. J. (1983). Destroyer!: German Destroyers in World War II. London: Arms & Armour Press. ISBN 978-0-85368-258-5.

## Further reading[edit]

* Blair, Clay (2000) [1998]. Hitler's U-Boat War: The Hunted 1942–1945. Vol. II. London: Cassell. ISBN 0-304-35261-6.
* Lambert, Andrew (1986). Warship. Vol. X. Naval Institute Press. ISBN 978-0-85177-449-7.
* Morison, Samuel (1947). The Battle of the Atlantic 1939–1943. History of United States Naval Operations in World War II. Vol. I. Boston: Little, Brown and Co. OCLC 162633216 - via Archive Foundation.
* Oldfield, Paul (2013). Cockleshell Raid. Battleground: French Coast. Barnsley: Pen & Sword. ISBN 978-1-78159-255-7.
* Šulc, Jiří (2011). Operace Stonewall (in Czech). Prague: Knižní klub. ISBN 978-80-242-5788-4.

## External links[edit]

* 70th Anniversary of the sinking of Alsterufer

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