Battle of Atlantic , July 1941 , Indigo : US takeover of Iceland from British , Shipping Losses decrease

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Hitler’s U-Boat War 1939-1945 , Clay Blair Jr

In a secret speech to the House of Commons on June 25, Prime Minister Churchill expressed satisfaction at the changing fortunes of the British in the Battle of the Atlantic. His decision to establish the Battle of the Atlantic Committee† to focus utmost attention on that struggle had paid dividends. In spite of the increase in the size of the U-boat force, merchant-ship losses in the vital North Atlantic convoys had actually declined, as had shipping losses to enemy aircraft. Moreover, British shipyards were making astonishing progress in clearing out the backlog of ships idled with damage; the German air raids on the docks at Bristol Channel, Liverpool, Firth of Clyde, and elsewhere had tapered off to nearly zero; a new organization, the Ministry of War Transport, presided over by the business tycoon Frederick Leathers, had already developed more efficient methods of handling shipping and rail traffic. There were two other big reasons for Churchill’s optimism in his secret appraisal to the House on June 25. These were:

• Barbarossa, the German invasion of the Soviet Union, launched three days before on June 22. Although the British believed the Germans would defeat the ragged Soviet Army within several months, the military effort put into Barbarossa appeared to preclude any German invasion of the British Isles in 1941. If indeed this proved to be the case, the destroyers and other light ships of the Home Fleet on anti-invasion duty could be reassigned to convoy escort and also, possibly, to hunter-killer groups. This added commitment of naval power to the North Atlantic would doubtless bring about the long-sought and necessary increase in U-boat kills.

• Indigo, the American occupation of Iceland. Even as Churchill spoke to the House, a powerful American task force was about to set sail for that purpose.

President Roosevelt had set Indigo in motion on June 6. A momentous American enterprise, its main purpose was to absolutely secure air and naval bases for the American forces that were to assume responsibility for escorting convoys between Canada and Iceland, and for British escort forces working on the middle and eastern legs of the route. London also expected that the arrival of the Americans in Iceland would free up the British occupation forces there for duty in North Africa. Admiral Stark in Washington ordered Atlantic Fleet commander Admiral King to carry out Indigo on June 16. This was the first large-scale American military operation of World War II and, of course, the first major American expeditionary force to embark for overseas duty. It was carried out with dispatch and with naval professionalism, a credit to King and all concerned.

In late June about four thousand Marines boarded four US Navy troopships (APs). Their impedimenta filled two attack cargo ships (AKs). Admiral King directed seventeen warships to protect the force: old battleships USS Arkansas and USS New York; light cruisers USS Brooklyn and USS Nashville; and thirteen destroyers* of Squadron 7, of which nine were new (1940) and four were aged four-stacks.

Designated Task Force 19, the convoy sailed from the United States on July 1. En route, one of the new destroyers, USS Charles F. Hughes, came upon one of the two Greenland-bound lifeboats from the Norwegian freighter Vigrid, sunk from convoy Halifax HX-133 by U-371. The Hughes rescued the fourteen survivors of that boat, who included four of the ten American Red Cross nurses, who had been in the boat for twelve miserable days. The convoy arrived in Reykjavik harbor on the evening of July 7. Ironically, the debarking American Marines—the First Provisional Marine Brigade—were greeted by the surviving American Marines of the 12th Provisional Company who were torpedoed by U-564 while on the Dutch freighter Maasdam, also in convoy Halifax HX 133.

The Americans promptly set about building bases on Iceland. The next important contingent to arrive, on August 6, was the U.S. Navy’s Patrol Wing 7, consisting of a squadron (VP 73) of Consolidated Catalinas and a squadron (VP 74) of Martin Mariners, a newer, more powerful, and heavily armed twin-engine flying boat. These three dozen aircraft were supported by two aviation destroyer tenders (AVDs), USS George E. Badger and USS Goldsborough. At that time there were three squadrons of RAF Coastal Command aircraft based in Iceland. These squadrons flew about fifty American-built aircraft: nine PBY Catalinas in Squadron 209, twenty-six Hudsons in the (overstrength) Squadron 269, and eighteen Northrop scout bombers in Squadron 330, manned by Norwegian pilots. In addition, the RAF had provided about ten Hurricane fighters to counter possible German air strikes.

German naval authorities were incensed. Believing this latest American move in the Atlantic was a provocation too brazen to ignore, Dönitz proposed to Admiral Raeder and the OKM that it be countered by a U-boat assault. He found willing ears in Berlin, and Raeder set off at once to petition Hitler to lift the restrictions against attacking American warships and merchant ships (and British warships smaller than cruisers) in Icelandic waters.

Raeder met with Hitler on July 9, the eighteenth day of the offensive against Russia, Barbarossa. The American occupation of Iceland, Raeder insisted, “greatly affects our U-boats as well as surface vessels in the execution of the war in the Atlantic.” But Hitler refused to lift the restrictions. The stenographer recorded his views thus:

The Führer explains that everything depends on the U.S.A. ’s entry into the war being delayed another month or two. First, because the Eastern Campaign must be carried out with all the aircraft allotted for that purpose, and the Führer does not wish to deplete their numbers; secondly, because the effects of the victorious Eastern Campaign on the whole situation, even on the attitude of the U.S.A., would be tremendous. For the present, therefore, he desires that no alteration be made in the instructions, and that all incidents should be avoided.

The American occupation of Iceland thus drew scant naval reaction from Germany.

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Fruitless July Patrols in North Atlantic and Inflated Sinking Records in West African Shores :

Owing to the complicated new restrictions Hitler had placed on U-boats pending the success of Barbarossa, Dönitz was compelled to give Iceland and the Northwest Approaches a wide berth. Hence in July 1941, he shifted most of the twenty boats that sailed afresh to more southerly waters to attack Gibraltar and Sierra Leone convoys. In addition, Dönitz sent another wave to Freetown: four boats, all commanded by Ritterkreuz holders. These four were to refuel secretly from the German tanker Corrientes in the Spanish Canaries.

Reading German naval Enigma currently and fluently, thanks to several recent “pirches” of Enigma materials from enemy since March , the British Admiralty and Royal Navy Western Approaches Command and Submarine Tracking Room (Room 40) in Liverpool (led by Commander Rodger Winn) , almost completely outwitted Dönitz in July. They reinforced the Gibraltar and Sierra Leone convoys with extra air and surface escorts and cleverly diverted the convoys, taking advantage of an unseasonably dense fog in the central Atlantic. They brought to bear such strong diplomatic pressure on Spain’s dictator Francisco Franco that he closed the Canaries to German U-boats, forcing a cancellation of the special four-boat task force to Freetown. As a result, no U-boat discovered a convoy in July. All the initial convoy contacts came from Focke-Wulf Condor bombers basing in Bordeaux, or from the Italian boats based there.

The first Condor contact came on July 1, about 600 miles due west of Lorient. Dönitz ordered five boats to operate against the convoy, including the crack U-96, commanded by Ritterkreuz holder Heinrich Lehmann-Willenbrock. The boats established the convoy’s precise position by taking widely spaced bearings on the Condor’s beacon signals. Late on July 2, Klaus Scholtz, inbound from the Greenland area in U-108, found the convoy—Gibraltar-bound, he reported. But before Scholtz could bring up the other boats or the aircraft, he lost the ships in a dense fog and put into France, completing a highly satisfactory patrol of forty-one days during which he sank seven ships for 27,000 tons. Pursuing this contact through fog to the southwest, on the morning of July 5, Lehmann-Willenbrock in U-96 happened upon a curious formation of five ships: a Royal Navy yacht, HMS Challenger, leading a 6,000-ton freighter, Anselm. Three corvettes, HMS Petunia, HMS Lavender, and HMS Starwort, were deployed to port, starboard, and astern of Anselm with good reason: Anselm was a troopship with 1,200 soldiers on board.

Braving the menace posed by this unusually heavy escort, Lehmann-Willenbrock closed submerged and fired a full bow salvo at the Challenger and Anselm. He missed Challenger but two torpedoes hit Anselm. The ship sank in twenty-two minutes, but that was time enough for the crew to launch all but one of the lifeboats. Nonetheless, 254 of the 1,200 soldiers were lost. The yacht Challenger pulled sixty survivors from the water.

The three corvettes immediately pounced on U-96. Starwort’s sonar was out of commission, so Petunia and Lavender, which had firm contacts, delivered the attack. Petunia launched six depth charges and Lavender, twenty. When the attack carried the corvettes close to the survivors in the water, the depth-charging had to be broken off, but it had been deadly accurate. Later in the day Lehmann-Willenbrock reported to Kerneval that he was aborting the patrol with “extreme” depth-charge damage.

The second Condor report came a week later, on July 7: another outbound convoy about 250 miles off North Channel. Dönitz alerted all boats in the vicinity, but none was able to find the convoy. Nor any other convoy. As a result, confirmed sinkings in the first three weeks of July were abysmal: Lehmann-Willenbrock’s troopship, plus three other ships for 13,300 tons; one by Klaus Scholz in U-108 and two by Robert Gysae in U-98.

Dönitz was baffled and frustrated. Twice in a period of six days (July 15 to 20) he logged: “The difficult problem as ever is to find convoys.” As usual, he blamed the lack of contacts on the shortage of U-boats. “Only when the number of boats is larger,” he logged, “and there are more of them to keep a lookout, will the situation become more favorable.” (it never occured to him that British Naval Intelligence almost daily reading German Naval Enigma encryption and thanks to that intelligence British Admiralty and Royal Navy Western Approaches Command rerouting convoys at sea constantly after first sighting reports) He shifted the boats here and there, forming temporary patrol lines, then dissolving them and reforming new lines in other areas. But the British Admiralty cleverly countered these moves. Nothing seemed to work for the Germans.

The third convoy contact came from the Italian boat Barbarigo on July 22, west of Gibraltar. She called in Bagnolini. Barbarigo sank a confirmed ship, the 8,300-ton British tanker Horn Shell; Bagnolini claimed hits on two ships, but no British report confirmed her attack. Upon learning of this contact, Dönitz attempted to bring up the four boats of the cancelled Freetown special task force. One of these four, the U-109, commanded by Heinrich Bleichrodt, could not respond. She had put into Cadiz, Spain, for emergency repairs from the German supply ship Thalia. Dönitz substituted Rolf Mützelburg’s U-203, which had come south in vain pursuit of another ship, but with Royal Navy Western Aprroaches Commands orders , the convoy took prompt evasive action and neither Mützelburg nor the other three skippers could find Barbarigo’s convoy.

The fourth convoy contact came from another Condor on July 25, 400 miles due west of the English Channel. This was a combined outbound Gibraltar-Sierra Leone convoy, designated Gibraltar 69. It was composed of twenty-six ships, escorted by nine corvettes and an armed trawler. Eleven widely dispersed U-boats picked up the Condor’s beacon, enabling Kerneval to plot the convoy’s position with fair accuracy. Attacks to this convoy by U-Boats between 25-30 July before convoy reached Sierra Leone and Gibraltar shores under RAF air cover , were reasonably successful but Misled by the overclaims from the six boats that had shot at convoy Outbound Gibraltar OG-69, Dönitz believed another “great convoy battle” had taken place. He calculated the skippers had sunk seventeen or eighteen ships for about 108,000 tons, plus a destroyer and a corvette, figures Berlin propagandists hastened to inflate and release. 141.000 tons were sunk ! In reality, the sinkings were half of the Dönitz calculation and the tonnage only one-quarter of the claim. Five U-boats had sunk seven confirmed Gibraltar-bound ships for 11,303 tons and Heinrich Driver in U-371 had sunk two of the thirteen Freetown-bound ships for 14,000 tons. Total: nine ships for 25,300 tons SUNK. No destroyer or corvette had been sunk. Seventeen of the twenty-six merchant ships reached port. It became a bad habit for U-Boat captains to over inflate and over claim their sinkings.

During the month of July, 412 loaded merchant ships sailed from Canada in Halifax and Sydney (or Slow) convoys to the British Isles. Remarkably, not one ship from these North Atlantic convoys fell victim to a U-boat. To avoid possible angry Axis reaction to the American occupation of Iceland, Halifax HX-135 convoy followed a “southerly” route. Halifax 136 included the first CAM (fighter-plane catapult) ship. At mid-month, Halifax 138 and Slow Convoy SC-37 sailed experimentally across the Gulf of St. Lawrence and into the Atlantic via Belle Isle Strait, thence to Cape Farewell, then north along the ice-bound east coast of Greenland. These convoys encountered heavy fog and icebergs and, as a result, a number of collisions occurred.

The heavy ship traffic in the opposite direction on the North Atlantic run also fared well. Altogether eleven outbound convoys comprising 536 vessels sailed from the British Isles. As related, Robert Gysae in U-98 sank two empty freighters for 10,800 tons from convoy Outbound 341. A Focke-Wulf Condor damaged an empty freighter in Outbound 346. In sum, upward of one thousand Allied ships of about 5 million gross tons sailed the North Atlantic route in east and west convoys in July 1941, virtually unharmed by the oceangoing U-boats.
Allies and Royal Navy particularly won first clear strategic sucess in Battle of Atlantic.

Toward the end of July, the British instituted a new system for naming these outbound convoys. After Outbound 346, all convoys bound ultimately for the West Indies, Latin America, or West Africa were named Outbound South (OS). Off North Channel on July 26, Philipp Schüler in the duck U-141 hit two empty freighters in OS 1. One of them, of 5,100 tons, sank; the other limped back to port. After Outbound 349, all convoys bound for Canada or the United States East Coast were named Outbound North (ON). The odd-numbered convoys were slow, the even-numbered convoys were fast.