In May 1943, Allied forces used a newly adopted offensive doctrine and technological innovations to reverse the course of the Battle of the Atlantic. The British, followed by the Canadians, led the way in the North Atlantic. But the U.S. Navy also played a role there.
On 20 May, the 23 U-boats of Wolf Pack Mosel were assembling a patrol line in the North Atlantic air gap as westbound Convoy ON 184 approached. Protecting the 39-ship convoy was its close escort, Canadian Escort Group C-1, comprising the Canadian destroyers St. Lauren and St. Croix, the British frigate Itchen, and three Canadian corvettes. Augmenting these warships during the transit through the air gap was a support group whose assignment was offensive—to find and sink U-boats.
That unit was built around the USS Bogue (CVE-9), which was making her fourth Atlantic crossing. Before setting out, while in Belfast, the carrier received a key piece of antisubmarine equipment: a high-frequency direction finding (HF/DF) set, which could detect the bearing of U-boat radio transmissions. It quickly would prove its worth, enabling one of the Bogue’s TBF-1 Avengers to home in on a Mosel submarine, which shortly thereafter became the first U-boat “kill” by escort carrier planes. That was after other Bogue Avengers had heavily damaged three other German submarines.
What follows is an edited version of the Bogue’s action report of the cruise, which is found in Record Group 38 at the National Archives in College Park, Maryland.
From: Commander Sixth Escort Group
To: Commander in Chief Western Approaches
Subject: Report of Proceedings—USS BOGUE Escorting Convoy ON 184
In compliance with sailing orders the Bogue departed Belfast Lough at 1837 Z, May 15, 1943, and effected rendezvous with surface escorts of Task Group 92.3 less the USS Lea (DD-118) off Lough Foyle at 2200 Z.1 This group—shortly to be referred to as the Sixth Escort Group—proceeded without incident to Iceland arriving outer entrance swept channel at 1500, May 17. The USS Belknap (DD-251), Osmond Ingram (DD-255), and George E. Badger (DD-196) were ordered to Reykjavik for refueling and provisions while the Bogue and Greene (DD-266) proceeded on to Hvalfjordur.
The Sixth Escort Group had received orders to escort the SS Toltec from Iceland to join up with ON 184. At 0035 Z on May 18, the Bogue and Greene got under way and proceeded to rendezvous with the Belknap, Badger, Osmond Ingram, and Toltec. At 0211 the rendezvous was effected and course was set to cross ahead of the projected track of Convoy ON 184, to avoid a tail chase and to scout ahead of the convoy.
The Lea had been delayed several hours at Iceland for repairs and fuel. She overtook the Sixth Escort Group and assumed position in the antisubmarine screen at 0900 Z.
At dawn on May 19, three planes were launched to locate and cover the convoy. At 0545 Z one of the planes reported sighting the convoy bearing 130 degrees T, distance 20 miles. Upon intercepting the convoy, the Toltec was delivered to the Commodore.
At about 0930 Z the Bogue’s destroyer escorts took previously assigned positions in the convoy’s antisubmarine screen and the Bogue took station in the Commodore’s column astern of the escort tanker.
Flight operations were held on May 18, 19, 21, 22, 23, 24, and 25.
On May 21, a TBF-1 on patrol attacked a submarine on the surface and probably sank it.2
On May 22, five attacks were made by planes from the Bogue on four submarines.3 One submarine surrendered, after being attacked by two TBF-1s, and was subsequently scuttled by the crew. The U-boat captain, 2 officers, and 21 enlisted ratings were rescued and taken as prisoners by the St. Laurent, which had been sent to the scene following the surrender of the U-boat to the plane.
The attacks on the other three submarines on May 22 resulted in the probable sinking of two and the probable inflicting of heavy damage to the third.4
From the time the Bogue left Belfast, a continuous watch had been maintained on the newly installed HF/DF. Three radiomen from the Bogue manned this equipment under the supervision of Sub-Lieutenant J. B. Elton, RNVR, who had been assigned by CiCWa to assist on this trip.5 The HF/DF equipment proved invaluable. On the morning of May 22, this equipment was used to home one of the TBFs. At 1051, an HF/DF bearing was obtained on a submarine, but before this bearing could be transmitted, a TBF on patrol had already attacked the submarine. In the afternoon, an HF/DF bearing was directly responsible for the attack on the submarine which surrendered.
An interesting point about the HF/DF bearing referred to above was that the U-boat was transmitting a 59 group enigma message on series eight. Shortly thereafter, Naval Service Headquarters Ottawa’s dispatch 221956 Z was received which is quoted below:
10 TH OF 58 AND 59 GROUP ENIGMA MESSAGES ON SERIES 8 AT 1323 Z AND 1727 Z FROM VICINITY OF ON-184 OR HX-239 PROBABLY THE LATTER X NO EVIDENCE THESE TRANSMISSIONS FROM U-BOAT IN CONTACT
Without doubt, the latter transmission at 1727 Z was made by the U-boat and wrote its death warrant.
On the morning of May 25, in compliance with orders from CiCWa and Commodore Commanding Newfoundland Forces, and in agreement with the senior officer of the escort, the Sixth Escort Group detached from the convoy in latitude 46º17’, longitude 43º50’ and proceeded to Argentia.
1. 1837 and 2200 Zulu time, or Greenwich mean time.
2. The submarine was heavily damaged but not sunk.
3. Only three U-boats were attacked.
4. The other two U-boats attacked were heavily damaged.
5. CiCWa—Commander-in-Chief Western Approaches.
The Bogue’s Avenger Attacks
21 May 1943
1. Flying 60 miles from Convoy ON 184, Lieutenant Commander William M. Drane spots a U-boat’s wake, circles ahead of the submarine, and attacks, releasing four depth bombs from 50 feet. The heavily damaged boat, U-231, is forced to head home for repairs.
22 May
2. Lieutenant (junior grade) Roger C. Kuhn spots a surfacing U-boat, U-468, and attacks, exchanging gun fire with the submarine as he closes in. Two of his depth bombs heavily damage the boat, which remains on the surface down by the stern for more than an hour before slowly sinking below the surface and heading back to France.
3. F4F Wildcat fighter pilot Lieutenant Richard Rogers sights a U-boat, U-305, 35 miles ahead of the convoy. The submarine quickly dives.
4. When U-305 surfaces, Avenger pilot Ensign Stewart Doty spots her at 1005 and closes in as she heads toward ON 184, 16 miles away. After Doty drops his depth bombs, the U-boat appears to go out of control before slipping below the waves. Two minutes later her bow breaks the surface with the boat at a 45-degree angle, before she again settles below the water.
5. U-305 eventually resurfaces and shortly after noon is spotted by Lieutenant (junior grade) Robert L. Stearns. Despite 20-mm antiaircraft fire from the boat, Stearns drops his four depth bombs from 125 feet. The heavily damaged U-boat dives, breaking off her pursuit of the convoy and heading for home.
6. That evening, Lieutenant (junior grade) William F. Chamberlain is investigating a HF/DF bearing when he spots a U-boat in the position reported. Catching the submarine, U-569, by surprise, he drops four depth bombs that straddle the vessel.
7. When U-569 surfaces 30 minutes later, Chamberlain’s relief, Lieutenant H. S. Roberts, is overhead. After he drops his four depth bombs, the submarine surrenders and her engineer officer scuttles her, going down with the boat. Twenty-four of her 46-man crew are rescued, including her skipper, Oberleutenant Hans Friedrich Johannsen.