Design
Type IXB submarines were slightly larger than the original Type IX submarines, later designated IXA. U-124 had a displacement of 1,051 tonnes (1,034 long tons) when at the surface and 1,178 tonnes (1,159 long tons) while submerged. The U-boat had a total length of 76.50 m (251 ft), a pressure hull length of 58.75 m (192 ft 9 in), a beam of 6.76 m (22 ft 2 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.70 m (15 ft 5 in). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 metric horsepower (740 kW; 990 shp) for use while submerged. She had two shafts and two 1.92 m (6 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 18.2 knots (33.7 km/h; 20.9 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph). When submerged, the boat could operate for 64 nautical miles (119 km; 74 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 12,000 nautical miles (22,000 km; 14,000 mi) at 10 knots (19 km/h; 12 mph). U-124 was fitted with six 53.3 cm (21 in) torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm (4.13 in) SK C/32 naval gun, 180 rounds, and a 3.7 cm (1.5 in) SK C/30 as well as a 2 cm (0.79 in) C/30 anti-aircraft gun. The boat had a complement of forty-eight.
Service history
U-124 conducted eleven war patrols, sinking 46 ships, totalling 219,862 gross register tons (GRT) and sinking two warships, totaling 5,775 long tons (5,868 t). She also damaged four ships, totalling 30,067 GRT. She was a member of two wolfpacks.
First patrol
U-124's first patrol began with her departure from Wilhelmshaven on 19 August 1940. Her route took her across the North Sea and through the gap between the Faroe and Shetland Islands. She attacked three ships northwest of Scotland; Stakesby, Harpalyce and Firecrest, all on the 25th. To avoid retaliation from HMS Godetia, the boat dived to 90 m (300 ft). The Royal Navy Flower-class corvette dropped 12 depth charges. Striking rocks on the sea-bed, the boat lay there for an hour, the corvette lost contact, but the collision had damaged three of her torpedo tubes. As a result, she spent the rest of the patrol reporting on the weather.
The submarine docked at Lorient on the French Atlantic coast, on 16 September.
Second patrol
U-124's second foray was conducted further northwest of the Scottish mainland. Her first victim was Trevisa; sunk on 16 October 1940 218 nmi (404 km; 251 mi) west of Rockall. The next day, 17 October, the Royal Navy River-class submarine HMS Clyde fired three torpedoes at her. All missed, and U-124 remained unaware of the attack.
U-124 went on to sink another four ships; Cubano, Sulaco (there was only one survivor) both on 20 October, Rutland on the 31st and the Empire Bison on 1 November. The latter ship's four survivors, on a raft when the U-boat came to investigate, played dead as they did not wish to be taken prisoner.
Third patrol
On her third sortie U-124 sank Empire Thunder north-northeast of Rockall on 6 January 1941.
Fourth patrol
On her fourth patrol the boat went to the Central Atlantic. U-124 refueled on 4 March in the neutral Spanish port of Las Palmas on the Canary Islands. On 6 March she rendezvoused with the German battleships Scharnhorst and Gneisenau under the command of Günther Lütjens. The ships operated loosely together in order to attack convoy SL 67. Escorting the convoy was the British battleship HMS Malaya. Lütjens wanted the U-boat to sink the Malaya so he could attack and sink the complete convoy. U-124 attacked north of the Cape Verde Islands during the night of 7/8 March and sank four ships: Nardana, Hindpool, Tielbank and Lahore. The Malaya escaped unharmed and the German battleships had to abort their attack.
She then destroyed another seven vessels southwest of Freetown, in Sierra Leone: Umona on 30 March, Marlene on 4 April, Portadoc on 7 April, Tweed a day later, Aegeon on the 11th, St. Helena on the 12th and the Corinthic on the 13th. 102 people died as a result of her sinking Umona. One account claims that after sinking her, U-124 surfaced and captured the liner's fourth officer from a lifeboat, and that he was never seen again. [3]
Corinthic was first struck by a dud torpedo, but another functioned correctly and sank the ship.
During this patrol U-124 also rendezvoused with the heavy cruiser Admiral Scheer in order to give her a Quartz spare part for her defective Seetakt radar.
Fifth patrol
U-124 drew a blank on her fifth sortie, failing to destroy a single target. She scoured the central Atlantic southwest of Gibraltar, but found nothing.
Sixth patrol
Her sixth patrol was successful. Mohr, (her new commander), rather ambitiously claimed two ships totaling 15,000 tons sunk and a third vessel of 8,000 tons damaged. The reality was rather different. Baltallin (1,303 GRT) on 20 September 1941 and Empire Moat (2,922 GRT) also on the 20th, were both lost from Convoy OG-74; they went down north northeast of the Azores.
In addition, Empire Stream was sunk on 25 September. Among the dead were two stowaways. A final effort on 26 September accounted for three more ships, also near the Azores: Petrel, Cortes, and Siremalm (there were no survivors from the latter vessel).
U-124 returned to Lorient on 1 October.
Seventh patrol
After almost a month in her base, U-124 started her seventh patrol on 30 October 1941. On 24 November, she was engaged by the Royal Navy Danae-class cruiser HMS Dunedin which, with two consorts, had been searching for the Armed Merchant Raider Atlantis and her supply ship Python. Dunedin was hit by two torpedoes, despite being outside the theoretical range of the U-boat's projectiles and sank 17 minutes later. 419 men died; there were 67 survivors.
The submarine remained in the South Atlantic and sank the American Sagadahoc on 3 December. [4] She was the fourth and last American ship to be sunk by the U-boat Arm prior to the U.S. entry into the war. Following a six-hour chase Mohr fired on Sagadahoc claiming her lights were not set correctly.
U-124 was shelled by the coastal battery at Fort Bedford, Georgetown on Ascension Island on 9 December; no damage was sustained.
Eighth patrol
A change of operational area saw the boat deploy to the Eastern United States seaboard following the success of Operation Drumbeat (Paukenschlag); leaving Lorient on 21 February 1942. Like the original 'drumbeaters', Mohr found the US defences easy to penetrate. [5]
The boat scored her first victory before reaching her destination; sinking British Resource about 230 nautical miles (430 km; 260 mi) north of Bermuda on 14 March.
She then sank seven ships and damaged two more – all in March. One of them, E. M. Clark , was hit in such a way that her whistle sounded continuously until the ship went down. Another, Esso Nashville, was hit by a torpedo which failed to detonate, but a subsequent torpedo broke the tanker's back. She was held together only by deck plates and piping. The bow and stern sections soon separated, and the bow soon sank. The stern was towed to Baltimore where it was fitted with a new fore-part and the ship returned to service in March 1943.
Two more ships were hit before U-124 returned to Lorient. It was her most successful patrol; 68,215 GRT of shipping was lost or incapacitated.
Ninth patrol
It was back to the mid-Atlantic for the boat's ninth patrol, as part of Wolfpack Hecht, beginning on 4 May 1942. Four ships from Convoy ON 92 were sunk on the 12th. U-124's next victim was the Free French corvette Mimosa which was sunk with heavy loss of life on 9 June. Many of the casualties came from St. Pierre et Miquelon. The impact of the sinking had a lasting effect in the community.
Two more ships were sunk before the boat returned to Lorient on 26 June.
Tenth patrol
Another change of operational zone, this time to the northern coastal area of South America. The submarine left Lorient on 25 November 1942. She sank Trewloras about 50 nautical miles (93 km; 58 mi) east of Port of Spain, Trinidad on 28 December.
The boat was attacked by a US Catalina flying boat on 1 January 1943 east of Port of Spain. No damage was caused.
She sank four more ships; Broad Arrow, Birmingham City, Collingsworth and Minotaur, all on the ninth. Collingsworth's helmsman swung the ship to port so hard that one torpedo missed by about 10 feet (3 m). Unfortunately this torpedo then hit Minotaur despite strenuous evasive action by her helmsman.
Wolfpacks
U-124 took part in two wolfpacks, namely:
- Süd (22 July – 5 August 1941)
- Hecht (8 May – 18 June 1942)
Nazi Germany 
