German submarine U-103 was a Type IXB U-boat of Nazi Germany's Kriegsmarine that operated during World War II. She was one of the most successful boats in the entire war, sinking of Allied shipping in 11 patrols, in a career lasting more than four years.
U-103 was laid down on 6 September 1939 at DeSchiMAG AG Weser in Bremen as yard number 966. She was launched on 12 April 1940 and commissioned on 5 July under the command of Korvettenkapitän Victor Schütze. After her warm-up, (designed to give her an opportunity to train and repair minor faults), she was deployed into the North Atlantic in September 1940 and saw overwhelming success, sinking 46 ships and damaging three other vessels.
Type IXB submarines were slightly larger than the original Type IX submarines, later designated IXA. U-103 had a displacement of 1051t when at the surface and 1178t while submerged. The U-boat had a total length of 76.5abbr=onNaNabbr=on, a pressure hull length of 58.75m (192.75feet), a beam of 6.76m (22.18feet), a height of 9.6m (31.5feet), and a draught of 4.7m (15.4feet). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4400PS for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1000PS for use while submerged. She had two shafts and two 1.92abbr=onNaNabbr=on propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-103 was fitted with six 53.30NaN0 torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.52NaN2 SK C/32 naval gun, 180 rounds, and a 3.7sp=usNaNsp=us SK C/30 as well as a 2sp=usNaNsp=us C/30 anti-aircraft gun. The boat had a complement of forty-eight.
The boat entered the Atlantic via the gap between the Faroe and Shetland Islands. Her first victory was sinking Nina Borthen in mid-ocean on 6 October. After being hit by a torpedo, the ship developed a list, which the crew corrected. Two more torpedoes hit the ship, which also caused a list. Another torpedo hit broke the vessel in two and she sank with all hands.
On 9 October, U-103 sank Zanes Gounaris and damaged Graigwen and Delphin. Delphin sank the next day. She sank Nora on 13 October and Thistlegarth, 45nmi west northwest of Rockall, on 15 October.
U-103 docked at her new base, Lorient on the French Atlantic coast, on 19 October.
U-103s second patrol began with her being unsuccessfully attacked by the northwest of Ireland on 11 November 1940.
She then sank Daydawn and Victoria on 21 November, Glenmoor on the 27th, and Mount Athos and on the 28th. The attacks continued with on 8 December and Empire Jaguar the next day.
The submarine returned to Lorient on 12 December.
On 13 February 1941 Arthur F. Corwin was damaged by U-103, and sunk by later that day. On 19 February U-103 sank the Norwegian motor ship Benjamin Franklin. The Flower-class corvette HMS Pimpernel rescued seven survivors, and landed them at Liverpool. The Egyptian steamship Memphis rescued 29 of her crew, but on 28 February Memphis suffered engine failure and sank with all hands.
U-103s fourth patrol was off the coast of West Africa. At 103 days, it was her longest patrol. She sank Polyana 41nmi southwest of the Cape Verde Islands on 24 April 1941. The ship sank with all hands in one minute.
U-103 sank Samsø, Wray Castle, Surat and Dunkwa in the first week of May. When Dunkwa sank, U-103s crew saw that there were 39 survivors in one lifeboat. The U-boat crew righted another boat and provided drinking water.
On 25 May, she sank the cargo ship Radames off the coast of Liberia. The sinking of the Radames was filmed, and is often shown on documentaries about the Battle of the Atlantic.
U-103 sank another seven ships off the African coast before returning to Lorient on 12 July.
U-103s fifth patrol was in the North Atlantic. It sank Niceto de Larrinaga, Edward Blyden and Lapwing west of the Canary Islands on 22 September 1941.
The U-boat's sixth patrol was part of Operation Drumbeat, off the Atlantic coast of the USA. She sank W. L. Stead about 90nmi off the Delaware River on 2 February 1942. The torpedo hit set the ship on fire but wave action soon extinguished it. Using her deck gun, U-103 fired 83 rounds, scoring 17 hits and reigniting the fire. She fired a further two torpedoes. The second missed, but the third detonated the tanker's cargo, sending flames 500feet into the air.
U-103 also sank San Gil on 4 February, and both India Arrow and the next day.
U-103 began her seventh patrol by leaving Lorient on 15 April 1942. She sank Stanbank northeast of Bermuda on 5 May. She continued to the Caribbean and the Gulf of Mexico, where she sank another eight merchant ships that month. U-103 returned to Lorient on 22 June.
U-103 sank Tasmania north of Madeira on 31 October 1942, and in mid-Atlantic northwest of the Azores on 6 December. She captured Henry Stanleys Master. He was eventually sent to the Milag Nord internment camp for merchant seamen.
U-103 also damaged Horata north of the Azores on 13 December.
On her ninth patrol U-103 sank no ships. She searched the Atlantic off Spain as far west as the Azores and as far south as Morocco, but found no convoys. Having left Lorient on 7 February 1943, she returned there on 26 March.
On U-103S tenth patrol, on 27 April a Vickers Wellington of No. 172 Squadron RAF equipped with a Leigh Light attacked her. The aircraft found the U-boat with its radar, and dropped six depth charges, but caused no damage. A Whitley bomber of No. 10 OTU (Operational Training Unit) attacked U-103 on 22 May. U-103 returned fire, preventing the aircraft from dropping its depth charges. Plane and submarine both returned safely to their bases.
U-103s last operational patrol was officially divided into two parts; the first of which saw her arrive in Brest in France only two days after her departure from Lorient. She then returned to the west African coast but without repeating her earlier success. She sailed to Norway via a reverse in the course of her first patrol and arrived at Bergen on 1 January 1944.
U-103 left Bergen on 3 January 1944 and reached Kiel on the 7th. In March she was taken out of service and used as a Schulboot (training boat). She went from Gotenhafen to Hamburg in January 1945, and in April from Hamburg back to Kiel. On 3 May 1945 she was scuttled at Kiel.
U-103 took part in nine wolfpacks, namely:
| - | Date | Ship | Nationality | Tonnage[1] | Fate[2] |
|---|---|---|---|---|---|
| 6 October 1940 | Nina Borthen |  Norway | 6,123 | Sunk | |
| 9 October 1940 | Delphin |  Greece | 3,816 | Sunk | |
| 9 October 1940 | Graigwen |  United Kingdom | 3,697 | Damaged | |
| 9 October 1940 | Zannes Gounaris | Greece | 4,407 | Sunk | |
| 13 October 1940 | Nora |  Estonia | 1,186 | Sunk | |
| 15 October 1940 | Thislegarth | United Kingdom | 4,747 | Sunk | |
| 21 November 1940 | Daydawn | United Kingdom | 4,768 | Sunk | |
| 21 November 1940 | Victoria | Greece | 6,085 | Sunk | |
| 27 November 1940 | Glenmoor | United Kingdom | 4,393 | Sunk | |
| 28 November 1940 | Mount Athos | Greece | 3,578 | Sunk | |
| 28 November 1940 | United Kingdom | 4,940 | Sunk | ||
| 8 December 1940 | United Kingdom | 9,515 | Sunk | ||
| 9 December 1940 | Empire Jaguar | United Kingdom | 5,186 | Sunk | |
| 13 February 1941 | Arthur F. Corwin | United Kingdom | 10,516 | Damaged | |
| 17 February 1941 | Edwy R. Brown | United Kingdom | 10,455 | Sunk | |
| 18 February 1941 | United Kingdom | 5,459 | Sunk | ||
| 19 February 1941 | Benjamin Franklin | Norway | 7,034 | Sunk | |
| 25 April 1941 | Polyana | Norway | 2,267 | Sunk | |
| 1 May 1941 | Samsø | United Kingdom | 1,494 | Sunk | |
| 3 May 1941 | Wray Castle | United Kingdom | 4,253 | Sunk | |
| 6 May 1941 | Dunkwa | United Kingdom | 4,752 | Sunk | |
| 6 May 1941 | Surat | United Kingdom | 5,529 | Sunk | |
| 9 May 1941 | City of Winchester | United Kingdom | 7,120 | Sunk | |
| 11 May 1941 | City of Shanghai | United Kingdom | 5,828 | Sunk | |
| 22 May 1941 | British Grenadier | United Kingdom | 6,857 | Sunk | |
| 24 May 1941 | Marionga | Greece | 4,236 | Sunk | |
| 25 May 1941 | Radames |  Egypt | 3,575 | Sunk | |
| 25 May 1941 | Wangi Wangi |  Netherlands | 7,789 | Sunk | |
| 8 June 1941 | Elmdene | United Kingdom | 4,853 | Sunk | |
| 29 June 1941 | Erani |  Italy | 6,619 | Sunk | |
| 22 September 1941 | Edward Blyden | United Kingdom | 5,003 | Sunk | |
| 22 September 1941 | Niceto de Larringa | United Kingdom | 5,591 | Sunk | |
| 26 September 1941 | Lapwing | United Kingdom | 1,348 | Sunk | |
| 2 February 1942 |  United States | 6,182 | Sunk | ||
| 4 February 1942 | United States | 8,327 | Sunk | ||
| 4 February 1942 | San Gil | United States | 3,627 | Sunk | |
| 5 February 1942 | United States | 8,403 | Sunk | ||
| 5 February 1942 | Stanbank | United States | 5,966 | Sunk | |
| 17 May 1942 | Ruth Lykes | United States | 2,612 | Sunk | |
| 19 May 1942 | Ogontz | United States | 5,037 | Sunk | |
| 21 May 1942 | Clare | United States | 3,372 | Sunk | |
| 21 May 1942 | Elizabeth | United States | 4,727 | Sunk | |
| 23 May 1942 | United States | 6,625 | Sunk | ||
| 24 May 1942 | Hector | Netherlands | 1,828 | Sunk | |
| 26 May 1942 | Alcoa Carrier | United States | 5,588 | Sunk | |
| 28 May 1942 | New Jersey | United States | 6,414 | Sunk | |
| 31 October 1942 | Tasmania | United Kingdom | 6,405 | Sunk | |
| 6 December 1942 | United Kingdom | 5,025 | Sunk | ||
| 13 December 1942 | Horata | United Kingdom | 13,945 | Damaged |