# German submarine U-107 (1940)

German submarine U-107 was a Type IXB U-boat of Nazi Germany's Kriegsmarine that operated during World War II. Between January 1941 and August 1944, she sailed on 13 active patrols at a time when a U-boat averaged a lifespan of seven to ten patrols. During that time, U-107 sank 39 Allied ships and damaged four. The U-boat was launched on 2 July 1940, based at the U-boat port of Lorient, with a crew of 53 under the initial command of Günter Hessler. She was later commanded, in order, by Harald Gelhaus, Valker Simmermacher and her final commander, Karl Heinz Fritz.

## Design

Type IXB submarines were slightly larger than the original Type IX submarines, later designated IXA. U-107 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-107 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
### First patrol

| Date | Name | Flag | Tonnage | Convoy | Position |
| 3 February 1941 | Empire Citizen | United Kingdom | 4,683 | Convoy OB 279 | 58°12′N 23°22′W﻿ / ﻿58.200°N 23.367°W﻿ / 58.200; -23.367 |
| 3 February 1941 | Crispin | Royal Navy | 5,051 | Convoy OB 280 | 56°38′N 20°05′W﻿ / ﻿56.633°N 20.083°W﻿ / 56.633; -20.083 |
| 6 February 1941 | Maplecourt | Canada | 3,388 | Convoy SC 20 | 57°33′N 17°24′W﻿ / ﻿57.550°N 17.400°W﻿ / 57.550; -17.400 |
| 23 February 1941 | Manistee | Royal Navy | 5,360 | Convoy OB 288 | 58°13′N 21°33′W﻿ / ﻿58.217°N 21.550°W﻿ / 58.217; -21.550 |

### Second patrol and most successful period

| Date | Name | Flag | Tonnage (GRT) | Convoy | Position |
| 8 April 1941 | Helena Margareta | United Kingdom | 3,316 | Convoy OG 57 | 33°00′N 23°52′W﻿ / ﻿33.000°N 23.867°W﻿ / 33.000; -23.867 |
| 8 April 1941 | Eskdene | United Kingdom | 3,829 | Convoy OG 57 | 34°43′N 24°21′W﻿ / ﻿34.717°N 24.350°W﻿ / 34.717; -24.350 |
| 9 April 1941 | Harpathian | United Kingdom | 4,671 | Convoy OG 57 | 32°22′N 22°53′W﻿ / ﻿32.367°N 22.883°W﻿ / 32.367; -22.883 |
| 9 April 1941 | Duffield | United Kingdom | 8,516 | Convoy OG 57 | 31°13′N 23°24′W﻿ / ﻿31.217°N 23.400°W﻿ / 31.217; -23.400 |
| 21 April 1941 | Calchas | United Kingdom | 10,305 | | 23°50′N 27°00′W﻿ / ﻿23.833°N 27.000°W﻿ / 23.833; -27.000 |
| 30 April 1941 | Lassell | United Kingdom | 7,417 | Convoy OB 309 | 12°55′N 28°56′W﻿ / ﻿12.917°N 28.933°W﻿ / 12.917; -28.933 |
| 17 May 1941 | Marisa | Netherlands | 8,029 | | 06°10′N 18°09′W﻿ / ﻿6.167°N 18.150°W﻿ / 6.167; -18.150 |
| 18 May 1941 | Piako | United Kingdom | 8,286 | | 07°52′N 14°57′W﻿ / ﻿7.867°N 14.950°W﻿ / 7.867; -14.950 |
| 27 May 1941 | Colonial | United Kingdom | 5,108 | Convoy OB 318 | 09°13′N 15°09′W﻿ / ﻿9.217°N 15.150°W﻿ / 9.217; -15.150 |
| 28 May 1941 | Papalemos | Greece | 3,748 | | 08°06′N 16°18′W﻿ / ﻿8.100°N 16.300°W﻿ / 8.100; -16.300 |
| 31 May 1941 | Sire | United Kingdom | 5,664 | | 08°50′N 15°30′W﻿ / ﻿8.833°N 15.500°W﻿ / 8.833; -15.500 |
| 1 June 1941 | Alfred Jones | United Kingdom | 5,013 | Convoy OB 320 | 08°00′N 15°00′W﻿ / ﻿8.000°N 15.000°W﻿ / 8.000; -15.000 |
| 8 June 1941 | Adda | United Kingdom | 7,816 | Convoy OB 323 | 08°30′N 14°39′W﻿ / ﻿8.500°N 14.650°W﻿ / 8.500; -14.650 |
| 13 June 1941 | Pandias | Greece | 4,981 | | 07°49′N 23°28′W﻿ / ﻿7.817°N 23.467°W﻿ / 7.817; -23.467 |

### Third patrol

| Date | Name | Flag | Tonnage (GRT) | Convoy | Position |
| 24 September 1941 | Dixcove | United Kingdom | 3,790 | Convoy SL 87 | 31°12′N 23°41′W﻿ / ﻿31.200°N 23.683°W﻿ / 31.200; -23.683 |
| 24 September 1941 | Lafian | United Kingdom | 4,876 | Convoy SL 87 | 31°12′N 23°32′W﻿ / ﻿31.200°N 23.533°W﻿ / 31.200; -23.533 |
| 24 September 1941 | John Holt | United Kingdom | 4,975 | Convoy SL 87 | 31°12′N 23°32′W﻿ / ﻿31.200°N 23.533°W﻿ / 31.200; -23.533 |

### Fifth patrol

| Date | Name | Flag | Tonnage (GRT) | Convoy | Position |
| 31 January 1942 | San Arcadio | United Kingdom | 7,419 | | 38°10′N 63°50′W﻿ / ﻿38.167°N 63.833°W﻿ / 38.167; -63.833 |
| 6 February 1942 | Major Wheeler | United States | 3,431 | | E of Cape Hatteras |
| 21 February 1942 | Egda | Norway | 10,068 | Convoy ON 65 | 41°12′N 52°55′W﻿ / ﻿41.200°N 52.917°W﻿ / 41.200; -52.917 Damaged |

### Sixth patrol

| Date | Name | Flag | Tonnage (GRT) | Position |
| 29 May 1942 | Western Head | United Kingdom | 2,599 | 19°57′N 74°18′W﻿ / ﻿19.950°N 74.300°W﻿ / 19.950; -74.300 |
| 1 June 1942 | Bushranger | Panama | 4,536 | 18°15′N 81°25′W﻿ / ﻿18.250°N 81.417°W﻿ / 18.250; -81.417 |
| 7 June 1942 | Castilla | Honduras | 3,910 | 20°15′N 83°18′W﻿ / ﻿20.250°N 83.300°W﻿ / 20.250; -83.300 |
| 8 June 1942 | Suwied | United States | 3,249 | 20°00′N 84°48′W﻿ / ﻿20.000°N 84.800°W﻿ / 20.000; -84.800 |
| 10 June 1942 | Merrimack | United States | 2,606 | 19°47′N 85°55′W﻿ / ﻿19.783°N 85.917°W﻿ / 19.783; -85.917 |
| 19 June 1942 | Cheerio | United States | 35 | 18°02′N 67°40′W﻿ / ﻿18.033°N 67.667°W﻿ / 18.033; -67.667 |
| 26 June 1942 | Jagersfontein | Netherlands | 10,083 | 31°56′N 54°48′W﻿ / ﻿31.933°N 54.800°W﻿ / 31.933; -54.800 |

### Eighth patrol

| Date | Name | Flag | Tonnage (GRT) | Position |
| 3 September 1942 | Hollinside | United Kingdom | 4,172 | 38°00′N 09°00′W﻿ / ﻿38.000°N 9.000°W﻿ / 38.000; -9.000 |
| 3 September 1942 | Penrose | United Kingdom | 4,393 | 38°00′N 09°00′W﻿ / ﻿38.000°N 9.000°W﻿ / 38.000; -9.000 |
| 7 October 1942 | Andalucia Star | United Kingdom | 14,943 | 06°38′N 15°46′W﻿ / ﻿6.633°N 15.767°W﻿ / 6.633; -15.767 |

### Ninth patrol

* 4 March 1943, came under attack from an unidentified Allied aircraft.
    Moderately damaged by the attack.
* 22 March 1943 at 14:35 it came under attack from another unidentified Allied aircraft
    Undamaged
| Date | Name | Flag | Tonnage (GRT) | Convoy | Position |
| 22 February 1943 | Roxborough Castle | United Kingdom | 7,801 | | 38°12′N 26°22′W﻿ / ﻿38.200°N 26.367°W﻿ / 38.200; -26.367 |
| 13 March 1943 | Oporto | United Kingdom | 2,352 | Convoy OS 44 | 42°45′N 13°31′W﻿ / ﻿42.750°N 13.517°W﻿ / 42.750; -13.517 |
| 13 March 1943 | Marcella | United Kingdom | 4,592 | Convoy OS 44 | 42°45′N 13°31′W﻿ / ﻿42.750°N 13.517°W﻿ / 42.750; -13.517 |
| 13 March 1943 | Sembilangan | Netherlands | 4,990 | Convoy OS 44 | 42°45′N 13°31′W﻿ / ﻿42.750°N 13.517°W﻿ / 42.750; -13.517 |
| 13 March 1943 | SS Clan Alpine | United Kingdom | 5,442 | Convoy OS 44 | 42°45′N 13°31′W﻿ / ﻿42.750°N 13.517°W﻿ / 42.750; -13.517 |

### Tenth patrol

| Date | Name | Flag | Tonnage (GRT) | Convoy | Position |
| 1 May 1943 | Port Victor | United Kingdom | 12,411 | | 47°49′N 22°02′W﻿ / ﻿47.817°N 22.033°W﻿ / 47.817; -22.033 |

### Eleventh patrol

| Date | Name | Flag | Tonnage | Convoy | Position |
| 28 August 1943 | Albert Gallatin | United States | 7,176 | | Off Savannah, Georgia Damaged |
| 11 September 1943 | USS Rapidan | United States Navy | 8,246 | Convoy NG 385 | 32°39′N 79°43′W﻿ / ﻿32.650°N 79.717°W﻿ / 32.650; -79.717 Damaged |

### Fifteenth patrol

| Date | Name | Flag | Tonnage (GRT) | Convoy | Position |
| 13 June 1944 | Lark | United States | 148 | | 43°00′N 65°12′W﻿ / ﻿43.000°N 65.200°W﻿ / 43.000; -65.200 Damaged |

### Sixteenth and final patrol

On 16 August 1944, U-107 departed from Lorient on a transport run to La Pallice. She was intercepted on 18 August in the Bay of Biscay, west of La Rochelle, in position 46°46′N 03°49′W﻿ / ﻿46.767°N 3.817°W﻿ / 46.767; -3.817, by Allied forces, and was sunk by depth charges from a Short Sunderland (serialEJ150) of No. 201 Squadron, Royal Air Force. All 58 hands were lost.

### Wolfpacks

U-107 took part in 15 wolfpacks, namely:
* Störtebecker (5 – 7 November 1941)
* Seeräuber (14 – 23 December 1941)
* Blücher (23 – 28 August 1942)
* Iltis (6 – 23 September 1942)
* Hartherz (3 – 7 February 1943)
* Delphin (11 – 14 February 1943)
* Robbe (16 February – 13 March 1943)
* Amsel 2 (4 – 6 May 1943)
* Elbe (7 – 10 May 1943)
* Elbe 2 (10 – 14 May 1943)
* Weddigen (24 November – 7 December 1943)
* Coronel (7 – 8 December 1943)
* Coronel 2 (8 – 14 December 1943)
* Coronel 3 (14 – 17 December 1943)
* Borkum (18 – 30 December 1943)

## Summary of raiding history

| Date | Name | Nationality | Tonnage (GRT) | Fate |
| 3 February 1941 | Empire Citizen | United Kingdom | 4,683 | Sunk |
| 3 February 1941 | HMS Crispin | Royal Navy | 5,051 | Sunk |
| 6 February 1941 | Maplecourt | Canada | 3,388 | Sunk |
| 23 February 1941 | HMS Manistee | Royal Navy | 5,360 | Sunk |
| 8 April 1941 | Eskdene | United Kingdom | 3,829 | Sunk |
| 8 April 1941 | Helena Margareta | United Kingdom | 3,316 | Sunk |
| 9 April 1941 | Harpathian | United Kingdom | 4,671 | Sunk |
| 9 April 1941 | Duffield | United Kingdom | 8,516 | Sunk |
| 21 April 1941 | Calchas | United Kingdom | 10,305 | Sunk |
| 30 April 1941 | Lassell | United Kingdom | 7,417 | Sunk |
| 17 May 1941 | Marisa | Netherlands | 8,029 | Sunk |
| 18 May 1941 | Piako | United Kingdom | 8,286 | Sunk |
| 27 May 1941 | Colonial | United Kingdom | 5,108 | Sunk |
| 28 May 1941 | Papalemos | Greece | 3,748 | Sunk |
| 31 May 1941 | Sire | United Kingdom | 5,664 | Sunk |
| 1 June 1941 | Alfred Jones | United Kingdom | 5,013 | Sunk |
| 8 June 1941 | Adda | United Kingdom | 7,816 | Sunk |
| 13 June 1941 | Pandias | Greece | 4,981 | Sunk |
| 24 September 1941 | John Holt | United Kingdom | 4,975 | Sunk |
| 24 September 1941 | Dixcove | United Kingdom | 3,790 | Sunk |
| 24 September 1941 | Lafian | United Kingdom | 4,876 | Sunk |
| 31 January 1942 | San Arcadio | United Kingdom | 7,419 | Sunk |
| 6 February 1942 | Major Wheeler | United States | 3,431 | Sunk |
| 21 February 1942 | Egda | Norway | 10,068 | Damaged |
| 29 May 1942 | Western Head | United Kingdom | 2,599 | Sunk |
| 1 June 1942 | Bushranger | Panama | 4,536 | Sunk |
| 7 June 1942 | Castilla | Honduras | 3,910 | Sunk |
| 8 June 1942 | Suwied | United States | 3,249 | Sunk |
| 10 June 1942 | Merrimack | United States | 2,606 | Sunk |
| 19 June 1942 | Cheerio | United States | 35 | Sunk |
| 26 June 1942 | Jagersfontein | Netherlands | 10,083 | Sunk |
| 3 September 1942 | Hollinside | United Kingdom | 4,172 | Sunk |
| 3 September 1942 | Penrose | United Kingdom | 4,393 | Sunk |
| 7 October 1942 | Andalucia Star | United Kingdom | 14,943 | Sunk |
| 22 February 1943 | Roxborough Castle | United Kingdom | 7,801 | Sunk |
| 13 March 1943 | SS Clan Alpine | United Kingdom | 5,442 | Sunk |
| 13 March 1943 | Marcella | United Kingdom | 4,592 | Sunk |
| 13 March 1943 | Oporto | United Kingdom | 2,352 | Sunk |
| 13 March 1943 | Sembilangan | Netherlands | 4,990 | Sunk |
| 1 May 1943 | Port Victor | United Kingdom | 12,411 | Sunk |
| 28 August 1943 | Albert Gallatin | United States | 7,176 | Damaged |
| 11 September 1943 | USS Rapidan | United States Navy | 8,246 | Damaged |
| 13 June 1944 | Lark | United States | 148 | Damaged |