German submarine U-172

German submarine U-172
Career
Name:	U-172
Ordered:	23 December 1939
Builder:	AG Weser, Bremen
Yard number:	1012
Laid down:	11 December 1940
Launched:	31 July 1941
Commissioned:	5 November 1941
Fate:	Sunk, 13 December 1943, by US aircraft and warships
General characteristics
Type:	Type IXC submarine
Displacement:	1,120 t (1,100 long tons) surfaced 1,232 t (1,213 long tons) submerged
Length:	76.8 m (252 ft 0 in) overall 58.7 m (192 ft 7 in) pressure hull
Beam:	6.8 m (22 ft 4 in) overall 4.4 m (14 ft 5 in) pressure hull
Height:	9.4 m (30 ft 10 in)
Draft:	4.7 m (15 ft 5 in)
Propulsion:	2 × MAN M9V40/46 supercharged 9-cylinder diesel engines, 4,000 hp (2,983 kW) 2 × SSW GU345/34 double-acting electric motors, 1,000 hp (746 kW)
Speed:	18.2 knots (33.7 km/h) surfaced 7.3 knots (13.5 km/h) submerged
Range:	24,880 nmi (46,080 km) at 10 knots (19 km/h) surfaced 117 nmi (217 km) at 4 kn (7.4 km/h) submerged
Test depth:	230 m (750 ft)
Complement:	48 to 56
Armament:	6 × torpedo tubes (four bow, two stern) 22 × 55 cm (22 in) torpedoes 1 × 10.5 cm SK C/32 naval gun (110 rounds)

Service record
Part of:	4th U-boat Flotilla (November 1941–April 1942) 10th U-boat Flotilla (May 1942–December 1943) Attached to Wolf pack Eisbär (August 1942)
Commanders:	Kptlt. Carl Emmermann (5 November 1941–31 October 1943) Oblt. Hermann Hoffmann (1 November 1943–13 December 1943)
Operations:	Six patrols 1st patrol: 22 April–3 May 1943 2nd patrol: 11 May–27 July 1942 3rd patrol: 19 August–27 December 1942 4th patrol: 21 February–17 April 1943 5th patrol: 29 May–7 September 1943 6th patrol: 22 November–13 December 1943
Victories:	26 commercial vessels (152,080 GRT)

German submarine U-172 was a Type IXC U-boat of the German Kriegsmarine during World War II. She was first assigned to the 4th U-boat Flotilla for training and on 1 May 1942 was reassigned to the 10th flotilla, an operational long-range organization.

Career

U-172 was laid down at the AG Weser yard in Bremen as 'werk' 1012. She was launched on 31 July 1941 and commissioned on 5 November under the command of Kapitänleutnant Carl Emmermann. She conducted six patrols, sinking 26 ships totalling (152,080 GRT). She was sunk by American aircraft and warships in December 1943, west of the Canary Islands.

1st patrol

U-172's first patrol commenced with her departure from Kiel on 11 Mary 1942. Her route took her through the Kattegat and Skaggerak, through the 'gap' between the Faroe and Shetland Islands and into the Atlantic Ocean. She arrived at Lorient in occupied France on 21 July. She would use this port as her base for the rest of her career.

2nd patrol

Having left Lorient on 11 May 1942, the boat moved into the mid-Atlantic and sank the Athelknight southeast of Bermuda on the 27th. Some survivors did not reach land until 23 June, having sailed some1,200 mi (1,900 km). Moving to the eastern Caribbean Sea, she sank three more ships, the City of Alma, the Delfina and the Sicilien in early June. She attacked the Lebore on the 14th, which assumed a 45° list to starboard on being hit. The ship was struck again in the engine room followed by fire from the U-boat's deck gun. A third torpedo caused the ship to capsize. Twelve more deck gun rounds and a 'coup de grâce' sent the ship to the bottom. Casualties were relatively light, the first assistant engineer was the only fatality, leaving 93 men to be rescued by US warships. Four more vessels were consigned to watery graves. One of them, the Colombian sailing ship Resolute, was stopped with U-172's 20mm gun and sunk with grenades. Another, the Santa Rita, had been abandoned by her crew, but was still afloat. A party from the U-boat boarded her and set scuttling charges. The master was found and taken prisoner. He was landed at Lorient when the submarine returned to base and was transferred, initially to Wilhelmshaven then the POW camp at Milag Nord near Bremen.

3rd patrol

U-172 left Lorient for her third sortie on 19 August 1942. It would be her longest (131 days) and in terms of tonnage sunk, most successful patrol. That total was boosted with the destruction of the British troopship Orcades (23,456 GRT) southwest of Capetown on 10 October. She was first struck by two torpedoes, but following a third hit, a skeleton crew, gunners and volunteers from the passengers remained on board to try and save the ship. They included a Petty Officer telegraphist who sent a second distress call after the radio operators had abandoned their position. In all, the Orcades was hit by six torpedoes before sinking with a broken back.
Forty-five men died, but there were 1,022 survivors.

Following the sinking of the Allington Court on 31 October, the survivors were only spotted and picked up by the City of Christinia when the third officer climbed a lifeboat's mast and waved a shirt.

The Benlomond was another victim sunk on 23 November. The only survivor of this attack was Poon Lim, who eked out an existence for 133 days in the South Atlantic on a Carley float, (a type of liferaft). He received the British Empire Medal from King George VI for this feat.

4th patrol

The true horrors of the Battle of the Atlantic were illustrated when the U-boat sank the City of Pretoria in mid-Ocean about 320 mi (510 km) northwest of the Azores on 16 March 1943. One of the passengers had already survived 51 days in a lifeboat from a previous sinking. This time he was not so lucky - nor were the other occupants of the ship; there were no survivors.

U-171 sank three other ships; one of them, the Benjamin Harrison, had been a member of the ill-fated convoy PQ-17.

The submarine did not escape unscathed; while attacking convoy RS-3 on 28 March, as one of eight U-boats, she was seriously damaged but still managed to sink the Moanda on the 29th. She was also attacked on 7 April by two B-24 Liberators of 1 Squadron, USAAF south of the Azores. Despite having 12 depth charges dropped on her, she stayed on the surface, fought it out and sustained no damage.

The boat returned to Lorient on 17 April.

5th patrol

For her fifth patrol, U-172 moved into the waters of the South Atlantic, departing Lorient on 29 May 1943. Having sunk the Vernon City south southeast of St Paul Rocks (between South America and Africa) on 28 June, she headed toward the Brazilian coast, where she caused the destruction of three more ships: the African Star (12 July), the Harmonic (15 July) and the Fort Chilcotin (24 July).

The submarine was attacked by unidentified aircraft on 11 August while rescuing the crew of U-604, in the aftermath of that boat's scuttling. One man from U-172 was killed.

6th patrol and loss

U-172 left Lorient for the last time on 22 November 1943. She was sunk on 13 December, in mid-Atlantic west of the Canary Islands by Avenger and Wildcat aircraft from the escort carrier USS Bogue (CVE-9), and the American destroyers George E. Badger (DD-196), Clemson (DD-186), Osmond Ingram (DD-255) and Du Pont (DD-152). The battle between U-172 and the small armada of ships and aircraft lasted for 27 hours and as many as 200 depth charges were dropped by the destroyers. Thirteen of U-172's crew were killed; 46 survived the sinking.

Summary of raiding history

Date	Ship	Nationality	Tonnage	Fate
27 May 1942	Athelknight	Great Britain	8,490	Sunk
3 June 1942	City of Alma	USA	5,446	Sunk
5 June 1942	Delfina	USA	3,480	Sunk
8 June 1942	Sicilien	USA	1,654	Sunk
14 June 1942	Lebore	USA	8,289	Sunk
15 June 1942	Bennestvet	Norway	2,438	Sunk
18 June 1942	Motorex	Great Britain	1,958	Sunk
23 June 1942	Resolute *	Colombia	35	Sunk
9 July 1942	Santa Rita	USA	8,379	Sunk
7 October 1942	Chicksaw City	USA	6,196	Sunk
7 October 1942	Firethorn	Panama	4,700	Sunk
8 October 1942	Orcades	Great Britain	23,456	Sunk
31 October 1942	Aldington Court	Great Britain	4,891	Sunk
2 November 1942	Llandilo	Great Britain	4,996	Sunk
23 November 1942	Benlomond	Great Britain	6,630	Sunk
28 November 1942	Alaskan	USA	5,364	Sunk
4 March 1943	City of Pretoria	Great Britain	6,049	Sunk
13 March 1943	Thorstrand	Norway	3,041	Sunk
13 March 1943	Keystone	USA	5,565	Sunk
16 March 1943	Benjamin Harrison	USA	7,191	Sunk
29 March 1943	Moanda	Belgium	4,621	Sunk
28 June 1943	Vernon City	Great Britain	4,748	Sunk
12 July 1943	African Star	USA	6,507	Sunk
15 July 1943	Harmonic	Great Britain	4,558	Sunk
24 July 1943	Fort Chilcotin	Great Britain	7,133	Sunk

* Sailing ship

References

• Bishop, C. Kriegsmarine U-Boats, 1939-45. Amber Books, 2006.
• [1] at Uboat.net
• [2] U-172 at ubootwaffe.net
• U-172 at u-boot-archiv.de (German)

External links

• [3] U-172 at uboat.net
• Uboat.net: SS Benlomond