German submarine U-66 (1940)

German submarine U-66 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II.[1] The submarine was laid down on 20 March 1940 at the AG Weser yard at Bremen, launched on 10 October and commissioned on 2 January 1941 under the command of Kapitänleutnant Richard Zapp as part of the 2nd U-boat Flotilla.[1]

U-66 U-117 Luftangriff.jpg
U-66 (left) and U-117 under attack by aircraft from USS Card on 7 August 1943
Nazi Germany
Name: U-66
Ordered: 7 August 1939
Builder: AG Weser, Bremen
Yard number: 985
Laid down: 20 March 1940
Launched: 10 October 1940
Commissioned: 2 January 1941
Fate: Sunk 6 May 1944 west of the Cape Verde Islands by US aircraft and warships[1]
General characteristics
Class and type: Type IXC U-boat
  • 1,120 t (1,100 long tons) surfaced
  • 1,232 t (1,213 long tons) submerged
  • 6.76 m (22 ft 2 in) o/a
  • 4.40 m (14 ft 5 in) pressure hull
Height: 9.60 m (31 ft 6 in)
Draught: 4.70 m (15 ft 5 in)
Installed power:
  • 4,400 PS (3,200 kW; 4,300 bhp) (diesels)
  • 1,000 PS (740 kW; 990 shp) (electric)
  • 13,450 nmi (24,910 km; 15,480 mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 63 nmi (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Complement: 4 officers, 44 enlisted
Service record[1][2]
Part of:
Identification codes: M 24 266
  • Nine:
  • 1st patrol: 13 May – 11 June 1941
  • 2nd patrol: 23 June – 5 August 1941
  • 3rd patrol: 28 August – 9 November 1941
  • 4th patrol: 25 December 1941 – 10 February 1942
  • 5th patrol: 21 March – 27 May 1942
  • 6th patrol: 23 June – 29 September 1942
  • 7th patrol: 6 January – 24 March 1943
  • 8th patrol: 7 April – 1 September 1943
  • 9th patrol: 16 January – 6 May 1944
  • 33 commercial ships sunk (200,021 GRT)
  • two commercial ships damaged (22,674 GRT)
  • two warships damaged (64 tons)


German Type IXC submarines were slightly larger than the original Type IXBs. U-66 had a displacement of 1,120 tonnes (1,100 long tons) when at the surface and 1,232 tonnes (1,213 long tons) while submerged.[3] The U-boat had a total length of 76.76 m (251 ft 10 in), 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).[3]

The submarine had a maximum surface speed of 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph).[3] When submerged, the boat could operate for 63 nautical miles (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 13,450 nautical miles (24,910 km; 15,480 mi) at 10 knots (19 km/h; 12 mph). U-66 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.[3]

Service historyEdit

After her transfer from a training organization to front line service in May 1941, until her sinking in May 1944, U-66 conducted nine combat patrols,[1] sinking 33 merchant ships, for a total of 200,021 gross register tons (GRT), and damaged two British motor torpedo boats.[1] She was a member of four wolfpacks.

U-66 was the seventh most successful U-boat in World War II.[4]

On 6 May 1944, during her ninth patrol, she was sunk west of the Cape Verde Islands by depth charges, ramming and gunfire from Grumman TBF Avenger and Grumman F4F Wildcat aircraft of the US escort carrier Block Island and by the destroyer escort USS Buckley.



On 13 May 1940, three days after the start of the invasion of France, U-66 departed her homeport of Kiel under the command of Richard Zapp, a future Knight's Cross recipient, on her first patrol. After about 10 days she rounded the northern coast of Britain and made her way into the mid-Atlantic ocean. After another 20 days, U-66 headed for her new base at Lorient, on the French Atlantic cost, where the Keroman Submarine Base was just about to begin construction[5] and where the U-boat was based for the rest of her career.


After refitting and refueling, U-66 set off to the Cape Verde islands. Following an uneventful six-day voyage, she came upon convoy SL-78, a convoy designated to give supplies to Allied African countries. The convoy had been attacked just recently by German submarine U-123 (1940) and German submarine U-69 (1940), one of which (U-123) was in her flotilla. U-66 sank George J. Goulandris and Kalypso Vergotti, two Greek merchantmen of 4,345 and 5,686 GRT, respectively,[6][7] west of the Canary Islands. She extended her tonnage sunk with the torpedoing of Saint Anselm on the next day, which was a British steam merchant ship of 5,614 tons. More than two weeks later, she sank Holmside, a 3,433-ton straggler from the convoy OG-67 northeast of the Cape Verde Islands. The remainder of the patrol was unsuccessful; she returned to Lorient in about a month.[8]


On 28 August, U-66 left Lorient for north-eastern South America. The patrol was mostly uneventful, but the boat found the Panamanian steam tanker I.C. White (7,052 GRT), off the eastern coast of Brazil on 24 September. After a two-day chase, U-66 hit the tanker with one torpedo. U-66 continued the remainder of the patrol without any further incident and returned to Lorient on 9 November.[9]


U-66's fourth sortie was part of Operation Drumbeat, a German attempt to hinder American convoys off the east coast of the United States.[10] U-66, leaving on 25 December 1941 and in compliance with orders, positioned herself off Cape Hatteras on 15 January 1942 and started to hunt for a target. She found the 6,635-ton American steam tanker Allan Jackson three days later and sank her with two torpedoes 60 nmi (110 km; 69 mi) north-east of Diamond Shoals, North Carolina. The next day she sank a 7,988 GRT Canadian passenger liner, RMS Lady Hawkins, with two stern-launched torpedoes, killing 246 passengers and crew. Another five died in a lifeboat before 71 survivors were rescued five days later by USAT Coamo.[11] Three days later with two stern-launched torpedoes she hit Olympic, a 5,335 GRT Panamanian steam tanker which broke in two after one minute. Two days after that, Empire Gem and Venore (an 8,139 GRT British motor tanker and an 8,017 GRT American steam merchant ship, the latter following the former), were both sunk by U-66. Empire Gem was hit amidships and aft by two torpedoes, while Venore, 20 miles behind, had only one torpedo hit that set her boilers on fire. U-66 then continued eastward back to Lorient, where she arrived on 10 February.[5]


On 21 March, U-66 left for what proved to be her most successful patrol, resulting in 43,956 gross metric tons sunk and 12,502 gross metric tons damaged in the Caribbean Sea. 24 days after departure she sank Korthion, a 2,116 GRT Greek steam merchantman just south of Barbados with one torpedo hit amidships.[12] Two days later, the boat sank Amsterdam, a 7,329 GRT Dutch steam tanker, which split in two after being hit by two torpedoes, one amidships, and one in the engine room. Most of the survivors were picked up near Port of Spain, (Trinidad) by Ivan, a Yugoslavian steam merchant vessel.[13] The next day U-66 attacked Heinrich von Riedemann, an 11,020-ton Panamanian motor tanker. The first torpedo severely damaged the steering control of her port engine and ruptured a tank of oil, making much of it leak out. 20 minutes after the first hit, just after the starboard engine was stopped, the ship was abandoned when the crew took to the lifeboats. An hour later U-66 hit her with a second torpedo, setting her afire. It extinguished itself within 25 minutes. 50 minutes later the submarine hit her with a third torpedo, which set the ship afire again. She remained that way for about 70 minutes before she finally sank.[14] Nine days later U-66 sank the 5,513 GRT US Alcoa Partner with a torpedo and a shot from her deck gun.[15]


After her fifth patrol, Richard Zapp left U-66 to take command of the 3rd U-boat Flotilla. This meant that Kapitänleutnant Friedrich Markworth was in charge.[16] The submarine started her sixth patrol with the sinking of Triglav, a 6,396 GRT Yugoslavian steamer, after depositing a sick crew-member in Spain.[17] After a couple of weeks, U-66 ran across the 4,942-ton Brazilian merchant ship Tamandaré, sinking her with a torpedo hit in her stern. The survivors were picked up by the USS PC-492.[18] Two days after the attack on Tamandaré, U-66 sank Weirbank, a 5,150 GRT British merchantman on 28 July 1942, with the second of two torpedoes launched at her.[19] Four days after her previous sinking, two mines from U-66 severely damaged two British motor torpedo boats that had left on a patrol from Port Castries, St. Lucia. Those two mines had been laid, along with four others, on 20 July.[16] U-66 subsequently sank the 766 ton Polish Rozewie on 6 August and the American 5,356 GRT Topa Topa on the 29th. The next day she sank both the 6,049 GRT Panamanian Sir Huon and the 5,637 GRT American West Lashaway in separate attacks. A raft with survivors from West Lashaway was sighted by three aircraft on 18 September; HMS Vimy, one of the escorts of a small convoy went to investigate. Deciding that the raft could be a disguised U-boat, Vimy opened fire, luckily with no result. The raft's sail was hastily cut down, upon which the British destroyer rescued 17 people.

U-66 also sank the 8,621 GRT Winamac on 31 August and the Swedish 6,390 GRT Peiping on 9 September.[20] She returned to Lorient on 29 September.[16]

Seventh (aborted)Edit

On 9 November 1942, U-66 left Lorient on what should have been her 7th war patrol. Soon after departure, leaks were encountered, and she decided to return. On 10 November, the day before she returned, a British Wellington bomber, equipped with a Leigh Light, spotted her and dropped four depth charges. The U-boat escaped without serious damage.[1]


U-66 left Lorient on 6 January 1943 for what was officially her seventh patrol. On 20 January, the ship landed an espionage agent on the coast of Mauritania, but the agent and two crewmen were immediately captured. Her first sinking came with the attack on the 113-ton French Joseph Elise on 1 February. On the 27th, U-66 attacked the 4,312-ton British coal merchant ship St. Margaret in mid-Atlantic near Bermuda, sinking her with one torpedo and, after several misses, a shell. Several survivors were captured and taken to the prison camp Marlag und Milag Nord.[21] U-66 then returned to port, arriving on 24 March 1943.[22]


U-66's eighth patrol started after a quick refit on 7 April 1943 when she left Lorient. At 148 days, it was to be her longest. She first sank the 10,173-ton American Esso Gettysburg, which was carrying crude oil, on 10 June after unsuccessfully attempting to attack several other American tankers. On 2 July, she successfully sank the 10,195-ton Bloody Marsh (this ship was on her maiden voyage), with a torpedo. The last ship encountered on the patrol was the 10,172-ton Cherry Valley, also American, which she sank on 22 July. U-66 then returned to Lorient.[23]


On 16 January 1944, U-66 left Lorient for what would be her last patrol and the last command of Oberleutnant zur See Gerhard Seehausen (posthumously promoted to Kapitänleutnant). A month and ten days after departure, U-66 sighted Silvermaple, a 5,313-ton British motor merchant in the convoy ST-12. She was sunk after one torpedo hit. Four days later, the boat came upon the French 5,202-ton St. Louis, which she sank with two torpedoes off Accra, Ghana. The ship broke into three parts, which sank in less than 50 seconds. Four days after the sinking of St. Louis, 'U-66 sank the 4,964-ton British John Holt with two torpedoes, and took the captain, Master Cecil Gordon Hime, and a passenger, Mr Elliott - an agent of the Holt Shipping Company, prisoner. These men were later lost with the U-boat. Nearly three weeks after the sinking of John Holt, the U-boat came across the 4,257-ton British Matadian, which she torpedoed and sank. After the attack, U-66 was forced to bottom out in the mud as British patrol craft engaged her. U-66 was supposed to be resupplied by U-488, but this boat, a Milchkuh supply submarine, was sunk[1][24] on 26 April.[25]


Survivors from U-66 aboard USS Block Island, 6 May 1944

On 1 May 1944, U-66 came under attack by American ships from an antisubmarine hunter-killer group formed around USS Block Island. Three Fido homing torpedoes were dropped near the boat, and numerous aircraft from Block Island, along with smaller craft, were designated to hunt for her. On the morning of 6 May, the destroyer escort USS Buckley found the submarine. After an exchange of gunfire and torpedoes, Buckley, under the command of Lieutenant Commander Brent Abel, rammed the submarine.[26]

The bow of the USS Buckley after the ramming of U-66

With the two vessels stuck fast, a party of Germans, under the command of U-66's first officer, Klaus Herbig, attempted to climb onto the American escort's forecastle[27] to create a diversion while Seehausen and the remainder of the U-boat's crew worked to free the boat. As American sailors saw the boarding party climbing on deck, hand-to-hand fighting broke out in which a number of Germans were killed or wounded before the U-boat was able to make good its escape. Five armed Germans remained on deck of the destroyer but they were quickly over-powered and taken prisoner.[28] Buckley's 3-inch gun was unleashed on the U-boat as the Americans chased after her, but U-66 then turned and rammed Buckley near her engine room, damaging the ship's starboard screw.[27] Soon afterward, U-66 was scuttled on Seehausen's orders to prevent her secret equipment from being captured. Buckley then began rescue operations, which lasted three hours.[28]

U-66 was lost at position 17°17′N 32°29′W / 17.283°N 32.483°W / 17.283; -32.483Coordinates: 17°17′N 32°29′W / 17.283°N 32.483°W / 17.283; -32.483 with 24 dead and 36 survivors, all of whom were captured by Buckley. Seehausen was not among the survivors, who were later transferred to Block Island.[28] For his act of ramming U-66, Brent Abel received the Navy Cross.[27][29]


U-66 took part in four wolfpacks, namely.

  • West (24 May – 5 June 1941)
  • Rochen (27 January – 1 March 1943)
  • Tümmler (1–17 March 1943)
  • Aufnahme (5–10 May 1943)

Summary of raiding historyEdit

Date Ship Nationality Tonnage[Note 1] Fate[20]
29 June 1941 George J. Goulandris   Greece 4,345 Sunk
29 June 1941 Kalypso Vergotti   Greece 5,686 Sunk
30 June 1941 Saint Aslem   United Kingdom 5,614 Sunk
19 July 1941 Holmside   United Kingdom 3,433 Sunk
26 July 1941 I. C. White   Panama 7,052 Sunk
18 January 1942 Allan Jackson   United States 6,635 Sunk
19 January 1942 RMS Lady Hawkins   Royal Canadian Navy 7,988 Sunk
22 January 1942 Olympic   Panama 5,335 Sunk
24 January 1942 Empire Gem   United Kingdom 8,139 Sunk
24 January 1942 Venore   United States 8,017 Sunk
14 April 1942 Korthion   Greece 2,116 Sunk
16 April 1942 Amsterdam   Netherlands 7,329 Sunk
17 April 1942 Heinrich von Riedemann   Panama 11,020 Sunk
26 April 1942 Alcoa Partner   United States 5,513 Sunk
29 April 1942 Harry G. Siedel   Panama 10,354 Sunk
2 May 1942 Sandar   Norway 7,624 Sunk
3 May 1942 Geo. W. McNight   United Kingdom 12,502 Damaged
9 July 1942 Triglav   Yugoslavia 6,363 Sunk
26 July 1942 Tamadaré   Brazil 4,942 Sunk
28 July 1942 Weirbank   United Kingdom 5,150 Sunk
2 August 1942 HMS MTB-339   Royal Navy 32 Damaged
2 August 1942 HMS MTB-342   Royal Navy 32 Damaged
6 August 1942 Rozewie   Poland 766 Sunk
29 August 1942 Topa Topa   United States 5,356 Sunk
30 August 1942 Sir Huon   Panama 6,049 Sunk
30 August 1942 West Lashaway   United States 5,637 Sunk
31 August 1942 Winamac   United Kingdom 8,621 Sunk
9 September 1942 Peiping   Sweden 6,390 Sunk
1 February 1943 Joseph Elise   Free France 113 Sunk
27 February 1943 St. Margaret   United Kingdom 4,312 Sunk
10 June 1943 Esso Gettysburg   United States 10,173 Sunk
2 July 1943 Bloody Marsh   United States 10,195 Sunk
26 February 1944 Silvermaple   United Kingdom 5,313 Sunk
1 March 1944 St. Louis   Free France 5,202 Sunk
5 March 1944 John Holt   United Kingdom 4,964 Sunk
21 March 1944 Matadian   United Kingdom 4,275 Sunk

See alsoEdit



  1. ^ Merchant ship tonnages are in gross register tons. Military vessels are listed by tons displacement.


  1. ^ a b c d e f g h Helgason, Guðmundur. "The Type IXC boat U-66". German U-boats of WWII - Retrieved 18 April 2010.
  2. ^ Helgason, Guðmundur. "War Patrols by German U-boat U-66". U-boat patrols - Retrieved 18 April 2010.
  3. ^ a b c d Gröner 1991, p. 68.
  4. ^ Helgason, Guðmundur. "The Most Successful U-boats". U-boat Operations - Retrieved 18 April 2010.
  5. ^ a b Helgason, Guðmundur. "Patrol info for U-66 (First patrol)". German U-boats of WWII - Retrieved 6 September 2010.
  6. ^ Helgason, Guðmundur. "George J. Goulandris (Greek Steam merchant)". German U-boats of WWII - Retrieved 3 May 2010.
  7. ^ Helgason, Guðmundur. "Kalypso Vergotti(Greek Steam merchant)". German U-boats of WWII - Retrieved 3 May 2010.
  8. ^ Helgason, Guðmundur. "Patrol info for U-66 (Second patrol)". German U-boats of WWII - Retrieved 6 September 2010.
  9. ^ Helgason, Guðmundur. "Patrol info for U-66 (Third patrol)". German U-boats of WWII - Retrieved 6 September 2010.
  10. ^ Dunmore 2002, p. 166.
  11. ^ Helgason, Guðmundur. "Lady Hawkins (Steam passenger ship)". German U-boats of WWII - Retrieved 18 April 2010.
  12. ^ Helgason, Guðmundur. "Korthion (Greek Steam merchant)". German U-boats of WWII - Retrieved 2 October 2011.
  13. ^ Helgason, Guðmundur. "Amsterdam (Dutch Steam tanker)". German U-boats of WWII - Retrieved 2 October 2011.
  14. ^ Helgason, Guðmundur. "Heinrich von Riedmann (Panamanian Motor Tanker)". German U-boats of WWII - Retrieved 2 October 2011.
  15. ^ Helgason, Guðmundur. "Alcoa Partner (American Steam Merchant)". German U-boats of WWII - Retrieved 2 October 2011.
  16. ^ a b c Helgason, Guðmundur. "Patrol info for U-66 (Sixth patrol)". U-boat patrols - Retrieved 6 September 2010.
  17. ^ Helgason, Guðmundur. "Triglav (Yugoslavian Steam Merchant)". German U-boats of WWII - Retrieved 2 October 2011.
  18. ^ Helgason, Guðmundur. "Tamandare (Brazilian Steam Merchant)". German U-boats of WWII - Retrieved 2 October 2011.
  19. ^ Helgason, Guðmundur. "Weirbank (British Motor Merchant)". German U-boats of WWII - Retrieved 2 October 2011.
  20. ^ a b Helgason, Guðmundur. "Ships hit by U-66". German U-boats of WWII - Retrieved 1 February 2015.
  21. ^ Helgason, Guðmundur. "St. Margaret (British Steam merchant)". German U-boats of WWII - Retrieved 2 October 2011.
  22. ^ Helgason, Guðmundur. "Patrol info for U-66 (Seventh Patrol)". German U-boats of WWII - Retrieved 1 January 2012.
  23. ^ Morission, pp. 181 – 183
  24. ^ Helgason, Guðmundur. "Patrol info for U-66 (Ninth patrol)". U-boat patrols - Retrieved 11 November 2012.
  25. ^ Helgason, Guðmundur. "The Type XIV boat U-488". German U-boats of WWII - Retrieved 1 February 2015.
  26. ^ Blair 2000, p. 547.
  27. ^ a b c "Sinking of U-66". Destroyer Escort Sailors Association. Retrieved 12 November 2012.
  28. ^ a b c Blair 2000, pp. 547–548.
  29. ^ "Navy Cross Awards to members of the U.S. Navy in World War II". Home of Heroes. Retrieved 12 November 2012.


  • Busch, Rainer; Röll, Hans-Joachim (1999). German U-boat commanders of World War II : a biographical dictionary. Translated by Brooks, Geoffrey. London, Annapolis, Md: Greenhill Books, Naval Institute Press. ISBN 1-55750-186-6.
  • Busch, Rainer; Röll, Hans-Joachim (1999). Deutsche U-Boot-Verluste von September 1939 bis Mai 1945 [German U-boat losses from September 1939 to May 1945]. Der U-Boot-Krieg (in German). IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2.
  • Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.
  • Blair, Clay (2000). Hitler's U-Boat War: The Hunted, 1942 – 1945. New York: Modern Library. ISBN 0-679-64033-9.
  • Dunmore, Spencer (2002). Lost Subs: From the Hunley to the Kursk. The Greatest Submarines Ever Lost – and Found. Cambridge, MA: Da Capo Press. ISBN 0-306-81140-5.
  • Morisson, Samuel (1956). The Atlantic Battle Won, May 1943 – May 1945. History of United States Naval Operations in World War II. X. Boston: Little, Brown and Company. OCLC 768913584.

External linksEdit