|Ordered:||14 October 1941|
|Builder:||Deutsche Werft AG, Hamburg|
|Laid down:||2 March 1943|
|Launched:||22 October 1943|
|Commissioned:||13 January 1944|
|Fate:||sunk 20 August 1944 by Allied aircraft in position Coordinates: , 18 dead, 41 survivors|
|Class and type:||Type IXC/40 submarine|
|Height:||9.60 m (31 ft 6 in)|
|Draught:||4.67 m (15 ft 4 in)|
|Test depth:||230 m (750 ft)|
|Complement:||4 officers, 44 enlisted|
|Identification codes:||M 55 295|
German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-1229 had a displacement of 1,144 tonnes (1,126 long tons) when at the surface and 1,257 tonnes (1,237 long tons) while submerged. 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 6.86 m (22 ft 6 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.67 m (15 ft 4 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 shaft horsepower (1,010 PS; 750 kW) 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 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph). 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 13,850 nautical miles (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph). U-1229 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) Flak M42 as well as two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of forty-eight.
U-1229 was ordered in October 1941 from Deutsche Werft AG Weser in Hamburg-Finkenwerder under the yard number 392. Her keel was laid down on 2 March 1943 and was launched on 22 October 1943. About three months later she was commissioned into service under the command of Korvettenkapitän Arnim Zinke (Crew 31) in the 31st U-boat Flotilla.
After completing training and work-up for deployment, U-1229 was transferred to the 10th U-boat Flotilla for front-line service on 1 August 1944. The U-boat left Kiel on 13 July 1944 for the first and only war patrol operating unsuccessfully against Allied shipping in the North Atlantic and off the coast of Canada. A special mission to infiltrate an Abwehr agent into the United States failed, when U-1229 was spotted south of Newfoundland by a Radar-equipped aircraft from USS Bogue and subsequently attacked by several more aircraft over a period of two hours. Having been heavily damaged in the initial air attack, U-1229 attempted to escape under water but was forced to surface again as poisonous fumes started to develop from the damaged battery sections. While the crew was abandoning ship, the U-boat was strafed by several aircraft resulting in the death of numerous crew members, including Zinke. In total 18 crew members died while 41 survivors were picked up by a US destroyer after seven hours in the water.
- Gröner 1991, p. 68.
- 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.