German submarine U-1172

German submarine U-1172 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 7 June 1943 by Danziger Werft, Danzig as yard number 144, launched on 3 December 1943 and commissioned on 20 April 1944 under Oberleutnant zur See Jürgen Kuhlmann.

Design
Like all Type VIIC/41 U-boats, U-1172 had a displacement of 759 t when at the surface and 860 t while submerged. She had a total length of 67.23 m, a pressure hull length of 50.50 m, a beam of 6.20 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 supercharged six-cylinder four-stroke diesel engines producing a total of 2800 to 3200 PS and two SSW GU 343/38-8 double-acting electric motors producing a total of 750 PS for use while submerged. The boat was capable of operating at a depth of 250 m.

The submarine had a maximum surface speed of 17.7 kn and a submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-1172 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, (220 rounds), one 3.7 cm Flak M42 and two 2 cm C/30 anti-aircraft guns. Its complement was between forty-four and sixty.

Passive sonar
U-1172 was one of only ten Type VIIC's to be fitted with a Balkongerät (literally 'Balcony apparatus or equipment'). The Balkongerät was used on U-boats (GS U-682, GS U-788, GS U-799, GS U-977, GS U-1021, GS U-1105, GS U-1306, GS U-1307 and GS U-1308). The Balkongerät was standard on the Type XXI and the Type XXIII. Nonetheless, it was also fitted to several Type IXs and one Type X. The Balkongerät was an improved version of Gruppenhorchgerät (GHG) (group listening device). The GHG had 24 hydrophones, the Balkongerät had 48 hydrophones and improved electronics, which enabled more accurate readings to be taken.

Service history
The boat's service career began on 20 April 1944 with the 8th Training Flotilla, followed by active service with 11th Flotilla on 1 December 1944. U-1172 took part in no wolfpacks. U-1172 was sunk on 27 January 1945 in St Georges Channel by depth charges from British frigates HMS Tyler (K576), HMS Keats (K482) and HMS Bligh (K467) at 52.4°N, -5.7°W.