German submarine U-712

History
Nazi Germany
Name	U-712
Ordered	7 December 1940
Builder	HC Stülcken & Sohn, Hamburg
Laid down	4 September 1941
Launched	10 August 1942
Commissioned	5 November 1942
Status	Surrendered to Allied forces
General characteristics
Class and type	Type VIIC submarine
Displacement	769 tonnes (757 long tons) surfaced; 871 t (857 long tons) submerged;
Length	67.10 m (220 ft 2 in) o/a; 50.50 m (165 ft 8 in) pressure hull;
Beam	6.20 m (20 ft 4 in) o/a; 4.70 m (15 ft 5 in) pressure hull;
Height	9.60 m (31 ft 6 in)
Draught	4.74 m (15 ft 7 in)
Installed power	2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels); 750 PS (550 kW; 740 shp) (electric);
Propulsion	2 shafts; 2 × diesel engines; 2 × electric motors;
Speed	17.7 knots (32.8 km/h; 20.4 mph) surfaced; 7.6 knots (14.1 km/h; 8.7 mph) submerged;
Range	8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced; 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged;
Test depth	230 m (750 ft); Crush depth: 250–295 m (820–968 ft);
Complement	4 officers, 40–56 enlisted
Armament	5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern); 14 × torpedoes; 1 × 8.8 cm (3.46 in) deck gun (220 rounds); 2 × twin 2 cm (0.79 in) C/30 anti-aircraft guns;
Service record
Part of:	Kriegsmarine; 8th U-boat Flotilla (training); 5 November 1942 – 31 October 1943; 3rd U-boat Flotilla (Front Boat, 0 patrols); 1 November – 31 December 1943; 21st U-boat Flotilla (training); 1 January 1944 – 28 February 1945; 31st U-boat Flotilla (training); 1 March – 8 May 1945;
Commanders:	Oblt.z.S. Walter Pietschmann; 5 November – 14 December 1943; Oblt.z.S. Walter-Ernst Koch; 15 December 1943 – 2 July 1944; Oblt.z.S. Eberhard Freiherr von Ketelhodt; 3 July 1944 – 8 May 1945;
Operations:	no patrols

German submarine U-712 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. Commissioned on 5 November 1942, she served with the 8th U-boat Flotilla until 31 October 1943 as a training boat, and as a front boat in the 3rd U-boat Flotilla under Oberleutnant zur See Walter Pietschmann until 14 December, before being replaced by Oberleutnant zur See Walter-Ernst Koch.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-712 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[2] She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two AEG GU 460/8–27 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).^[2]

The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph).^[2] When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-712 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.^[2]

Service history

Built as yard number 778 at the HC Stülcken & Sohn shipyard in Hamburg, U-712 was launched on 10 August 1942. After the completion of system checks and crew training, U-712 was transferred to the 3rd Flotilla on 13 October 1943. On 1 January 1944, she was re-assigned to the 21st U-boat Flotilla as a training boat. On 3 July 1944, Oberleutnant zur See Koch handed over to Eberhard von Ketelhodt, leaving to command U-975.^[3] U-712's purpose was succeeded by a similar function with the 31st from 1 March 1945.^{[citation needed]}

In the rest of her career under Walter-Ernst Koch and Freiherr Eberhard von Ketelhodt, she served as a training vessel, never having made a single patrol.^{[citation needed]}

Fate

After Germany's surrender in May 1945, U-712 was scuttled at Kristiansand in Norway. She was later taken to Loch Ryan in Scotland, where the British used her bulk for testing before breaking her up at Hayle in 1950

References

^ ^a ^b ^c ^d ^e ^f Helgason, Guðmundur. "U-712". German U-boats of WWII - uboat.net. Retrieved 1 March 2010.
^ ^a ^b ^c ^d Gröner 1991, pp. 43–46.
^ Helgason, Guðmundur. "Oblt.z.S. Koch". German U-boats of WWII - uboat.net. Retrieved 27 March 2010.

Bibliography

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. {{cite book}}: Invalid |ref=harv (help)
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] (in German). Vol. IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2. {{cite book}}: |work= ignored (help); Invalid |ref=harv (help)
Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4. {{cite book}}: |work= ignored (help); Cite has empty unknown parameter: |last-author-amp= (help)

External links

Helgason, Guðmundur. "The Type VIIC boat U-712". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.

[uboat-1] ^ ^a ^b ^c ^d ^e ^f Helgason, Guðmundur. "U-712". German U-boats of WWII - uboat.net. Retrieved 1 March 2010.

[FOOTNOTEGröner199143–46-2] Gröner 1991, pp. 43–46.

[3] Helgason, Guðmundur. "Oblt.z.S. Koch". German U-boats of WWII - uboat.net. Retrieved 27 March 2010.

[1]

[2]

[3]

v t e Type VII submarines
Type VIIA	U-27 U-28 U-29 U-30 U-31 U-32 U-33 U-34 U-35 U-36
Type VIIB	U-45 U-46 U-47 U-48 U-49 U-50 U-51 U-52 U-53 U-54 U-55 U-73 U-74 U-75 U-76 U-83 U-84 U-85 U-86 U-87 U-99 U-100 U-101 U-102
Type VIIC	U-69 U-70 U-71 U-72 U-77 U-78 U-79 U-80 U-81 U-82 U-88 U-89 U-90 U-91 U-92 U-93 U-94 U-95 U-96 U-97 U-98 U-132 U-133 U-134 U-135 U-136 U-201 U-202 U-203 U-204 U-205 U-206 U-207 U-208 U-209 U-210 U-211 U-212 U-221 U-222 U-223 U-224 U-225 U-226 U-227 U-228 U-229 U-230 U-231 U-232 U-235 U-236 U-237 U-238 U-239 U-240 U-241 U-242 U-243 U-244 U-245 U-246 U-247 U-248 U-249 U-250 U-251 U-252 U-253 U-254 U-255 U-256 U-257 U-258 U-259 U-260 U-261 U-262 U-263 U-264 U-265 U-266 U-267 U-268 U-269 U-270 U-271 U-272 U-273 U-274 U-275 U-276 U-277 U-278 U-279 U-280 U-281 U-282 U-283 U-284 U-285 U-286 U-287 U-288 U-289 U-290 U-291 U-301 U-302 U-303 U-304 U-305 U-306 U-307 U-308 U-309 U-310 U-311 U-312 U-313 U-314 U-315 U-316 U-331 U-332 U-333 U-334 U-335 U-336 U-337 U-338 U-339 U-340 U-341 U-342 U-343 U-344 U-345 U-346 U-347 U-348 U-349 U-350 U-351 U-352 U-353 U-354 U-355 U-356 U-357 U-358 U-359 U-360 U-361 U-362 U-363 U-364 U-365 U-366 U-367 U-368 U-369 U-370 U-371 U-372 U-373 U-374 U-375 U-376 U-377 U-378 U-379 U-380 U-381 U-382 U-383 U-384 U-385 U-386 U-387 U-388 U-389 U-390 U-391 U-392 U-393 U-394 U-396 U-397 U-398 U-399 U-400 U-401 U-402 U-403 U-404 U-405 U-406 U-407 U-408 U-409 U-410 U-411 U-412 U-413 U-414 U-415 U-416 U-417 U-418 U-419 U-420 U-421 U-422 U-423 U-424 U-425 U-426 U-427 U-428 U-429 U-430 U-431 U-432 U-433 U-434 U-435 U-436 U-437 U-438 U-439 U-440 U-441 U-442 U-443 U-444 U-445 U-446 U-447 U-448 U-449 U-450 U-451 U-452 U-453 U-454 U-455 U-456 U-457 U-458 U-465 U-466 U-467 U-468 U-469 U-470 U-471 U-472 U-473 U-475 U-476 U-477 U-478 U-479 U-480 U-481 U-482 U-483 U-484 U-485 U-486 U-551 U-552 U-553 U-554 U-555 U-556 U-557 U-558 U-559 U-560 U-561 U-562 U-563 U-564 U-565 U-566 U-567 U-568 U-569 U-570 U-571 U-572 U-573 U-574 U-575 U-576 U-577 U-578 U-579 U-580 U-581 U-582 U-583 U-584 U-585 U-586 U-587 U-588 U-589 U-590 U-591 U-592 U-593 U-594 U-595 U-596 U-597 U-598 U-599 U-600 U-601 U-602 U-603 U-604 U-605 U-606 U-607 U-608 U-609 U-610 U-611 U-612 U-613 U-614 U-615 U-616 U-617 U-618 U-619 U-620 U-621 U-622 U-623 U-624 U-625 U-626 U-627 U-628 U-629 U-630 U-631 U-632 U-633 U-634 U-635 U-636 U-637 U-638 U-639 U-640 U-641 U-642 U-643 U-644 U-645 U-646 U-647 U-648 U-649 U-650 U-651 U-652 U-653 U-654 U-655 U-656 U-657 U-658 U-659 U-660 U-661 U-662 U-663 U-664 U-665 U-666 U-667 U-668 U-669 U-670 U-671 U-672 U-673 U-674 U-675 U-676 U-677 U-678 U-679 U-680 U-681 U-682 U-683 U-701 U-702 U-703 U-704 U-705 U-706 U-707 U-708 U-709 U-710 U-711 U-712 U-713 U-714 U-715 U-716 U-717 U-718 U-719 U-720 U-721 U-722 U-731 U-732 U-733 U-734 U-735 U-736 U-737 U-738 U-739 U-740 U-741 U-742 U-743 U-744 U-745 U-746 U-747 U-748 U-749 U-750 U-751 U-752 U-753 U-754 U-755 U-756 U-757 U-758 U-759 U-760 U-761 U-762 U-763 U-764 U-765 U-766 U-767 U-768 U-771 U-772 U-773 U-774 U-775 U-776 U-777 U-778 U-779 U-821 U-822 U-825 U-826 U-901 U-903 U-904 U-905 U-907 U-921 U-922 U-923 U-924 U-925 U-926 U-927 U-928 U-951 U-952 U-953 U-954 U-955 U-956 U-957 U-958 U-959 U-960 U-961 U-962 U-963 U-964 U-965 U-966 U-967 U-968 U-969 U-970 U-971 U-972 U-973 U-974 U-975 U-976 U-977 U-978 U-979 U-980 U-981 U-982 U-983 U-984 U-985 U-986 U-987 U-988 U-989 U-990 U-991 U-992 U-993 U-994 U-1051 U-1052 U-1053 U-1054 U-1055 U-1056 U-1057 U-1058 U-1101 U-1102 U-1131 U-1132 U-1161 U-1162 U-1191 U-1192 U-1193 U-1194 U-1195 U-1196 U-1197 U-1198 U-1199 U-1200 U-1201 U-1202 U-1203 U-1204 U-1205 U-1206 U-1207 U-1208 U-1209 U-1210
Type VIIC/41	U-292 U-293 U-294 U-295 U-296 U-297 U-298 U-299 U-300 U-317 U-318 U-319 U-320 U-321 U-322 U-323 U-324 U-325 U-326 U-327 U-328 U-691 U-827 U-828 U-929 U-930 U-995 U-997 U-998 U-999 U-1000 U-1001 U-1002 U-1003 U-1004 U-1005 U-1006 U-1007 U-1008 U-1009 U-1010 U-1011 U-1013 U-1014 U-1015 U-1016 U-1017 U-1018 U-1019 U-1020 U-1021 U-1022 U-1023 U-1024 U-1025 U-1063 U-1064 U-1065 U-1103 U-1104 U-1105 U-1106 U-1107 U-1108 U-1109 U-1110 U-1163 U-1164 U-1165 U-1166 U-1167 U-1168 U-1169 U-1170 U-1171 U-1172 U-1271 U-1272 U-1273 U-1274 U-1275 U-1276 U-1277 U-1278 U-1279 U-1301 U-1302 U-1303 U-1304 U-1305 U-1306 U-1307 U-1308
Type VIID	U-213 U-214 U-215 U-216 U-217 U-218
Type VIIF	U-1059 U-1060 U-1061 U-1062
Preceded by: Type II Followed by: Type IX List of U-boats of Germany