German submarine U-721

History
Nazi Germany
Name	U-721
Ordered	25 August 1941
Builder	H. C. Stülcken Sohn, Hamburg
Yard number	787
Laid down	16 November 1942
Launched	23 July 1943
Commissioned	8 November 1943
Fate	scuttled in May 1945
General characteristics
Class and type	Type VIIC submarine
Displacement	769 t (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 × torpedo tubes (four bow, one stern); 14 × 53.3 cm (21 in) torpedoes or 26 TMA mines; 1 × 8.8 cm (3.46 in) deck gun (220 rounds); various AA guns;
Service record
Identification codes:	M 53 697
Commanders:	Oblt.z.S. Otto Wollschläger
Operations:	no war patrols
Victories:	no ships sunk

German submarine U-721 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 16 November 1942 at the H. C. Stülcken Sohn yard at Hamburg, launched on 23 July 1943, and commissioned on 8 November 1943 under the command of Oberleutnant zur See Otto Wollschläger.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-721 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[1] 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 Garbe, Lahmeyer & Co. RP 137/c 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).^[1]

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).^[1] 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-721 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 an anti-aircraft gun. The boat had a complement of between forty-four and sixty.^[1]

Fate

It was scuttled on 4 May 1945 in Geltinger Bucht as part of Operation Rainbow. Later raised and broken up for scrap.^[2]

References

^ ^a ^b ^c ^d Gröner 1991, pp. 43–46.
^ Busch, Röll 1999, pp. 366.

Bibliography

Busch, Rainer; Röll, Hans-Joachim (1999). Deutsche U-Boot-Verluste von September 1939 bis Mai 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-721". German U-boats of WWII - uboat.net. Retrieved 23 July 2015.

54°48′N 9°49′E / 54.800°N 9.817°E / 54.800; 9.817

[FOOTNOTEGröner199143–46-1] Gröner 1991, pp. 43–46.

[FOOTNOTEBusch,_Röll1999366-2] Busch, Röll 1999, pp. 366.

[1]

[2]

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

v t e Shipwrecks and maritime incidents in May 1945
Shipwrecks	1 May: Argo, TA 43, U-3006, U-3009 2 May: Admiral Hipper, USS Thornton, U-8, U-14, U-60, U-61, U-62, U-71, U-72, U-120, U-121, U-137, U-139, U-140, U-141, U-142, U-146, U-148, U-151, U-152, U-316, U-552, U-554, U-612, U-717, U-929, U-1007, U-1308, U-2327, U-2359, U-2510, U-2526, U-2527, U-2528, U-2531, U-3002, U-3016, U-3018, U-3019, U-3020, U-3021, U-3504, U-3516, U-3517, U-3521, U-3522 3 May: Arcona, Cap Arcona, Deutschland, Emden, USS Lagarto, USS Little, USS LSM(R)-195, Medusa, Nordland, Schlesien, TA22, Thielbek, UA, UB, UD-1, UD-2, UD-3, UD-4, U-48, U-52, U-57, U-58, U-59, U-101, U-328, U-339, U-428, U-446, U-475, U-560, U-704, U-708, U-747, U-748, U-795, U-822, U-828, U-876, U-903, U-922, U-924, U-958, U-1166, U-1170, U-1192, U-1196, U-1201, U-1205, U-1210, U-1227, U-1275, U-2330, U-2332, U-2355, U-2371, U-2501, U-2503, U-2504, U-2508, U-2512, U-2519, U-2520, U-2521, U-2524, U-2533, U-2534, U-2535, U-2536, U-2539, U-2543, U-2545, U-2546, U-2548, U-2552, U-3001, U-3005, U-3010, U-3011, U-3012, U-3013, U-3014, U-3023, U-3024, U-3025, U-3026, U-3027, U-3028, U-3029, U-3031, U-3032, U-3037, U-3038, U-3039, U-3040, U-3507, U-3509, U-3511, U-3513, U-3518, U-3525, U-3530, U-4705, U-4712, Z43 4 May: USS LSM(R)-190, USS LSM(R)-194, USS Luce, USS Morrison, Orion, USS PGM-17, U-30, U-46, U-267, U-393, U-711, U-721, U-792, U-793, U-904, U-1132, U-1161, U-1168, U-1303, U-1304, U-2338, U-2540, U-3033, U-3034, U-4709, U-4711 5 May: T36, U-17, U-38, U-236, U-290, U-349, U-351, U-370, U-397, U-534, U-579, U-733, U-746, U-750, U-794, U-827, U-999, U-1008, U-1016, U-1025, U-1056, U-1162, U-1193, U-1204, U-1207, U-1223, U-1234, U-1306, U-1405, U-2333, U-2339, U-2343, U-2346, U-2347, U-2349, U-2352, U-2357, U-2358, U-2360, U-2362, U-2364, U-2366, U-2367, U-2368, U-2369, U-2507, U-2517, U-2522, U-2525, U-2541, U-2544, U-2551, U-3015, U-3022, U-3044, U-3501, U-3510, U-3524, U-3526, U-3527, U-3528, U-3529, U-4701, U-4702, U-4703, U-4704, U-4707, U-4710 6 May: U-853, U-881, U-3523 7 May: Avondale Park, Sneland I, U-1407 8 May: U-37, U-320, U-382, U-2365, U-2538, U-3030, U-3503 16 May: Haguro, Hatsutaka, U-287 18 May: USS Longshaw 20 May: U-963 24 May: HM Motor Gun Boat 2007, U-979 25 May: USS Bates, USS LSM-135 28 May: USS Drexler 29 May: Tenryo Maru 31 May: I-361, Uzbekistan
Other incidents	3 May: USS Aaron Ward 4 May: HMS Formidable, USS Sangamon 9 May: USS England, USS Oberrender 11 May: USS Bunker Hill, USS Evans, USS Hugh W. Hadley 19 May: Kashima, HMS Terrapin 20 May: USS Chase, USS Thatcher 25 May: USS Barry, USS Spectacle, William B. Allison 26 May: USS PC-1603 29 May: USS Shubrick 31 May: Hebrides Unknown date: Nymphe, U-1197
1944 1945 1946 April 1945 June 1945