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Appendix 4

North Atlantic Convoys and U/B Groups
December 1942 - May 1943


Convoy Date U/B's
ON 1/12 Draufgänger (9 U/B's) moving N. after operation in BD. To form by 2200/5/12 from 48° to 55°30'N along 25°W. To operate on SW convoy beginning 6/12.
On 7/12 ordered westward to close HX 217.
ONS 152   (Ungestüm, see under HX 218)
ON 153 15/12 Raufbold (14 U/B's, some ex-Panzer, others fresh from port) 13/12 ordered to form from 55°03'N - 25°55'W to 51°51'N - 20°55'W. Rudloff (U-609) made contact in 53°27'N - 23°05'W at 1400/15. Operation continued to 18/12, broken off because of bad weather. 4 M/V's and 1 escort sunk from convoy.
ON 154 22/12 Spitz (8 fresh from port) to form by 0000/23 from 54°09'N - 24°45'W to 52°27'N - 21°55'W for SW convoy expected noon 23rd. 3 ex-Raufbold ordered 22/12 to form a wing backing up Spitz to SW of main line. Convoy position for 23rd given to U/B's.
Convoy Date U/B's
HX 217 3/12 Panzer formed before 3/12, N. of Flemish Cap. Reporting convoy beginning a.m. 4/12. Contact made 1223/6/12, after 2 days of patrol line shifting which followed U-524's (Steinaecker) intercept of a convoy voice transmission.
HX 217   Combined Panzer-Draufgänger action continued into AL. 2 M/V's sunk from convoy.
HX 218 13/12 Contacted by Loeser (U-373), 1355/13/12 in 53°09'N - 42°25'W. (U-373 was ex-Dranfänger but had not rejoined group after Nov. operation in BD)
1415/13: Büffel formed (3 U/B's, only two others besides U-373 being in the vicinity)
1934/13: Ungestüm (9 U/B's, ex-Panzer-Dranfänger) ordered west to area 57°N - 33°W to close HX 218 from ahead. Could not find HX 218 but picked up ONS 152, which lost 1 ship from the action.
Ungestüm reformed to operate on ON 154, q.v.

-- 91 --

Convoy Date U/B's
  22/12 Ungestüm to reform for SW convoy by 0800/25 from 50°21'N - 32°15'W to 48°09'N - 29°55'W, thus to "surround convoy." Total of 22 U/B's set for the convoy.
  26/12 Contact by Graef (U-664) in 48°15'N - 23°55'W at 1756. (Graef was southernmost boat of Spitz wingback).
  28/12 Ungestüm entered operation which continued to 43°N - 34°W, resulting in sinking of 14 ships (plus 1 torpedoed) out of 45 in convoy.
  29/12 Falke forming: by 3 Jan 13 U/B's, nearly all fresh from Biscay ports or from Norway, in line from 50°45'N - 26°35'W to 49°09'N - 22°35'W.
  4/1 Reforming for the line from 58°N - 26°45'W to 54°N - 26°45'W to be occupied by 1600/7. 2 new U/B's added from the north; 1 ex-Falke ordered to refuel from U-117 and then support Jaguar. (Falke had evidently been dissappointed in the initial expectation of a SW convoy and was shifting north for a westbound convoy.)
  7/1 Falke: expect westbound convoy from p.m. 7 to 9/1. (No contact)
  8/1 4 fresh U/B's being added to Falke.
  10/1 Habicht forming (9 U/B's) to extend Falke line southward to 51°N. Line to be reached by 16/1.
Convoy Date U/B's
  2/1 Jaguar forming "to size Am-Eng convoy" in area 51°30'N - 45°15'W. Actual formation delayed until about 10/1 as a result of weather interference with Neumann (U-117) refueling R/V which was supplying ex-Spitz U/B's to join the 5 that were making for Newfoundland area from port. By 16/1 Jaguar consisted of only 8 U/B's.


  10/1 Jaguar: expect 9 knot convoy on 12/1.
Jaguar: expect 7 knot convoy on 13/l.
(Patrol line shifts taking place)

-- 92 --

Convoy Date U/B's
  14/1 Falke: expect westbound convoy on 16/1. (No contact)
  17/1 Falke-Habicht line shifted to the north, now to extend from 61°30'N to 53°27'N along 26°W.
  20/1 (approx) Falke-Habicht line dissolved.
The above sequence due to successful convoy diversions.
    Comment: By 18 Jan 32 U/B's had been involved in this attempt to block ON-ONS convoys. About 28 were still in line when the groups were dissolved. Originally formed in anticipation of another southwest convoy, to be caught like ON 154 beyond A/C coverage, Falke was shifted north when it became evident that ON-ONS convoys were evading the patrol line. Then Habicht was formed lest the convoys were proceeding on a southerly route after all. Finally the entire line was shifted still farther to the north lest the convoys be using the extreme northern route.
  20/1 (approx) Landsknecht (approx 20 U/B's) formed from ex-Falke-Habicht and U/B's fresh from port along line from about 54°N - 26°W to 50°45'N - 24°30'W. (To continue block against southwest convoys after disbanding Habicht)
Convoy Date U/B's
  13/1 "you can count on announced convoy."
(No contact)
  18/1 Jaguar: 2 northeast convoys expected, 1 beginning a.m. 20/1. Line to be from 51°45'N - 50°15W to 50°51'N - 46°15'W. (8 U/B's)
    Comment: As in the eastern part of the North Atlantic, so too in the western part, convoy diversion had successfully foxed the U/B's. Jaguar's line had been successfully changed so that by 21 Jan it had wheeled from a NW-SE line north of Flemish Cap to an almost W-E line north of Virgin Rocks. It was apparent that COMSUBs believed his eastbound convoys were evading his lines by proceeding due north along the Newfoundland-Canadian coast. When, however, U-96 (Hollriegel) enroute from Jaguar to the Baltic ran across a convoy (later corrected to AS group) on 22/1 in 52°45'N - 39°15'W, Command presumed "that expected convoys went south of group Jaguar." (1848/22/1)
  20-21/1 Haudegen (20 U/B's) formed from ex-Falke-Habicht which had by this time moved to west of 30°W. Hindered by bad weather, Haudegen began slow cruise to west which developed into a fan-sweep pivoting on area 52°N - 36°W and grazing Cape Farewell as the northern end came around.

-- 93 --

Convoy Date U/B's
  24/1 Landsknecht: expect convoy beginning today.
(No contact)
  28/1 Landsknecht dissolved.
10 U/B's to proceed westward, heading for area 46°45'N - 50°33'W, thus to catch eastbound convoys before effective evasion could begin.
4 U/B's to hold their stations in Landsknecht area. (SW convoy line)
Convoy Date U/B's
HX 223 22/1 Graef (U-69) (Haudegen) had hydrophone contact in area 58°N - 41°W. Northernmost Haudegen U/B's went in search. No luck. Rest of Haudegen ordered to line from 56°21'N - 36°30'W to 52°51'N - 32°05'W, then to sweep on course 235°.
SC 117 23/1 Poel (U-413) (Jaguar) contacted convoy escorts in 53°09'N - 50°55'W. Jaguar unable to maintain effective contact. Haudegen lines shifted to seal off area from Cape Farewell to point approx. 450 miles south-southeast. Operation failed completely. Given up on 27/1.
  27/1 Jaguar departed area for refueling. Haudegen to reform by 30/1 from 58°N - 47°W to 53°39'N - 38°45'W for convoy operations on 30/1.
The maneuver succeeded in that it ran into convoys (SC 118 and HX 224) which were proceeding south of U/B concentration in Greenland-Newfoundland pocket.
  31/1 Haudegen: before 2/2 expect 3 convoys steering north or northeast and 1 southwest.
Line for 2/2: 56°51'N - 48°42'W to 52°45'N - 40°05'W.
Line for 3/2: 55°45'N - 49°55'W to 51°51'N - 41°25'W.
    Comment: Two of the above convoys were HX 224 and SC 118 which evaded Haudegen but were caught by ex-Landsknecht.

-- 94 --

Convoy Date U/B's
Convoy Date U/B's
HX 224 1/2 Teichert (U-456) ex-Landsknecht on cruise west ran into convoy escort in 53°09'N - 30°55'W. By 1401/1 U-456 had found the convoy and began to shadow for former Landsknecht U/B's and others in area who were ordered to attack. Convoy was pursued to 17°W where operation was called off 4/2. U/B's turned back to meet SC 118. (2 ships sunk from HX 224)
SC 118 1/2 Pfeil (11 U/B's, 7 of them ex-Landsknecht) to sweep west from a line 52°45'N - 34°55'W to 50°51'N - 29°35'W "to seize a second north bound convoy, suspected to be on about the same route as Teichert's." (2131/1/2) Contact was made 4/2 in 50°09'N - 37°05'W. After 2 days of shadowing U/B's penetrated the strong defense and sank 7 ships in 3 hours. 3 additional ships were lost. Action was called off on 9/2, the U/B's heading for refueling in area 51°N - 32°W.
"Greenland Convoy" 2/2 Waechter (U-223) (Haudegen) contacted convoy in 56°57'N - 49°24'W.
Nordsturm (5 U/B's) formed from northern Haudegen U/B's to operate on what proved to be the "smaller Greenland convoy" rather than "the larger England convoy."
  4/2 Haudegen to continue sweep southwest to line from 52°15'N - 50°35'W to 49°39'N - 44°25'W. Then to break into individual attack areas running from Virgin Rocks northeast to Newfoundland coast.
  9/2 ex-Nordsturm rejoining Haudegen.
  10/2 Northeast convoy expected in Haudegen area beginning today.

-- 95 --

Convoy Date U/B's



ON 165 17/2 Contacted accidentally by U-69
(Graef, ex-Haudegen, on return) in 51°15'N - 40°45'W. Taifun formed with ex-Haudegen U/B's.
U/B's already low on fuel, could operate for 2 days only. They were ordered to go as low as 5-6 cbm fuel, since supply U/B was enroute. 3 ships lost. Ex-Haudegen U/B's returned to Western France after refueling.
ON 166 18/2 Ritter-Neptun to form continuous line by a.m. 20/2 from 59°45'N to 52°45'N along 30°W. To sweep southeast.
  20/2 Hoeltring (U-604) in Knappen made contact at 1055. Operation continued for 5 days area south of Virgin Rocks. 15 ships lost. Neptun did not operate.
Convoy Date U/B's
  11/2 Haudegen line pulled back and arched from Flemish Cap to Belle Isle.
  11/2 Ritter (11 U/B's, increased to 16 by 14/2) forming or 14/2 from 55°03'N - 31°25'W to 51°15'N - 30°55'W to scout course 235°.
  13/2 Haudegen expect northeast convoy beginning 14th. "Don't weaken."
  15/2 Neptun (10 UB's) forming for 18/2 from 61 °33'N - 30°38'W to 59°09'N - 27°00'W. To scout on course 235°.
Haudegen dissolved.
HX 226 16/2 Ritter line successively ordered to shift to north in a hurry (thus close gap between Ritter and proposed Neptun line). Northeast convoy expected that night.
  17/2 Neptun ordered to take its position in line at once.




  18/2 Ritter-Neptun orders cancelled (due to good intelligence on ON 166) See under ON 166.
  20/2 Neptun held its line and returned to southwest sweeping course beginning a fan sweep similar to that of Haudegen.

-- 96 --

Convoy Date U/B's
ON 167 21/2 Graef (U-664), enroute from Biscay to form with Burggraf, ran across convoy at 1850 in 50°49'N - 24°15'W. Other Biscay boats heading for Burggraf were ordered to join attack. By 22/2 straggler U/B's from Ritter operation on ON 166 were ordered to turn back east and close convoy.
Sturmbock all U/B's operating on this convoy to which were added 3 ex-Haudegen U/B's on 23/2. Contact was lost.
Sturmbock (11 U/B's), 24/2, ordered to line from 49°57'N - 38°35'W to 46°21'N - 38°45'W for a further attempt but the action was not resumed for lack of the convoy.
(2 ships sunk from ON 167)
  26/2 Sturmbock dissolved. 5 to refueling, 6 to form Wildfang.
ON 168 1/3 Sighted by Struckmeier (U-608) of Neptun at 1312 in 59°45'N - 36°24'W. After some confusion Neptun boats were ordered to operate on either convoy depending on individual situation. Convoy not damaged. Search ended on 4/3.



Convoy Date U/B's
  21/2 Burggraf (9 U/B's, fresh or new) to form 24/2 from 56°09'N - 28°25'W to 53°21'N - 26°15'W. To scout on course 235°. Delayed in forming.
  26/2 Wildfang from 51°27'N - 42°05'W to 49°45'N - 40°15'W. (Burggraf's delay in getting started may have determined the formation of Wildfang, whose line was such as would join on to Neptun by 27/2, thus leaving no gap in the long line across the northeastern route off Newfoundland.)
HX 227 26/2 Neptun expect northeast convoy today. Sighted by Freidrich (U-759) at 0430 in 56°27'N - 44°48'W. Pursued by Neptun U/B's until 2/3.
(1 ship sank)
In course of operation Neptun ran into ON 168. Neptun absorbed by other groups following this combined operation.
  3/3 Neuland (18 U/B's half new from north, half fresh from Biscay ports). To form by noon 7/3 from 54°45'N - 27°15'W to 50°57'N - 23°45'W. To scout on course 240°.
SC 121 4/3 Wildfang-Burggraf now constituting a single line of about 30 U/B's from 55°N - 50°W to 50°N - 39°W, Wildfang having moved to northwest to replace Neptun, now engaged in Greenland - Iceland area, and Burggraf having

-- 97 --

Convoy Date U/B's
ON 170 9/3 Raubgraf expect southwest convoy 10/3. U/B's informed of delay in convoy arrival because of weather.



Convoy Date U/B's
    completed its southwest sweep to effect union with Wildfang. Both groups reinforced by U/B's as they refuelled following ON 165 - 166 actions. At same time ex-Neptun U/B's moving southwest to back up Wildfang-Burggraf line. Expect northeast convoy with speed 7, p.m. 4/3.
  6/3 Hopman (U-405) (ex-Neptun) contacted SC 121 at 1056 in 54°57'N - 40°15'W, apparently behind the Wildfang-Burggraf line. How convoy got through the line is not clear unless the two groups had failed to join up as ordered. 15 U/B's were at once pulled from middle of Wildfang-Burggraf line to pursue, together with all available unattached U/B's in the area. This group called Westmark for operation. The 10 northern U/B's from Neuland were at once detached as Ostmark to complete the encirclement of SC 121. Action continued to 11/3 in Rockall area. (13 ships torpedoed)
Raubgraf, as Westmark was detached from Wildfang-Burggraf the remaining 15 U/B's from the ends moved in to close the gap and maintain the block off Newfoundland.
  7/3 Raubgraf expect northeast convoy beginning a.m. 8/3 (Presumably HX 228, which went south of Raubgraf but was met by Neuland).
HX 228 10/3 Neuland, augmented by refuelled U/B's, continued cruise west, now on course 265°. At 1335 Hunger (U-336) reported convoy in 50°27'N - 31°15'W, course O80°. Operation continued to noon 13/3. (4 ships lost)

-- 98 --

Convoy Date U/B's
  13/3 Bertlemann (U-603) made contact on southwest convoy in 5403'N - 4425'W but contact could not be maintained.
  14/3 Interest changed to a northeast convoy.














ONS 1 17/3 Seeteufel (8 U/B's, mostly on 1st cruise out from north) to form a.m. 21/3 from 60°45'N - 29°48'W to 58°15'N - 28°12'W.
Convoy Date U/B's
  13/3 Dränger (11 U/B's) ex-Neuland returning westward to reform a.m. 15/3 from 53°45'N - 37°55'W to 50°33'N - 36°15' W. To scout on course 260°.
HX 229

SC 122

14/3 Raubgraf to reform for northeast convoy by 15/3, line to run NW-SE across 50°N in longitude of Virgin Rocks - Flemish Cap. 6 hours after order to reform Raubgraf was sent at high speed toward 50°N - 42°W to get hold of eastbound convoy. (Source of info probably decryption intelligence, although this is not confirmed). Contact was made by Walkerling (U-91) late on 14/3 but convoy escorts were successful in keeping U/B's down. For next 30 hours U/B's endeavored to get into favorable sweep lines for contact and were constantly hammered at by U/B Command's "Convoy must be found!" (U/B's were a few miles too far to north).

Sturmer (approx 25 U/B's) forming just west of 30°W and running from about 60°N down to latitude of Dränger.

  16/3 Contact on convoy established by Feiler (U-653, Raubgraf) at 0627 in 49°27'N - 37°25'W, course 070°, 7 knots. Feiler had just been released from group and was enroute to refueller off to the south when he discovered the convoy.

Dränger ordered to head convoy off and join in Raubgraf operation.

  17/3 Kinzel (U-338) of Sturmer ran into convoy (HX 229) at 0302 in 51°57'N - 32°45'W. By end of day COMSUBs recognized that 2 convoys were involved. Northern parts of Sturmer and Dränger detailed to attack the second convoy, now being shadowed by Bahr (U-305). Operation against convoys continued to 20/3 and involved

-- 99 --

Convoy Date U/B's


  20/3 Seeteufel (increased to 14 U/B's) shift by a.m. 22/3. New line from 61°15'N - 28°52'W to 57°39'N - 27°00'W. Westbound convoy expected a.m. 22/3. (on basis of Allied cipher compromise, precise source unknown but presumably Combined cipher #3). The line moved westward beginning 22/3 apparently to catch convoy, as it came down from an assumed northerly diversion. Convoy expected. Seeteufel's interest turned to eastward convoys.
Convoy Date U/B's
    practically every U/B in North Atlantic. 21 ships were lost and Dönitz called it "the greatest success yet achieved against a convoy." (1036/21)
  20/3 Wolfchen (6 U/B's) to take up line by a.m. 25/3 from 50°45'N - 35°35'W to 49°27'N - 34°05'W. To contact a northeast convoy (A "shadowing" group of U/B's fairly low on fuel who were to pick up the convoy and turn it over to other U/B's before going to refueller). (Presumably HX 230 - SC 123)
Seewolf (19 U/B's, most of them moving back west after operation on SC 122 and HX 229) to line by a.m. 25/3 from 55°15'N - 39°15'W to 49°51'N - 34°45'W for northeast convoy expected on or after 25/3. Wolfchen absorbed by Seewolf.
  24/3 Seeteufel (16 U/B's) continuing westerly sweep. By 26/3 to reach line running southeast from Cape Farewell, thus joining onto Seewolf line. On 25/3 at north end of Seeteufel caused a prolonged confusion contacting what later proved to be an iceberg formation. Since the target's speed was reported as slow and its size as big, COMSUBs was at first irritated because the U/B's didn't sink it.
  26/3 Fiedler (U-564) (Seeteufel) contacted a southwest convoy in 57°33'N - 40°12'W at 1850. (apparently ICS 1) Operation was discontinued when HX 230 was found the next day in same area.
HX 230 27/3 Bahr (U-505) (Seewolf) discovered a convoy in 56°39'N - 40°24'W at 1450. Approximately 27 U/B's (from Seewolf-Seeteufel plus a few new

-- 100 --

Convoy Date U/B's












ON 176 10/4 Bülow (U-404) in Adler made contact on convoy at 1335 in 53°51'N - 38°55'W. Action continued for 2 days. Several ships torpedoed.
Convoy Date U/B's
    ones which were added later) tried to operate for 3 days. Severe hurricane made conditions difficult for U/B's as well as for the convoy. (1 ship sunk)
  31/3 U/B's in northwest Atlantic informed to expect northeast convoy beginning 31/3 between 54°10'N - 46°45'W and 53°15'N - 42°15'W.
HX 231 2/4 (approx) Löwenherz (14 U/B's, mostly ex-Seewolf-Seeteufel) had returned to area of Seeteufel line. By a.m. 5/4 to line from 59°57'N - 38°36'W to 55°39'N - 36°45'W. Northeast convoy expected.
  4/4 Lange (U-530) sighted convoy at 1224 in 55°03'N - 36°45'W, course 060°. Convoy pursued across North Atlantic, COMSUBs reprimanding U/B's for failure to take "advantage of the rare opportunity of assaulting a convoy." (1030/6) (5 ships sunk)
  5/4 Adler (9 UB's) to form a.m. 7/4 from 54°41'N - 44°35'W to 52°57'N - 39°55'W. Northeast convoy expected beginning 7/4.
HX 232 10/4 Lerche (10 U/B's, ex-Löwenherz) forming in a hurry from 54°39'N - 34°35'W to 51°45'N - 32°05'W. Convoy sighted 11/4 by Deecke (U-584) in 53°39'N - 33°35'W. Group operated for 2 days. (3 ships sunk)
  10/4 Meise (7 U/B's) disruption of Adler by ON 176 operation necessitated speedy replacement of line for northeast convoys. A few Adler boats were held in place and formed up with new arrivals from 52°09'N - 37°05'W to 49°51'N - 35°25'W. (Meise line was further to south than Adler's had been)

-- 101 --

Convoy Date U/B's
Convoy Date U/B's
  11/4 Uphoff (U-84) taken from Adler operation against ON 176 and ordered to area 53°15'N - 46°45'W, to transmit several messages of different types (using different operators) "to give the impression that several U/B's are enroute to that point." (2158/11) (Clearly designed to force northeast convoy on to route blocked Meise, which at the moment was not sufficiently long to cover area effectively)
HX 233
SC 126
12/4 Meise (9 U/B's) drifted to southwest. By a.m. 13/4 to be from 50°09'N - 40°15'W to 47°45'N - 38°35'W. Northeast convoy expected beginning 13/4. Additions arriving.
  13/4 Meise (18 U/B's) by a.m. 14/4 from 51°03'N - 44°14'W to 46°51'N - 38°55'W via 49°15'N - 41°05'W.
  15/4 Meise (24 U/B's) 6 more U/B's to extend line to the north. "Another northeast bound convoy is expected beginning tonight." (1927/15) Between 15 and 17/4 Meise U/B's reported signal strengths of convoy voice intercepts and COMSUBs was led to believe that his expected convoy was still west of the line. (Actually the UB's were hearing ONS 3; SC 126 and HX 233 had been successfully diverted to the south but were contacted in area 45°N - 26°W on 16/4 by U/B's outbound from Biscay.) 6 U/B's operated. At least 1 ship was lost.
HX 234 17/4 Meise (now 26 U/B's) new line for a.m. 19/4 from 53°45'N - 46°15'W via 52°09'N - 43°25'W via 51°03'N - 41°45'W to 49°45'N - 39°55'W. Northeast convoy expected beginning 19/4.

-- 102 --

Convoy Date U/B's
ONS 3 20/4 Northwest end of Meise made contact, Neide (U-415) apparently on ONS 3 during night 20-21/4 in 54°10'N - 46°45'W where he claimed to have sunk 2 ships. By noon 21/4 Zitzewitz (U-706) reported a convoy which COMSUBs recognized as a second southwest convoy proceeding about 80 miles behind the first. Meanwhile operation against HX 234 had already begun. A few U/B's were permitted to press the attack against southwest convoys while all others were put on HX 234.






ONS 4 22/4 Carlsen (U-732) one of the new U/B's ordered to operate on Trotha's convoy (HX 234) ran into a southwest convoy in 57°45'N - 33°48'W at 1008. (Convoy was first reported on course 180°, hence presumably trying to clear area of Trotha's convoy.)
  23/4 Specht (17 U/B's) ordered to take up new line by 25/4 from 54°15'N - 43°15'W to 51°15'N - 38°55'W scouting course 040°, to operate on Carlsen's convoys. 2 other new UB's had been assigned as shadowers to assist Carlsen. The situation was thus set for a head-on attack.
Convoy Date U/B's
  20/4 Specht (15 U/B's, a few ex-Adler and Meise U/B's that had operated on southwest convoys plus U/B's from port) Expecting eastbound convoy in latitude of 46°05'N at about 39°15'W. By 22/4 noon line to be from 48°51'N - 37°45'W to 44°15'N - 37°45'W. (Probably influenced by southern route taken by HX 223 and SC 126, as established by contact in 45°N - 26°W on 16/4. Designed for SC 127?)
  21/4 Trotha (U-306) sighted convoy (HX 234) at 0924 in 56°39'N - 42°24'W, course east. Recognizing that huge group Meise had at last found a notheast convoy, COMSUBs ordered: "Now go after it and see red!" (1001/21) 5 new U/B's on cruise out from north were ordered to intercept. Later others were put on the convoy. The operation lasted until 25/4 and constituted what COMSUBs recognized as a brilliant job of shadowing on U-306's part. U-306 had also put a few torpedoes into the convoy. But despite exhortations the rest of the boats lagged behind.
  22/4 Amsel (11 U/B's from port) to form by a.m. 25/4 from 56°41'N - 32°00'W to 53°45'N - 29°35'W, on course 260° for eastbound convoy. (HX 235?)

-- 103 --

Convoy Date U/B's
  25/4 Convoys reached area of Specht, operation started, during which Bülow (U-404) assumed that he had sunk an aircraft carrier in 54°21'N 35°55'W at 0817. German Command announced that Bülow had sunk the Ranger and called Bülow home at once to receive the Oak Leaves to the Knight's Cross.
Convoy Date U/B's
  25/4 Meise reformed (16 U/B's) in line from 59°15'N - 32°36'W to 56°45'N - 28°12'W in expectation of a "slow northeast convoy" beginning 26/4. (presumably SC 127)

Traffic gap from 26/4 to 1/5


  1/5 Specht after attempt to operate on southwest convoys, ONS 4 and ON 179, had apparently remained in area just to north of Virgin Rocks-Flemish Cap.
ONS 5   Star (ex-Meise U/B's) had presumably been formed at conclusion of Meise's unsuccessful line up on 25-26/4 for a "slow northeast convoy" and had moved southwest to support Specht. On the way they had made contact of some sort for they were being ordered to discontinue search on 1/5.
SC 128   Amsel likewise must have continued its cruise to the west but with a more southwesterly course to bring it to area just east of Flemish Cap. Both Amsel and Specht were expecting a convoy (presumably eastbound) on 1/5 but the convoy was already overdue. (HX 236 - SC 128). Later on 1/5 Hasenschar (U-628) in group Specht reported smoke clouds in 50°51'N - 45°45'W (2029/1) COMSUBs ordered ail to operate if the smoke proved to come from a northeast convoy, otherwise as opportunity offered.

-- 104 --

Convoy Date U/B's














ONS 5 4/5 Fink (27 ex-Specht-Star) to be in line a.m. 5/5 from 56°45'N - 47°12'W to 54°09'N - 36°55'W. Southwest convoy expected beginning 5/5. Before U/B's could get into new line Hasenschar (U-628) discovered convoy in 55°45'N - 42°55'W. at 2017. All Specht-Star U/B's to operate as group Fink, "your position is favorable as never before." (2050/4) (It is not clear whether COMSUBs thought U-628 had found a northeast or southwest convoy. There was some confusion
Convoy Date U/B's
  2/5 Hasenschar's convoy confirmed as northeast. All Specht and Star were ordered to operate (total of 31 U/B's). Contact was lost. COMSUBs replied "Convoy must be found again ...Something can and must be accomplished." (2215/2)
  3/5 Specht-Star to form at maximum speed from 56°12'N - 44°35'W to 54°57'N - 39°35'W via 55°51'N - 41°15'W, to find northeast convoy by scouting on course 205°.
Amsel (23 U/B's) broken-up into 4 parts as follows:
Amsel 1: from 51°51'N - 49°05'W to 51°39'N - 46°25'W
Amsel II: from 51°33'N - 43°25'W to 50°27'N - 41°25'W
Amsel III: from 48°45'N - 41°45'W to 47°03'N - 41°25'W
Amsel IV: from 45°47'N - 39°35'W to 44°15'N - 39°35'W
Changes made on 4/5 in line positions:
Amsel II shifted to northeast
Amsel III: shifted to east
Amsel IV: shifted to southwest
  4/5 3 destroyers were sighted by Specht-Star but convoy situation remained obscure.

-- 105 --

Convoy Date U/B's
    at first as to whether U-628 had reported a north or south course. By 2213/4, however, COMSUBs was ordering complete destruction of the convoy which was then recognized as proceeding south.)

Amsel I and II ordered to close Hasenschar's convoy.

  5/5 COMSUBs estimated that 40 UB's were attacking the convoy and called for most decisive and immediate action in view of limited time and area for operation. The attack was pressed vigorously and 11 ships were sunk out of a convoy of 42 before action ceased on 6/5. COMSUBs was very pleased.
Convoy Date U/B's





HX 237
SC 129
7/5 Rhein (12 U/B's, ex-Ansel III and IV) to line up by a.m. 8/5 from 47°33'N - 40°55'W to 43°57'N - 40°05'W in expectation of eastbound convoys, "one fast and one slow." Elbe (17 U/B's, ex-Ansel I and II and Fink) to line up by a.m. 8/5 from 52°45'N - 43°55'W to 47°51'N - 41°05'W. (Cipher compromise was responsible for these formations as well as for the sudden changes in scouting courses which defeated convoy diversion to south of the lines.)
  9/5 Foerster (U-359) in Rhein made contact at 1306 in 41°09'N - 36°54'W. (HX 237)

Drossel (7 UB's) which had been operating off Cape Finnisterre against England-Gibraltar convoys ordered to discontinue and head for Foerster's convoy at high speed.

Contact was lost on HX 237, then regained by Clausen (U-403), who was to shadow for Drossel. Meanwhile, Rhein-Elbe were reformed for SC 129 as Elbe I and II. Drossel met HX 237 at 1908/11 in 44°15'N - 27°25'W (Seibicke U-436). (Again cipher compromise played a decisive part.) Contact on SC 129 by Elbe was also made on the same day in 41°39'N - 33°58'W.

-- 106 --

Convoy Date U/B's










ONS 7 13/5 Westbound convoy sighted by outbound Nagel (U-640) in 60°39'N - 23°48'W. Isar and Inn reformed as Donau I. Lerch and Nab reformed as Donau II. Iller shifted to north, thus forming long line with the two Donaus, running from approx 61°N - 40°W to 56°30'N - 34°30'W, No group operation. Hope of Nagel's convoy given up 17/5. 1 ship lost.
Convoy Date U/B's
    Operation was discontinued on 14/5. COMSUBs had initially believed the opportunity a most favorable one, for the convoy had been found in an area "where only slight air protection can reach it." (1855/9) But the attack proved more costly to the U/B's than it did to the convoys. 4 stragglers and 2 ships from SC 129 were lost.
  10/5 Isar (4 new U/B's) forming from 58°33'N - 41°00'W to 57°27'N - 39°24'W.
Lech (4 U/B's) forming from 56°39'N - 38°48'W to 55°51'N - 37°45'W.
  11/5 Inn (4 U/B's) forming from 56°39'N - 42°24'W to 55°45'N - 41 °25'W.
Iller (6 U/B's) forming from 56°21'N - 34°45'W to 55°03'N - 32°55'W.
  12/5 Nab (6 U/B's) forming from 52°21'N - 37°45'W to 50°57'N - 36°15'W. (above new groups were reformed 13/5 because of Nagel's contact on westbound convoy.)
SC 130 17/5 Donau I to form by p.m. 18/5 from 56°03'N - 37°55'W to 53°21'N - 35°25'W.
Donau II to form by p.m. 18/5 from 50°21'N - 35°15'W to 50°33'N - 33°35'W.
Oder to form by p.m. 18/5 from 50°21'N - 33°25'W to 48°39'N - 32°35'W.
(Iller now joined Donau I, forming northern part of Donau I line.)
Expecting northeast convoy 18/5 at 2000 speed 7.5.

-- 107 --

Convoy Date U/B's
Convoy Date U/B's
    Koch (U-304) (Donau I) sighted convoy (SC 130) at 0018/19 in 54°45'N - 36°45'W, easterly course, speed 7. 20 U/B's (all of Donau I and part of Donau II) ordered to operate on Koch's convoy. Remaining Donau II U/B's ordered to join Oder. Operation discontinued 20/5.
HX 239 19/5 Mosel (22 U/B's) to form by p.m. 21/5 from 55°15'N - 44°25'W to 52°09'N - 37°15'W. Northeast convoy expected beginning 2000/21.
Oder U/B's absorbed in Mosel line.
  21/5 Mosel line shifted to east-southeast at high speed (on basis of decryption intelligence). Following a stern message in which U/B's were reminded of their recent lack of success and their "high responsibility," COMSUBs ordered new line in accordance with information on convoy.
  22/5 Contacts on escorts in area 51°10'N - 34°50'W. Donau U/B's ordered to join in search for convoy.
  23/5 Convoy defense encountered in area 51°45'N - 30°00'W. Operation discontinued. U/B's suffered heavy losses.

24/5 U/B withdrawal from North Atlantic

-- 108 --

North Atlantic Convoys and U/B Groups
September 1943 - March 1944


Convoy Date U/B's


ONS 18
ON 202
20/9 Leuthen (21 U/B's from waiting areas) formed 2000A from 59°N - 29°W to 54°N - 26°W. To operate on westbound convoys only. Kept informed of convoys progress. Operated successfully 20-23/9.
(4 destroyers and 7 merships sunk)
ON 203 26/9 Rossbach formed from 12 ex-Leuthen U/B's plus 8 others, from 58°N - 34'W to 54°N - 31 °W. To operate 26/9 on ON 203. Convoy diverted to north.
ONS 19
ON 204
26/9 Rossbach informed. Expected 29th, then 1/10, then 3rd, with ON 204. Line shifted to north and west on 30/9, but offensive contact not made.




ONS 20
ON 206
11/10 Ex-Rossbach U/B's heading for area of ON 206 attack planned for 16/10.
  13/10 Schlieffen formed from these U/B's. To be in line 16/10 across route of ON 206 and ONS 20. ON 206 diverted to north, ONS contacted, operation fizzled.
Convoy Date U/B's
HX 256 16/9 Leuthen not to operate "if eastbound convoy sighted." (HX 256 was in area 18-19/9)



HX 257 23/9 Leuthen to operate. Plans abandoned. Group dissolved.






HX 258 1/10 To Rossbach: "If eastbound convoy sighted, do not operate on it."
SC 143
HX 259
4/10 To Rossbach: to operate 8/10 on eastbound convoy. On 7/10 U/B's told of "another" (SC 143) "by D/F." U/B's found only destroyers from SC 143.




HX 261 19/10 U/B's informed of HX 261 noon position for 20/10. No operation. (Cipher compromise presumed)

-- 109 --

Convoy Date U/B's




ONS 21
ON 208
30/10 Körner and Jahn, formed from ex-Siegfried boats, from 52°N - 42°W to 42°N - 40°W; informed. Convoy traffic passed to north.


ON 210 7/11 U/B's which were to become Eisenhart informed.




ON 123 25/11 Radio silence imposed on U/B's in AL because of intended operation.
ON 123 26/11 Temporary attack areas of pre-Coronel boats.
  30/11 U/B's informed of expected convoy
ONS 24 2/12 Coronel formed of 16 U/B's from waiting areas south-southeast of Iceland, in mid-North Atlantic, closer to UK. To operate on slow westbound convoy 5/12.
Convoy Date U/B's
HX 262 18/10 U/B disposition planned for 24/10
  20/10 Lined up for 24/10 operation.
  22/10 Siegfried formed from 19 U/B's (ex-Rossbach) from 52°N - 41°W to 49°N - 39°W.
  26/10 Operation discontinued. Convoy presumed to be east. (had proceeded via southerly course)
SC 145 30/10 Siegfried disbanded after failing to contact SC 145.
HX 263 31/10 Körner-Jahn formed p.m. for HX 263.
HX 264 2/11 Körner-Jahn disbanded. Tirpitz formed to operate 5/11, from 51°N - 46°W to 42°N - 43°W. Convoy passed to the south.
SC 146
HX 265
7/11 Tirpitz disbanded. U/B's heading for new type lines: small, scattered.
  9/11 Eisenhart formed (30 U/B's) from 60°N - 45°W to 45°N - 25°W. Lines shifted on 12/11 and 14/11 to southeast because of "persistent avoiding action of convoys." Contact made too late for operation. (Cipher compromise presumed)



SC 147
HX 267
30/11 U/B's which were to be Coronel informed.
HX 268 5/12 Coronel to operate evening of 7/12, expecting shift to north. (HX 268 passed to north 7-8/12)

-- 110 --

Convoy Date U/B's
    Comment: German Command indicates awareness that convoy was proceeding on northern route. Longitude estimate was good.
ON 214   See England-Gibraltar section.
ON 215 13/12 Coronel grown to 25 U/B's. Spit into 3 sections. ON 215 was sighted southeast of line.
  14/12 Convoy was steering west.
  15/12 10 U/B's, Coronel III, detached and sent southwest to catch ON 215, now steering southwest.
  16/12 D/R plotting of convoy sent to Osorno and Alsterufer blockade runners. Coronel III found nothing; withdrawn to east.
ONS 18/12 Geider (U-761) to count on southwest convoy in ED 10, 20, 50 on 21/12.

Comment: The Germans were right in believing that these convoys were proceeding on southerly route, although they were behind Command's schedule.

ON 217 27/12 To Rügen: count on 1 westbound convoy in vicinity of group at present. "No info as to north or south routing."

Comment: Unlike SC 149 and HX 271, ON 217 was a good 24 hours east of Rügen. Rügen lines were well placed, however, for south convoys on much different routes.

  30/12 2 U/B's of northernmost section of Rügen stumbled on ON 217. 1 ship sunk. Remainder of U/B's pursued, but no further successes.
Convoy Date U/B's
SC 148 8/12 Coronel to operate on 13/12.


HX 269 12/12 Beginning this evening, passage of 2 eastbound convoys. (convoys had passed far to the south)




HX 270
SC 149
16/12 D/R plot given to Osorno and Alsterufer for HX 270 and SC 149.



  22/12 Rügen formed of 18 ex-Coronel in 6 lines to the east and south of Coronel.
  24/12 Command counting on Rügen operation by this date. HX 270 cleared Rügen area by 23/12.
HX 271 27/12 To Rügen: count on 2 eastbound convoys in vicinity of group at present. "No info as to north or south routing."

Comment: These convoys were near the group.

-- 111 --

Convoy Date U/B's
ON 219 8/1 To Rügen at 2000A expect 1 westbound convoy. Keep good lookout.

Comment: At this time Rügen was approx 20°W. ON 219 seems the only westbound convoy to which Command could refer. On a.m. 10/1 ON 219 was 56°25'N - 13°02'W (Admiralty) still 2 days away. Had the old cycle been observed, ON 219 would have sailed 4 days earlier, in which case Rügen's convoy warning, coming on the actual day of sailing, would not seem unusual.

ONS 27 15/1 To Rügen: count on 2 westbound convoys today.
Convoy Date U/B's
HX 273 8/1 To Rügen at 200A expect 2 eastbound convoys. Keep good lookout.

Comment: Convoy and Routing estimates for 2000Z/8:
SC 150: 49°23'N - 32°57'W
HX 273: 50°04'N - 33°12'W
These convoys were 2 full days west and south of Rügen p.m. 8/1.


HX 274 15/1 To Rügen count on 1 eastbound convoy today.

Comment: By the 15th, Rügen had shifted to the east, so that concentration was along 19°W. HX 274 was 43°N - 30°W at 2000Z/15, just before altering course sharply to northeast. Had she sailed 2 days earlier and followed more of a great circle route she might have hit Rügen's area on 15-16/1. ONS 27 passed through area 15° to 19°W on 17/1, ON 220 on 18/1, hence were being plotted ahead of time, although not quite as much as would have resulted from strict German observance of the earlier cycle.

  17/1 ON 220 contacted by U/B and A/C on 17-19/1. No orders to operate issued.
ON 221 18/1 To Rügen westbound convoy in about 55°03'N - 18°15'W, night of 20-21/1.
  19/1 13 remaining Rügen boats brought further east.
  21/1 Rügen westbound convoy expected. ON 220 out of danger because of shift of Rügen to east on 19/1.

Comment: Convoy not due in area until 26/1.

  26/1 To Rügen at 0900A westbound convoy tonight.



SC 151 21/1 To Rügen beginning 22/1 count on eastbound convoy.


  26/1 To Stürmer eastbound convoy tonight.

-- 112 --

Convoy Date U/B's
  26/1 Stümer formed of ex-Rügen boats. Surrounded island of Rockall.
  26/1 To Stürmer at 2100A westbound convoy tonight.
Convoy Date U/B's

Comment: The above suggests that the Germans may have corrected their plotting for westbound convoys at this time - on the assumption that when Command says westbound convoy he still meant an ON or ONS convoy as he did in the past. The situation is somewhat puzzling, including the shifting of Stürmer to area from 13° to 15°W, where U/B's would not have operated in the winter of 1942-1943. A clarification of the convoy situation might have been forthcoming from German Air Force's sighting of ON 221 and Command's erroneous directions to new group Hinein (formed 27/1 from ex-Rügen boats a short distance west of southern Ireland), under the impression apparently that ON 221 was KMS 40 (Eng-Gib). This needed clarification was forgotten, however, in the invasion scare of 29 Jan.

ONS 28 31/1 To Stürmer and Hinein expect westbound convoy today.
HX 276 31/1 To Stürmer and Hinein beginning tomorrow east bound convoy also.

Comment: The expectation of ONS 28 would seem to indicate that Command now had the cycle straightened out for westbound convoys, but this does not seem to apply to HX 276. To expect HX 276 on 1/2 in area 14°W would necessitate its having sailed not later than 17/1, the date according to the old cycle, instead of 21/1, as it actually did.

ON 222 1/2 To Stürmer tonight count also on westbound convoy.


  4/2 To Bremen (U-764): Convoy in 51°09'N - 17°15'W, course 220°.
  4/2 Convoy presumed American, course southwest, 8-9.
  4/2 Count on speed 9, southwest course.

Comment: "Speed 9" suggests Command was sure Bremen's convoy was an ON.

HX 277
SC 152
3/2 Igel I and II formed of the 20 remaining Stürmer boats, from 62°N - 12°W to 48°N - 12°W.





  7/2 To Igel II: eastbound convoy sighted by Tillessen (U-516) at 0758A/7 in 44°09'N - 28°25'W. May be expected evening 9/2 at speed 9, forenoon 10/2 at speed 7.

Comment: Command was not sure whether Tillessen had sighted an HX or SC convoy.

-- 113 --

Convoy Date U/B's


ONS 29 12/2 To Igel I and II: beginning 16/2 operation preceded by German Air Force recce [reconnaissance - HyperWar] planned against outbound convoy.

Comment: Igel I shifted farther west to about 240 miles west of Rockall. Igel II between 48° - 50°N and 20° - 25°W.

  14/2 Convoy sighted by aircraft 1800A in 55°21'N - 10°35'W, course 200°. Igel I and II distributed for interception from 54°N - 25°W to 48°N - 20°W.
  15/2 Igel I proceeding farther south to intercept.
  15/2 At 2130A lines A and B formed, based on aircraft sighting at 1730A in 54°39'N - 13°05'W, course 230°, speed 5, operation presumably not before p.m. 18/2.
  16/2 To Igel at 1913A: aircraft sighting 1610 in 52°39'N - 15°35'W, course 180°. Presumably deceptive course. Speed 6-6.5.
  17/2 To Igel at 1536A: cruise underwater 125°.
  17/2 To Igel at 1633A: convoy sighted 1530, 51°51'N - 18°45'W, course 270°. Igel I not to advance south of 51°N. Igel II, cruise underwater 340°.

Comment: The two groups were to converge on convoy course.

Convoy Date U/B's
HX 278 10/2 To Igel: operation planned on AM-Eng convoy with German Air Force on 16/2.

Comment: This operation apparently given up in favor of ONS 29. Plotting seems fairly accurate.












  17/2 From Reisener (U-608): at 0300 was passed over by a fast eastbound convoy. Last hydrophone bearing 60°T, 50°45'N - 22°45'W.

-- 114 --

Convoy Date U/B's
  17/2 Hai formed from 15 U/B's ex-Igel for 1800/18 across convoy course 270°. 2 lines, the forward line with wings to catch diversions from route, with a southwest diversion anticipated.

Comment: During the night of 17-18 Command sent a series of messages to group Hai from which one can gather that he felt the stage had been carefully set and a vigorous operation assured. "This long prepared operation must succeed." (0105/18)

  18/2 To Hai at 1351A: move both patrol lines 20 miles in direction 150° by 2000.

Comment: There had been no aircraft recce during the night of 17-18. According to Command's 1048/18 aircraft scouting would begin at 2000A/18. At 2000Z/18 Convoy and Routing plotted ONS 29 at 48°35'N - 23°32'W. The southern end of the forward Hai line was 48°57'N - 23°15'W, hence moving 20 miles on 150° Hai should intercept the convoy.

  18/2 Looks (U-264) encountered sweep group in 49°03'N - 22°55'W.

Comment: This was apparently sufficient confirmation of Command's anticipation that the convoy was cutting under his line, for at 2021 -

  18/2 Hai I and II were ordered on course 180°, speed 11. I8/2
  18/2 To Hai II at 2208A: course east, speed 12.

Comment: Presumably in an effort to mass his U/B's for a night operation.

Convoy Date U/B's

-- 115 --

Convoy Date U/B's
  18/2 To Hai I and II at 2219A: speed 13, course east. No result from aircraft recce yet.

Comment: Throughout the night the U/B's attempted to get at the convoy with the aid of German Air Force but without success. They may have been confused by ON 224 which was some 75 miles farther east and proceeding on a more southerly course.

  19/2 U/B's only sighted destroyers and noted enemy radar activity. Operation terminated at daylight when U/B's detected the presence of an aircraft carrier with the convoy.



ON 225 25/2 To Preussen at 1655A: beginning p.m. 27/2 southwest convoy expected. Distribution of U/B's between 45° - 50°N and 22°-27°W.

Comment: The concentration was across Standard Route C.

  26/2 Cremer (U-333) added to Preussen; southwest convoy expected tomorrow evening.
  28/2 To Preussen at 1504A: beginning tonight cruise to new positions.

Comment: These new attack areas maintained a less concentrated coverage of Route C while distributing some boats as far north as 53°. Meanwhile ON 225 had proceeded on Route B instead of Route C.

Convoy Date U/B's







  22/2 Preussen formed of 18 boats to southwest of former groups, from 53°N - 30°W to 44°N - 22°W.
  25/2 To Preussen at 1530A: eastbound convoy expected beginning today.

Comment: The only eastbound convoy to which Command could have referred was either SC 153 or HX 279, both of which passed through Preussen's assigned area on the 23rd and 24th. Command may have realized this when he shifted his attention so quickly to ON 225.

-- 116 --

Convoy Date U/B's
  28/2 To Preussen at 1740A: 1504/28 cancelled. Remain in your present area.

Comment: This suggests that Command's hopes for ON 225 were revived. It is possible that the D/F he reported in 1638/28 may have suggested that ON 225 was out maneuvering him by an extreme swing to south.

  29/2 To Preussen at 1004A: convoy no longer expected. Occupy areas ordered in 1504/28.
Convoy Date U/B's


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Transcribed and formatted for HTML by Rick Pitz, HyperWar Foundation