Chapter VII
US Anti-Submarine CVE Task Groups and The Critical Refueling Rendezvous of June, July and August

  1. The attack on Manseck (U-758), 8 June, and the sinking of Czygan (U-118), 12 June.
    1. One attack could alter whole refueler network of interdependencies.
    2. Manseck damaged by Bogue.
    3. Confusion begins.
    4. Refueling plans.
    5. Immediate results of Manseck's distress.
    6. The Bogue returns.
    7. Czygan is sunk.
    8. Makeshift.
    9. Repercussions.
    10. Reconstruction of events.
    11. The cost to U-boat operations.
    12. The U-boats that reached their operational areas.
    13. Refueling rendezvous as a center from which combat U-boats could be tracked.

  2. Refueler losses in July 1943.
    1. German achievements, June - July 1943.
    2. U-boat losses in July.
    3. Inauguration of Biscay "Joint Cruise." Failure of Joint Cruise.
    4. The sinking of Metz at rendezvous, July 13, 1943.

  3. Refueler losses in August 1943: The sinking of Neumann and Kuppisch.
    1. State of refueling fleet at beginning of August 1943.
    2. Importance of Neumann's cruise.
    3. Part played by radio intelligence in sinking of Neumann.
    4. Neumann's fueling assignment passed to Drewitz and Harpe.
    5. The loss of Drewitz.
    6. The substitution of Kuppisch.
    7. The role of radio intelligence in sinking of Kuppisch.
    8. Effect of the loss of Kuppisch.
    9. Result of losses of refuelers.
    10. State of refueling fleet at end of August 1943.


  1. The attack on Manseck (U-758), 8 June, and the sinking of Czygan (U-118), 12 June.

    1. One attack could alter whole refueler network of interdependencies.

      The necessity of supplying U-boats bound for or returning from distant areas meant that an elaborate network of interdependencies, with the refueler at the center, was developed between the U-boats on passage through the Middle Atlantic area at any given time. This network would collapse with the loss of the refueler. It could also be seriously disturbed by a successful attack on any of the U-boats in the group; for this could draw the refueler and perhaps other boats aside for the relief and protection of a damaged U-boat, thus upsetting the sequence not only of scheduled provisionings but of other planned movements as well. The manner in which one misfortune could involve U-boat Command's whole plan for the Middle Atlantic in confusion is seen in the complicated series of events that preceded and followed the sinking of the refueler Czygan (U-118) on 12 June. This series of events was set in motion by the bombing of the 500 tonner Manseck (U-758) on 8 June by aircraft from CTG 21.12.

    2. Manseck damaged by Bogue.

      Manseck, cruising with his new quadruple anti-aircraft and destined after refueling for operations in the Trinidad area, had accidentally come upon UGS 9 in the area of 29°N - 33°W, on the afternoon of 8 June. The Bogue obtained a bearing on Manseck's Beta (1636/8) reporting a destroyer, which was followed by another Beta (1931/8) reporting two steamers. The Bogue judged that a sighting of UGS 9 had been signaled. Four planes were dispatched to attack, found Manseck and inflicted heavy damage.


    1. Confusion begins.

      CTG 21.12 believed that the U-boat whose transmission it had heard was shadowing UGS 9 for a wolfpack. German U-boat traffic was not being read currently on 8 June, so information on the actual situation was not available. Actually - as later became evident - there was no U-boat group in the area and no operation against UGS 9 had been planned (Group Trutz, the only wolfpack in the Middle Atlantic, was far to the west). The circumstances were such, however, that the bombing of Manseck caused more confusion than if he had in fact been shadowing for an attacking group. He was part of an intricate pattern of plans involving several other U-boats, including the two refuelers Schnoor (U-460) and Czygan (U-118), and his distress caused the entire pattern to be shifted and revised.

    2. Refueling plans.

      In order to make possible his operation in the Trinidad area, Manseck was to pick up fuel from Czygan in 30°45'N 33°40'W, according to plans announced in traffic on 31 May. Two other U-boats intended for operations in distant areas, Cremer (U-333) and Borm (U-592) were likewise to rendezvous with Czygan, who was ordered to be in position by 10 June. Meanwhile, however, Schnoor, after refueling seven South Atlantic U-boats, was coming up from the St. Paul Rocks area with more fuel than he needed for his return. (This was in part owing to the fact that one U-boat, Steinert (U-128) had been sunk off Brazil before receiving fuel from Schnoor as planned). On 5 June, therefore, Command changed his plans for Manseck, who was now to refuel not from Czygan but from Schnoor in 28°21'N - 33°42'W on 9 June. Schnoor was then to proceed to Czygan's rendezvous position for Cremer and Borm (30°45'N 33°40'W) and give any remaining fuel to Czygan before proceeding homeward. (At this period there were frequent lags in the reading of U-boat traffic. The above information, though historically valuable in showing the detailed structure of Command's plans, was not available in time of operational importance.)


    1. Immediate results of Manseck's distress.

      1. Radio intelligence made available to Allies.

        The bombing of Manseck necessitated further changes in Command's plans. Schnoor and Czygan were at once ordered to Manseck's rescue. As a result of this move, valuable information became available to Allied radio intelligence. None of the several messages giving Czygan's rendezvous position had been decrypted up to this time. But Command's order to Schnoor and Czygan (2116/8) containing the position at which the were to look for Manseck, was read on 11 June, as was a later message (0707/9) acknowledging a position Beta from Czygan. This was the first precise information on Czygan's whereabouts. In addition, since Schnoor and Czygan had some difficulty in finding Manseck, there were several other transmissions on 9 and 10 June from the three U-boats involved. These were not read until 13 June, but the D/F's secured gave immediate evidence of U-boat movements in the area that on 12 June was to be searched by Bogue's aircraft.

      2. Change in Czygan's assignment.

        Czygan found Manseck on the afternoon of the 9th. Schnoor met them on the 10th, gave Czygan his extra fuel, and took charge of Manseck. Czygan then proceeded to his rendezvous station, 30°45'N - 33°40'W, but not to carry out his original assignment. A mine laying U-boat, Stock (U-214) returning with extra fuel from the completion on a task, had been pressed into service as a refueler for Cremer, originally assigned to Czygan. Borm, the remaining U-boat from the original Czygan assignment, had been held up in the North Atlantic by the distress of Böhme (U-450), a new U-boat that had gotten through the Iceland passage only to be nearly sunk by aircraft in the Northeast Atlantic. Thus Czygan was free for the new assignment of refueling four further outbound U-boats - Lange (U-530), Emmermann (U-172), Kummetat (U-572) and Friedrich (U-759) - which he was to carry out between 12 and 18 June in his original rendezvous station, 30°45'N - 33°40'W.


    1. The Bogue returns.

      Meanwhile CTG 21.12, fearing that Manseck's transmission on 8 June might herald a large scale attack on UGS 9, remained with the convoy until Africa-based aircraft appeared on the evening of 10 June. The task group then put about and proceeded westward along the 30th parallel to continue its offensive against U-boat concentrations believed, partly on the basis of D/F's on the messages transmitted in connection with the relief of Manseck, to be in the vicinity. Instead of the patrol line it expected, the task group ran into Czygan's refueling rendezvous for U-boats bound for distant operational areas.

    2. Czygan is sunk.

      It seems clear that the offensive character of the task group's assignment was not grasped by German U-boat Command. After the attacks on Group Trutz on the evening of 4 June, Command was aware that Flight 10 was under the protection of carrier aircraft. In 2259/9 Czygan was instructed to "count on an eastbound convoy with air escort from about 7 June on." Again in 2146/8, Schnoor and Czygan were warned: "Manseck's sightings probably an eastbound convoy. Watch for carrier aircraft." Whether or not German Command had by this time distinguished between Flight 10 and UGS 9 (the latter running parallel to the former but somewhat to the south and about a day behind) is not clear. It is clear, however, both from the messages just quoted and from his failure to alter the position of Czygan's rendezvous, that Command thought of carrier aircraft as having the strictly defensive task of protecting one or more eastbound convoys, and did not take into account the possibility of an independent offensive sweep. In 2358/12 Emmermann, one of the four U-boats newly assigned to Czygan for refueling, complained that there was continual carrier aircraft patrol at the rendezvous, asserting that the position was not suitable and that he was moving off to the south. Not until the next morning did Command order Czygan's provisioning group to move 100 miles to the south. By that time, however, Czygan himself had been sunk. U-118 had been sighted by Bogue aircraft at 121347Z June and, under attack from nine planes, blew up in 25 minutes after five accurate hits with depth charges. Once again German Command


      had failed to adjust his orders rapidly enough to the expanding range of American air power.

    1. Makeshift.

      The combined effect of Manseck's distress and Czygan's loss on the U-boat situation in the Middle Atlantic was considerable. Manseck did reach port safely under Schnoor's escort, though in a damaged condition. But the attack he suffered interrupted his war cruise before he had reached his area of operation or inflicted any damage on enemy shipping, forced Schnoor and Czygan to expend fuel in coming to his rescue, and disrupted Czygan's original rendezvous, and as has been seen above, made valuable radio intelligence available to the U.S. Navy. There was a further complication, Manseck had been ordered to take on a Metox (GSR) from Czygan for delivery to Muller-Stöckheim (U-67). After the damaging of Manseck and the sinking of Czygan the plans for getting a Metox to Muller-Stöckheim had of course to be completely redrawn. The task of delivery was given to Kummetat, who after the loss of Czygan was ordered to get an extra Metox from Lange. This latter point illustrates Command's fear of Allied radar and consequent insistence on supplying operating U-boats with search receiving equipment at all costs; it illustrates also, once again, the intricately interrelated character of Command's plans and the extent to which these could be disorganized by the failure of a single U-boat.

    2. Repercussions.

      The loss of Czygan was of course far more serious than the damaging of Manseck. First of all, there was the permanent loss of one of Command's limited fleet of U-boat tankers. More immediate was the effect on the refueling situation in the Middle Atlantic during the period directly following Czygan's sinking. Czygan carried about 426 cbm of fuel; this, allowing for his own consumption, left him with well over 300 cbm for delivery to combat U-boats. In addition, he had taken on some fuel from the returning Schnoor. At the time he was sunk, Czygan had made no deliveries. The plan, for him was to give 30 cbm each to Kummetat, Lange, Emmermann and Friedrich. This would have left at least 200 cbm for further delivery. The additional U-boats, (besides the four just mentioned) that


      Command had intended to refuel from Czygan, had not been identified in traffic up to the time of the latter's sinking. But they must have included a number of those subsequently refueled by Bartke (U-488) which meant in turn that the refuelings originally planned for Bartke had to be reduced. Thus a process of borrowing from the future was begun, which was to continue at an increasing rate throughout the summer as further refuelers were lost.

    1. Reconstruction of events.

      More immediate still was the problem of providing for Kummetat, Lange, Emmermann and Friedrich, who could continue their cruises to their areas of operation if the fuel they had been counting on from Czygan could be supplied from elsewhere. German U-boat traffic from 1200B/13 to 1200B/15 June was not read, so Command's manner of meeting this problem can only be determined indirectly. Fortunately the combination of later traffic with ONI's "Report on the Interrogation of Survivors from U-172" (commanded by Hoffmann at the time of sinking, 13 December 1943, but by Emmermann during the summer of 1943) gives a fairly clear picture of Command's reaction to Czygan's loss.1 According to prisoner of war reports, Emmermann arrived at his rendezvous with Czygan (12 June) and dived as an aircraft was spotted. While submerged, Emmermann heard explosions indicating heavy attack, and on resurfacing could not find Czygan. He presumed Czygan lost and signaled (presumably during the afternoon of 13 June) to this effect to Command. He was thereupon ordered to search until the following evening (14 June) for Czygan, and to signal "Negative" if the search was fruitless. This proved to be the case and the signal was sent.

    2. The cost to U-boat operations.

      At some time between the reception of Emmermann's negative report and 1200B/15 June (when OP-20-G started reading German U-boat traffic again) Command evidently


      ordered Lange (U-530) - one of the four U-boats scheduled for refueling from Czygan between 12 and 18 June - to abandon his assigned operation, to proceed some distance southward with the other three boats, and after refueling them, to return. This fact is nowhere clearly stated, but it is to be inferred from the following: According to the "Report on the Interrogation of Survivors from U-172" Emmermann was refueled by Lange somewhere below the Azores and above the bulge of Brazil. Friedrich and Kummetat, despite the disappearance of Czygan, went on to distant operational areas, (Friedrich around the coast of Cuba, Kummetat off the northeast coast of Brazil), which would have been impossible had not a substitute refueling been effected.2 Further, from message 2258/6 June, in which Kummetat is ordered to take on a second Metox from Lange, it is evident that a rendezvous between the two U-boats was already scheduled. Finally, in 0127/20 Control acknowledges the reception of a Beta from Lange stating that he has completed the task and is returning. The task must have been the provisioning of Emmermann, Kummetat and Friedrich. Thus the first effect of Czygan's sinking was the discontinuance of Lange's war cruise, in other words, the neutralizing of one U-boats fighting effectiveness for a period of several months. This effect is of interest not merely in itself but as an indication of what was to come. As further U-tankers were sunk in the course of the summer, the stop-gap procedure of cutting short the operational plans for combat U-boats for the sake of emergency refuelings had to be called on more and more frequently. The net result, over and above the permanent loss by actual sinkings, was to reduce the fighting power of the U-boat fleet at sea by a considerable margin.

    1. The U-boats that reached their operational areas.

      The fortunes of those combat U-boats that survived the refueling rendezvous of the summer and managed to reach their assigned areas of operation, will be treated as a general topic in the next chapter. It is worth noting here, however, that of the four U-boats assigned to refuel from Czygan, only


      one, Emmermann, actually completed his operation as planned and returned safely to port. Lange, it has been seen, returned without operating. Kummetat was sunk (presumably) on 3 August in 11°33'N - 54°05'W by a U.S. Navy PBM, Friedrich on 15 July in 15°58'N - 73°44'W by the same type of aircraft. Radio intelligence made available the essential information for locating and sinking both U-boats. It is interesting to observe that both U-boats were followed in traffic, though at a certain distance because of lags in decryption, from their assigned rendezvous with Czygan out to their respective operational areas, where D/F's supplemented the information derived from traffic and narrowed the extent of the search required to find and sink them.

    1. Refueling rendezvous as a center from which combat U-boats could be tracked.

      These instances illustrate a certain pattern that recurs with some frequency in the summer of 1943. The refueling rendezvous was a kind of center from which combat U-boats could be tracked to their attack areas on the edges of the ocean. Command's refueling system, added to his policy of announcing operational areas to U-boats at approximately the time of their refueling, required him to pass extensive information in traffic. Even if this was not decrypted in time to permit an attack on the rendezvous itself, it offered a valuable starting point for the study of the movements of individual U-boats.

  1. Refueler losses in July 1943.

    1. German achievements, June - July 1943.

      Despite the failure of Trutz and the confusion following the sinking of Czygan, it should, of course, not be assumed that the Germans felt their summer campaign to have proved fruitless by the end of June. German U-boat Command had many resources left and the resilience to use them. New antiaircraft armament and new tactics appeared. As far as refueling is concerned, the feat of Bartke (U-488) in successfully supplying 22 U-boats in June showed that the delicate operation of rendezvousing with large number of U-boats in mid-ocean could still be carried out without disaster. Some of these boats went on to operate successfully in the next


      month. Allied tonnage sunk during July showed a considerable increase over both May and June, proving that despite the difficulties that attended them, the distant war cruises in which so many U-boats had been risked were still capable of achieving their purpose.

    1. U-boat losses in July.

      Despite these successes, however, it is probable that from the point of view of losses suffered July was the most expensive month of the summer for the U-boat. The total number of U-boats lost in July is higher than for any other month, except May 1943, in the entire course of the war. Of the more than thirty U-boats sunk, four were refuelers, of which three were lost in the Biscay approaches.

    2. Inauguration of Biscay "Joint Cruise."

      In ENIGMA 2231/16 June and its continuations, Command promulgated Permanent Order Number 14, subject "Joint Group Returns Through Bay of Biscay." This order, according to which U-boats were to proceed through the dangerous Biscay area in groups of two or three, originally applied to return cruises only, but was later extended to include outbound cruises as well. The main purpose was to make the combined anti-aircraft fire of several submarines available for common defense in the event of surprise from the air. There were supposed to be collateral advantages; the possibility of mutual aid in case of damage, the increased number of lookouts and GSR operators whose observations could be communicated and shared by all members of the group, . . . etc.

    3. Failure of Joint Cruise.

      1. Early appearance of success; loss of two refuelers on 30 July.

        At first the group cruise seemed to justify itself. The case of Piening (U-155) is interesting and has a certain representative value. In 2137/11 July Piening, outbound, reported "Joint cruise is good. One sees, and especially one hears, more." Other commanders reported favorably on the


        new tactics. Meantime, however, the British had been organizing a special offensive directed precisely against groups of U-boats cruising together. It turned out that the hazard brought about by the bunching of targets more than balanced the advantage of increased anti-aircraft fire and mutual assistance in other respects. The joint cruise was decisively tested and found wanting in a single action on 30 July, when a group of three U-boats cruising together - including two of the valuable type XIV refuelers - were all sunk within 24 hours by British aircraft assisted by surface forces. The two refuelers were U-461 (Stiebler) and U-462 (Vowe), the latter of whom had already been forced back to port by aircraft damages earlier in the month.

      1. Piening's lane.

        Within a little over three days of the costly losses of 30 July, Command had decided to try a new method for moving his U-boats in and out of aircraft infested approaches to the French bases. The first step was to order all groups to break up "because of the present situation in the Bay of Biscay." (1155/2 August) The next step was to attempt a new route. In 1831/2 August, four returning U-boats, including Piening despite his earlier enthusiasm for joint cruise through the open Biscay, are ordered to proceed (singly) close inshore along the northwest and north Spanish coast, not troubling themselves to remain clear of territorial waters. The new route applied to outbound U-boats also. In 1211/2 August, the sailing orders of four U-boats are canceled, and they are told to cruise separately under the Spanish coast. The high coastal bluffs and the numerous fishing vessels were expected to interfere with Allied airborne radar. Piening's report on his successful cruise over this route was given by Command in 1002/14 August. The approach to the Biscay bases along the Spanish coast was thereafter referred to as "Piening's Lane." In 1960/19 August, all returning, U-boats are ordered until further notice, to cruise along Piening's Lane. The use of this route, in permitting which Spain violated her official neutrality, was kept as secret as possible. It was discovered with the aid of radio intelligence and aircraft and surface vessels were assigned to patrol it. Though the Germans did to some extent reduce their losses in the Biscay approaches by means of this subterfuge, Command did not long enjoy a sense of security with regard to it.


Piening's Lane

      In 1733/24 August - five days after the general order to all returning boats to proceed along the Spanish coast - U-boats returning in Piening's Lane are authorized to change their cruising route if patrol near the coast "seems, too strong."

    1. The sinking of Metz at rendezvous, July 13, 1943.

      In addition to U-461 and U-462, U-459 (Wilamovitz) had been sunk off the French coast by aircraft on 24 July. There three losses added up to a heavy toll on the refueler fleet. But from the point of view of the confusion produced in Command's immediate and distant plans, the greatest single blow in July suffered by the supply system was undoubtedly the sinking of Metz (U-487) by aircraft from the USS Core on 13 July. This sinking occurred at a refueling rendezvous and directly affected plans for more than a dozen of U-boats.


      1. Metz and the Monsun undertaking.

        The sinking of Metz will be discussed in relation to the Monsun venture, which involved the projected sending of 11 large U-boats to the Far East in the summer of 1943, in Chapter XIV. The Monsun undertaking was the most ambitious of Command's attempts to exploit the opportunities offered by relatively undefended distant waters, of which the Indian Ocean had at various times in the past proved to be one of the most fruitful. The loss of Metz, added to the sinking of several combat U-boats, caused this large scale project (which included the strengthening of the German submarine base at Penang) to be largely reorganized and reduced.

      2. Combat U-boats pressed into refueling service.

        The function of radio intelligence in the sinking of Metz will be considered in the section already referred to. In the present connection, it remains only to observe in one or two interesting particulars how the pattern of disruption already noticed in the case of Czygan is repeated in that of Metz.

        1. Damaging of Vowe.

          From 1820/13 July it is evident that Vowe (U-462) had been planned as the refueler for the Monsun U-boats. Vowe, outbound, was damaged by aircraft on 2 July and forced to return to port. Metz was, therefore, diverted from completing his original refueling assignment (not known in detail) to take Vowels place.

        2. Apologies to combat U-boats.

          Pommer-Esche. Metz had already refueled several U-boats, and required replenishment himself if the Monsun refueling was to be adequately taken care of. This meant that the now familiar device of curtailing a combat U-boats war cruise had to be applied once more. By this time Command was evidently beginning to feel embarrassed at the frequency with which he had to call on his fighting boats to abandon their operations. In 1820/13 Pommer-Esche (U-160) is told he must turn over his entire fuel and food supply to Metz for the


          Monsun boats; saving only enough to return. He is promised a quadruple mount anti-aircraft and an improved tower on returning. He is, moreover, offered a grain of hope for carrying out his war cruise, for Command continues: "If next tanker puts out to sea in time, however, complete replenishment of fuel and food is intended." The next tanker would doubtless have been Wilamowitz (sunk 24 July) or possibly Vowe or Stiebler (sunk 30 July). This consideration, however, is strictly academic, for Pommer-Esche had already been sunk before 13 July, though Command did not become aware of this fact until nearly a week later.

          Piening. Command became convinced of Metz's loss by 18 July. In 1258/18, Piening and Pommer-Esche (still believed afloat)3 are ordered to take over Metz's assignment, refueling the Monsun U-boats directly, returning to port immediately afterwards. In 1635/18 Piening protested this order: "We do not feel like returning. Request exchange with Monsun boat." In 2109/18 Command explains to Piening: "No other solution possible. Carry out refueling." A month later, when the 1200 ton cruiser Kuppisch had to take over the refueling assignment left vacant by the sinking of Neumann, and his substitute Drewitz, Command knew enough to anticipate the objection and to state in his original order, "No other solution is possible." (0437/19 August) It is obvious that not the least of the effects of the continuous disruption of Command's refueling plans was the lowering of morale, as well as the cancellation of the fighting effectiveness, of the U-boats that found themselves called upon to act as emergency refuelers.

  1. Refueler losses in August 1943: The sinking of Newmann and Kuppisch.

    1. State of refueling fleet at beginning of August 1943.

      Despite the addition of a new U-tanker (U-489), in July, the active refueling fleet had been reduced to four boats by the end of the costly experiences of that month. This meant that a


      net loss of five had been sustained since the first of June. To increase Command's difficulties in supplying U-boats at sea in August, U-489 (Schmandt) was sunk on 4 August by aircraft in 61°18'N - 14°36'W only fourteen days out of Kiel on her first patrol. This left three refuelers still afloat: U-460 (Schnoor), U-488 (Bartke), and U-117 (Neumann). Of these, Schnoor and Bartke, having completed long refueling cruises in late June and early July respectively, were in port for overhauling. Neumann was thus the only refueler available for actual supplying operations in August.

    1. Importance of Neumann's cruise.

      There were still a large number of U-boats in the Middle and South Atlantic in early August. Command must have had extensive provisioning plans for keeping these U-boats at sea, for in the last week of July, no less than five supply boats left port. It has been seen that three of these (Wilamowitz, Vowe and Stiebler) were sunk in the Biscay area before the end of the month; the loss of Schmandt on 4 August meant that in Neumann Command had only one refueler left to do the work of the five he had expected to have at sea during August. Thus, well before the sinking of Neumann himself on 7 August, the strained provisioning situation, with the usual effect of the cancellation of war cruises, shows itself in traffic. In 1320/4 August, Graef (U-664) is ordered to turn over his fuel to Franke and Blum and then come home. It must be remembered that the U-tankers acted not only as refuelers but also as general supply ships, particularly for heavy pieces of machinery. In 1145/4 August, Cremer is told that "the intended delivery of a Junkers compressor is impossible because no tanker available"; he is to patch up a compressor as best he can by trading parts with another combat U-boat, U-571 (Lussow). These are instances of the collapsing supply system. It was no longer to any important degree a question of refueling U-boats for continued operations. It was simply a question of providing the means to get them back to port. Command's dependence on Neumann for this purpose is shown in 1925/7 August, where "all returning submarines that need refueling" are ordered to head for a square to which Neumann is likewise ordered. "In an area of 400 miles around this square, radio silence is ordered for all submarines except if making reports important for tactics."


    1. Part played by radio intelligence in sinking of Neumann.

      Actually - Neumann had signaled an aircraft attack at 1221B/7, seven hours before the time of origin of the message quoted just above. The attack, by planes from the USS Card, proved fatal to U-117. Radio intelligence had played an essential part in making this decisive sinking possible. In 2301/30 July, read 1 August, Neumann had been ordered to "stand by" in an area within 100 miles of 38°50'N - 37°20'W. In 0146/1 August, read on the date of origin, Neumann was given a more precise heading near 37°57'N - 38°30'W; in 1135/1 August, likewise read currently, Neumann was told to provision Markworth (U-66) at that position "on or after 3 August" and after completion to "wait in that area." This rendezvous was actually not effected because of Markworth's failure to find Neumann, and Command ordered a new rendezvous for the U-boats in 38°51'N - 38°14'W (0535/6), which was finally effected, though not at the exact position ordered, on the morning of 7 August. The latter message was not read until 14 August, but enough information was available to establish the fact that a rendezvous between a tanker and a combat U-boat was to take place within an area which could be limited with sufficient definiteness to make a successful aircraft search possible. That the attack occurred during the process of provisioning appears from Markworth's message 0017/8 August. Markworth himself, who had suffered a damaging aircraft attack at an earlier date, escaped without damage on this occasion. But the loss of Neumann was a blow that caused extensive repercussions. As Command (still in ignorance of his refueler's loss) remarked in 0720/10 August: "Neumann is urgently needed for further provisioning."

    2. Neumann's fueling assignment passed to Drewitz and Harpe.

      The loss of Neumann, when Command became convinced of it on 14 August, resulted in a series of emergency messages whose pattern by this time had become so well established as to be almost classical. The first step was to call on outbound combat U-boats, in this case two 750 ton IXc boats, U-525 and


      U-129, to act as substitute refuelers. "The strained fuel situation brought about by the loss of a tanker necessitates using Drewitz and Harpe as tankers." (1222/14 August) Six U-boats are listed which are to provision from the two emergency refuelers "only for economical return." Harpe completed his refueling task and made a successful return voyage.

    1. The loss of Drewitz.

      With Drewitz, Command repeated his unhappy experience of the previous month with Pommer-Esche. Drewitz had already been sunk (presumably) on 11 August by aircraft from the Card in approximately 42°N - 39°W, though Command was not persuaded of this fact until 19 August when Drewitz failed to answer an order to report his position. Because of lags in decryption, radio intelligence played no part in this sinking, except in the wide sense that U-boats could be presumed to be concentrated in this general area because of the previously determined heading of the refueler Neumann. Actually Drewitz and Harpe were, as far as is known, the only outbound U-boats scheduled to refuel from Neumann for further operations. This is to be contrasted with the extensive refueling rendezvous undertaken in June and July for offensive purposes.

    2. The substitution of Kuppisch.

      In early August, Lt. Kuppisch, in command of the 1200 ton cruiser U-847, was outbound in mid-Atlantic, headed for Penang, where he is said by prisoners of war to have been scheduled to become the Commander of the German Far Eastern U-Flotilla. Kuppisch was the last of the 11 large U-boats, the Monsun boats, that left Europe in the summer of 1943 for the Indian Ocean and Far East. As has been seen in the preceding part of this chapter, the earlier Monsun boats had run into one misfortune after another, one of the most serious being the sinking of Metz, their refueler. Since Command was most eager to get large U-boats, especially type IXd cruisers such as that commanded by Kruppisch, safely to the Far East, Kruppisch's cruise is one that would not lightly be interrupted. The large fuel capacity of the type IXd boats made it possible for them to supply a smaller combat U-boat or two with a limited quantity of diesel oil in passing; and the fact that Kuppisch was called on in 0929/14 August to refuel the


      patient Markworth (who had been vainly trying to find Neumann for a week) with 15-20 cbm did not interfere with his cruise. But by 19 August, with the loss of Drewitz known, the refueling situation of a large number of Middle Atlantic U-boats had become desperate. In 0437/19 August, Kuppisch is ordered to take over Drewitz's provisioning assignment. This meant that yet another Monsun boat was not to reach the Far East. As Command put it, "There is no other solution."

    1. The role of radio intelligence in sinking of Kuppisch.

      As has been shown in preceding paragraphs, refueling rendezvous were planned sufficiently well in advance so that a decryption lag of several days did not seriously affect the accuracy of the information which radio intelligence was able to provide. An order to Kuppisch at 1138/18 (read here on the 21st) gave as his heading point the area 29°50'N - 38°30'W. An amplifying order at 0437/19 (also read on the 21st) directed four U-boats - Dahlhaus (U-634), Siegmann (U-230), Feiler (U-653) and Neide (U-415) - to arrive at the rendezvous beginning 23 August in order to provision for a most economical return. Past experience was certainly responsible for the warning to send no beacon signals. It was planned that Kuppisch should also refuel five other U-boats likewise enroute home form distant areas - Staats (U-508), Rahe (U-257), Manke (U-358), Emmermann (U-172) and Maus (U-185). However, circumstances combined to reduce the total number of U-boats requiring refueling to a mere five; Manke had sufficient fuel on board, Siegmann took on enough from Dahlhaus so that he could make port, and Dahlhaus and Maus were sunk enroute to the rendezvous by aircraft from USS Core on 24 August - the former in 28°N - 38°W, the latter in 27°N - 37°06'W. Three days later Kuppisch himself was sunk in 29°N - 37°W by aircraft from USS Card.

    2. Effect of the loss of Kuppisch.

      The five U-boats which had refueled from Kuppisch before he was sunk had taken on only enough fuel for a most economical return. Since U-847 was the only 1200 tonner available at the time, COMSUBs may have restricted the amount given to each of the nine U-boats originally planned for, in order to reserve surplus to permit Kuppisch to continue his


      cruise to the Far East. At the time of his sinking it is likely that he still had about 300 cbm on board. Whatever reasons lay behind the rationing, there was no possibility that the seven homeward bound U-boats could capitalize on any opportunities for attack which might arise, due to the necessity that there would be no other refueler available.

    1. Result of losses of refuelers.

      By the end of August, the effect of the loss of refuelers on operations was even more disastrous than in previous months. There were only forty operational U-boats at sea as compared with seventy-one in July. Of these the majority were homeward bound, their cruises having been shortened because there was no provisioner in the area, or outward bound for operations limited by the amount of fuel which each U-boat could carry. Of the twenty-four submarines in distant areas at the beginning of the month, only three remained to continue their patrols. There were, of course, no operations on the convoy lanes.

    2. State of refueling fleet at end of August 1943.

      It was fortunate for Command that two refuelers, Schnoor (U-460) and Bartke (U-488) had been confined to port during August, for they were the sole remaining members of the once efficient refueling fleet. The situation was temporarily relieved by the addition of Barber (U-220) in September and of Burghagen (U-219) in October, but only temporarily since both Schnoor and Barber were sunk in October. Thus Command was faced with the resumption of offensive U-boat warfare crippled by a lack of supply ships.


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1. U.S. Navy, Office of Naval Intelligence, OP-16-Z, Final Report - G/Serial 29, "Report on the Interrogation of Survivors from U-172," 7 April 1944, World War II Command File, Box 168, Operational Archives/Naval Historical Center, Washington, D.C.

2. There is no prisoner of war report on Friedrich and Kummetat, since both were sunk with no survivors - Friedrich on 15 July and Kummetat on 3 August, Lange's submarine (U-530) was off our own coast at the end of the war. (Commander at that time was Wermuth)

3. When Command became aware of Pommer-Esche's loss, a third combat U-boat, Tillessen (U-516), was ordered to take his place as an emergency refueler.

Transcribed and formatted for HTML by Chuck Roberts for the HyperWar Foundation