The S-102 on patrol, the low profile of these fast craft is clear to see in this photograph.
A view across the 2cm Flak 38 gun towards the fully armoured bridge section (Kalottenbrücke) which was introduced with S-100.
KKpt Werner Töniges, the most successful S-Boot commander of the war, sinking eighteen ships on 281 combat patrols, for a total of 86,200 tons of Allied shipping. He was awarded the Knight’s Cross in recognition of his success.
January 1943 – May 1944
At the beginning of 1943 FdS had twenty-two operational boats at his disposal from a total of thirty-nine in the west: twelve in Ijmuiden, six belonging to 2nd S-flotilla, six to the 6th S-flotilla; four 4th S-flotilla boats in Rotterdam and six 5th S-flotilla boats in Cherbourg.
January storms lashed the English Channel, curtailing operations until five days into the New Year when all flotillas sailed. In the west the 5th S-flotilla headed for Lyme Bay, but in a strong gust of wind S116 rammed Führerboot S82, forced to limp slowly to St Peter Port in Guernsey, and the operation was cancelled. To the east, in extraordinary conditions of sleet and snow, S-boats found nothing of a reported FN convoy, two boats from Obermaier’s 6th S-flotilla – S76 and S119 – colliding in snow flurries and returning damaged for shipyard repair.
On 8 January fifteen boats from the three Netherlands-based flotillas put to sea, at once facing limited visibility and atrocious weather. Midway between Ijmuiden and Lowestoft in the early hours of the morning, ObltzS Ullrich Roeder’s S104 hit a floating mine. The explosion wrecked the foreship, killing one man instantly and wounding six others. Shocked survivors were evacuated and, unable to be taken under tow, the abandoned vessel was scuttled with explosives.
On 18 January the weather moderated enough for large-scale mining northwest of Cromer. In total nineteen boats departed and laid 100 LMB mines as planned. During the return, disaster befell S109 when it too struck a floating mine. The blast destroyed the foreship and blew the forward gunner overboard, never to be seen again. One other man was injured and the battered boat taken in tow by S78 and S87, who dragged it toward Ijmuiden, passing her over to a tugboat which took S109 into harbour. From Cherbourg, Klug’s 5th S-flotilla conducted partially successful minelaying near Dungeness on 28 January, S68 and S65 returning with mines intact due to defective mine carts that prevented them sliding along fitted rails.
Bad weather closed in once more and it wasn’t until the middle of February that the S-boats were in action again. On 17 February, fifteen set out from the Netherlands to mine the waters north of Sheringham. Less than four hours from port a Fairey Albacore dropped five bombs, lightly wounding one man but nothing more. However, the British were clearly aware of the S-boats’ movement and destroyers HM Ships Montrose, and Garth from 21st Destroyer Flotilla, supported by sloop HMS Kittiwake and a group of MGBs sailed to intercept. At 0051hrs HMS Garth sighted three S-boats eleven miles from Lowestoft and opened fire. ObltzS Rüdiger Suhr’s S71 was hit in the engine room and catching fire, radioed appeals for help intercepted by HMS Montrose’s Headache operator. HMS Garth came alongside the stricken S-boat, finding the skipper and seventeen crewmen dead, rescuing seven survivors as well as the boat’s canine mascot before S71 sank. Unaware of this, the remaining S-boats returned to base and Luftwaffe aircraft searched for the missing boat, but found no trace. In a decision that drew sharp criticism, amounting to a personal reprimand from Generaladmiral Wilhelm Marschall at MGK West, Rudolf Petersen despatched seventeen boats from three flotillas in a futile search operation. Marschall reasoned that the deployment of all combat-ready boats on anything other than an offensive operation constituted unnecessary risk. Though they later reconciled during a private meeting, the relationship between Petersen and his superiors remained uneasy.
On 26 February Luftwaffe Reconnaissance Group 123 reported twenty freighters and five destroyers near Start Point, Klug’s 5th S-flotilla putting S77, S65, S85, S81 and S68 into action, sailing toward Lyme Bay. Führerboot S77 hit rocks and was forced to abort, but the remainder made contact before Berry Head at 0119hrs, ObltzS Sobottka’s S65 firing first toward the ships of convoy WP300. His torpedo hit 445-ton ASW trawler HMT Lord Hailsham, sending her under with nine confirmed dead and nine missing. Norwegian minesweeping trawler Harstad was also hit, ObltzS Goetschke’s S68 sinking the 258-ton ship with all but one of her crew, the sole survivor wounded but later rescued. ObltzS Kolbe’s S85 hit the 625-ton tank landing craft LCT381 with a single torpedo, bringing the vessel to halt, during which time some of Kolbe’s crew boarded her with small arms and, after a brief battle, took eleven prisoners. A coup de grâce was fired by S65 to put the ship under. Kolbe also claimed to have hit two more 2,000-ton freighters, but they remain unconfirmed. The largest ship of the convoy, 4,858-ton MV Modavia was also sunk in a combined attack by S68 and ObltzS Wendler’s S81; by 0600hrs the S-boats were back in Guernsey.
The next mission on 28 February ended with nothing but damage to S110 from 40mm gunfire before poor visibility curtailed operations until 4 March. That night 5th S-flotilla was driven away from Lyme Bay by destroyers, S68 and S85 grounding on rocks and forced to abort to Guernsey, later requiring extensive shipyard time in Cherbourg. As the remaining four boats returned, S81 and S90 collided, putting both out of commission until repaired. In the North Sea, however, S-boats suffered greater casualties. ObltzS Hans Klose’s S70 of the 2nd S-flotilla struck a mine which detonated a reserve torpedo, immediately sinking the boat with five men killed. The 6th S-flotilla’s S74 and S75 were attacked by Spitfire and Typhoon fighters, ObltzS Wolfgang Hörning’s S75 severely hit and set ablaze, sinking within forty minutes. Eleven crewmen had been killed, including the chief engineer. Kptlt Herbert Witt’s S74 was also heavily damaged, two men killed and the skipper and four others badly injured, but the boat was able to limp back to Ijmuiden under its own power – no Luftwaffe cover was available despite urgent requests. In a little over two months, Petersen’s operational force had been significantly reduced. Of his four western flotillas only nineteen boats remained operational, eight out of commission due to heavy damage, ten others under scheduled refit.
On 7 March things did not improve for Petersen’s flotillas, despite the inauguration of a new tactic using radar technology. In a combined operation the 2nd and 6th S-flotillas carried out a normal Stichansatz attack, while boats of the 4th S-flotilla hung back from the convoy route. Equipped with newly installed radars, their task was convoy detection, a tactic named FuMB-Lauer (radar lurking). However, British changes to the convoy lanes put the radar boats too far seaward and only a few 6th S-flotilla boats made contact, deflected by enemy escorts. The Rotte S114 and S119 were pursued by HMS Mackay and MGB20 and 21 when S119 rammed LzS d Res August Licht’s S114, the former so heavily damaged that it was abandoned and scuttled. Licht returned to port with the rescued crew and was later praised by SKL for his ‘initiative and foresight’ during the event.
While diplomatic sources in Portugal indicated an Allied offensive within the Mediterranean was imminent, Hitler remained obsessed with a potential invasion of Norway. German intelligence reported large concentrations of troops and material along Britain’s east coast and rumours of invasion reaching levels similar in proportion to that which preceded Operation Torch. With this tension permeating MGK West, Petersen placed his flotillas in defensive readiness throughout the English Channel within small groups that shifted port regularly. Gradually, following several false alarms, the threat level declined and boats returned to their original ports. Petersen, however, remained under pressure to further reduce his western combat strength. From four flotillas of a theoretical strength of forty, he stood at an operational level of fourteen S-boats by the middle of March. A gradual addition of eighteen new or repaired boats was expected within a month, but he was being asked to allow six boats to be sold to Spain and transfer reinforcement to the 1st S-flotilla in the Black Sea.103 Petersen strongly urged against these decisions, warning of a ‘great aggravation of the present catastrophic situation of operational readiness.’ He requested immediate return to the Channel of the idle 8th S-flotilla from Norway, rejected immediately by Hitler.
In ‘E-Boat Alley’ the battle continued. During the night of 28 March S-boats encountered fierce defence of convoy FS74 (Phase 9), S92 and S29 battling MGB333 and 321 and British gunfire hammering S29’s unarmoured bridge, killing ObltzS Hans Lemm and six of his crew. Lieutenant Donald Bradford aboard MGB333 charged forward and rammed the disabled S-boat in the stern, slicing the aft section clean away, but was forced to retire with his own damage. German survivors were later taken aboard returning S-boats, S29 sunk at 0714hrs with scuttling charges.
Kapitänleutnant Niels Bätge moved on from command of 4th S-flotilla in March 1943. He transferred initially to the post of first officer aboard the destroyer Hans Lody before taking command of torpedo boat T20 and, subsequently, destroyer Z35 following promotion to Korvettenkapitän.104 In his place, KK Werner Lützow, former first officer aboard Karl Galster and Admiralty staff officer, arrived to take charge of the flotilla.
In early April several torpedo patrols guided by Luftwaffe reconnaissance failed to make contact with the enemy, although S90 reported a torpedo hit on a patrol craft near Start Point. Although the Luftwaffe had provided sighting information, visibility at sea was so poor that S-boats were unable to find the convoys. Two Bf109 reconnaissance aircraft reported sixteen freighters, two tankers and four escorts in Lyme Bay during Friday, 13 April, Klug’s 5th S-flotilla sailing to intercept. In order to operate further west than previously possible, Klug’s unit had moved to the Breton port of Aberwrach, eight boats putting to sea but two aborting, S84 with rudder damage accompanied by the other half of the Rotte S116. The remaining six managed to find and attack PW323 off Lizard Head. ObltzS Johann Konrad Klocke’s S121 torpedoed and sank 1,742-ton SS Stanlake, while Norwegian destroyer HNoMS Eskdale was also torpedoed and sunk, twenty-five crewmen going to the bottom with their ship. It is possible the destroyer was hit and disabled first by S90, before being finished off by both S65 and S111. Oberleutnant zur See Hans Dietrich’s S82 claimed one other unconfirmed 4,000-ton tanker sunk.
The following night 2nd and 4th S-flotillas laid mines, clashing with enemy forces led by HM Ships Westminster and Widgeon and sinking radar-equipped HMT Adonis in the brief battle. Rating T Roy Sparkes later recalled the attack:
On the night of the 14th, after manoeuvring my way across the pitching deck to take over the middle-watch, I had been settled down in the radar caboose astern for about an hour when I became aware of movement on the screen. There was a blip or two at about 6,000 or 7,000 yards. With the general conditions and the hand-turned radar ‘aerial’ to contend with, the blip was at about 2,000 yards before I could make any really definite report. At 1.15 a.m. I whistled up the old voice-pipe to the bridge to report my suspicions, but they could see nothing. The range then closed to 1,700 yards. From the bridge I heard the muffled order given to fire star-shells, a task for our fo’c’sle gun crew with their pride of weaponry, an old Japanese 14-pounder.
Then all hell was let loose. Faintly I heard the gun’s report, followed almost immediately by a huge explosion – the whole ship appeared to heave her guts and shudder. Up in my radar caboose, on its four spindly angle-iron legs, I was flung violently forward, crashing my nose into the radar tube. All the lights had gone out and I felt the floor beneath me begin to tilt.
Only eleven men out of the thirty-two aboard ship survived, later plucked from the sea by an RAF rescue launch. As nights shortened, Petersen moved his flotillas west once more to operate within the Channel; Feldt’s 2nd S-flotilla transferred to Cherbourg, while both the 4th and 6th went first to St Peter Port, Guernsey, to load torpedoes and then onwards to Cherbourg. Petersen and his FdS staff moved back to Wimereux.
Towards the end of May minelaying took precedence, S-boats attempting to vary routes to and from target areas and use their speed advantage to throw off potential pursuit and confuse radar and radio location monitoring. Only a few inconclusive engagements with enemy aircraft or surface vessels appeared to validate their efforts: 321 mines and eighty-four explosive buoys laid along the south coast of England between 23 May and 12 June. Not one single sinking can be attributed to them. Indeed, B-Dienst interceptions showed that the British were still able to accurately pinpoint minefield locations, avoiding routing convoys through them or having them swept. With the Luftwaffe no longer on hand to interfere with British mine-sweeping, the entire minelaying offensive proved an exercise in futility.
While torpedo missions were in a lull, Petersen rotated half of his frontline Channel strength at any one time to shipyards where they were up-gunned and fitted with the new Kalotte armoured bridge. Sixteen S-boats were fitted with 40mm C/28 Bofors anti-aircraft guns, the remainder carrying the new fully automatic 37mm flak weapon, theoretically allowing each Rotte to carry one of each.
At the beginning of 1943 Raeder had resigned as head of the Kriegsmarine, Hitler’s strategic decisions concerning German naval power no longer tolerable to him. He was replaced by Grossadmiral Karl Dönitz, previous head of the U-boat service, who appeared to understand the potential and requirements of the S-boats, and lobbied for increased production of them to interdict the British coastal convoys from the strategically advantageous Channel coast ports. This boded well for Petersen’s Schnellboote. During 1942 thirty-four new German S-boats had been commissioned, another seven smaller Dutch boats in Schiedam. During 1943, the number remained more or less the same, peaking at thirty-eight new boats. However, in 1944 Dönitz’s support and Albert Speer’s genius for production raised the number of boats commissioned into service to sixty-three. Of course, the problem remained of equipping them with skilled crews.
As available combat boats slowly increased in the Channel, Petersen transferred the 2nd and 6th S-flotillas back to Ostend, planning operations within the Thames Estuary and splitting British defenders from the south coast. S-boats continued to rotate through shipyards for upgrade and refit. S90 and S122 were caught by radar-equipped aircraft during the early hours of 19 June while sailing from Boulogne to Rotterdam, one man killed aboard S122, while ObltzS Hans-Jürgen Stohwasser and seven of his crew were wounded aboard S90, the boat badly damaged but diverting under its own power to Dunkirk for emergency repair.
On 25 July S77 and S68 of Klug’s 5th S-flotilla sailed from Boulogne headed for refit in Germany, running unexpectedly into four MGBs north of Dunkirk. The ensuing firefight caused an engine failure and the jamming of two machine guns aboard ObltzS Josef Ludwig’s S77, which then came under sustained fire, igniting one of the torpedoes that engulfed the boat in flames as she began to flood. Ludwig lay dead on his shattered bridge, six other men also killed as MGB40 and 42 rescued four survivors from the water between them as prisoners of war. The remaining twelve crewmen still aboard S77 scuttled the boat and paddled for the French shore aboard a life raft, found on a beach near Dunkirk the following day by men of a Luftwaffe flak battery. From Führerboot S68, ObltzS Helmuth Moritzen had not exchanged fire with the enemy, nor had he issued a contact report via radio, continuing on to Ostend where a furious Kptlt Obermaier immediately scrambled five S-boats and led them on a search for survivors. Moritzen’s judgement was severely criticised and he was relieved of his command and court-martialled.
Seven S-boats swept into action off Orfordness during the night of 4 August, targeting a British minesweeping group. Seconds after making contact, they opened fire with machine guns and flak weapons, ObltzS Hans-Joachim Wrampe’s S86 torpedoing HMT Red Gauntlet, the trawler caught with her sweep gear still extended and unable to evade. The explosion blew the 338-ton vessel apart and from the seventeen crew only one body of a leading seaman was recovered by an RAF rescue launch the following day.
On the night of 7 August seven operational boats of the 4th and 5th S-flotillas were transferred to Brest in an effort to spread S-boat range further west. From the heavily defended harbour they moved to Aberwrac’h in preparation for an attack on Plymouth Sound. Moored in the outer harbour, they were vulnerable when Cornwall-based 263 Squadron Whirlwinds and a Spitfire escort screamed into the attack, raking the S-boats with cannon fire and bombs. S121 was squarely hit by bombs that exploded stored ammunition and set the shattered hulk on fire; ObltzS Johann Konrad Klocke, two petty officers and eight men were killed and three men wounded, one of whom died shortly afterward in a Brest hospital. All of the S-boats received damage requiring repair before they could sail again, S84 and S136 officially put out of commission with damage to the hulls and engines and at least two weeks’ repair time expected. The chief of the 4th S-flotilla, KK Werner Lützow and commander of S110, ObltzS Ludwig Graser, were also lightly wounded in the attack that the RAF called ‘The Massacre at the Aber Vrach [sic] River’, incorrectly claiming four S-boats sunk.
With more boats in Germany for engine replacement and overhaul and the disaster at Aberwrac’h, Petersen prepared his few S-boats for another concerted minelaying offensive using newly developed AA1 sub-sonic acoustic detonators. S-boats were kept at a state of intermittent alert as MGK West continued to fear Allied landings somewhere on the French coast, an alternating rota of crews kept at half-hour readiness into September. S-boats were also tasked with scouring inshore waters south of Cap Gris Nez for evidence of enemy activity. R-boats engaged in minelaying were also allocated S-boat escort and despite small skirmishes with enemy naval and air forces – including rocket-firing Typhoon fighter bombers for the first time – there were no losses.
New boats were also arriving, S100, S138 and S140 docking in Cherbourg on the last day of the month. S100 marked the beginning of a new class of boat. While retaining the outward dimensions of the S38-class they incorporated the Kalotte armoured bridge as standard, with additional armour-plating for the three 2,500hp MB511 engine superchargers. The bow 20mm was retained, with an additional 37mm or 40mm on the aft platform and twin 20mm flak weapon amidships. By mid September the four western flotillas were almost at full strength once more, all boats now carrying Kalottenbrücke and 40mm or 37mm quick-firing guns. Additionally, Klug’s 5th S-flotilla had received new 2,500hp MB 511 engines, allowing a cruising speed of 35 knots.
As the nights lengthened Petersen moved his flotillas once more, the 2nd and 6th transferring to Ijmuiden, the 4th to Boulogne and Rotterdam, while the 5th remained on station in Cherbourg. In Boulogne the 4th S-flotilla celebrated the award of the Knight’s Cross to ObltzS Karl-Erhart Karcher on 13 August. On 12 September a newly formed incarnation of the 8th S-flotilla began deploying into the Channel. S-boat veteran KK Felix Zymalkowski had been promoted to take charge of the new flotilla which initially comprised S64, S65, S68, S69, S93 and S127, sailing into Hoofden as they prepared for the minelaying scheduled for the night of 24 September.
At the allotted hour all four flotillas from the Netherlands carried out their assigned missions. The 2nd S-flotilla left Ijmuiden with eight boats at 2000hrs, dropping forty-two LMB mines as planned and all boats returned to the Hook of Holland by 0800hrs. Seven boats of the 4th S-flotilla had left the Hook at 2115hrs, S39 ramming S90 while trying to avoid an R-boat during departure. The damaged S90 was towed back into harbour by S39 and S74. From 0123hrs onwards the rest of the flotilla was within sight of the convoy route south of buoy 52 when they stumbled upon four minesweeping trawlers, ObltzS Sander’s S96 firing a torpedo that hit and sank 314-ton HMT Franc Tireur with half the crew killed. As the remaining trawlers tried desperately to evade the oncoming S-boats, two of them collided, sending HMT Donna Nook to the bottom also. The S-boats went on to lay thirty-four active mines, before withdrawing in bad visibility. As they did so, four British MGBs coming at high speed from a Z-patrol to the north suddenly blundered into the S-boats, Sander’s S96 colliding with ML150 and 145, damaging the British vessels but also dooming herself. Sander, aware that the ruined S96 was defenceless and going down, requested and received permission to scuttle his ship from flotilla headquarters, sixteen survivors, including Sander, taken prisoner by the British.
Eight S-boats of the 6th Flotilla left Ijmuiden at 2000hrs and carried out their minelaying operation according to plan. Engine trouble forced the first group of S74, S90 and S39 to return immediately after laying ten TMB mines near Shipwash, while the second group started on its return passage after an unsuccessful search for S96 survivors, clashing with MGBs in the swirling fog. The six newly arrived members of the 8th S-flotilla left the Hook at 2115hrs, laying thirty-four LMB mines as planned. Chancing upon a trawler group, S69 fired two torpedoes at HMT Corena but missed, S68’s side engine room hit by return cannon fire and the starboard engine put out of action. Nonetheless, they all returned to the Hook by 0900hrs. Six of the participating S-boats were rendered non-operational by the mission, three by unexplained crankcase explosions attributed to potential sabotage.