They had all but completed their sixth war patrol, their first under Kapitänleutnant Otto Ites, and they believed they had sunk four or five ships, all stragglers, in the notorious North Atlantic waters southeast of Cape Farewell, Greenland.
The record would attribute the sub with one kill but, no matter: no convoys had been sighted and U-94 was never attacked. To top it off, their boat was going in for an extended refit at Stettin on the Baltic, now the Polish city of Szczecin.
After 43 days at sea, a captured crewman told British interrogators 10 months later, they were “overjoyed” at the prospect of making port in Stettin, as “Stettin offers much greater opportunities for entertainment than Kiel.”
It apparently offered more than the German U-boat men bargained for: sabotage.
After a brief stop at Kiel, where their skipper’s former commander wined and dined all 36 of them, U-94 reached Stettin in the third week of October. Crew were granted three- to four-weeks’ staggered leaves while their boat was overhauled at the Oderwerke, a German shipbuilder employing Polish slave labour.
One prisoner said after U-94 was sunk the following August that the interior had been refitted in detail in drydock and that, sitting up partially disassembled on the ways, it had resembled a half-completed U-boat.
The full crew returned to duty in January 1942 and took their boat back to Kiel. The trip was to serve as a test run. The problems became evident almost immediately.
“There is good reason to believe that the repair work on U-94 at the Oderwerke in Stettin suffered grossly from inefficiency, negligence or sabotage,” said the U.S. naval intelligence report. “The U-boat was in such precarious shape upon leaving Stettin that, according to prisoners, she almost sank on the trial run to Kiel.”
“Precarious” and the terms “inefficiency” and “negligence” seem understatements. Among the problems U-94 encountered on its trial run after the refit:
- a part had been removed from a valve, allowing water to pour into the boat as it submerged;
- wiring in the boat’s diesel engines was cross-connected;
- the batteries and apparatus connected with them were damaged;
- the indicators for ‘Ahead’ and ‘Astern’ were inverted;
- and the main bilge pump was unusable.
“Apparently there was considerable trouble stirred up by authorities after U-94 reached Kiel,” wrote the interrogators.
There, the boat’s ills were evidently remedied before it set out on its seventh of 10 war patrols, a month-long venture to the Shetland Islands. U-94 was sunk in South Atlantic waters by HMCS Oakville and an American PBY aircraft on Aug. 27, 1942. Nineteen crew were killed; 26 survived.Nazi industrial production was heavily dependent on forced labour, and sabotage plagued factories and foundries of the Third Reich throughout the war.
Hitler’s forces abducted some 12 million people from almost 20 European countries—about two thirds of them from central and eastern Europe. Many died from mistreatment, malnutrition, overwork, torture and execution. Some were killed by Allied bombs.
In his 2005 paper profiling the wartime exploitation of foreign workers in the German town of Osnabruck, British historian Panikos Panayi said slave labour constituted 20 per cent of the German workforce during the war, or about 15 million men and women.
The Forced Labor 1939-1945: Memory and History project says that, at the height of the ausländereinsatz, or use of foreign labour, in August 1944, six million civilians were unwilling workers in the German Reich, most of them from Poland and the Soviet Union.
Some notable German firms still operating today, including BMW, Volkswagen and “Hitler’s tailor,” Hugo Boss, used slave labour.
“It was the forced laborers who kept the agricultural supply and arms production going,” said the project website. “Industry profited from the expansion of production.”
But the German military campaigns also paid a price for their crimes.
In an account recorded for the U.S. Holocaust Memorial Museum, Holocaust survivor Ruth Meyerowitz described her efforts at sabotaging bullets while working slave labour under the watchful eyes of Schutstaffel (SS) guards at a munitions factory in Malchow, Germany.
Working with trays of product at a time, she said she would intentionally misalign the two parts of bullets by squeezing them in “a crooked way so that it would close but not quite,” and possibly misfire.
She would attempt this, she said, “as much as I could without being detected because I really didn’t want to be hit or killed or whatever.
“It would be my part of the war effort against the Nazis.”
Efforts big and small aimed to undermine Nazi aggression. Bombs, weapons, fuel, even food rations were compromised.
In 1943, prisoners at the Dora-Mittelbau concentration camp in central Germany began building large underground factories and development facilities for the V-2 rocket program and other experimental weapons.
The underground site was the centre of a region-wide network of forced-labor camps. Its prisoners quarried stone and worked in construction, munitions factories, a nearby ammonia works and other weapons-related development and production. It was naturally rife with Allied sympathizers who, with nothing left to lose, were willing to put their lives on the line to slow Hitler’s reign of terror.
“Dora-Mittelbau had a prisoner resistance organization, which sought mainly to delay production of the Weapons of Retaliation and to sabotage the rockets that were produced,” said the Washington, D.C.-based Holocaust museum.
“Prisoners suspected of sabotage were usually killed; more than 200 were publicly hanged for sabotaging production.”
“Several U-Boats had had to change their fuel pumps as they had been found to be mysteriously blocked by sand.”
U-boats seemed particularly vulnerable to gremlins in the dockyards that built and maintained them. Allied intelligence reports based on interrogations of captured crews are rife with accounts of potentially deadly mischief by slave workers ashore.
Two chief petty officers aboard U-111, which sank in October 1941, told their interrogators that a sack filled with either sand or flour was discovered in one of their boat’s diving tanks in Lorient, France, at the end of their first cruise.
“On the second cruise a long copper bolt was found in the hydroplane machinery, and it was suspected that it had been maliciously placed there,” wrote the British naval intelligence officers. “Several U-Boats had had to change their fuel pumps as they had been found to be mysteriously blocked by sand.”
Crew aboard U-76 were hounded by defects, citing problems with the compressed air system in the control room due to a severed bolt; bad welding at the exhaust; flooding at depth due to a non-functional exhaust cap; and engine issues.
“Prisoners severely criticised the construction and hasty commissioning of new U-Boats,” wrote their interrogators after the boat was sunk in action in April 1941.
Sabotage in German-occupied French ports was practised chiefly by Frenchmen, said the interrogation report on the crew of U-135, sunk in July 1943.
“On one occasion when U-135 was to sail (13th May, 1943), she made a practice dive, during which defects occurred which were attributed to sabotage by dockyard workmen. Officers had heard of other cases of sabotage in Bordeaux.”
U-131 crew said “a number of cases of sabotage in U-Boats had occurred in Lorient and St. Nazaire, all being committed by German dockyard labourers who had been bribed by foreign agents.”
“In Lorient,” said another report, “the French workmen were described as having taken every opportunity to sabotage German efforts.”
A crewman from U-569, sunk in May 1943, said a U-boat mysteriously blew up shortly after it left the harbour at La Rochelle, France, in the summer of 1942. “The story was widely known among U-boat men who blamed the accident on sabotage.”
Crew of U-570 “indicated that the German authorities were sorely troubled by the attitude of Norwegian workmen in occupied ports in Norway.
“It had been found necessary to forbid Norwegians to go on board German U-Boats, as acts of sabotage had constantly occurred. It was now arranged that, should it be necessary to employ a Norwegian workman in a German ship, he should be attended by a German guard.”
Zschech lost it in the heat of the battle and suffered a complete mental breakdown. He shot himself in the head.
Crew who survived the December 1941 sinking of U-434 “seemed to be of the opinion that the work of the Schichau Yard at Danzig had been unsatisfactory, possibly due to the number of Dutchmen employed there.”
“Soon after U-434 had sailed on her first war cruise in October, it was found that the gearing for the venting and flooding valves was partially defective,” said the report. “Although capable of operation under normal circumstances, this defective gearing made operation inadequate when under a depth charge attack.
“The Chief Mechanician said that a substitute had been used for insulating purposes in the water circulator, resulting in overheating of one of the Diesels. This he considered had been due to sabotage.”
Other reports detailed holes that appeared to have been drilled into the bilges by a U-boat’s batteries, allowing water to leak into the electrical system; large cracks in a boat’s forward torpedo tubes; compromised fuel oil, and engines in at least two boats seized up by aluminum paint leeching off storage tanks. Even the periscope aboard U-128 was sabotaged by dust or sand in the hydraulics.
Generally, sabotage of U-boats, while potentially deadly, amounted more to nuisance than death and destruction—delaying war patrols, tying up resources, aggravating the German high command.
Ites, the U-94 skipper, claimed that “not a single ‘Front’ U-boat had been lost as a result of sabotage.”
“He said he considered this remarkable in view of the large number of foreigners employed at bases, at building yards, and in the Organisation Todt,” intelligence officers wrote. “These foreigners included even ‘Red’ Spaniards, Dutch, Belgians and French. ITES, nevertheless, revealed some concern about sabotage at Stettin and at the Schichauwerft at Danzig.”
Ites told his American interrogators that “special construction engineers were now attending the building of each U-boat to minimize the possibility of sabotage.” Subs were also X-rayed before entering war service to ensure they were “properly welded and otherwise correctly constructed.”
Maybe the most bizarre case of U-boat sabotage was suspected to be by a U-boat commander himself, a well-seasoned Kapitänleutnant Peter Zschech of U-505.
On Nov. 11, 1942, a month into its first war patrol under Zschech’s command, U-505 was heavily damaged by a direct hit from a 250-pound bomb dropped by a Lockheed Hudson in the Caribbean.
The foredeck was a twisted wreck—the deck gun was torn from the boat and the hull severely breached. Zschech ordered his crew to abandon the boat, but his officers refused and kept it afloat through a marathon two-week voyage back to Lorient. It arrived on Dec. 12 and was said to be the most damaged U-boat to make port in the entire war.
Repairs took six months, after which the Zschech-led U-505 made six, or some say seven, consecutive attempts to go sea, only to be foiled every time by mechanical failures or technical issues that forced the boat to turn back for critical repairs.
While some U-boats were building massive tonnage totals and others were lost with all hands, U-505 hadn’t succeeded in leaving the Bay of Biscay in almost a year. Their skipper became the butt of jokes around the flotilla: “There is a captain who will always return home—Zschech.”
French dockyard workers were initially blamed, but U-boat command eventually became suspicious and placed a spy among the crew, who reported Zschech to be a shrewd and able master of sabotage. Zschech was nevertheless ordered on another war patrol and U-505 left port on Oct. 10, 1943.
Fourteen days out, the sub came under depth charge attack by two Allied destroyers. Zschech lost it in the heat of the battle and suffered a complete mental breakdown. He shot himself in the head with a Walther PPK pistol in his control room, in full view of his shocked crew.
Oberleutnant zur See Paul Meyer immediately took command, rode out the rest of the attack and returned the boat to port lightly damaged.
Zschech’s suicide apparently had a profound and lasting effect on U-505’s crew, who reportedly panicked when the boat was attacked southwest of the Canary Islands on its next patrol. Their new captain surfaced and abandoned the vessel before it was significantly damaged.
The sub was captured intact, complete with its Enigma machine, a fresh Kriegsmarine codebook and other documents. The Allies also recovered its G7es acoustic homing torpedoes, which were reverse engineered to improve the Allied decoy system.
U-505 is on permanent exhibit at Chicago’s Museum of Science and Industry.