NEW! Canadian Military History Trivia Challenge

Canadian Military History Trivia Challenge

Take the quiz and Win a Trivia Challenge prize pack!

Canadian Military History Trivia Challenge

Take the quiz and Win a Trivia Challenge prize pack!

Hidden Victory In The St. Lawrence: Navy, Part 53


HMCS Arrowhead leads a convoy.

By any measure, admitting defeat in the St. Lawrence in September 1942 was a blow to the Royal Canadian Navy and to the government. Both took intense heat in Parliament and in the media for their inability to keep the nation’s main artery open in the face of enemy attack. Moreover, there were no compensating U-boats kills which either could trumpet: no banner headlines in the newspapers, no prisoners marched ashore under guard. The enemy had attacked convoys and destroyed ships in Canadian waters with apparent impunity, while Canadians watched—literally—from shore. Wreckage, oil and bodies lay on beaches for all to see, while survivors brought their harrowing tales into homes and church halls up and down the Gaspé coast. How could this be anything other than a defeat?

As dramatic as these events were, historians have long known that losses to local convoys in the Canadian coastal zone in 1942 were actually negligible. Even with the high-profile battles around the QS-SQ convoy series, the loss rate to convoys in Canadian waters, including the Atlantic between Newfoundland and the gulf of Maine, was only 1.2 per cent. Most ships and most convoys moved without incident. Of the 100 QS-SQ convoys that plied the St. Lawrence in 1942, only a dozen were intercepted by U-boats. Historians have also known that the formal closure of the gulf to oceanic shipping meant little in reality. Ships destined for overseas had to be cleared from St. Lawrence ports, and inbound ocean-going ships with cargoes consigned to Quebec ports had to be brought through the gulf, reloaded and cleared again. This took weeks to accomplish. And enough local shipping carrying lumber, pulp, newsprint, coal, fuel oil and other heavy cargoes remained to run the QS-SQ convoys until the end of the season. Supply ships for remote communities and convoys rushing supplies to the northern airfields before the freeze-up also continued to sail. The gulf remained a busy place.

The Germans were so convinced of the importance and vulnerability of the Gulf that they ordered a massive wave of U-boats into the area in mid-September to build on the success achieved by Hoffman (also spelled Hoffmann) and Hartwig. The scale of this German assault was unknown until Canadian official historians published Vol. II Part 1 of the new RCN official history, No Higher Purpose, in 2002. That work revealed that the crisis of September 1942 actually masked a significant Canadian tactical victory over the U-boats later that fall, a victory hidden at the time because of the ongoing blackout in the Allies’ ability to read German U-boat signal traffic. What the navy’s historians discovered in the 1990s was that in the fall of 1942 the largest ever deployment of U-boats to the St. Lawrence took place, and that it was harried and harassed into abandoning operations. That story is laid out in even greater detail in historian Roger Sarty’s new book, War In The St. Lawrence. It is not a tale of great drama: no unknown U-boat kills have been uncovered, and there was no single decisive battle. The Canadian victory in the St. Lawrence in late 1942 was the quiet work of intelligence and operational staffs, routine and targeted patrols, growing skill on the part of the defenders and new technologies. No one noticed at the time but the Germans.

A Gyro compass undergoes repair at HMC Dockyard, February 1943. [PHOTO: JACKSON GEORGE KEMPSTER, LIBRARY AND ARCHIVES CANADA—PA106969]

A Gyro compass undergoes repair at HMC Dockyard, February 1943.

The storm that shook Canada in September 1942 was the work of two enterprising submariners, Hoffman in U-165 and Hartwig in U-517. Fully two-thirds of the 18 ships and two warships sunk in the St. Lawrence between May and late September were claimed by these two. As the gradual extension of the interlocking convoy system throughout the Western Hemisphere denied German submariners easy targets further south, the success of Hoffman and Hartwig served as a kind of beacon for the U-boat fleet. Indeed, so successful were their exploits, that Admiral Karl Dönitz, the commander of the U-boat fleet, ordered six more U-boats to follow them into the Gulf.

The first to arrive, U-69, commanded by Oblt Ulrich Graf, reached the Cabot Strait on the night of Sept. 29-30. U-69 was the first U-boat to operate the new Metox radar warning system in Canadian waters. Its antenna was fixed to a simple wooden cross, dubbed the Biscay Cross in reference to its extensive use crossing the Bay of Biscay to bases in western France. The cross was stuck into a fitting on the conning tower when the sub was surfaced. It was effective at detecting the presence of radar waves in the metric (eg. 1.5m) band, which was what the majority of Allied aircraft, including the Royal Canadian Air Force, in Canada, carried. The SW1/2C radar equipment most common in the RCN at this time was also metric wavelength. Metox was non-directional and gave no sense of the distance to the transmitting radar set: all it did was alert submariners to the presence of radar transmissions so they could dive to safety. In the gulf by the fall of 1942 Metox proved to be a mixed blessing because the air was frequently saturated with radar waves even when no enemy was in sight.

U-69 quickly confirmed what Hartwig knew from the last three weeks of his cruise: by late September the Gulf of St. Lawrence was an unproductive and unhealthy place for U-boats. During his final days in Canadian waters Hartwig achieved nothing except heightened anxiety, and on at least two occasions—the 24th and 26th of September—U-517 was nearly sunk (again) by a Hudson from 113 Squadron RCAF. On the 24th a depth charge which narrowly missed the U-boat simply failed to explode. Air patrols, in particular, were guided by increasingly effective naval intelligence derived from DF (direction finding) fixes.


HMCS Gananoque.

U-69 achieved initial success on Oct. 9 when Metox alerted Graf to the presence of two Canadian corvettes and their convoy, NL-9. Graf stalked the convoy in the dark for several hours amid the continuing alarms from his Metox: the Canadian radars operators “must be asleep!” he commented to his Metox operator. They were not, of course. But the SW1C radar of HMCS Hepatica and Type 186 (the RN’s 1.5m set) on HMCS Arrowhead’s mast searched very narrow cones and, in any event, could not easily detect so small a target as a surfaced sub. The Type 271 10-centimetre radar carried by Arrowhead in 1942, with its fine definition and automated 360-degree sweep, was a greater threat to U-69, and was why Arrowhead was leading the convoy. But Graf escaped detection and after several hours fired two torpedoes at long range. One sank the Carolus, a Finnish ship which, despite that country’s alliance with Germany, was operating in Allied service. Twelve of her crew of 30 perished, and the resulting pyrotechnical show could be seen from the Gaspé coast.

Harried by radar-equipped aircraft and suffering compressor problems, U-69 retreated—submerged—to the Cabot Strait: like Hartwig, Graf had been driven out, and he would not be the last.

As U-69 abandoned the gulf, U-106 under Hermann Rasch crossed her path heading west. The sub had entered the Cabot Strait on Oct. 10 and the next day sank the 2,140-ton steamer Waterton, laden with sulphite and newsprint, from the Cornerbook to Sydney convoy BS-31. BS-31’s escorts, the armed yacht Vison and a Canso bomber, delivered—despite foul-ups in procedure, and failures in communications on the ship—frighteningly quick and accurate depth charge attacks on U-106. By the time U-106 reached the St. Lawrence River, Rasch’s crew was spooked by Metox warnings and air patrols. “Strong defenses since 16.10,” U-106’s log noted. “Search units using asdic…air surveillance co-operating with surface search forces and also operating everywhere without surface forces.” U-106 soon abandoned the gulf.

U-43, following Rasch by a few days into the entrance of the river, encountered the same oppressive patrolling but Oblt-zur-see Hans-Joachim Schwantke decided to stay on and see what luck would bring. It was all bad. U-43’s failed attack on SQ-43 off Gaspé on Oct. 21 resulted in what Sarty described as, “one of the most effective counterattacks during the St. Lawrence battle…” Six depth charges from the Bangor-class minesweeper Gananoque knocked out lights, blew the battery circuit breaker and activated a torpedo in one of the sub’s stern tubes. Schwantke pushed his sub down to 130 metres to avoid what he thought was a co-ordinated attack. Bangors are treated rather dismissively by historians in their escort role because they were small, poor sea boats and weakly armed. But because they were fitted with gyro compasses (to allow for accurate navigation while sweeping mines), Bangors also carried a much better asdic than contemporary RCN corvettes. Short of destroyers, in 1942 they were the best equipped asdic vessels in the navy.

So it is no surprise Bangors frequently got their teeth into U-boats in the Gulf in 1942. But it took experience to distinguish a sub from a non-sub, and the difference saved Schwantke on Trafalgar Day 1942. When Gananoque failed to regain contact after the initial attack, her crew believed U-43 was just another non-sub contact, a “shoal of fish or a riptide.” According to Sarty, Gananoque’s action “reflected the improved readiness on the part of escorts” by late 1942, and saved both SQ-43 and QS-40 (in the area the next day) from attack. Schwantke fared no better when he tried to attack LN-12 three days later, and U-43 abandoned the gulf at the end of the month.

Meanwhile, Dönitz ordered two more type IX U-boats into the gulf in October, U-183 and U-518. Both arrived in the Cabot Strait on Oct. 18, where they were to wait until the new moon before venturing deep into the gulf. U-522 was also waiting there, and Dönitz planned to send it to the area off St. John’s to hunt once the moon changed. It was reflective of the increasing effectiveness of Canadian inshore anti-submarine operations that U-boats were held in waiting areas until conditions were ideal. Ironically, it was U-522 idling south of Newfoundland that intercepted the RCN escorted transatlantic convoy SC-107 south of Cape Race in the first week of November. That precipitated one of the most decisive convoy battles in Canadian naval history, a topic we will explore in another column.

Police photos of the German spy Walter Alfred Waldemar von Janowski. [PHOTO: RCMP HISTORICAL COLLECTIONS UNIT, REGINA, SASK.]

Police photos of the German spy Walter Alfred Waldemar von Janowski.

By November, Canadian patrols in the gulf were known to be highly effective, so much so that U-183 simply refused to enter it. Opining to headquarters that traffic was, as quoted by the RCN official history, “completely dead” and air patrols oppressive, U-183 (and U-522) moved south off Nova Scotia instead. Only U-518 braved the angst of near continuous Metox alerts to push deep into the gulf in November, but Oblt-zur-see Friederich-Wilhelm Wissman had a special mission. In the pre-dawn hours of Nov. 9, U-518 nosed inshore off New Carlisle, Que., and put Walter Alfred Waldemar von Janowski on the beach.

Janowski was not much of a spy. After burying his uniform and equipment he wandered into New Carlisle around 6 a.m., asked for a room in the local hotel. After six weeks in a U-boat Janowski reeked of diesel fumes and body odour. If that was not enough, he paid for the room in outdated money, asked about the train to Montreal (there was none), and flashed his Gaulois cigarettes. The young lad at the hotel desk was alert to the possibility that the U-boats might land agents and having given Janowski a room, he went straight to the police. Arrested within minutes, Janowski admitted everything, took the police to recover his uniform and radio, and was whisked off to Montreal where he was interrogated and turned in to Allied service—without much known effect.

Wissman, for his part, did not linger long in the gulf. Instead, he headed for Conception Bay, Nfld., where he attacked the iron ore ships, the second such successful attack at Wabana in 1942.

The departure of U-518 from the gulf in mid-November ended the final phase of the 1942 campaign, and it was a clear Canadian victory. In the aftermath of Hartwig’s patrol, four U-boats entered the gulf and St. Lawrence River to attack shipping in October and November. They sank three ships, a dismal reward for the effort. A fifth U-boat (U-183) had been ordered in, but turned away because of oppressive Canadian patrols. Sarty concludes emphatically that “Canadian forces shut down the U-boat assault in the St. Lawrence.” However, because of the gap in Ultra intelligence in 1942, Canadian authorities had no “idea that as many as four subs operated in the St. Lawrence in the fall of 1942, nor that all four made discouraging reports to U-boat headquarters.” No one in the navy or the air force, and certainly no one in the government or media—and no historian until very recently—had any notion that Canadians had won a quiet, but decisive victory in the St. Lawrence in late 1942.


Email the writer at:

Email a letter to the editor at:


Sign up today for a FREE download of Canada’s War Stories

Free e-book

An informative primer on Canada’s crucial role in the Normandy landing, June 6, 1944.