Torpedoes in the St. Lawrence - 75th anniversary of the Battle of the St. Lawrence

LINK - April 2017 / May 31, 2017

By Fabrice Mosseray

When German submarines - the famous U-boats - fired their torpedoes in the St. Lawrence River, they wreaked death and destruction. From 1942 to 1945, 23 merchant ships and warships were torpedoed by eight submarines. Those attacks gave rise to many rumours that the German submariners had not only won a great military victory, and that they had also landed at the nearest coastal village and come ashore to gather intelligence or have a drink. Some considered the Battle of the St. Lawrence a humiliation for Canada, but others regarded it as the price paid by the Royal Canadian Navy (RCN) for engaging with the enemy far from home.

"Torpedoes away!"

Beginning in 1939, the Nazi submarines ruled the Atlantic. Operating in packs, they harassed the Allied convoys tasked with connecting the United Kingdom, the USSR and North Africa. Although the Third Reich had no specific plan for the St. Lawrence, U boats hunted for convoys there. From May to October 1942, four submarines sank 19 cargo ships and two warships between Rimouski and Gaspé. The attacks were alarming as no one was expecting to see the enemy so close to our shores, and barely 300 km from Quebec City. MPs accused the federal government and the RCN of neglecting national waters in favour of the United Kingdom. The Allies, like the Germans, considered the St. Lawrence a secondary objective and, due to their limited resources, they abandoned vast sections of the trade routes linking the Gulf of Mexico, the Caribbean and the eastern seaboard of the United States with the United Kingdom. The RCN had its hands full in the Atlantic and the Mediterranean and could not adequately protect the St. Lawrence. In addition, its ships had difficulty detecting submarines in the St. Lawrence because the mixture of saltwater and freshwater interfered with their sonar.

The closing of the river

These losses, though relatively minor, were disturbing enough that on September 9 the Canadian government ordered the St. Lawrence closed to trans-Atlantic traffic. That decision created the impression that Canada had lost the battle, but it actually afforded no strategic advantage to the Germans. The movement of supplies and equipment continued apace, with merchandise being transported to Halifax by train. However, that did not prevent the torpedoing of a ferry, SS Caribou, in October, resulting in the deaths of 136 of its 237 passengers. Although the U boats never stopped at the villages along the coast, two German spies did land, one on the Bay of Fundy in May 1942 and one in New Carlisle on the Gaspé Peninsula in November of that year. One was caught by the RCMP, and the other was taken prisoner in November 1944. In Labrador, a U boat installed a miniature automatic weather station.1 However, the air patrols out of Gaspé, Mont-Joli and other airfields were so effective that in 1943 the German navy prohibited any attacks in the St. Lawrence.

The tide turns

In 1943, the U boats began to sustain heavy losses when pitted against the Allies' naval, air and technological power. The RCN was now better armed and equipped: in 1939 it had had only a few ships and 2,000 men, but now its strength was 50 times greater. It escorted 48% of the convoys and proved more than a match for the U boats. The St. Lawrence was reopened in April 1944, and the Nazi submarines hunted for isolated prey. Between October 1944 and May 1945, two U boats damaged the frigate HMCS Magog off Pointe-des-Monts and sank a cargo ship near Matane and the corvette Shawinigan in the Cabot Strait. The last battle in the St. Lawrence, in May 1945, ended with two U boats surrendering to the RCN.

The St. Lawrence River was never a high-priority target for the Germans, but the U boats launched sporadic attacks because they knew that the convoys were poorly protected. A total of 2,600 ships were sunk during the Battle of the Atlantic, 23 of them in the St. Lawrence by eight U boats in the space of three years. The Battle of the St. Lawrence was won in the Atlantic, where the RCN distinguished itself. The Navy made almost 26,000 crossings and transported 165 million tonnes of supplies and equipment. On its own or with the assistance of Allied ships, it destroyed about 50 German and Italian submarines. By the end of the war, with a strength of 90,000 men and women and more than 400 vessels, the RCN was the third-largest naval power in the world.

1 The antenna and batteries are at the Canadian War Museum in Ottawa.