The corvette HMCS Moose Jaw became the first Canadian ship to sink a submarine on the 10th September 1941. Moose Jaw was newly commissioned and still working up when she was ordered to sea urgently. Ultra intercepts had indicated that convoy SC 42 was set to cross the path of a waiting U boat wolf pack. They left port short of crew and with little fresh food – and immediately ran into a storm which left most of the crew suffering from sea sickness. Five days out they were in company with HMCS Chambly when they were about to catch up with the convoy. Lieutenant F.E. Grubb, Commanding Officer of HMCS Moose Jaw described the action:
7. At about 2100 on 10th September, flares and star shell were sighted ahead on either bow.
8. Hands went to action stations at 2130.
9. At about 2200 Chambly signalled that he was about to blow a depth charge, and altered course to port. At the time the two ships were in line abreast, Moose Jaw disposed to starboard.
10. I altered course to port in a wide sweep in order to keep clear of Chambly, and to place myself in an advantageous position to carry out a depth charge attack.
11. A few minutes later I saw a submarine surface between Chambly and ourselves, which appeared to be stopped. (A good echo was reported by the A/S operator just before I was [in sight of] the submarine). The submarine made a series of “I’S” on a small lamp just abaft the conning tower. It got under weigh at this point, and I gave chase, opening fire with the 4 inch gun as soon as it was clear of Chambly. Only one round was fired (which fell over), as No. 2 at the gun jammed the second tube in the lock. The gun is not fitted with a loading light and it is considered essential that this be done at the earliest possible opportunity.
12. The submarine appeared to be moving at about 13 knots. It attempted to place me dead astern, altering course to do so each time I tried to alter out of it’s wake.
13. I ordered the 10 inch signal projector trained on it. This disclosed the crew on the upper deck. They appeared to be so demoralized that I did not believe them to be German and remarked to the navigating officer that they must be Italian. Considering this state of “panic” I thought there might be some chance of capturing the submarine.
14. The next few minutes was spent in chase, the submarine attempting to get directly ahead of me, and I trying to keep on his quarter in case he fired torpedoes. At one time four of the submarine’s crew made a determined move to the after gun. As our own gun was still jammed, no action could be taken except to increase speed and try to ram before they could fire. This I did, although the chance was small, but, fortunately, someone on the conning tower ordered them back. The .5 inch machine guns were bearing at the time, but when the trigger was pressed, they failed to fire. A subsequent check showed no defects, so I assume that in the excitement the crew failed to cock them.
15. I managed to go alongside the submarine, starboard side to, and called on her to surrender. To my surprise, I saw a man make a magnificent leap from the submarine’s deck into our waist, and the remainder of her crew move to do likewise. Not being prepared to repel boarders at that moment, I sheered off. The submarine altered across my bows and I rammed her, increasing to 185 revolutions to do so, and altering course in order to hit her forward diving rudders, so as to prevent her submerging.
16. After the impact she moved across my bows at reduced speed. The gun being cleared by that time I opened fire again. The crew jumped into the sea as soon as the first round went, and I ordered fire to be stopped. I subsequently learned that the shell had passed low enough over the conning tower to knock down the men who were standing thereon. The submarine was then on my port beam.
17. Chambly at this point signalled, “Where is submarine”. He was coming up astern at the time. He closed the submarine and, as there were survivors around my screw and so many of them in the water that I feared for the safety of any boat I might lower, I asked Chambly to send a boarding party.
18. The man who I had seen jump on board turned out to be the submarine’s commanding officer. He was badly shaken and when he was brought to me on the bridge appeared to be worried at the amount of light we were showing in order to pick up survivors.
19. As soon as I considered the water clear enough of men to allow the boats to be lowered without danger of swamping I dropped both skiffs.
Naval Intelligence made the following observation after the subsequent interrogation of the crew in Britain:
The captain of “U 501” explained his precipitate leap from his U-Boat by stating that he felt impelled to get aboard “Moosejaw” at once in order to insist on the British rescuing his men; otherwise, he added, the German crew might have been left to drown. His explanation, while failing to convince the British, succeeded in infuriating his own men into a state of high blood pressure.
This was far from the end of the trials and tribulations for Lieutenant Grubb on this maiden voyage – a voyage that ended with him in hospital in Scotland. Read the full report at Juno Beach. The full story of Convoy SC 42 is at Legion Magazine.