Britain's very ability to continue fighting.

[The Aviator]

It was close. Very close. Churchill's darkest hour.

October 5th 1940, convoy SC7 departed Ontario bound for Liverpool. Composed of 34 ships deployed in nine columns, for the first eleven days, the convoy was guarded by a lone escort sloop. The first attack came in the early hours of October 16th, on Rockall Bank, west of Scotland. Seven u-boats converged and attacked – sending ship after ship to the bottom. Twenty were sunk, including six torpedoed by Otto Kretschmer. The escort screens could do nothing but pick up survivors of the attack. Of the 34 ships, only 12 made it to port, and that too was because Otto Kretschmer received news that another large convoy HX79 was coming into range behind them. On October 19th, the second convoy battle ensued. Five u-boats attacked convoy HX79, with another twelve ships going down and two damaged (out of 49). Six were torpedoed by Gunther Prien (U-47). The combined attack on SC7 and HX79 came to be known as the “Night of the Long Knives”. Finally on December 1st, ten u-boats (including three Italian boats) caught the fast moving convoy HX90 and torpedoed 13 ships, of which ten were sunk and three damaged.
The wolfpack attacks were extremely successful, leading to a colossal slaughter of British shipping. In the three month period from September 2 to December 2 1940, 157 allied ships had been sunk for a total of 847,000 tons. In the same period, only three u-boats had been lost, making the exchange rate of 1 to 52 - a horrendous rate of loss. Oil imports in Great Britain fell to half the normal rate covering only two thirds of her consumption. This rate of loss would soon bring Britain to her knees. Such was the calamity of the looming crisis, that it was at this point that British Prime Minister Winston Churchill had privately confided that he feared the Battle of the Atlantic may have been lost – along with Britain’s ability to continue fighting.

In the photo below, a stricken merchant ship struggles to stay afloat.

[canadiancitizen]

Aviator :

I don't think that convoy departed from "Ontario " as the Province of Ontario is located about 1,000 miles inland from the Atlantic ocean. Much more likely is that it departed from a " east coast port " which is what the WW2 era newspapers used to call the city of Halifax, Nova Scotia.

Jim Bunting. Toronto. Ontario . Canada.