From 1921 to 1932 Canadian Transporter was owned by the Canadian Government. In 1932 she was transferred to the Canadian National Steamships Ltd and was renamed Cornwallis.
On 6 November 1935, a crew member was severely injured after a wave struck the deck of Cornwallis. The operator Canadian National Steamships Ltd was taken to court and was sued for CAD 4,000 in damages.
1942 First U-boat attack
On 11 September 1942 while moored at the harbour of Bridgetown, Barbados she was fired upon by with multiple G7e torpedoes at a distance of. Although the majority of the torpedoes were caught by the harbour's torpedo net, a single torpedo managed to breach the net and hit Cornwallis just abreast of the #2 hold. The ship sunk only partially due to its location in shallow waters. She was raised and then towed to the port at Trinidad and then towed again to Mobile on 24 January 1943. She would finish repairs in August 1943 and would subsequently return to service.
1944 Second U-boat attack and sinking
On 20 November 1944, Cornwallis would leave Barbados with a cargo of sugar and molasses. She left port with a crew complement of 48 including seven armed guards and a British DBS. The ship's captain, Emerson Robinson, was instructed to sail unescorted through the Cape Cod Canal and then up the coast of New England before finally arriving at their destination Saint John. On 3 December 1944, she was spotted and fired upon by. At 06:00 a single torpedo struck the forward section of the ship. An SOS radio call was sent out by the crew and was received at Yarmouth, Nova Scotia. The crew attempted to lower the amidships lifeboat on the starboard side but the lifeboat was caught on the davits rendering it unusable. The ship would sink on its starboard side in under ten minutes. Of the 48 crew members, only 6 would escape the sinking vessel and make their way to a lifeboat which had floated free when the vessel sunk. The survivors would later be picked up by fishing vesselNotre Dame with one perishing en route due to hypothermia. The five survivors would be dropped off at Rockland, Maine.
s were a forerunner to IMO Numbers. Cornwallis had an official number of 150448 and the Code LettersTPWB. In 1932 her code letters were changed to VGBY.
Wreckage
The wreckage of Cornwallis can be found beneath the ocean southwest of Mount Desert Rock in the Gulf of Maine. The coordinates of the wreckage are located approximately at.