Taken as a prisoner of war at the Siege of Tobruk

My father was in the Royal Corps of Signals. He was in the Siege of Tobruk (Tobruk is in North Africa). The Germans surrounded them on three sides; the fourth side was the sea. They got captured, and my grandparents thought that he had died. He was announced dead in June 1942, but announced as a prisoner in August 1942. Before being captured, my father went to Cape Town to visit troops. He was taken to Europe by a ship across the Mediterranean. The captured soldiers did not have proper clothes, and most of them froze to death on the way back. They were taken to prisoner of war camps. At some point on his journey to the camp, in October 1941, the ship he was on was bombed, but they were rescued by another ship. The report of the ship sinking is recorded in a newspaper. He got PTSD, which was then called shell shock.