A side note to Susan Barnes' article
* Website note: Commander Rodger Winn was Commander of the Submarine Tracking Room in the Admiralty's underground Citadel, the Operational Intelligence Centre. His wrong assessment of the incoming naval ULTRA messages persuaded him, quite reasonably, to deduce that the battleship Tirpitz had sailed to attack the convoy, and on the evening of July 4, 1942 the Admiralty issued the fateful order to Captain Broome to scatter Convoy PQ.17's merchant ships and escorts. Disaster followed. Admiral Sir Norman Denning, director of Naval Intelligence, knew of this background, but he rightly declined to reveal it to Mr Irving at an interview. "The chap you've got to see is Winn," he said. "He knows, but it is for him to tell you." Winn declined to be interviewed. In retrospect it seems plain that the Admiralty had instructed him to refuse. The ULTRA secret was kept until 1974. Years later, the ULTRA signals were put in the public domain, and the full story came out -- too late.