Ah, the
San Demetrio, what a story indeed.
But she'd never have made it, and neither would most of the ships of that convoy, without the sacrifice of her sole escort. His Majesty's Armed Merchant Cruiser
Jervis Bay hoisted battle ensigns and took on the Panzerschiff
Admiral Scheer - and bought the precious time needed for the convoy to effectively carry out the order 'Convoy disperse, all ships proceed independently'.
A Canadian-born seamen, Oswald Preston, known to his shipmates aboard the
San Demetrio as 'The Yank', joined the ship just before she sailed from Halifax. A born defaulter and regarded as bone-idle, he didn't make many friends until he got into the lifeboat - but his subsequent courage, determination and good humour led to the unanimous decision of his fellow survivors to present him with the tanker's 'Red Duster' ensign after they reached the Clyde.
The best book on the story of the fight of convoy HX84 is
If the Gods Are Good: The Sacrifice of HMS Jervis Bay by Gerald L. Duskin and Ralph Segman; 2005, Crecy Publishing Ltd., ISBN 0 859791 07 6.