HMS Ultimatum (P34): Sinking a Submarine Off Calabria

Laid Down at Barrow

HMS Ultimatum was built by Vickers-Armstrongs at Barrow-in-Furness, her keel laid on 19 June 1940, launched on 11 February 1941 and commissioned on 29 July 1941 under Lieutenant Peter Robert Helfrich Harrison, a third-group U-class submarine that went on to fight nine demanding patrols out of Malta's 10th Submarine Flotilla.

A Productive Winter

On 25 January 1942, Ultimatum sank the Italian passenger ship Dalmatia L. south-west of Cape dell'Armi, and on 14 March that year sank the Italian submarine Ammiraglio Millo off Punta Stilo in Calabria, a truly significant success against an enemy underwater adversary within just seven weeks of her earlier sinking.

She also attacked Italian convoys on 5 December 1941 and 23 February 1942, though the results of the latter attack, against three modern merchant ships escorted by seven destroyers, remained uncertain.

Later Wartime Service

Under Lieutenant Hedley Kett from January 1943, Ultimatum continued operating in the Mediterranean, attempting an attack on the German U-boat U-73 off Toulon on 30 October 1943 without success, before shelling Kalamata harbour in Greece on 2 May 1944, sinking two sailing vessels, destroying five more still on the slips, and sinking the German barge F 811, a notably thorough piece of harbour harassment.

The End of Her Service

HMS Ultimatum was sold to be broken up for scrap on 23 December 1949 and was scrapped at Port Glasgow in February 1950, closing out the career of a submarine whose Mediterranean war had ranged from passenger liners to enemy submarines to a harbour full of stranded sailing vessels.