The ("patrol boat abroad") (PA)-class patrol ships were a class of vessels commissioned into the Kriegsmarine (German Navy) in the Second World War. The ships were under construction in French shipyards that were seized by the Germans in 1940 at the Fall of France. Work on them continued under German control but progressed slowly, being subject to reluctance, or even sabotage, by the French workforce. Eventually only four were completed. The ships were commissioned in 1943–44 and deployed as escort vessels. Three were bombed and sunk by Royal Air Force (RAF) aircraft in 1944; the fourth was sunk as a block ship at Le Havre later the same year. Background The PA-class patrol vessels were originally laid down as part of a 1939 order by the French Navy for anti-submarine warfare vessels to a British design, called s in the Royal Navy. They were adapted from a merchant ship design and were suitable for building at merchant yards. Of the 18 ships ordered, 12 were under construction at British and six at French yards, four of which were at Chantier de St Nazaire-Penhoët. The order was overtaken by events, and none of the ships ordered was completed before the fall of France in June 1940. Saint-Nazaire, with four ships still under construction, fell into German hands, and as the town was in the occupied zone the Germans decided to complete the vessels for use by the German Kriegsmarine. Design The PA-class ships differed in several respects from the original Smiths Dock design, and therefore from the Flower-class corvettes in service with the Allies. This reflects their construction history and their intended use. The PAs retained the short forecastle which was a feature of the original design, but which the Royal Navy found impractical in heavy weather. Later Allied vessels were given a longer forecastle, and the early ships were altered as they refitted. This did not happen with the PAs, which retained the un-weatherly short forecastle throughout their service careers. The PAs had another original feature, the enclosed merchant-style bridge, though it was abandoned in Allied ships. The focus of the PA class's role was as inshore and coastal escorts, where the chief danger was from mines or attack by aircraft and small craft, such as motor torpedo boats and gunboats. A number of changes to their armament and layout were made to reflect this. The PAs were equipped with