September 1940 – Battle of the Atlantic

British problems in coastal waters increase when German E-Boats (see below) now begin major operations off the east coast of the British Isles.


This was the Western Allies designation for fast attack craft of the Kriegsmarine during World War II. They were known to their German operators as ‘S-Boot’ for Schnellboot meaning “fast boat”. These craft were 35 metres (114′ 10″) long and 5.1 metres (16′ 9″‘) in beam, half again longer and much sleeker than any of the Allied PT boat. Their diesel engine propulsion had substantially longer range (approximately 700 nautical miles) than the gasoline-fueled American PT boat and the generally similar British Motor Torpedo Boat (MTB). The most popular E-Boats, the S-100 class, were very seaworthy, heavily armed, and fast – capable of sustaining 43.5 knots (50 mph) and briefly accelerating to 48 knots (55 mph). They carried two 21 (inches) torpedoes ready to fire plus two spares as reloads.

German E-Boat
German E-Boat

The majority of sinkings by U-Boats are still off the Irish coast with 70 percent being achieved by surface attack by night.

U-Boats sink 59 ships out of a total of 100 ships.

Total tonnage lost = 448,600 tons.