Information sheet

Battle of the Atlantic

Sheet number 4

The Battle of the Atlantic was the longest running campaign of the Second World War and began with the sinking of the passenger liner SS Athenia on 3 September 1939.  The capabilities of the U-boats were demonstrated very soon after the outbreak of war when the Royal Navy's main port at Scapa Flow had been infiltrated and HMS Royal Oak was sunk with the loss of 830 lives.  With the fall of France and Norway in the summer of 1940 the U-boat became a greater threat.  The German air forces were able to use air bases in Europe to locate the convoys and direct the U-boats to them.  The resources of the Royal Navy were severely stretched with the reintroduction of the convoy system for merchant vessels and the supplies of raw materials and foodstuffs began to be affected.  The Royal Navy, however, adapted quickly improving training, tactics, equipment and weapons, and the involvement of the Canadians helped to reduce the allied losses.

The capture of U-110 was an important event in the campaign.  HMS Bulldog's crew seized the 'Enigma' machine, which decoded commands and directions sent to U-boats.  The Allies used the machine to break the German naval codes, enabling allied convoys to be directed away from the U-boat wolf packs.

An area known as the mid-Atlantic Gap where U-boats operated freely, because allied aircraft could not reach them, was causing major problems for the convoys.  The Catapult Armed Merchant vessels were developed to combat this.  These involved fitting normal ships with a rocket-powered catapult capable of launching a single, small fighter type aircraft, to provide air support.  The only drawback was that the pilot would have to bale out in the sea when the fuel ran out because there was nowhere to land.  This problem was overcome with the development of the escort carriers, initially manufactured using existing older vessels, the flight deck was constructed on top of the vessel's hull.  By 1943 the combination of the escort carriers, which made a valuable contribution to this campaign, and the introduction of long-range aircraft, the mid-Atlantic Gap was finally closed.

Liverpool played an important role in the Battle of the Atlantic, maintaining a lifeline, with the USA and Canada in particular, which was vital to Britain's survival, and eventual victory.  Much of the 'Battle of the Atlantic' against the U-boats was indeed, fought and won from Liverpool.  From 1941 the headquarters of Britain's Western Approaches Command was established in the fortified basement of Derby House, Exchange Flags, Liverpool.  From there the anti-submarine war was planned.  Pivotal to the campaign against the U-boats was the work of the Special Support Groups, composed of escort vessels such as corvettes, frigates and destroyers.  One of the most famous and successful of these groups was that based in Liverpool's Gladstone Dock (where a plaque still hangs in its honour) and commanded by the legendary Captain 'Johnny' Walker.  Gladstone Dock was used as a base for the many warships, while at Birkenhead, Cammell Laird was building new warships and repairing others damaged through enemy action.  June 1942 was the worst month for the Allies with the loss of 830,000 tons of shipping, however, the result of the Americans joining the Allies began to have a positive effect, and July 1942 saw the first month where replacement shipping began to exceed losses.

The result of new tactics, intelligence and aircraft, saw the German navy suffering heavy losses, and by May 1943 the U-boats were called off by the German Naval Command.  Although the battle did not end there, the threat of the U-boat had been greatly weakened.  The campaign resulted in high casualties on both sides, and it is estimated that some 80,000 allied seamen were lost, while some 28,000 out of 41,000 U-boat crews were also lost.  12.8 million tons of allied and neutral shipping was destroyed.

Winston Churchill summed up the importance of the Battle of the Atlantic:

"Battles might be won or lost, enterprises might succeed or miscarry, territories might be gained or quitted, but dominating all our power to carry on the war, or even keep ourselves alive, lay in the mastery of the ocean routes and the free approach and entry to our ports.  The only thing that really frightened me during the war was the U-boat peril."

See also Information Sheet 30, The Port of Liverpool at War.


BROWN, J.D.  The Battle of the Atlantic, 1939-45.  London: Lockwood, 1992.

HOWARD, Chris Bailey.  The Battle of the Atlantic, the Corvettes and their Crews - an Oral History.  Alan Sutton: Gloucestershire, 1994.

JACKSON, Pat.  A Retake Please - Night Mail to Western Approaches.  Liverpool: Liverpool University Press, 1999.

LENTON, H.T. & COLLEDGE, J.J.  Warships of World War II.  London: Allan, 1973.

MACINTYRE, Donald.  The Battle of the Atlantic.  London: Severn House, 1961.

MIDDLEBROOK, Martin.  Convoy.  New York: Quill, 1976.

ROSKILL, Captain S.W.  The War at Sea, Vols. 1-3.  London: HMSO, 1961.

KEMP, Paul.  Liverpool and the Battle of the Atlantic, 1939-1945.

ROSKILL, Captain S.W.  A Merchant Fleet in War, 1939-1945.  London: Collins, 1962.

RAYNER, Captain D.A.  Escort: The Battle of the Atlantic.  London: Kimber, 1955.

Battle of the Atlantic - An Anthology of Personal Memories from those involved with the

Battle of the Atlantic.  Birkenhead: Picton Press, 1993.

British Vessels Lost at Sea, 1939-1945.  Cambridge: Patrick Stephens, 1984.

Lloyd's War Losses - The Second World War, Vol. 1.  London: Lloyd's of London Press, 1989.

STOCKBRIDGE, Ian.  Book of Remembrance: the Merchant Navy World War Two.  London: Numast, 2003.

HOWARTH, Stephen & LAW, Derek (ed.).  The Battle of the Atlantic, 1939-1945: The 50th Anniversary International Naval Conference.  London: Greenhill Books, 1994.

U-Boat Warfare

GALLERY, Rear Admiral Daniel V.  We Captured a U-boat.  London: Popular Book Club, 1958.

HACKMANN, Willem.  Seek and Strike, Sonar, Anti-Submarine Warfare and the Royal Navy. London: HMSO, 1984.

HAY, Doddy.  War Under the Red Ensign.  London: Jane's, 1982.

HOYT, Edwin P.  The U-Boat Wars.  London: Robert Hale, 1985.

JONES, Geoffrey P.  Defeat of the Wolf Packs.  London: Kimber, 1986.

LANYARD.  Stand-By to Ram.  London: Lockwood, 1943.

LUND, Paul & LUDLAM, Harry.  Night of the U-boats.  London: Foulsham, 1973.

MALLMANN, Showell, Jak P.  U-boat Under the Swastika.  London: Ian Allan, 1987.

ROHWER, Jürgen.  Axis Submarine Success, 1939-1945.  Cambridge: Patrick Stephens,  1983.

TERRELL, Edward.  Admiralty Brief: The Story of Inventions that Contributed to Victory in the Battle of the Atlantic.  London: Harrap, 1958.

THOMAS, David A.  The Atlantic Star, 1939-1945.  London: W.H. Allen, 1990.

WITHERS, Lt. Cmdr. Andrew J.  The U-boat War in the Atlantic, 1939-1945.  London: HMSO, 1992.

Individual Contributions

CHALMERS, Rear Admiral W.S.  Max Horton and the Western Approaches.  London: Hodder & Stoughton, 1954.

ROBERTSON, Terence.  The Story of Captain Frederic John Walker, CB, DSO.  London: White Lion, 1975.

VAUSE, Jordan.  U-Boat Ace: The Story of Wolfgang Luth.  Shrewsbury: Airlife, 1990.

WEMYSS, Cmdr. D.E.G.  Walker's Groups in the Western Approaches.  Liverpool: Liverpool Daily Post & Echo, 1984.

WILLIAMS, Mark.  Captain Gilbert Robert R.N. and the Anti U-Boat School.  London: Cassell, 1979.

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