Convoys

Following the outbreak of World War II in 1939, the Royal Navy began convoying seaborne commerce with the limited resources available to it. This practice entailed naval vessels as escorts to protect merchant ships. Usually, a rectangular column was deployed 12 ships abreast and four to six ships deep for a distance of 1,000 yards. Several of these columns would make up the actual convoy while armed escort vessels assembled in the van, on the flanks, and in the rear of the procession. Submarines launching a torpedo attack on the convoy were likely to be quickly detected by sonar and attacked by rockets and depth charges, sometimes with deadly effect. Initially the German attackers enjoyed modern submersibles and torpedoes, as well as the additional advantage of air power, and British shipping suffered enormously. But the Battle of the Atlantic slowly turned in the Allies’ favor following American entry into World War II and the influx of numerous U. S. Navy warships into the struggle. The Allies were further abetted by improved sonar and detection technology, better naval intelligence, deciphering of the German submarine code, and most important, the introduction of small, escort aircraft carriers into the convoy system. This enabled armed warplanes to attack U-boats directly, and by 1944 the enhanced convoy system had effectively won the Battle of the Atlantic. The Germans managed to sink nearly 2,600 merchant vessels totaling 14.5 million tons, but at a cost of more than 780 U-boats sunk, along with 32,000 highly skilled sailors.

Further reading: Arnold Hayne, The Allied Convoy System, 1939-1945: Its Organization, Defense, and Operation (Annapolis, Md.: Naval Institute Press, 2000).

—John C. Fredriksen