Hartmann's wolfpack

Hartmann’s wolfpack was a formation of Nazi Germany's Kriegsmarine in World War II, a "wolfpack" of U-boats that operated during the early stages of the Battle of the Atlantic. Hartmann’s wolfpack was the first essay by the Kriegsmarine during the Second World War in its wolfpack tactic against allied convoys. Its operations were in October 1939, during the earliest stage of the Atlantic campaign. The name "Hartmann" was unofficial, taken from that of its commander, Werner Hartmann. Unlike later packs which had specific code names this formation was left without an official designation. The original intent of the U-boat Command (BdU) was to organize two packs of five boats each; one composed of Type VIIB’s from 7th ("Wegener") flotilla and the other of the larger Type IX’s of 6th ("Hundius") flotilla. In the event, several boats were unavailable, so the operation was adjusted to form a single pack comprised six boats. This arrangement meant forming a unit of different type of vessel, who had not previously operated together. The whole force was commanded by Hartmann, flotilla commander of the Hundius flotilla. The first five boats sailed independently in October 1939 from bases in NW Germany, sailing northabout around the coast of Scotland in order to reach the Western Approaches. The last boat, , which was delayed in departing, was ordered to take the southabout route through the Channel; this was more dangerous, but was deemed practicable. In the event U–40 became trapped by the Allies' Channel defences, the Dover Barrage; on 13 October she struck a mine and was destroyed. The remaining five boats under Hartmann’s command took station in the Western Approaches. The German signals intelligence branch, B-Dienst, which had penetrated British naval codes, was able to give notice of a convoy (KJF 3) from the Caribbean and BdU instructed the pack to intercept. Three boats found the convoy and attacked, while a fourth failed to make contact. The fifth, , met a freighter sailing independently; she attacked, but was counter-attacked by two destroyers that came to the scene and was destroyed.