6. The First Happy Time saw the U-boats wreak havoc in the Atlantic
From their new bases in France, German U-boats attacked the Atlantic convoys carrying Great Britain’s lifeblood. During a period of five months, June through October 1940, the U-boats sank more than 270 ships. Merchant captains of newer, faster ships at that period of the war continued to attempt crossings without escort. By necessity, a convoy’s top speed was limited to that of the slowest vessel. Also, some captains did not trust operating in such close quarters in the North Atlantic. Those that did often experienced difficulty keeping station in relation to the rest of the formation. Until September, most U-boats operated singly, rather than in concert with others.
Wolfpack tactics, in which several U-boats attacked a convoy, emerged in the late summer of 1940. On September 21 a convoy of 43 ships, escorted only by an armed merchant cruiser (AMC) was attacked by a wolfpack. The convoy was sighted by Gunther Prien in U-47. Prien was out of torpedoes due to earlier attacks, so he radioed the position and course of the convoy and shadowed it while a pack of six U-boats formed to attack. An escort formed for the convoy as it reached the Western Approaches, but the U-boats attacked and sank 11 ships of over 70,000 total tons.
