The attack on HX72 was one of the first attempts to use the "wolfpack" technique, and the first effective or 'true' pack attack.² Two relatively unsuccessful attempts had been made against convoys in August and early September before the successful action against HX72 two weeks later.³ In his war diaries Dönitz asserted that the action against HX72 provided confirmation that his "wolfpack" tactics were right. In the entry for September 22nd, 1940 he wrote that :

"Five boats, which lay up to 380 miles away at the time of the first sighting, were able to attack this homeward-bound convoy as a result of the accurate shadowing reports : 13 ships were sunk. This success was due to ; early interception far to the west of the weakly escorted convoy ; correct tactical procedure of the boats in shadowing and operating over wide areas ; and favourable weather. The action of the past two days has shown the soundness of details, worked out before the war, concerning attacks on convoys and the use of radio when in contact with the enemy."⁴

Commander Knapp was astonished to conclude that U-100 had kept station within the convoy taking deliberate aim at the ships on her beam. He described the attack in terms which clearly demonstrated the strengths of surface attacks at night ;

"Submarines are now operating amongst convoys at night as surface vessels with the advantage of a minute silhouette and therefore extremely difficult to see in the dark, and have the advantage of being able to dive quickly to avoid collision or make their getaway when sighted by merchant ships. Against this type of attack our Asdic is of little use."⁵

Convoy HX72 had displayed a number of weaknesses common to the early convoys. A report based on an interview with the Commanding Officer of H.M.S. Lowestoft (Commander Knapp) was put together by the Anti-Submarine Warfare Division of the Naval Staff. It notes that:

"H.M.S. Lowestoft joined HX72 from Rosyth and so had no opportunity of discussing any plan with the remainder of the escort. This necessarily results in poor team work." ⁶

The merchant seamen felt that they were receiving inadequate protection from the Royal Navy, whilst they in turn complained about navigational inaccuracies and careless showing of lights by the merchantmen. The Commanding Officer of H.M.S. Calendula stated that HX72 was the worst convoy for lights showing that he had yet escorted.⁷ Furthermore, Knapp reported that the master of the Canonesa walked off the bridge without checking that everybody was in the boats, and that he failed to ditch secret and confidential documents, leaving some open on the bridge.⁸

Eleven ships, totalling 72,727 tons and carrying over 100,000 tons of American supplies and some 45,000 tons of fuel, had been sunk. HX72 was the first allied convoy of the war to lose six or more ships. Before the end of 1941 only three other convoys suffered greater losses (SC7, HX79 and SC42).⁹ Kretschmer sank three ships of 17,978 tons and Schepke alone accounted for seven, totalling 50,340 tons. (In U-100’s war diary he claimed 8 victims, with a tonnage estimated at between 61,300 and 67,900 - he was credited with 61,300 by the German authorities). On the torpedoed ships 116 men lost their lives.¹⁰

That these losses were grave blows to Britain cannot be doubted. John Colville, a civil servant working with British Prime Minister, Winston Churchill, recorded in his diary on 22nd September 1940 that:

"we lost another large convoy of ships off the Bloody Foreland last night, as well as the night before. These losses are assuming serious proportions and the P.M. [Prime Minister Churchill] is very displeased with the Admiralty."¹¹

Churchill later recalled that "towards the end of 1940 I became increasingly concerned about the ominous fall in imports." In a letter to his Minister of Transport on December 13th, 1940 he noted that "oil imports during September and October were only half what they were in May and June, and covered only two-thirds of our consumption."¹²

Click here to see Table of Ships Lost and Damaged in Convoy HX72

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