World War II Day by Day

Berlin, Germany • November 29, 1939

On this date in 1939, nearly 3 months after the Wehr­macht (German armed forces) over­ran neigh­boring Poland, launching World War II in Europe, German dicta­tor Adolf Hitler issued Fuehrer Direc­tive Num­ber 9, the first of 2 direc­tives on mea­sures his coun­try would have to take to ren­der the British econ­omy and infra­struc­ture incap­able of sus­taining the war against Nazi Germany. “In the war against the Western Powers, . . . the con­quest of Britain is . . . the pre­req­ui­site for final victory,” Hitler wrote. “The most effec­tive means to achieve this is to para­lyze Britain’s eco­nomy through inter­rupting it at criti­cal points.” Titled “Prin­ciples for the Con­duct of the War against the Enemy’s Eco­nomy,” the focus of Direc­tive Num­ber 9 was, inter alia, on attacking British mer­chant and escort vessels, destroying port instal­la­tions, and inter­dicting the sea lanes between Britain’s over­seas empire and North America using air­craft, aerial-dropped magnetic mines (Luftminen in German), U‑boats, and S‑boats, or E‑boats as these fast torpedo boats were known to the Allies.

The British and later their North Ameri­can allies responded with naval and aerial convoy systems to protect the water life­line to the British Isles in this Battle of the Atlantic. The second of Hitler’s direc­tives on the same sub­ject, Num­ber 23, “Conduct of the War Against the English War Eco­nomy,” issued on Febru­ary 6, 1941, acknow­ledged that the mea­sures taken during the pre­ceding 14 months had not so far had any “dis­cern­ible” effect on British morale or their capacity to “resist.” Direc­tive Num­ber 23 doubled-down on destroying British shipping using the Kriegs­marine’s growing fleet of new Type VII U‑boats under the com­mand of Rear Admiral Karl Doenitz. “The sinking of merchant­men is more impor­tant than [an] attack on enemy war­ships,” in Hitler’s esti­ma­tion. “By reducing the avail­able enemy ton­nage, not only will the block­ade, which is deci­sive to the war, be inten­si­fied, but enemy operations in Europe or Africa will be impeded.”

With the prospect of moving substan­tial Luft­waffe units from the French Channel coast to the East­ern Front for Opera­tion Bar­ba­rossa (June 1941), Germany’s planned liqui­da­tion of the Soviet Union in 8 to 10 weeks, Hitler thought it was pos­sible to keep the British off balance by pro­gres­sively stepping up sub­ma­rine opera­tions against mer­chant shipping in coor­di­nation with bombing the key centers of mili­tary air­craft pro­duction to both inflict the greatest pos­sible damage and simu­late the appear­ance of a German inva­sion of their isles, code­named Opera­tion Sea Lion, or Unter­nehmen See­loewe in German. (The one small-scale Sea Lion test exer­cise off Bou­logne, south­west of Calais in German-occu­pied North­ern France, con­ducted in good wea­ther and good visi­bility, with no navi­ga­tion hazards or enemy defenses to con­tend with, por­tended a dicey, even unsuc­cess­ful am­phib­ious assault on South­ern England. “An undeni­able fiasco,” was how one German admiral char­ac­terized the dress rehearsal.) Thus, the period from 1940 to 1942 repre­sented the best chance Germany had to win the Battle of the Atlantic: indeed, during this time frame 973 Allied ships were lost. And up through 1943 the Kriegs­marine, with as many as 100 U‑boats at sea at any time (Janu­ary 1943), came terrifyingly close to winning the Battle of the Atlantic.

German U-Boats and the Earliest Days of the Battle of the Atlantic

Left: Escorts and merchant ships at the Hvalfjord (Hval­fjörður) naval base, Iceland, late June 1942. During the World War II nearly one-third of the world’s mer­chant shipping was British. Out of 36,000 mer­chant sea­men who lost their lives between 1939 and 1945, over 30,000 were from the British Mer­chant Navy. More than 2,400 British ships were sunk out of the total of 2,900 Allied ships lost, or a loss of 14.6 million gross tons. A little over 9,500 U.S. mer­chant marines died at sea, in POW camps, or of their wounds out of the roughly 243,000 who served. (The U.S. govern­ment never kept accu­rate records for its mer­chant marine.) Most of the ships sunk during the Battle of the Atlantic were not in convoys, but sailing alone, or had become separated from convoys.

Right: Officers on the bridge of an escorting British destroyer keep a sharp lookout for enemy submarines, October 1941.

Left: An unnamed U-boat shells a merchant ship that had remained afloat after being torpe­doed (no date). The focus on U‑boat suc­cesses—the “aces” and their scores, the num­ber of con­voys attacked, and the ships sunk—ob­scures the fact that during the Battle of the Atlantic only 10 per­cent of trans­atlantic con­voys were ever attacked, and of those attacked only 10 per­cent on aver­age of the ships were lost. Over­all, more than 99 per­cent of all ships sailing to and from Great Britain during World War II did so safely.

Right: The 8,046-ton U.S. tanker Dixie Arrow was torpe­doed by U‑71 on March 26, 1942, off North Caro­lina’s Cape Hat­ter­as. The unescorted, unarmed ship is shown crumbling amid­ships under the heat of fire. Twenty-two crew­members out of 33 on board were rescued by a U.S. destroyer. Between June 1, 1941, and May 31, 1943, U‑71 carried out 10 war patrols. Operating out of the huge U‑boat pens at St. Na­zaire in occupied France, U‑71 on her fifth foray sank 38,894 tons of shipping between March and April 1942. She was scuttled on May 2, 1945, in Wilhelms­haven, Germany, several days before the country’s surrender.

Left: A Grumman TBF Avenger of the Royal Navy’s Fleet Air Arm fires its machine gun at the conning tower of U‑288 during a con­voy run to the Soviet Union, April 3, 1944. The U‑boat was eventually sunk by rockets and depth charges. Forty-nine men died; there were no sur­vivors. The Kriegs­marine lost a total of 783 sub­ma­rines and 30,000 sail­ors during the war. Despite their best efforts, German sub­ma­rines failed to stop the flow of stra­te­gic supplies to Britain. Between existing Allied mer­chant ships, U.S.-built Liberty ships (totaling 38.5 million tons), and hundreds of British-built Empire ships, the Allies launched millions more ship tonnage than the 14 million tons of shipping lost to the U‑boat menace.

Right: At the height of the Atlantic campaign U‑boats failed to hin­der or even detect the U.S. invasion fleet headed to North Africa in November 1942 (Opera­tion Torch), and they failed to pre­vent the buildup of troops and supplies needed for the D-Day landings in June 1944. As early as May 1943, when a fifth of his U‑boats was sunk in “Black May,” Adm. Doenitz conceded that Germany had lost the Battle of the Atlantic.

Snipers of the Ocean: U-Boats of the Kriegsmarine and the Earliest Days of the Battle of the Atlantic