Military history


Allied Tanker Losses to Axis Submarines in the Atlantic Ocean Area: September 1939–December 1942


Throughout the war, a prime target of German U-boats was the combined Allied tanker fleet, which was engaged in the vital task of transporting crude oil and petroleum products to the United States East Coast, to Canada, and to the British Isles.

At the beginning of the war, September 1939, the individual tanker fleets of the non-Axis nations were of substantial size:

In the period from 9/1/39 to 12/31/42, British and American shipyards completed 176 new tankers for 1,754,000 gross registered tons.

In the first twenty-eight months of the war—up to the Japanese attack on Pearl Harbor—Axis submarines sank 117 tankers for 936,777 gross registered tons. During this period (as shown) shipyards in the British Empire and the United States completed eighty-four new tankers for about 829,000 G.R.T. Thus the loss of non-Axis tanker tonnage to Axis submarines in the Atlantic area in this period was nearly matched by Allied new tanker construction. Although London feared—and often predicted—dire oil shortages in the British Isles during this period, none ever really occurred. Hardships and inconveniences, such as civilian gasoline and fuel-oil rationing, resulted not solely from actual tanker losses, but rather from the drastic slowdown of oil imports due to convoying and, of course, to the diversion of oil imports to war-making purposes. Losses in detail:

Many historians and popular writers assert that in 1942, when the Germans launched Drumbeat, the U-boat attack on shipping in American waters, Allied tanker losses “on the United States East Coast” were simply horrific. Furthermore, some British historians stress that most of these tankers were of British registry or of Norwegian and Dutch registry under British charter. Neither statement is true.

In the first six months of 1942, the Germans sank forty-three Allied tankers in United States East Coast waters. Of these, thirty-two (about 75 percent) were of United States or Panamanian registry. Only nine were of British, Norwegian, or Dutch registry. No Allied tankers whatsoever were sunk by U-boats in East Coast waters in the second half of 1942.

In detail:

This was not by any means the whole story of Allied tanker losses in 1942. Axis submarines sank more than twice as many tankers in the Gulf of Mexico, the Caribbean Sea, and in the western Atlantic near Trinidad: 99 vessels for 742,571 tons. In detail:

From the foregoing two lists, it can be seen that the total loss of Allied tankers to Axis submarines in “American waters” in 1942 was 142 ships for 1,073,283 gross registered tons. The total tanker losses in these areas by registry:

From this tabulation it can be seen that British tanker losses in “American waters” in 1942 were not nearly so heavy as often depicted in British accounts. Altogether Axis submarines sank twenty-seven British-registered tankers, fewer than the loss of British-registered tankers to Axis submarines in 1940 (36) and 1941 (33). Axis submarines also sank twenty-four Norwegian and Dutch tankers, presumed to be under British charter, bringing the total loss of “British-controlled” tankers in “American waters” in 1942 to fifty-one. American and Panamanian losses totaled eighty vessels.

To complete this analysis it is necessary to take into account Allied tankers sunk in 1942 by Axis submarines in areas of the Atlantic other than “American waters.” These losses reflect the resumption of U-boat attacks on the North Atlantic convoys in the late summer and the fall of 1942, some of which are described in the text of Volume II. In this third and last category, Axis submarines sank another 71 tankers for 594,222 gross registered tons.

When the foregoing three tabulations of Allied tanker losses to Axis submarines in 1942 are combined, the result is a total of 213 vessels of 1,667,505 gross registered tons. The loss of United States-registered tankers actually exceeded those of the British in 1942 by eleven vessels. Viz.:

During this period, 1942, Allied shipyards (as shown) completed ninety-two tankers11 for 925,000 tons. Thus in 1942, tanker losses to Axis submarines exceeded new tanker completions by 121 ships for 742,505 gross tons. This deficit left the combined Allied tanker fleet on January 1, 1943, at 1,291 ships for 9,311,718 tons, a net loss to Axis submarines of 154 tankers for 850,282 gross registered tons since the beginning of the war, or about 10 percent of the fleet.

This deficit was more than offset by the spectacular tanker gains over losses in 1943. That year, American and British shipyards completed 245 new tankers for 2,031,000 gross registered tons. Meanwhile, in 1943, Axis submarines sank only forty-eight Allied tankers for 373,138 gross tons. Hence, the net gain over all losses was forty-three tankers for 805,304 gross registered tons. On January 1, 1944, the combined Allied tanker fleet numbered about 1,488 vessels for about 10,969,580 gross tons, slightly more than in September 1939.

From this analysis it can be seen that while the U-boat campaign against the combined Allied tanker fleet caused great hardships and inconveniences, it failed to achieve a decisive strategic success. The only really serious Allied setback occurred in 1942, but this was quickly overcome in 1943. To recapitulate, the numbers at a glance:

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