Military history


The bemedaled U-boat sailors had good reasons to swagger in the bars of Wilhelmshaven and Kiel. For political ends, Hitler had forbidden Luftwaffe attacks on Great Britain and the Royal Navy. Only German submariners had carried the war to England in the first month of hostilities.*Although the statistical returns (sinkings per boat) had been disappointing, in aggregate U-boats had landed stinging psychological and physical blows. The first wave had sunk thirty-nine British ships, including the carrier Courageousand five important tankers, against the loss of two U-boats and eighty-one men—all captured. They had created panic and confusion at sea and prompted the British decision to initiate convoying, which, as Churchill estimated, was to reduce imports by about one-third, and to wear down hundreds of aircraft and ships on ASW missions, and to divert scores of other vessels to minelaying and minesweeping.

Besides that, and of transcendent importance, during September, while the U-boat sailors were at sea, Hitler had approved a switch from the Z Plan to the construction of a massive U-boat arm. The main emphasis was to be on the improved mediums (VIIBs, VIICs), which Dönitz had been urging for three years. Sixteen shipyards were to tool up for U-boat construction, thirteen for the mediums and three for improved Type IXs (IXB, IXC).* In approving the switch, Hitler assured Raeder that U-boat construction was to take priority over most Third Reich military programs, including the Luftwaffe’s improved JU-88 (Stuka) dive bomber, and that skilled shipwrights who had been drafted into the Wehrmacht were to be released. The program envisioned a buildup to a production rate of twenty to thirty U-boats per month. Long the impoverished stepchild of the Kriegsmarine, the U-boat force was to become its dominant arm, as it had in World War I.

It would take time—much time—to tool up and build all these U-boats. No one was exactly certain how much time; that would depend upon a number of factors, including the sincerity of Hitler’s promises of priorities for materials and the release of skilled shipyard labor from the Wehrmacht. At the very least, Dönitz estimated, it would be nearly two years—the late summer of 1941—before U-boats began to join the force in significant numbers. In the meantime, owing to the current glacial pace of U-boat construction, which could barely keep pace with actual and predicted battle losses, the “U-boat war” could be little more than psychological warfare, a reign of terror.

The extent of the daunting challenge facing the U-boat force bears repeating. Not counting coasters and other vessels of 1,600 tons or less, the merchant fleet of the British Commonwealth comprised about 3,000 ships of about 17.5 million gross tons. Of these ships, about 450 were tankers of about 3.2 million gross tons. By way of comparison, the United States merchant marine was only about half that size: about 1,400 ships of about 8.5 million gross tons, including about 390 tankers of about 2.8 million gross tons, plus another sixty-four tankers registered in Panama. Excluding those of Italy and Japan, the third-ranking merchant marine fleet was that of Norway, with about 800 ships of about 4.2 million gross tons, including 268 tankers of 2.1 million gross tons.

To offset the loss of shipping—and imports—caused by U-boats and convoying, and to wage effective warfare, Churchill concluded that the Commonwealth was to require about 3 million gross tons of new merchant ships annually. At his urging the War Cabinet approved an emergency program to build ever greater numbers of cargo ships and tankers. However, British shipyards, already jammed with orders for new warships and hobbled by antiquated construction methods and labor problems, could produce less than half the wartime need: about 1.2 million gross tons per year.


There were several ways to make up the predicted shortfall. The first and cheapest way was to seize German merchant ships at sea. Another way was to purchase “laid up” ships from the United States.* Yet another way, a very expensive one, was to charter merchant ships from Norway, Greece, and the Netherlands. In the first eight months of war the British brought under control about 100 ships of about a half million gross tons from these sources.

Apart from the sale of a few “laid up” ships, the United States could not provide Britain any meaningful assistance. That was because of the 1935 Neutrality Act. This act strictly forbade American merchant ships from entering declared war zones to trade with “belligerents” and, as one enforcement measure, forbade the arming of American merchant ships. The act was modified November 11, 1939, to allow the British to purchase armaments from United States firms on a “cash and carry” basis, but the restrictions on American shipping remained in force and the British had to transport the armaments in Commonwealth vessels.

The American merchant-ship construction industry was only just emerging from a deep sleep. The slow awakening had been prompted by the U.S. Maritime Commission, which Roosevelt had established in 1936 to help upgrade America’s aged dry-cargo fleet.* Under the chairmanship of a feisty retired rear admiral, Emory S. (“Jerry”) Land, in prewar days the commission had embarked on a ten-year program to build fifty new ships a year. In pursuit of that objective, the commission had designed and ordered several prototypes of big, fast, modern tankers and dry-cargo ships. In the year 1939, the commission delivered the first ships of the new program (twenty-eight for 242,000 gross tons), all to the United States merchant marine fleet.

Upon the outbreak of war in Europe, Roosevelt directed Jerry Land to draw up contingency plans for a massive expansion of the American shipbuilding industry. Land produced these plans—and the specifications required to carry them out—promptly. Thus the stage was set for a maritime race of unprecedented scale. On the one hand, the Germans were poised to build hundreds of U-boats. On the other hand, the Allies were poised to build hundreds of merchant ships. The outcome of this maritime race was to profoundly influence the entire course of World War II.

Dönitz later suggested—and others have echoed him—that if Hitler and Raeder had listened to him and had built 300 U-boats in the prewar years, the U-boat arm alone could have won the naval battle promptly. This is nonsense. A peacetime U-boat construction program of that size would have been exceptionally provocative. It would have forced Hitler to abrogate his prized 1935 naval treaty with Britain almost as soon as it was signed, introducing a complex new geopolitical climate. In that era of intensely competing naval powers and renewed naval construction, it is unlikely that the British Admiralty would have sat on its hands and not proceeded to build U-boat counterforces, such as large fleets of destroyers and modern ASW aircraft. Moreover, a massive U-boat construction program would almost certainly have triggered the construction of a counterforce by the United States Navy, which, as one contingency, had to plan against a German defeat of the Royal Navy and the possibility of German naval aggression in the western hemisphere.

* The U-boats and skippers are described in appendices 1 and 2.

 Northabout the British Isles, it is about 1,400 sea miles from Wilhelmshaven to the western mouth of the English Channel.

* Early submarines had glass portholes in the conning tower, enabling the boat to be steered, or conned, on the surface from this elevated space. But glass portholes could not withstand depth-charge explosions and had been eliminated. While traveling on the surface, the boat was actually conned from the bridge above the conning tower.

 Submarine candidates practiced escape procedures ashore in control-room mockups built into the bottom of water towers. Not surprisingly, many candidates failed this scary test.

* So rigged, the maximum cruising speed was a leisurely 6 knots.

* A large, fast commercial vessel fitted with 5” or 6” guns, hence, a warship.

* The American ambassador to Great Britain, Joseph P. Kennedy, sent an official embassy delegation to Ireland to assist the American survivors and investigate the incident. One member of the party was his second-oldest son, John F. Kennedy, a Harvard student, winding up a summer of travel in Europe.

* Eleven new capital ships were under construction: five King George V-class battleships and six Illustrious-class aircraft carriers.

* From 1931, the British Empire or British Dominions became the British Commonwealth of Nations.

 For more detailed information on the British destroyer situation, see Appendix 9.

 At the outbreak of the war, a total of 185 British ships had sonar: 100 modern destroyers, forty-five sloops and old destroyers, and forty trawlers.

* Four Hunts were commissioned in December 1939, the other sixteen between February and September 1940.

* A substantial number of the superior S-, T-, and U-class submarines were under construction.

* Called the “grid” system: north-to-south latitudes and west-to-east longitudes were defined alphabetically, A to Z. The large area where the alphabetized designators intersected was denoted by a “bigram.” For example, the general area where U-30 sank Athenia was AM. The large bigram areas, such as AM, were further subdivided into a system of numerical squares, which in turn were further subdivided. By the German grid system, Athenia was sunk in AM 1631, a substitute for latitude 56 degrees, 44 minutes north and longitude 14 degrees, 5 minutes west.

* Ten torpedoes in the bow compartment, like the VIIs; two torpedoes for the stern tube; and two spare torpedoes carried in watertight canisters in the superstructure, which, in calm sea conditions, could be lowered below.

* Unaware of this rescue, Churchill wrongly assumed that “40 or 50” of the crew had died in the lifeboats. He likened that to “murder” and demanded that London publicize this “outrage” to the fullest. It should be characterized, he urged, as “an odious act of bestial piracy on the high seas.”

 Ten in the bow compartment like the VIIs, four in the stern compartment (two in the tubes; two reloads in the bilges), and up to eight air or G7a torpedoes stored in topside canisters.

* Three sizes of aircraft bombs had been developed for ASW: 100-pound, 250-pound, and 500-pound—half the weight composed of explosives. The fuse was armed by a little propeller protruding from the nose. To kill a U-boat, extreme accuracy was required. For example, the 500-pound bomb (with 250 pounds of explosives) had to explode within eight feet of the U-boat hull to inflict fatal damage. Aircraft could also be fitted to drop the standard ashcan-shaped depth charge, but lacking a conical nose and tailfins, it tended to tumble in the air and thus follow an erratic path. Since they were not strongly constructed, depth charges also tended to break apart when they hit the water. Hence pilots preferred bombs to depth charges.

* Depth charges had not been much improved since World War I. The standard British depth charge, with an adjustable hydrostatic fuse, weighed 450 pounds and contained 300 pounds of Amatol explosives. It could be preset to explode at fifty-foot intervals from depths of fifty to 500 feet.

* Changed from Portsmouth to Bristol because of intense British asw measures in the English Channel and because she sailed with an Enigma before the okm prohibited Enigmas in minelaying boats.

* Courageous and her sister ships, Furious and Glorious, 22,500 tons, were originally battle cruisers, laid down in 1916 and converted to aircraft carriers in the 1920s. Each carried about twenty-four Swordfish biplanes and had a crew of about 1,200.

* So he was. When British forces occupied Iceland in 1940, Schmidt became a prisoner of war and was interrogated repeatedly. He did not reveal the Athenia sinking.

* The relaxations also applied to the “pocket” battleships Deutschland and Admiral Graf Spee, which were authorized to commence raiding on September 25.

 To which should be added the work of the homebound Atlantic boats, which, as related, had sunk one Norwegian and captured one Estonian and two Finns for a total of 5,400 tons.

* The “pocket” battleships Deutschland and Admiral Graf Spee did not get into action until October.

 See appendices 2 and 17.

* The VIIs and IXs were to be built at a three-to-one ratio. In addition, construction of four big Type XB minelayers and four big Type XIV tankers was continued, as well as construction of sixteen improved ducks, Type IID. But the four 3,000-ton U-cruisers were canceled.

 France and the Netherlands ranked next, each with about 500 ships of 2.7 million gross tons. Greece, with about 400 ships of about 1.7 million gross tons, came next.

* In 1939 the United States had about 1 million gross tons of merchant shipping in “laid up” status, most of it not worth activating.

* In contrast, the oil companies, which were in stiff competition with foreign carriers, were compelled to keep the American tanker fleet in first-rate condition.

If you find an error please notify us in the comments. Thank you!