Military history


In 1936, when the five-power London Naval Treaty expired, there was no chance of a renewal. Japan had walked out of the League of Nations, occupied Manchuria, and had already embarked on a naval buildup in excess of treaty limits. Italy had occupied Abyssinia (Ethiopia), intervened in the Spanish Civil War on the side of fascist general Francisco Franco, and had made plans for a substantial naval buildup, which had provoked the French to follow suit. Although Great Britain and the United States agreed in principle to certain naval limitations, they were not binding, and each nation went its own way. Thus the remarkable era of naval arms limitation among the major naval powers expired.

That same year, 1936, the Führer of the Third Reich, Adolf Hitler, commenced military operations. Goose-stepping Wehrmacht forces reclaimed the Rhineland in March. Later in the year Hitler joined Mussolini in support of Franco, sending Luftwaffe and tank (panzer) units to Spain. But Hitler continued to seek amicable relations with the appeasing British government. As a consequence, the Kriegsmarine strictly adhered to the terms of the Anglo-German Naval Treaty and courted the Royal Navy by ceremonial ship visits, sailing regattas, and other means.

The treaty allowed the Germans to build 24,000 tons of submarines. In 1935 the OKM expended half that allowance (12,500 tons) to order thirty-six U-boats based on the IVS Finnish and Spanish prototypes.* Since the plans had already been drawn and the prototypes tested in Finland and Spain, and some matériel pre-assembled, these thirty-six boats were built quickly and commissioned in 1935 and 1936, except one Type VII, U-32, which was delayed to 1937.

A bitter dispute arose over how to expend the remaining 11,500 tons allowed by the treaty. In support of his conviction that war with Great Britain was inevitable and that groups, or wolf packs, of U-boats would be required to defeat the convoy system, Dönitz urged that the full 11,500 tons be allocated for the construction of twenty-three improved Type VII medium (500-ton) boats, so that he could war-game his ideas and train his men. In opposition, the OKM proposed twenty-three boats of a different mix: eight more improved small Type lis, eight more large, long-range submarines (improved versions of the Type I, designated Type IX), and seven improved Type VII mediums. After months of procrastination, Raeder sided with the OKM.

This decision was a major setback for Dönitz and his fledgling U-boat arm. Berlin had rejected his convictions and theories about war with Great Britain. The procrastination entailed in reaching the decision and the emphasis on the large Type IXs, which took much longer to construct, delayed the buildup of the U-boat arm. No U-boats of the second order were to be commissioned in 1937 and only nine in 1938 and twelve in the first eight months of 1939. That he had failed to persuade Raeder and the OKM to adopt his theories and concepts—and submarine types—was to haunt Dönitz for the rest of his life.

The first small Type II U-boats, U-1 to U-12, were commissioned in the summer of 1935. The first six of these were assigned to the submarine school in Kiel for basic training. The second six, improved Type IIBs of greater range, formed the nucleus of an organized flotilla for advanced training, also based in Kiel. Commanded by Dönitz, the flotilla was named in honor of a renowned submarine hero of the Imperial Navy, Otto Weddigen, who had sunk four British cruisers before being killed in action. Dönitz formally commissioned the Weddigen Flotilla on September 25, 1935.

The skippers of the Weddigen Flotilla were handpicked senior lieutenants averaging about twenty-eight years in age with about ten years’ service in the German Navy.* Some had trained on the secret IVS prototypes in Finland and Spain; some had trained on the IVS boats in Turkey. All were recent graduates of or instructors from the submarine school. It was a small, tight group, a navy within a navy. Everyone knew everybody intimately. Two skippers, Hans-Günther Looff (U-9) and Hans-Rudolf Rösing (U-11), were married to sisters. All the men shared Dönitz’s convictions that war with Great Britain was inevitable and that U-boats were to bear the burden of waging the naval war.

The Weddigen Flotilla commenced sea training on October 1, 1935, flying the new flag of the Kriegsmarine, the black and red swastika. Six more Type IIBs—which the Germans half-jokingly called “dugout canoes” or “ducks”—joined the flotilla over the next three months, making a total of twelve. Under the direction of Dönitz and his flotilla engineer and right arm, Otto (“Pappa”) Thedsen, a fifty-year-old salt who had risen from the enlisted ranks of the Imperial Navy, the crews trained with a sense of urgency. The OKM had decreed that the flotilla must be “war ready” by March 1936, to support Hitler’s reoccupation of the Rhineland, possibly provoking a war with France, which had allied not only with Poland but also with the Soviet Union, posing the possibility of a two-front naval war in the Baltic Sea.

Dönitz went to sea daily on one duck or the other. He was a demanding but fair and forgiving instructor. In contrast to customs in the Imperial Navy, he encouraged camaraderie between officers and enlisted men, a “democratic” navy, where one and all shared the same food, work, hazards, and hardships. Confined inside the little boats every day, Dönitz got to know his men well and they him. He was a charismatic leader. The men, who called him “The Lion,” idolized him for his obvious competence and for the respect and concern he showed for them.

Dönitz put the ducks through a variety of drills but the main emphasis was on torpedo shooting. Every duck in the flotilla was required to carry out sixty-six daylight submerged and sixty-six night surface attacks, in which “water slugs” (shots of compressed air) were fired in place of training torpedoes. These drills were tough on all hands, but especially so on the captains. They had to plan and conduct the approaches on the target ships by day and night, taking into account winds, seas, currents, visibility, water depth, phases of the moon, and other factors, meanwhile estimating the target course and speed and calculating the proper interception course and speed for the U-boat. They were encouraged to develop a kind of sixth sense about whether or not they could be—or had been—spotted by aircraft or surface ships and therefore when to surface or submerge, when to use and when not to use the periscope, and the most effective tactics for evading pursuers submerged. After these 132 simulated attacks, the boats graduated to fire real torpedoes with dummy warheads, set to run deep beneath the target ships.


During these torpedo drills, Dönitz developed new shooting procedures which were to become standard on all U-boats. In submerged daylight attacks the captain, who had sole access to the attack periscope, conducted the approach, assisted by the first watch officer at a plotting board, then aimed and fired the torpedoes. In the night surface attack, the captain conducted the approach at the plotting board in the control room, but he did not fire the torpedoes. That task was delegated to the first watch officer on the bridge, using high-power Zeiss binoculars mounted on a gyroscope compass repeater. It was a more efficient system, but not many captains willingly delegated the torpedo firing to the first watch officer. No other navy adopted this technique.

The little boats were at sea five days a week, twenty-four hours a day. The routine was exhausting. Some days they conducted as many as eight submerged daylight attacks and six night surface attacks. As one skipper remembered, fourteen attacks in twenty-four hours was “the upper limit of our physical and nervous capacity.”

The ducks had strong, welded steel hulls, capable (on paper) of withstanding sea pressure to a maximum depth of about 500 feet. One way to outfox enemy sonar was to shut down all unnecessary machinery and dive to maximum depth (“run silent, run deep”). Dönitz encouraged deep-diving drills, but a near-disaster on U-12, commanded by Werner von Schmidt, put a damper on these maneuvers. At 341 feet, an internal angle-bar joint failed, the hull cracked, and the boat flooded dangerously. The boat was saved and the hull was later reinforced, as were the hulls of the other ducks, but as a result of the accident, the OKM restricted all U-boats to a maximum diving depth of 150 feet. Inasmuch as Dönitz believed deep diving would be a necessary routine in wartime and should be rehearsed to the extent that it caused no anxiety, he pleaded for cancellation of the order, but his arguments were rejected. In his memoir, he commented bitterly: “For the lessons which one fails to learn in peace, one pays a high price in war.”


When the Wehrmacht marched into the Rhineland on March 7, 1936, twelve boats of the Weddigen Flotilla—as well as the six Type lis at the submarine school—deployed for possible naval war with Poland, France, or the Soviet Union in the North and Baltic seas. In a sense, the war deployment constituted a “graduation” exercise for the flotilla. All boats “passed” with high marks. Dönitz drew a rave review from a superior: “Through indefatigable work and personal instruction he has demanded so much from the ‘U-Flotilla Weddigen’ in planned training that already … they are ready for employment on war tasks.”

Later in the year 1936, the other six ducks and the bigger boats were commissioned: the two large, 750-ton Type Is, U-25 and U-26, and nine of the ten 500-ton Type VII mediums, U-27 to U-36. Notwithstanding all the work in Spain on the IVS prototype, E-1, the large boats, U-25 and U-26, turned out to have many design flaws. They were dangerously unstable, slow in diving, difficult to maneuver, and easy to detect and hold on sonar. Both were therefore declared unsuitable for combat and relegated to experimental status or used for propaganda purposes, such as showing the swastika in Spanish waters in company with other Kriegsmarine warships. The nine Type VII mediums, which also had serious design and mechanical flaws and proved to be voracious fuel hogs, were organized into a second combat flotilla, named in honor of another Imperial Navy submarine hero, ReinhoW Salzwedel. The Salzwedel skippers—from the crews of 1924 to 1926—were former skippers or senior watch officers on the ducks of the Weddigen Flotilla.

With all these new boats, the OKM reorganized the U-boat force. The eighteen ducks were divided into two flotillas, Weddigen and a new one, named in honor of another Imperial Navy submarine hero, Johannes Lohs. Promoted to Führerdes U-boote(Commander, U-boats, abbreviated as FdU), Dönitz commanded all three flotillas, which comprised twenty-eight production boats (eighteen ducks, ten Type VIIs), as well as the experimental showboats U-25 and U-26. The FdU senior staff was kept small: Dönitz; his chief engineer, “Pappa” Thedsen; a smart, newly recruited planner and tactician, Eberhard Godt, from the crew of 1918; and a few others.

After the Salzwedel boats had completed workup and torpedo training, Dönitz initiated the first experiments with coordinated group (or “wolf pack”) attacks against simulated “enemy” convoys in the Baltic Sea. He directed these exercises from a command ship equipped with a superb array of radio transmitters and receivers. He formed the boats into “patrol lines” to intercept convoys. When a boat found and reported the convoy, he directed the others to mass and attack. Although these war games were rigged to favor the U-boats, Dönitz was well satisfied with the outcome and more than ever convinced he was on the right track.

There were many difficulties to be worked out. The most urgent was to find a way to add fuel-storage capacity, or bunkerage, to the Type VII. The engineer Thedsen, Dönitz remembered, provided the solution. He designed external “saddle” tanks that could be wrapped around the hulls amidships. These tanks increased the fuel storage capacity of the Type VII (from 67 tons to 108 tons). Nothing could be done about the first ten Type VIIs, but the extra tanks were incorporated in the seven Type VIIs of the second order (U-45 to U-51), which were designated Type VIIB.

In midsummer 1937, Great Britain, in conformance with the terms of the Anglo-German Naval Treaty, notified Germany that it intended to increase its submarine force by 17,300 tons—from 52,700 tons to 70,000 tons. Still adhering strictly to the treaty, which limited Germany to 45 percent of the British submarine tonnage, the increase allowed Germany to increase its U-boat force by 7,785 tons. This dividend provoked another bitter dispute between Dönitz and the OKM. Dönitz again urged that all the new tonnage go for improved 500-ton mediums (Type VIIBs). The OKM again urged that the tonnage go for improved 750-ton large boats, the Type IXB. Raeder again ruled against Dönitz. He split the tonnage almost evenly between medium and large boats, ordering eight Type VIIBs (of 4,000 tons) and five IXBs (of 3,750 tons). Including this third order, after all the boats had been commissioned, the U-boat force was to be comprised of seventy-two boats aggregating 31,750 tons: thirty-two ducks, twenty-five medium Type VIIs, thirteen large Type IXs, plus the two large duds, U-25 and U-26.

When Hitler commenced the rape of Europe in 1938, the embryonic U-boat arm deployed for war on three occasions: during the annexation (Anschluss) of Austria in March; the abortive attempt to absorb the Sudetenland area of Czechoslovakia in May; and the Munich Crisis of September, when Hitler gained the Sudetenland by diplomacy. On all three occasions, all thirty-six commissioned boats—including the six ducks at the submarine school—loaded war stores and sailed to predes-ignated stations in the North and Baltic seas, under Dönitz’s command, to fight a naval war with an array of potential enemies: France, Poland, the Soviet Union, and possibly even Great Britain. It was realistic training for the crews, but the exercises left no doubt that the U-boat arm was absurdly inadequate, both in size and weaponry, for the tasks envisioned.

In late May of 1938, after Hitler had been rebuffed and humiliated in his first attempt to absorb the Sudetenland, he summoned Raeder to the Reichs Chancellery and presented him with astounding news. Reversing all previous directives, Hitler informed Raeder that the Kriegsmarine must now consider “the possibility” of Great Britain as a naval opponent. Hitler would continue to court the appeasing British government, seeking to cement the friendship, but at the same time, he wanted Raeder to lay firm plans for a huge naval buildup, to include “big warships” for “political purposes”—that is, “symbols of power” that were to “influence England not to join the other side in case of any political difficulties arising between us and any other nation.” Hitler also wanted more U-boats. He would invoke the escape clause in the Anglo-German Naval Treaty, which, under certain circumstances, allowed Germany parity with Great Britain in submarines—a planned 70,000 tons.

Raeder assumed that Hitler intended to promptly invoke the submarine escape clause, but owing to the tense political situation that developed in the Munich Crisis, Hitler deferred naval negotiations. Nonetheless Raeder—in technical violation of the treaty—proceeded with plans to order thirty-six more U-boats, comprising 25,250 tons. Again Dönitz and the OKM locked horns over tonnage allocation, and again Raeder ruled against Dönitz. The final order included nine Type IXs (for 6,750 tons), two very large Type XB minelayers (for 3,600 tons), two huge Type XI “U-cruisers” mounting four 5” guns in two turrets (for 6,000 tons), and seventeen Type VIIs (for 8,500 tons). The Type VIIs, which Dönitz urgently needed, comprised only 34 percent of the total new tonnage.

That year—1938—Dönitz received nine newly commissioned boats. These included the first of the Type VIIBs with the “saddle” fuel tanks, U-45; the first of the large Type IXs, U-37; and the first of the improved ducks, U-56 and U-57, designated Type IIC. These, and the sister ships to come, were assigned to three new flotillas, named for Imperial Navy submarine heroes: Bernhardt Wegener, Paul Hundius, and Hans Joachim Emsmann. The VIIBs were to form the Wegener Flotilla, the IXs the Hundius Flotilla, and the IICs the Emsmann Flotilla.

Meanwhile, in the last days of 1938, the OKM finalized plans for expansion of the Kriegsmarine. Known as the Ziel (Target) Plan, or Z Plan, it was an admiral’s dream. It recommended a surface ship force of seventeen capital vessels (six super-battleships of 72,000 tons each, four large battleships, four aircraft carriers, three battle cruisers), three “pocket” battleships, five heavy cruisers, forty-eight light cruisers, sixty-eight destroyers, ninety motor torpedo boats, numerous minelayers and minesweepers, and a host of auxiliaries and small craft. When completed in 1948, the Kriegsmarine was to comprise over one million tons of surface warships.

The Z Plan also included a plentitude of U-boats—a total of 249, comprising about 200,000 tons. But the proposed mix was another sharp defeat for Dönitz, who had not been consulted. The OKM recommended sixty small Type lis, twenty-seven huge “U-cruisers” and minelayers, sixty-two large Type IXs, but only 100 medium Type VIIs. If this mix was approved, it meant that 75 percent of the submarine force (150,000 tons) would be composed of U-boats Dönitz did not deem desirable, leaving only 25 percent (50,000 tons) for the 500-ton medium Type VIIs he considered to be most effective for his evolving doctrine.

Dönitz did his utmost to modify the Z Plan to fit his concepts. He wrote a monograph, Die U-bootswaffe (The U-boat Arm), propagandizing for U-boats. For security reasons he did not describe his “wolf pack” concept, but he advocated a “trade war” by U-boats and stressed the advantages of the night surface attack, doubtless to counter the views at the OKM that U-boats were highly vulnerable to sonar and aircraft attacks and were therefore of limited utility and value in British waters.* He also enlisted the political help of the biggest gun at hand: fleet commander Hermann Boehm, who advised the OKM that in a naval war with Great Britain he would rank U-boats and mines at the top of a list of desirable weapons. When Raeder presented the Z Plan to Hitler, the Führer approved it without change, but with one stipulation. Hitler demanded that the force envisioned be completed not by 1948 but by 1945. To assure that this deadline could be met, Hitler guaranteed Raeder that the Kriegsmarine was to have “priority over programs of the other services.”

The adoption of the Z Plan was a flagrant violation of the spirit and terms of the Anglo-German Naval Treaty. It was to be kept secret until Hitler could devise a politically expedient way to abrogate the treaty and blame the break on the British. Meanwhile, Berlin would pretend to adhere to the treaty. As a part of that pretense, on December 12, 1938, the Foreign Minister, Joachim von Ribbentrop, belatedly invoked the submarine escape clause, which legally permitted Germany to build to parity with Great Britain, or 70,000 tons of U-boats. This move came as a nasty shock to the Admiralty, but the British government accepted the declaration without objection.

A month later, in January 1939, Raeder ordered another sixteen new U-boats, comprising about 13,000 tons. These additions were to bring the U-boat arm to parity with the British by 1942—118 boats comprising 70,000 tons. Again Dönitz lost the debate on type allocation. Raeder directed that about half the new tonnage (6,500 tons) be assigned to build another very large Type XB minelayer and two more huge Type XI U-cruisers. The other half of the tonnage was assigned for Type VIIs. This was the last U-boat order placed in compliance with the submarine tonnage limits of the Anglo-German Naval Treaty. When these orders had been fulfilled in 1942, the U-boat arm was to consist of the following types and tonnages:

This mix was, of course, far from satisfactory to Dönitz. The Type VII, which he desired above all others, still comprised only 39 percent of the total tonnage. Moreover, the total number of VIIs—fifty-five—to be completed by 1942 was less than one-fifth the number he deemed necessary for a decisive attack on the British merchant marine.

Abrogating the agreements reached with Great Britain and France at Munich, in March 1939, Hitler occupied the rest of Czechoslovakia by bluff and political intrigue and rode triumphantly into Prague. That outrage overshadowed another Nazi conquest a week later when the Kriegsmarine reclaimed Memel, Lithuania, for Germany in another bloodless operation. As Hitler had correctly foreseen, neither France nor Great Britain lifted a finger to assist Czechoslovakia.

Having flanked Poland, Hitler intended to absorb that nation by bluff and intrigue as well. Should those methods fail, he advised his military chiefs, the Wehrmacht, Luftwaffe, and Kriegsmarine should be prepared to seize Poland by military force, no later than September 1, 1939.

The Nazi rape of Czechoslovakia produced an unexpected reaction among the citizens of Great Britain. They rose up in fury and demanded that the chief appeaser, Prime Minister Neville Chamberlain, draw a line on Hitler’s aggression. Confronted with this public outrage and the possibility of his ouster, Chamberlain was compelled to declare that should France honor its long-standing mutual defense treaty with Poland, Great Britain would support France.

Hitler seized upon the Anglo-French guarantees to Poland as a pretext for abrogating the Anglo-German Naval Treaty. He did so publicly, in a sarcastic speech to the Reichstag on April 28. Soon thereafter the Kriegsmarine laid the keels for the two super-battleships, Bismarck and Tirpitz. Despite these provocations and the public indignation and the stepped-up military preparations in Great Britain, Hitler continued to assert to his Nazi cohorts that neither Great Britain nor France would fight for Poland. Believing Hitler would pull another political rabbit out of his hat, Raeder naively—and irresponsibly—assured the Kriegsmarine that there would be no war with Great Britain.

Dönitz was more convinced than ever that the opposite was the case. He believed that the “high state of tension” which Hitler had created between Great Britain and Germany could explode “into actual hostilities at any moment.” He therefore pleaded with Raeder and the OKM to approve a rapid increase in U-boat orders, with a major emphasis on Type VIIs, and to authorize theretofore prohibited U-boat exercises in the Atlantic Ocean. He got nowhere with his pleas for an increase in U-boat orders—the available shipyards were already jammed—but Raeder did permit the Atlantic exercises.

These exercises culminated in May 1939 with group or “wolf pack” attacks against a simulated convoy, composed of some Kriegsmarine vessels assigned to the annual fleet cruise to Lisbon and the western Mediterranean. A total of fifteen VIIs and IXs from the Salzwedel, Wegener, and Hundius flotillas participated. The “convoy” consisted of four German surface ships: a tanker, a freighter, Dönitz’s “command ship,” Erwin Wassner, and the Flotilla Salzwedel tender, Saar—the latter two vessels alternating as targets and defending escorts.

The fifteen U-boats deployed in five packs of three boats along a patrol line several hundred miles long. One pack quickly “found” the “convoy” and radioed a contact report to the other boats. In spite of clever evasive and defensive measures by the convoy—and extremely foul weather—the other boats converged on the target and attacked it relentlessly for over forty-eight hours, May 12 to 14. At the end of the exercise, thirteen of the fifteen boats converged for the final “kill.”

The exercise was wholly artificial and weighted to favor the U-boats. There were serious lapses in communications and tracking and gross errors in position reporting. Nonetheless, Dönitz could not have been more pleased. In a lengthy after-action critique, he concluded that the “principle of fighting a convoy of several steamers with several U-boats” was “correct” and that “the convoy would have been destroyed.” His group or “wolf pack” concept was therefore a sound one for defeating Great Britain; he renewed his pleas to Raeder for a step-up in the construction of Type VIIs.

Absorbed in the grandiose Z Plan, the OKM emphatically disagreed with Dönitz. The senior submarine planner at the OKM, Werner Fürbringer, a rear admiral and an assistant to Raeder’s chief of staff, Otto Schniewind, framed the response. “At the present moment,” Fürbringer wrote, “U-boat blockade of England has very little prospect of success for Germany. Any contradictory opinion, which takes comfort in the large number of our U-boats or in the idea that the English U-boat defense will not be effective far out in the Atlantic, can be dismissed as misleading” and, furthermore, it would be “irresponsible to commit the valuable U-boat crews” to such a war. “It can be taken as proven,” Fürbringer went on, “that every English convoy, no matter whether it operates along the coast or on the high seas, will be secured by defensive forces, fully capable of destroying with certainty any attacking U-boat, even under the surface.” In support of has argument, Fürbringer stressed the effectiveness of British sonar and predicted that the British would again resort to defensive minefields, which had been so deadly effective against U-boats in World War I. Until U-boats could be made “sonar-immune,” it was pointless to even consider starting a U-boat campaign against British commerce.

The Fürbringer paper dismayed and enraged Dönitz. In response he drafted a reply for Fürbringer’s superior, Otto Schniewind, vigorously rebutting Fürbringer’s arguments point by point. Going a step beyond—a large and career-risking step—he communicated his arguments directly and emphatically to Raeder, and asked that Raeder in turn place his views “before Hitler.” Hitler’s response, relayed to Dönitz through Raeder, was, as Dönitz remembered it, that “he would ensure that in no circumstances would war with Great Britain come about. For that would mean finis Germaniae. The officers of the U-boat arm had no cause to worry.”

* The Admiralty law entailed was very complex and much influenced by the practice of privateering, which had been abolished by the Declaration of Paris in 1856.

 The codes had been legally defined and adopted by the major naval powers at the International Peace Conference at The Hague in 1899, and reaffirmed at the second such Hague conference in 1907. Hence the codes were known as “The Hague Conventions.”

* The “First Lord” of the Admiralty, a civilian, was a political appointee, comparable to the Secretary of the Navy in the United States. The “First Sea Lord,” an admiral, was the uniformed naval chief.

* Total figures vary by source. Generally speaking, in this period the U-boats sank about 1,000 ships for about 2 million gross tons.

* Strictly speaking, the convoy sailed from Hampton Roads, Virginia, an expansive anchorage at Norfolk. Here and below, “Norfolk” is used freely to designate Hampton Roads.

* Ramming, gunfire, depth charges, etc.

 Stranding, German mines, own U-boats, etc.

* Quoted in Tarrant (1989).

* Any vessel of 10,000 tons or more armed with guns larger than 8”.

 Britain was allowed an extra 100,000 tons to compensate for the age and certain shortcomings in her capital ships.

 Any cruiser larger or more heavily gunned was to be considered a capital ship.

* For greater detail on American and British destroyer programs, see appendices 9 and 12.

* The United States scrapped thirty-two ineffective prewar or wartime boats, reducing its total force to about eighty submarines, the majority (fifty-one) of these the inferior S class. Great Britain retained about fifty submarines in commission, twenty of them fairly new. Japan retained about sixty boats, about twenty of them fairly new. The treaty contained a special exemption to the 2,000-ton and 5.1” gun limitations in order that the United States could keep three new 2,800-ton boats: Narwhal, Nautilus, and Argonaut, mounting 6” guns. A similar exemption allowed Britain to keep its X-I, with 5.2” guns and France to keep the 3,000-ton Surcouf, with 8” guns.

 In the years 1930-1932, France ordered twenty new submarines, for a total of about eighty; Italy, twenty-six, for a total of about fifty-six.

 And later by ten other nations: Germany, Belgium, Russia, Haiti, Nepal, Sweden, Finland, Panama, Bulgaria, and Albania.

* Hoover’s proposed cutback in naval power was to include 33 percent in capital ships (fifteen to ten for Great Britain and the United States); 25 percent in tonnages of aircraft carriers, cruisers, and destroyers, and 33 percent in submarine tonnage—no submarine force to exceed 35,000 tons. By one estimate, if Hoover’s plan had been approved, the United States would have scrapped a total of 300,000 tons in naval vessels, over 1,000 heavy artillery pieces, nearly 1,000 tanks, and 300 bombers.

 Plus two old battleships, two old cruisers, four destroyers, and four torpedo boats in layup.

* In violation of the Versailles Treaty, these “pocket” battleships actually displaced 12,000 tons, rather than 10,000 tons.

* The initial agreement specified a limit of 35,000 tons on capital ships to conform to the limits imposed on the major naval powers by the 1930 London Naval Treaty, but the limit was later raised to 45,000 tons. In their final configuration, Gneisenau and Scharnhorst displaced 32,000 tons; Bismarck and Tirpitz, 42,000 tons.

* Twenty-four small (250-ton) Type II (U-1 to U-24); two large (750-ton) Type I (U-25 and U-26); and ten medium (500-ton) Type VII (U-27 to U-36).

* Normally, Germans entered the Navy at age eighteen, straight out of high school. Like recruits in the Imperial Navy, all spent the first year at sea crewing a full-rigged sailing ship. Hence the year of entry into the Navy was known as “crew” year, the equivalent of “class” year in other navies. The Weddigen Flotilla skippers came from the crews of 1924 to 1927.

* The monograph was published in 1939, but British intelligence apparently missed it. The Admiralty finally came by a copy in 1942, but by that time the insights it contained, foreshadowing the trade war and U-boat tactics, were of no value.

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