Plan Z

• 1. Versailles Naval Restrictions

  ›

  The Treaty of Versailles ended World War I with a stranglehold on German naval power. Article 191 explicitly prohibited Germany from possessing or building submarines for any purpose. The new Reichsmarine was limited to six pre-dreadnought battleships and twelve destroyers. Only two additional pre-dreadnoughts could be kept in reserve alongside four torpedo boats. This strict limitation forced the Germans to create a dummy corporation called NV Ingenieurskantoor voor Scheepsbouw in the Netherlands. This entity secretly continued submarine development while violating international law. They built several vessels for foreign navies including the Turkish Turgut Reis. That ship became the basis for the Type I U-boat used later by Germany. A similar arrangement existed for Finland with the Vesihiisi prototype for the Type II U-boat. The treaty also allowed replacement of old battleships after twenty years but capped displacement at ten thousand tons. German engineers responded by designing heavy cruisers known as panzerschiffe. These ships carried six 28 centimeter guns instead of the standard eight-inch caliber. British and French designs were bound by the Washington Naval Treaty to a maximum of ten thousand tons. The Deutschland class outclassed these Allied ships significantly. France opposed any concessions to Germany regarding these treaties. Consequently, the Deutschland and two sister ships were built despite diplomatic friction.

• 2. Strategic Evolution And Planning

  ›

  Konteradmiral William Michaelis issued a memorandum in September 1920 outlining coastal defense goals. The German Army viewed Poland as the primary future enemy. The Navy assumed France would support Poland in such a conflict. Britain was expected to remain neutral during a war against Poland. Construction through the mid-1930s focused on countering the perceived French threat. Any hypothetical submarines would generally support the main fleet rather than conduct commerce raiding. This view remained orthodoxy until Kapitän zur See Karl Dönitz took command of the U-boat arm. Dönitz advocated unrestricted submarine warfare and wolfpack tactics to overwhelm convoy defenses. Vizeadmiral Erich Raeder became head of the Reichsmarine in 1928. He fully endorsed long-range surface raiders due to his service under Franz von Hipper. Hipper had seen the fleet rendered impotent by crushing British naval superiority. Hitler's aggressive foreign policy made conflict with Britain increasingly likely after the Munich crisis of September 1938. Hermann Göring announced a colossal armament program on October 14 that year. The plan aimed to complete expansion by 1942 when Hitler planned to go to war. Hitler nevertheless assured Raeder that war would not come until 1948. Raeder believed Britain could be defeated through surface raider strategy instead of direct engagement.

• 3. The Plan Z Specifications

  ›

  Adolf Hitler approved Plan Z on the 27th of January 1939. The fleet was meant to challenge the naval power of the United Kingdom. It was scheduled for completion by 1948. Development began in 1938 reflecting two decades of strategic thinking from the Oberkommando der Marine. The plan called for ten battleships and four aircraft carriers to battle the Royal Navy. This force would be supplemented with numerous long-range cruisers attacking British shipping. A relatively small force of U-boats was also stipulated. By 1948, the German fleet included a total of 797 ships. The cost amounted to 33 billion reichsmarks spent over nine years. Six H-class battleships were to be built alongside three O-class battlecruisers. Twelve P-class panzerschiffe were ordered before cancellation in July 1939. Five ships fulfilled heavy cruiser mandates while M class light cruisers met other requirements. Spähkreuzer 1938 designs formed the basis for fleet scouts. Extensive upgrades to Germany's naval infrastructure accompanied these orders. Larger dry docks were planned for Wilhelmshaven and Hamburg. Much of the island of Rügen was removed to provide a large harbor in the Baltic. On March 1, further revisions to cruiser numbers were approved. Raeder retained his philosophy of using battleships and aircraft carriers to support surface raiders.

• 4. War Outbreak And Cancellation

  ›

  World War II broke out in September 1939 before construction could begin on new ships. Almost no work had been done on vessels ordered under Plan Z. The need to shift manufacturing capacity forced the Kriegsmarine to abandon the program immediately. Only a handful of major ships completed during the war were all ordered before Plan Z. Two Scharnhorst-class battleships cost close to 150 million reichsmarks apiece. Two Bismarck-class ships cost nearly 250 million reichsmarks each. Without six H-class battleships or four aircraft carriers, the Kriegsmarine remained unable to meet the Royal Navy on equal terms. Most heavy ships became commerce raiders in early years. Deutschland and Graf Spee were already at sea when war started. The latter was trapped and scuttled after the Battle of the River Plate in December 1939. Admiral Scheer captured or sank seventeen ships between October 1940 and March 1941. Operation Rheinübung saw Bismarck sink the British battlecruiser Hood but be sunk three days later. Hitler prohibited further Atlantic sorties after this loss. Remaining capital ships concentrated in Norway for use as fleet in being. Work on the aircraft carrier Graf Zeppelin was cancelled definitively in 1943.

• 5. Operational Impact On The War

  ›

  Admiral Karl Dönitz's U-boat fleet did not reach 300 units until 1943. He deemed that number necessary to win a commerce war against Britain. By that time his forces had been decisively defeated. Only a few dozen U-boats had been completed by the outbreak of war. The Oberkommando der Marine favored surface combatants over submarines needed for North Atlantic campaigns. This left him with only a handful of submarines at the start of conflict. For the cost of two Scharnhorst-class battleships, Germans could have built more than one hundred additional Type VII U-boats. The shift to submarine warfare was not made until 1943 when the campaign was already lost. Most heavy ships were used as commerce raiders during early years. Scharnhorst and Gneisenau conducted Operation Berlin into the Atlantic in early 1941. Bismarck sank the British battlecruiser Hood but was sunk three days later. Hitler prohibited further sorties after this loss. Remaining capital ships concentrated in Norway for use as fleet in being. The lack of U-boats due to Plan Z priorities significantly affected the Battle of the Atlantic.

• 6. Economic Feasibility And Logistics

  ›

  The feasibility of the plan had never been considered by Raeder and planners. Securing fuel oil necessary to operate the fleet likely was an insurmountable problem. Fuel consumption would have more than quadrupled between 1936 and completion in 1948. Consumption rose from 1.4 million tons to approximately 6 million tons. The navy would need to construct 9.6 million tons worth of storage facilities. This amount allowed for just a year of wartime operations. Longer conflicts necessitated even larger stockpiles. Projected domestic production by 1948 totaled less than 2 million tons of oil. Combined with 1.34 million tons of diesel fuel, this figure is absurdly low compared to requirements. These figures must be weighed against combined fuel needs of the Army, Air Force, and civilian economy. Construction of ships themselves was not a concern assuming sufficient time existed. But securing fuel oil remained an impossible task given industrial constraints. The plan represented strategic thinking that ignored logistical realities entirely. No consideration was given to how Germany could sustain such a massive fleet operationally.