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The theme of this discourse is the evolution of U-Boat designs in an extremely compressed time scale. Today, we are told that development of a single new submarine design (computer aided design (CAD) notwithstanding) takes 10-13 years. During the four years of World War I, Germany refined mobilization plans, developed more than a dozen different new designs, and built most of them in quantity.

The Imperial German Navy (IGN) commissioned 346 UBoats during the Great War, 1112 times the combined August 1914 submarine strengths of the seven leading maritime powers of the world: UK – 74, France – 46, U.S. – 30, Germany – 24, Russia- 20, Italy- 18, Japan- 13, Total: 225.

Hans Techel, who had guided submarine development at Germaniawerft, Kiei(GW) since 1907, provided the inspiration for this incredible accomplishment and was truly Father of the U-Boat.

The Germans were late-comers to the submarine world because of efforts to build up their capital ship inventory vis-avis the British. Although slow starters, German designers provided double hull boats with bow planes from the beginning, never used gasoline engines, and avoided the pitfalls of steam. In August of 1914,24 U-Boats were in fighting trim, with 12 more building. Ironically, at the outset, only 17 additional mobilization (Ms) overseas boats were ordered for delivery between December 1915 and December 1916, because nobody thought the war would last that long.

U-1. commissioned on 14 December 1906, was the first GW design accepted by the IGN.

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At the end of six months of hostilities, both the British Grand Fleet and the IGN High Seas Fleet were at anchor for fear of submarines. Germany, suffering from a British blockade, hoped to bring Britain to her knees in a guerre de course against her merchant ships.

A study conducted before the war predicted that 222 UBoats would be required to successfully blockade the British Isles. The highest U-Boat inventory was 177 (September 1918) and 178 U-Boats were lost during the war.

Major U-Boat offensives against commerce began in February (1915, 1916, 1917). We shall examine summary results of offensives and intersperse design data of emerging classes of U-Boats as the first of each class came into commission.

Coastal submarines emerged early on for deployment from Flanders. The UBI and UCI classes were designed and built in record time. These single screw, single hull craft could be shipped by rail in three sections. The first UBI was built in 75 days, and all 17 of the class were in service by May 1915. UCis were minelayers, the lead craft was commissioned in April1915, and all 15 were in service by July of that year.

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The British blockade was strangling Germany by early 1916. There were other exacerbations as well:

  • Shipyards without previous submarine building experience had to join the effort.
  • Diesel engine production had to be expanded.
  • Skilled labor was in short supply because of Army mobilization.

Because of these problems, most U-Boat deliveries during the war were late. Yet, U.S. inspections after the war reported that “nothing in the boats bore the mark of being constructed or fitted hastily.”

Cumulative results by the end or April 1916 were:

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The menace of U-Boats during the Great War should have sobered naval leaders of the major powers, but guerre d’escardre proclivities prevailed for another 20 years. Allied engineers were pleased to paw over surrendered U-Boats, and gained from the experience. German diesels were legendary. In the late 1920s and early 1930s, the evolving U.S. fleet Type Submarine took features from both U-135 and U~140. It took us a long time to get our engine act together, but we finally managed.

On 29 August 1939, DOnitz indicated in his War Diary that the minimum requirement to win the war would be 300 UBoats. He had 57, including 26 capable of operations in the Atlantic. By the end of April 1942 he had surpassed his goal, but that’s another story.


I am trying to locate a book which covers the history of the accidental losses of U.S. submarines. I purchased it in the 19711973 time frame at the GPO Bookstore in the Pentagon. It was published by the GPO, date unknown, and the last I checked it was not listed in their listing of books. I do not have the exact name, but it was something like U.S. Nayy Accidental Submarine Losses. It had a blue cover with gold lettering. I have checked out the libraries at the Submarine School, Washington Navy Yard and the Pentagon to no avail. As a matter of fact, I can’t find anyone who even knows of it.

Two of the incidents it tells about was the sinking of a submarine nested along side a tender with several other submarines at Newport, Rhode Island. The safety interlock on one of the torpedo tubes failed to catch and when the tube door was opened the submarine flooded almost taking other boats in the nest with it. A second incident was a submarine flooding in the Delaware River and going bow first into the mud with only the stem showing above water. The stem was cut open to rescue the crew.

Please send any information on this subject to: Bemo.rd D. Dunn, 5817 Shalott Court, Alexandria, VA 22310. (703) 971-0540

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