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The title caught my eye, but then the subtitle really captured my attention: The untold story of how America broke the final U-Boat Enigma code. Using information not available to the public until the late I 990’s, combined with interviews with numerous participants, the authors present the riveting tale of wartime code breakers, how their successes enabled U-boat sinkings and the development of the Bombes that could decrypt both the German and Japanese communications. In the late 1990’s, a change in British declassification policies resulted in a significant number of documents from WWII British Ultra projects appearing at the Public Record Office. This lead to an understanding of how we broke the German code used by Admiral Donitz.

As with a number of my contemporaries, I graduated from the I 0 I 11 submarine class in New London in 1955 and upon reporting to HARDHEAD was assigned as Communications and Crypto officer. For the next year, including a special operation off Murmansk, I spent a lot of time manipulating those rotors and rings on the crypto machine. This book presents in great detail the way in which the code breakers of Washington and London were able to read the German transmissions, encrypted by their four-rotor Enigma machines.

In the early I 920’s the Office of Naval Intelligence secretly financed 04a series of break-ins at the Japanese consulate in New York City whose scope and daring make the Nixon-era burglary at the Watergate Hotel look like child’s play. The entire Japanese fleet codebook was photographed, page-by-page, during repeated undercover operations never detected by the Japanese … ” It was during that time-period that Agnes May Driscoll began a career in codebreaking, eventually becoming the Navy’s top cryptanalyst and working in the office of OP20G. Her counterpart in England, at Bletchley Park, was Commander Alastair G. Denniston. When they met in Washington in August 1941, Denniston offered to share Britain’s hard-won expertise but was rejected by Driscoll who was convinced she had already arrived at an old-fashioned paper-and-pencil solution to the German code system, the Enigma. Neither Driscoll, nor her boss (submariner Captain Laurance F. Safford) informed Naval superiors of the rejection-actions that not only were not recorded in Navy records but also “hampered British-American relations for the next four years.”

In late 1941, OP20G recognized the limitations of their manual efforts and turned to National Cash Register (NCR) in Dayton, Ohio in order to utilize their expertise in the codebreaking efforts. By the end ofl942,Joseph R. (Joe) Desch, NCR’s lead electronic engineer, was selected to head the project-to create electro-mechanical decrypting machines that would be called Bombes.

By mid-1943 the project had employed more than one thousand manufacturing workers and required material and components from thousands of different suppliers. President Roosevelt had given it the highest possible priority, the president’s AAA designation. It was then that the Navy took over a 36,800-square-foot building at NCR. Erected just four years earlier, Building 26 (NCR numbered their buildings as they were constructed) was one of the first structures in the country to use steel-reinforced concrete floors. It was strong enough to support the 5,000-pound machines (we now call them computers) that were to be constructed and roomy enough with its 12-foot-high ceilings and wide hallways for moving the massive machines, which stood seven feet high, eight feet long and two feet wide.

Secrecy was paramount. Joe Desch was concerned that the building’s name (the alphabet has 26 letters) might give a clue as to his project. Subcontractors could not be told the why of their work, and every effort was made to prevent them from guessing. For example, the number 26 was never used on parts specifications. The manufacturers of the commutators were told to number their contacts from 00 to 25. The cable manufacturers were told to make the cords in 28, not 26, different colors. Even Joe Desch’s daughter did not know the nature of his work until after his death in 1987.

March 1943: “As the Spring U-boat offensive opened, the Germans changed some of their codes and tightened up their procedures so that the Allies were again shut out of the submarine code systems. They remained blind for more than a week during what became the worst month for the Allies in the Battle of the Atlantic. More than twice as many Allied merchant ships (95) went to the bottom in March as in February.”

The assassination of Admiral Yamamoto: On April 14, 1943, a Japanese message was intercepted and broken by OP20G, revealing that Admiral Yamamoto would be flying under escort of six fighters planes and would arrive on April 18 for an inspection tour on Ballale, a small island in the Solomons. Henderson Field on Guadalcanal hastily fitted 16 P-38’s with long-range fuel tanks for the 1,000 mile round-trip journey. Three Zeros and both bombers were shot down, including the one carrying Yamamoto.

During the summer of 1943, the engineers and technicians at NCR struggled to perfect their machines. “In July the Navy’s faith and insistence that Joe Desch could work out the glitches … paid off, and the early production models began to show that they could do the job. By August, the machines scored their first useful break into Shark (the German code system), within a week of message transmission.”

The night of September 11, 1943, Midshipman Torchon stood guard by a railroad siding behind Building 26. He kept watch as six huge wooden crates were rolled into a waiting baggage car. In an interview in 2001 he stated : “All I knew, it was NCR, and I thought they were cash registers. What did we know? Nobody knew-not for fifty years.” The train transported its cargo to the Naval Communications Annex near Tenley Circle in Washington, where eventually 120 of the Bombes were operated, around-the-clock, by WAVES. The machines made a deafening noise, whirring and clacking as they raced through the millions of permutations possible on the Enigma machine. The Bombes were prone to sparks and short circuits that ruined decoding runs, and oil leaks that created maintenance nightmares. (The reader must appreciate the present-day computers, in comparing them to an assembly of 120 noisy, 2.5-ton Bombes)

The number and quality of the Bombes increased. “By the summer of 1944, hundreds of submarine messages were being read the same day, some within minutes of their transmission, giving Allied antisubmarine forces a fresh bead on the subs’ whereabouts.”

“Over the next three months that summer, the percentage of operating U-boats sent to the bottom reached a high of76 percent.” Although the German cryptologists had doubts about the security of their Enigma system, “many in the (German) military believed that the Allies’ superior radar was the prime culprit for their U-boat troubles.” Changes to Enigma were not implemented.

After the war, NCR missed its chance to get a head-start on the digital age, ignoring the rise of data processing and programmable computing. One of its young executives, Thomas Watson, left the company and started IBM.

On a secret ceremony at the Navy Department in 1947, Joe Desch “was awarded the National Medal of Merit-the highest civilian honor for wartime service-for his work in developing the Bombe.” However he did not tell anyone of the nation’s gratitude, not even his daughter. “The medal hung in the study of his home, without explanation, until his death in 1987. Two years later, his daughter rummaged through his desk. looking for anything that might help her ten-year-old son with a school assignment to write about his grandfather. She came upon two thick transcripts that she had never bothered to read previously. They were her father’s interview with the Smithsonian’s historian, dated January 1973. For the first time she understood what he did during the war years. When she contacted the Smithsonian she was referred to NSA. When NSA learned of the content, it was requested that the documents be brought to Fort Meade. After the brief NSA review, she was told: “You realize, of course, I can’t Jet you take these out of the building.”

The Secret In Building 26 presents in fascinating, historical detail the efforts of the US and British crypt analysts in breaking the German and Japanese communication codes during WWII. The authors did a magnificent job of researching the facts and writing this book. The book is significant in that these details remained classified for over 50 years. It is worth the read.

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