Title: The Secret Capture
Author: Stephen W Roskill
Roskill, Stephen W. (2011). The Secret Capture: U-110 and the Enigma Story. Annapolis, MD: The Naval Institute Press
- U 110 (Submarine)
- World War, 1939-1945–Naval operations, British.
- World War, 1939-1945–Naval operations–Submarine.
- World War, 1939-1945–Cryptography.
- World War, 1939-1945–Electronic intellegence–Great Britain.
- World War, 1939-1945–Electronic intelligence–Germany.
- ULTRA (Intelligence system)
- Originally published: Barnsley, England : Seaforth Press, 2011. With new introd. & foreword.
Date Updated: February 22, 2016
For fifteen years after the end of the war all official Admiralty records showed the German submarine U 110 as sunk on 9 May 1941 by the surface escorts of convoy OB.318. As this book was the first to reveal, this was a deliberate deception, as the U-boat was actually captured and its contents fully investigated before being allowed to sink a day later, a fact skillfully kept from even the survivors of the submarine’s crew.
As the official historian of the naval war, Roskill had followed the party line when writing his authorized account, but provoked by exaggerated claims concerning a US Navy capture of a U-boat in 1944, Roskill decided to set the record straight. His narrative is prefaced by brief coverage of previous submarine captures by the Royal Navy three Italian and one German before covering the U 110 operation in great detail, underlining the skill and bravery of those involved. We now know that the reason for the secrecy was that the U-boat gave up valuable codebooks, charts, ciphers and, most significantly, a complete and undamaged Enigma machine. At the time of the book’s first publication, Ultra was still a secret, so Roskill (who clearly knew about it) had to be discreet about the exact details of what was taken from the submarine while insisting on its crucial value to the war effort. However, a new introduction puts the capture into context, making clear its vital importance in the history of allied codebreaking in World War Two.
Reviewed by George C. Constantinides
The story of the capture by the British of the German submarine U-110 in May 1941 is handled by this skillful naval historian on two levels. One is the tactics of the battle in which the U-110 was captured, which are thoroughly described. The other is the intelligence meaning of the capture. Here Roskill is more indirect as to the exact nature of the haul and how the intelligence war was affected. He speaks of the capture as coming at a critical time in the war and says that it was “perhaps the most important and far-reaching success achieved by our anti-submarine forces during the whole course of the last war”; however, he does not explain the cryptanalytic importance of the capture and its relationship to Enigma. He was writing long before the release of the secret of Ultra and its role in the war; the book was first cleared by the Admiralty. Since Roskill could not be more specific at the time on the cryptologic aspects, The Secret Capture cannot be called the full story of the U-110 affair, as McLachlan said in Room 39. It does contain, on the other hand, one of the earliest hints in print of the Allied cryptanalytic successes. The contribution the material aboard the U-110 made to the breaking of German naval ciphers is discussed in a number of later and sometimes conflicting accounts. Among these are Lewin’s Ultra Goes to War, Beesly’s Very Special Intelligence, Calvocoressi’s Top Secret Ultra, and Hinsley’s British Intelligence in the Second World War. Note that Roskill mentions the capture of three Italian submarines during the war and the valuable intelligence, documents, and equipment obtained from them, again without elaboration.
Reviewed by Paul W. Blackstock and Frank L. Schaf
An account of naval intelligence during the critical Battle of the Atlantic. Stresses the intelligence value of the documents and equipment acquired from the capture of German U-boat 110 by the escort vessels of a westbound North Atlantic convoy from England in May 1941.
 Constantinides, George C. (1983). Intelligence and Espionage: An Analytical Bibliography. Boulder, CO: Westview Press, pp. 393-394
 Lewin, Ronald (1978). Ultra Goes to War: The First Account of World War II’s Greatest Secret Based On Official Documents. London: Hutchinson
 Beesly, Patrick. (1981, 2006). Very Special Intelligence: The Story of The Admiralty’s Operational Intelligence Centre, 1939-1945. Annapolis, MD: Naval Institute Press
 Blackstock, Paul W. (1978) and Frank L. Schaf, Jr. Intelligence, Espionage, Counterespionage, And Covert Operations: A Guide to Information Sources. Detroit: Gale Research Co., pp. 66-67