Deception at Sea WWII

By MSW Add a Comment 10 Min Read

n51-mfv2020

Lt. Richard Townsend onboard N51, dressed as a French fisherman.

British naval codes and ciphers were easily penetrated during the early stages of the Second World War. Well before the outbreak of hostilities the German Kriegsmarine developed its ‘B-Dienst’, or ‘Beobachtung-Dienst’ (‘Observation Service’). The service was minute and had little contact with the other German codebreaking agencies, yet its subsequent success was out of all proportion to its size.

When war eventually came ‘B-Dienst’ enabled German surface raiders to elude the British Home Fleet, spared German heavy ships from chance encounters with superior British forces, permitted surprise attacks on British warships and helped sink six British submarines in the Skagerrak area between June and August, 1940. Astonishingly the Royal Navy failed totally to appreciate the extent of German interception. Instead they deceived themselves into believing that they were suffering from nothing worse than bad luck. Even when, in July, 1940, the German merchant raider Atlantis captured a copy of the ‘BAMS code’ used universally by British merchant shipping, together with a series of superencipherment tables, Royal Naval Intelligence failed to make a connection between this and the subsequent increase in U-boat successes and did nothing to change the codes.

The Germans also became adept at the use of ‘Q’ ships or armed merchant cruisers. Unlike British armed merchant cruisers, which were cruise liners hurriedly pressed into service in the early stages of the war to provide convoy protection, these were raiders which masqueraded as merchant ships to decoy and sink genuine merchant ships. Arguably the most fascinating of these was the ex-British steamship Speybank, captured by the Germans in 1941, renamed the Doggerbank and put under the command of Captain Paul Schneidewind. Equipped as a minelayer but in outward appearance still a British merchantmen, she was selected for Operation KO, the covert laying of mines in Cape Town Harbour.

In every outward respect an innocent merchant ship, she was allowed to sail unmolested into the harbour, where she successfully laid her mines before sailing out, still unchallenged. Allied complacency caused them to suffer two ships sunk, three ships badly damaged, 200 casualties and serious disruption to their supply lines which took months to repair.

Subsequently, while minelaying in the nearby Agulhas Bank, Schneidewind deceived the Royal Navy twice, once when Doggerbank was challenged by the light cruiser HMS Durban, the second time when challenged by the armed merchant cruiser HMS Cheshire.

When approached by HMS Durban at night he initially failed to recognize and respond to the coded order to identify himself. Fortunately for Schneidewind British merchantman were notoriously bad at responding to coded messages and the warship therefore repeated the order in plain language. When Schneidewind flashed back ‘Levernbank from New York to Durban,’ the cruiser, which had been badly damaged in action against the Japanese and was thus in no condition for action, and which had no reason to doubt the merchantman’s story, bade the raider good night and sailed on.

The next day, when challenged by HMS Cheshire, Schneidewind claimed to be the Inverbank sailing from Montevideo to Melbourne. Cheshire, which was carrying a large consignment of troops bound for the Middle East at the time, had no reason to doubt this deceit and let the German sail on.

The ease with which the British warships allowed themselves to be deceived should not be construed as negligence on the part of their captains. The larger German raiders were extremely potent and had to be approached with considerable care. Several would have been a match for the damaged Durban, which could bring only one gun to bear, or the under-armed and over-laden Cheshire.

Some four months earlier, on 19 November, 1941, the Australian cruiser HMAS Sydney had sighted and challenged a lone merchant ship, from which she had received a garbled response, and had closed to within 2km for greater clarification. She had paid a tragic price for her carelessness. The pseudo-merchant ship had been the Kormoran, the largest of all the disguised German ocean raiders. As HMAS Sydney approached, Kormoran torpedoed her. Although the cruiser was mortally stricken her guns remained operational, and had sunk the Kormoran at close range before being blown apart by a great explosion. None of the Australian ship’s crew survived. Indeed the Royal Navy would have known nothing of the action had not some of Kormoran’s crew, escaping in lifeboats, reached the West Australian coast where they were taken prisoner.

On 3 March, 1942, in an ironic twist of fate, Schneidewind’s daring caught up with him. Doggerbank was torpedoed by the German submarine U-43. In strict adherence to orders the U-boat made no attempt to pick up survivors. Several died of their wounds or of exposure. Of nearly 200 men on board only one lived to tell the terrible tale.

During the Second World War a considerable number of British ‘irregular’ naval formations came into being to perform certain special tasks beyond the normal naval ambit. They were commanded by the DDOD (I) or Deputy Director Operations Division (Irregular), Captain Frank Slocum RN, who had been seconded to MI6 in 1937 but had ‘returned’ to the Naval Intelligence Division in 1940. The formations included a small unit designed specifically to deceive the enemy as to where a landing was to take place, and a larger outfit tasked with the infiltration and exfiltration of agents and other personnel to and from enemy held territory.

Although the latter had fast patrol boats at its disposal, where possible it used converted French or Belgian fishing vessels, a number of which had come over with refugees after Dunkirk. The first boat to be requisitioned was a former Brittany trawler, then acting as a patrol boat in Newhaven where she had been registered with the Newhaven number N51. She was taken to Falmouth for a refit after which she was moved in complete secrecy to an isolated anchorage in the Scilly Isles. There N51, as she continued to be known, was painted in the appropriate French colours and given the false registration of a tunny fishing vessel typical of those operating under German licence off the Concameau region of Brittany. Her volunteer crew consisted of two officers and six ratings who were dressed in the manner of local French fishermen, but who nonetheless optimistically carried British identity cards in case of capture. N51 was fitted with a radio capable of receiving SOE agent traffic and was lightly armed with a number of hand guns, together with an anti-tank weapon to disable the engine of a challenging patrol boat if necessary.

N51’s first mission was to liaise with a small fishing smack and take on board a French agent, Colonel Gilbert Renault, who had returned to France by air in order to evacuate his wife and family. Not only was the mission successful – Renault his wife and four children were safely evacuated – but it proved that a regular line of communications could be maintained with occupied Europe. During her time in French waters N51 had been spotted by numerous genuine fishing boats, not all with crews sympathetic to the Allied cause, and by a number of German patrol boats. Yet none had questioned her; on the face of it she had been fishing in permitted waters and they had had no reason to challenge her bona fides. Once again well-planned deception, supported by enemy lethargy, had proved a potent weapon.

N51 was later joined by two other trawlers and by a small motor torpedo boat converted to resemble a Brittany fishing boat. As the flotilla grew it was designated with the cover name Inshore Patrol Flotilla, although its craft continued to appear in the Navy List as Motor Fishing Vessels. Using one boat or another, the flotilla continued to operate until the end of the war in Europe, usually carrying out one trip a month in the moonless period.

By MSW
Forschungsmitarbeiter Mitch Williamson is a technical writer with an interest in military and naval affairs. He has published articles in Cross & Cockade International and Wartime magazines. He was research associate for the Bio-history Cross in the Sky, a book about Charles ‘Moth’ Eaton’s career, in collaboration with the flier’s son, Dr Charles S. Eaton. He also assisted in picture research for John Burton’s Fortnight of Infamy. Mitch is now publishing on the WWW various specialist websites combined with custom website design work. He enjoys working and supporting his local C3 Church. “Curate and Compile“
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