Engineering Hitler's Downfall. Gwilym Roberts

many isolated country houses were taken over and adapted for specific purposes – not only Bletchley Park, but also Beaulieu in Hampshire and Arisaig House in Invernessshire for the training of Special Operations Executive (SOE) operatives.

      Communications with forces operating overseas and Allied governments were either by radio or submarine cable. There were major pre-war radio transmitting stations at sites such as the beam wireless transmitter at Dorchester, Dorset; the very low frequency transmitter at Rugby, Warwickshire; and the wartime reserve station at Criggion, Powys. With their masts up to 250 metres in height they were impossible to conceal.

      On the other hand, major efforts were made to conceal the activities taking place in the many villages and houses throughout Britain where covert communication centres were sited. One was at Porthcurno, a small coastal village near Land’s End in Cornwall, which as early as 1870 had been chosen as the British terminal for the first submarine cable. By the outbreak of the Second World War it operated as many as 14 cables and was able to receive and transmit up to two million words a day – for a time it was the largest submarine cable station in the world. Situated some 150 km from Brest, it was considered to be extremely vulnerable following the fall of France, and elaborate measures were taken to protect the station’s equipment. Local tin miners were engaged in June 1940 to dig two parallel tunnels, and two smaller cross-tunnels, in the granite headland behind the station. This was completed within 12 months, and the receiving and transmitting equipment was then moved into the main tunnels. The entrances, emergency exits, and operatives’ housing were all camouflaged to blend in with the local topography. The station was closed in the 1970s and is now a museum

      Another was at Heighton Hill, just north of Newhaven, East Sussex, and known as HMS Forward. In 1941 a labyrinth of tunnels was constructed in the chalk of the South Downs to house facilities for a Royal Naval headquarters. These were demolished at the end of the war, and virtually nothing was known about HMS Forward until Geoffrey Ellis – a Post Office engineer who as a local boy had seen it being built and was intrigued to know what had taken place there – investigated it in his retirement. His researches established that there had been two telephone exchanges, ten teleprinters, two Typex machines, a wireless telegraphy office with 11 radios, and a voice-frequency telegraph terminal for 36 channels. The tunnels housed a standby generator, an air conditioning system with gas filters, a galley, toilets, cabins for split shifts, and the recently invented phenomenon of ‘daylight’ fluorescent lighting. The complex was equipped for every contingency from failure of the public utilities to direct enemy action. Ten coastal radar stations along the Sussex coast reported directly to HMS Forward every 20 minutes. All their information was filtered and plotted before being relayed by teleprinter to similar plots at Dover and Portsmouth. The HMS Forward plot maintained a comprehensive maritime surveillance of everything that moved on, under, or over the English Channel from Dungeness to Selsey Bill. Further intelligence was obtained from military airfields by private telephone lines. For operational security reasons, each plot understudied its neighbour, with HMS Forward standing in for Fort Southwick at Portsmouth and vice versa. Wrens operated the station on a continuous three-watch rota and were supplemented by RN ratings for special occasions. On D-Day, they were joined by RAF, WAAF, and ATS personnel. HMS Forward was heavily involved in the saga of the German battle cruisers Scharnhorst, Gneisenau, and Prinz Eugen in February 1942; the Dieppe raid; the nightly naval Motor Torpedo Boat (MTB) harassment raids on enemy harbours and waters; the frequent SAS commando ‘snoops’ on the occupied French coast; the D-Day landings; and, ultimately, the liberation of France. The centre was abandoned and neglected after the war, but on Ellis’ initiative the Newhaven Historical Society undertook a detailed survey of the complex, including photographs and videos. A model of the station was then produced which is on display at the Newhaven Local and Maritime Museum

      American service personnel were a common sight in Britain during the latter years of the war, particularly airmen in East Anglia, soldiers in southern England, and sailors in the major ports. However, sailors were also a common sight in the small rural village of Hurley, by the Thames in Berkshire. Chosen because of its good reception for radio signals, it was Station Victor, the main UK communication centre of the US Office of Strategic Services (OSS), the predecessor of today’s CIA; it was used for communicating with OSS agents on the European mainland. Operating in great secrecy, the sailors claimed to be in training but were in fact skilled radio operators – local inhabitants thought the station’s transmitting and receiving towers to be elaborate radar equipment. As with HMS Forward, there is little in the official record about the station’s activities, and it came to light only when a local resident who had been told by his father-in-law about the American sailors in the village during the war decided to investigate its history.

      Underground Hideaways

      In addition to the numerous secret bunkers built for the Auxiliary Units in the counties deemed to be at risk of invasion (see Chapter 3), there was also a network of bunkers with hidden radio and other communications. Comprising a relatively small number of IN and OUT stations, these would have maintained two-way contact between the Units and higher authorities had the Germans invaded. Comparatively little was known about them until recently, when a station built under a tennis court in Norfolk was accidentally discovered. This was found to include a radio room, aerials on a nearby pine tree, a cast iron pipe (which researchers say may have been used by civilian informants to drop split tennis balls containing secret messages into the bunker), an escape tunnel, and a water tank.

      Decoding of enemy signals was said to have shortened the war by two years…

      BRITAIN’S TIMELINE TO DUNKIRK

      1939

      1 Sep Germany invades Poland.

      3 Sep Britain and France declare war on Germany.

      Phoney War (on land and in the air) begins.

      Churchill appointed First Lord of the Admiralty.

      Allies start naval blockade of Germany and mine approaches to English Channel and German ports.

      German submarines (U-boats) and ocean raiders start attacking Allied shipping.

      SS Athenia torpedoed off Ireland with loss of 112 lives (28 American).

      Germans start laying magnetic mines off UK east coast resulting in many sinkings.

      10 Sep Britain starts sending Army and RAF units to France.

      17 Sep Aircraft carrier HMS Courageous torpedoed and sunk off Ireland.

      15 Oct First World War battleship HMS Royal Oak torpedoed and sunk inside RN base at Scapa Flow; Britain then starts strengthening Scapa Flow’s defences.

      22 Nov RN engineers recover and start to dismantle magnetic mine.

      23 Nov HMS Rawalpimdi (armed merchant cruiser) sunk by German battlecruisers Scharnhorst and Gneisenau who then abort planned breakout into Atlantic.

      13 Dec Battle of the River Plate when cruisers HMS Exeter and HMS Ajax and HMNZS Achilles engage the German pocket battleship Graf Spee. All four ships are damaged and Graf Spee retires to Montevideo harbour for repairs where it is eventually scuttled (a case where new German technology was outfought by superior tactics and traditional RN determination to engage the enemy more closely).

      1940

      8 Apr Britain lays mines off the Norwegian coast (to force shipping onto the high seas where it could be inspected by the RN).

      9 Apr Germany invades Denmark and Norway.

      Apr Naval engagements off Norway resulting in RN losing one carrier, two cruisers, seven destroyers, and four submarines and Germany losing three cruisers, ten destroyers, and three submarines.

      11 Apr Allied troops land in Norway.

      6 May Allied troops evacuated from central Norway.

      9 June Last Allied troops evacuated from northern Norway.

      10 May Germany invades Belgium, Holland, and Luxembourg thus outflanking