"The Day the Cold War warmed up a bit!"

It was approaching midnight on a chilly autumn night in 1960. A bright moon illuminated the buildings of the British army camp situated near the small German town of Heinsberg on the Dutch/ German border. A cold easterly wind moaned around the supporting wires of the tall masts of the short-wave aerials in the adjoining aerial field. This covered an area of several football pitches and was surrounded by a high security fence. The camp was the home of a Royal Signals Regiment charged with the monitoring of Eastern Block military radio traffic. It was the height of the cold war period and the work carried out by the regiment was top secret.

A group of Royal Signals Special Operators emerged from one of the accommodation blocks and set off to start their midnight to 8 a.m. shift in the Operations Centre a few hundred yards away. They were casually dressed and all carried the standard china-one-pint-mug in which they would be served hot tea or cocoa during the night shift. There were about 30 Operators in the group, forming an operational Troop. There were 4 Troops in the Squadron working on a complicated four-day shift system. Tonight 153 Troop were relieving the operators of 154 Troop who had been on watch since 6 pm.

The Operators were mainly National Servicemen who had been specially selected and who had undergone a demanding 8 months’ training learning to read morse code signals transmitted at high speed. Only about 60 per cent of those starting the training completed the course. They were sworn to secrecy regarding their work and could tell no-one at all what they were doing. On completion of their training, they were posted to various intercept stations in Europe and the Middle East

The Regiment concerned in this short narrative had Squadrons located near Braunschweig and in Berlin and smaller additional Direction Finding outstations in various locations over northern Germany and worked closely with similar units of the British Army located in the UK and Cyprus.

The Operators walked up the slope to the entrance to the Ops Centre and exchanged their normal Identity Cards for the special ID cards admitting them to the Set Room. This was a long room containing two parallel banks of radio equipment running the length of the room. Each bank consisted of 25 operator positions.

Each position consisted of two ‘state of the art’ short wave radio receivers, a tape recorder, sets of aerial switches so each receiver could be connected to a selected aerial, connections for at least two sets of headphones and various other items of equipment.

At one end of the room was a control room separated from the main set room by a partition wall with a large glass panel through which the shift Sergeant could see the length of the room. He could tap into any one of the operator positions to hear what the operator was monitoring.. He could speak to any operator position through the operator's earphones if necessary. The operator could answer him via a microphone attached to his headset.

At the side of the control room was a further small glass-walled room in which sat the Direction Finding Controller, usually an experienced corporal. If an operator intercepted a transmission from an unkown source he could ask for the DF Controller to locate the position of the transmitter. He would give the DF Controller the frequency of the transmitter and switch the signal to the DF Controller. He in turn would pass this information to three or four DF Outstations and switch the signal to them. The DF Operator would hear this signal in one ear and would tune his receiver to that frequency and match the signal from his aerial to that being received in the set room. He could then turn his rotating directional aerial to get the maximum strength signal. This would give him the bearing of the transmitter. The bearings from the DF stations would be plotted on a map and the transmitter would be located in the area where the bearings intersected. This procedure could be completed in under one minute.

A further technical possibility for identifying a transmitter was by what was known as Radio Finger Printing. Every short-wave radio transmitter has certain characteristics dictated by the components of the transmitter and these can be identified. The signal being received by an operator could be diverted to the RFP room where the signal would be analysed and shown in the form of a wave on the screen of a cathode ray tube. The wave would show spikes at certain points rather like an ECG print-out showing human heart problems. This would then be photographed and stored and could be retrieved at some future date for comparison with the RFP of a transmitter suspected of having already been intercepted but perhaps now at a new location, indicating movement of an enemy unit.

One of the most important ways of identifying a transmitter or unit was the simplest. Each operating position in the set room was tasked with intercepting a particular Eastern Bloc unit, for example the headquarters of the Soviet Armoured Shock Army based in Magdeburg. Their radio traffic was operated by radio operators working on a similar shift system to ours, and the Special Operators monitoring them could recognize these operators by their style of sending morse. Every operator has an individual style just as everyone has an individual, recognizable style of handwriting.

The operators of the new shift entered the Set Room and sat down next to the operators they were relieving and plugged in their headphones to the plug-board above the receivers and listened to what their colleagues were intercepting. The operator on Position 20 glanced at the log sheet on which his colleague had been recording the call signs, frequencies and other relevant details of the units he had been covering. He took a clean log pad and filled in his personal details ready to take over the position as soon as an opportunity arose. The hands on the set room clock showed two minutes to midnight when the Russian operator finished the message he was sending and signed off. The Special Operator gave a sigh of relief tore off the sheet of the message pad on which he had been writing and put it in his out basket together with the log and message sheets he had filled in during his shift. These sheets would be collected regularly and taken to the rooms where members of the Intelligence Corps would process them further. The relieving operator slid into the seat vacated by his colleague, made a note on his log sheet recording the hand over, adjusted his ear-phones and waited for the Russian unit to start transmitting again.

He waited some minutes, stirred uneasily and glanced around him. Many other operators were looking around with somewhat puzzled expressions. Above the glass window of the Shift Supervisors room there were three lamps, a green, an orange and a red. The green was currently lit, but it suddenly extinguished and the orange lamp lit up. The Sergeant Supervisor's voice crackled in the operator's earphones. “Attention everyone – suspected wireless silence. Possible frequency and call sign changes- Security Status Orange. Start frequency search. Call out 151 Troop".

Down the hill in the accommodation block occupied by the Operators of 151 Troop there was immediate pandemonium - whistles shrilled and NCOs scurried from Barrack Room to Barrack Roon rooting out off-duty operators, who grabbed their mugs and headed for the Ops Centre at the double.

On arrival they immediately sat down together next to the operators occupying the positions they normally occupied when on duty and donned headphones. The operators of 153 were already twiddling the tuning knobs of their sets, searching up and down the frequencies, looking for their target units transmitting on new frequencies. This was not an unusual occurrence. It happened every few weeks, and caused a minor scare, but usually the units were located within a couple of hours, the new call signs and frequencies noted and it was then back to business as usual.

This time, however, there appeared to be a difference in the procedure. 10 minutes passed without any Russian traffic being found. The sense of unease grew. It was general knowledge that if the Russians decided to mount a surprise invasion of the West, it would be preceded by a period of radio silence. It was further generally known that in the event of such an attack, the Radio Intercept locations would be amongst the first targets to be hit. Possibly by a nuclear weapon. There had however been no signs of trouble reported from any other intelligence source and this sudden extended wireless silence was extremely unusual.

The sense of unease grew perceptibly, and the operators began to talk amongst themselves as the silence grew to 15 minutes. The set room door opened and the Commanding Officer of the Regiment entered. He had a tense look on his face and he paced up and down the middle of the set room. The silence grew unbearable. The C.O ordered the Shift Supervisor to contact a monitoring unit and DF station situated on an escarpment overlooking the East German border to see if they could see any signs of movement on the Eastern side of the border but was advised there was nothing out of the ordinary happening.

The operators twirled the tuning knobs on their sets, switching aerials and filters and cursing under their breath as the receivers remained stubbornly silent

The minute hand approached the 30 minute marker on the set room clock and many of the operators were growing noticeably pale and nervous, when suddenly, a loud chirrup was heard, breaking the silence. An operator near the end of the room raised his hand and called out a frequency. The Supervisor tuned to the frequency and almost immediately the chirping sound, so typical of Russian transmitters was heard, repeatedly sending a call sign and a succession of V's, (the letter V in morse code is ...- / didididah) giving the units/outstations belonging to his net the chance to tune in to the new frequency.

Another hand shot up, an operator claiming to recognize the hand of the Russian operator thus possibly identifying the unit concerned. DF and RFP was immediately called for and the signal frequency was switched through to all DF stations from situations as far north as Scotland and as far south as Cyprus and locating aerials were immediately swinging around to obtain maximum signal strength and bearing of the transmitter. Within two minutes the transmitter and location had been positively identified.

Slowly, one after another, more Units were located on new frequencies and their call signs noted. After a few hours of concentrated effort, the most important units were discovered and identified and there was no indication of any units moving from their known locations. Calm slowly descended over the set room once again. The cook house trolley arrived and the Operators mugs were filled with piping hot cocoa. 151 Troop were stood down and went off to their beds, grumbling about the lost hours of sleep, and the status lamps switched back to green.

It was never known why the Russians had imposed the unusually long Radio silence. It was assumed they were testing our reaction or maybe the efficiency of their own radio discipline. Experience showed that the Russian operators, especially in the lower echelons, were poorly trained but there was no certainty about this. However, for those experiencing it, it was a reminder of just how serious the cold war was. It also showed how quickly the boredom of hours of listening to Russian radio operators (sending practice messages to keep their frequencies open) could change almost instantly to a state of high alertness.

Michael Simpson
Corporal
Special Operator, Royal Corps of Signals
National Service 1959 - 1961