In the July, I left school aged 18 and joined the WAAF at ‘Adastral House’, Kingsway, London. Thus began a very exciting and frightening 5½ years. I found my way to the reception depot at West Drayton to be kitted out, lectured, drilled, with great emphasis on good hygiene! Then my training as a Clerk S.D. (Special Duties) began; but first - sign the “Official Secrets Act” and ordered not to write a diary. I was sent for a week to a place near Leighton Buzzard to learn to plot. We lived in a workhouse on the first floor, access by an outside iron staircase and slept in a dormitory. The ablutions were primitive — a line of sinks with small lead bowls chained to the wall; lavatory doors didn’t shut - and a bath was a rare event. We marched to a large building to train. The whole building was covered with camouflage netting with trees and figures of lambs sticking out skyward: We learnt to plot on a replica of fighter command plotting table and were kept there, not allowed to stray; everywhere else was secret. I realised later that it was 60 Group HQ for radar.
Posted then to Digby (near Lincoln), a fighter sector station in 12 Group. So 3 weeks after leaving school, I was plotting the Battle for Britain from the safety of Lincolnshire. The plots came thick and fast and it seemed beyond belief that 100 plus raids were attacking Kent and London. We could not understand how we were getting plots from over the sea, and only later discovered the secret of the R.D.F. Coastal Chain (radar). As a break during the day we would be sent in turn up onto the flat roof of the Ops. room to skip for 10mins. Up there was a good view of dispersal with the aircraft taking off and landing. We had two Canadian squadrons of Hurricanes.
In October the raids over the Midlands kept us busy: I was on the telephone line to the observer Corps man on the night of the first raid on Coventry. He said he was sitting with water up to his ankles. Warning of the raid was received about 2 hours beforehand, when the RAF sergeant supervisor stuck a strip of plaster on the plotting table to indicate the route that the bombers would take and they did. Our Beaufighters were on patrol, but too few and the job was overwhelming. We worked on a shift system, different every day and night. We were bombed and machine-gunned at times, as were the bomber stations nearby.
The first Ground Control Interception (G.C.I.) Stations were at Sopley (see left) and Ventnor on the Isle of Wight and in early 1941 Digby had it’s own GCI station at Orby near Skegness.
The plotters were sent two at a time for a trial period and were either retained or returned to Sector Ops. We worked in a small trailer in the middle of a field. Working conditions were very cramped, the consoles holding the two cathode ray tubes being very large.
The “plan position indicator” at last gave us instant plots although the blips would often fade and the controller had to guess where the bomber had gone and rely on dead reckoning. The second tube gave height and range but was very difficult to read and work out on a chart. Two airmen underneath in a shed bicycling on a fixed frame rotated the aerials through 360 degrees manually — it seems incredible now!
We lived in “Civvy Billets” spread through the village. At night in the dark, I had to walk to the village square to catch the transport to work and on the way I passed fields and cows loomed out of the darkness and moo-ed at me — gave me quite a fright! There was no entertainment or social life at all except for an occasional “hop” in the village hall with the local people. The winter of 1941-1942 was very cold, the freezing winds came from Siberia and swept across Lincolnshire and there was no heating at work and only a kitchen fire in the billet.Our job (2 W.A.A.F. officers) was to work out the courses for the Spitfires to rendez-vous with the bombers en route, bearing in mind the changing wind speed and direction as they climbed. We were then taken to dispersal to compare our courses with those of the Wing Commander and hear his briefing. Then we stood on the end of the runway and watched the 24 Spitfires take off in threes — one on the runway and two either side on the grass, form up and then set off on course. It was a simply marvellous sight against a clear blue sky and something I shall never forget (see right). After that back to the Ops room to watch the progress and very successful operations they proved to be and very necessary.
For the next course, a private house called “Woodlands” close to Fighter Command H.Q. at Stanmore had been taken over and turned into an “Ops”; a sort of combined Group Ops and Sector Ops with the back garden turned into sky! We took turns at all the jobs including ordering and scrambling the fighters on patrol and controlling interceptions. Outside the lawn set the battle with old Wall’s ice cream vans (icebox on wheels propelled by man on cycle) becoming Spitfires and those on the course becoming pilots and cycling to the beat of a metronome with radio contact from the ops room giving instructions. Airmen walked about being the target. A shield on the “Wall’s” van prevented us from seeing the airmen, but a slit in the shield allowed us to see the feet of the airmen and that was “Tally ho”. All this to scale and quite incredible. Also we had lectures, tests, voice tests, R.T. procedure and exams, and visited 12 Group H.Q. at Uxbridge.
Finally on to the final course and the worst of them all, 4 weeks of an intensive, concentrated scary course at a G.C.I. at Easthill near Luton. It was winter, so long hours of darkness in which to do practice interceptions. Lectures during the day when the importance of knowing compass bearings accurately was drilled into us. We practised on a simulator at first, then the real thing with instructors breathing down our necks, and very frightening it was; and more so because the pilots were under training too. The timing of giving orders was very exact as given too early might put your fighter in front of the target (not desirable) or given too late meant a stern chase and the fighter never able to catch up. It was such a small area in which to operate and too close to London where the guns were allowed to fire at anything unidentified under 20,000 feet! No time off and very exhausting — no weekends in wartime! I think there were 8 of us. 2 W.A.A.F., 3 R.A.F. and 3 Americans. The Americans failed, their Alabama drawl meant they were too slow giving orders. An interception should take only 3 instructions: general direction, cut off and turning onto the target’s course 2 miles behind, when the pilot’s radar should take over.
So I returned to Trimley as a fully qualified controller, and now lived in a house taken over as an R.A.F. mess. The patrols continued, and if no enemy activity we did practise interceptions all night with 2 mosquitoes — separating the a/c (aircraft) to set up another run was difficult. The R.T. (radio transmitter) “packed up” quite often, and very worrying if the pilot was on an easterly course — and such a relief when the a/c turned around. We had much improved radar now.
A new Air Ministry Order came out saying “W.A.A.F. Controllers on final type G.C.I. Stations to be given air and navigational experience” — i.e. allowed to fly. So I went up in a Beaufighter, an Anson and a Lysander. Impossible to fly in a Mosquito as there was no room for a 3rd person — room for pilot and observer only.
The patrols and the escort duties continued and the troops assembled round the coast and 20 miles inland. Security was at its utmost and in our off-duty time officers had to censor all the mail leaving the camp. There was a feeling of great expectation and nervous tension in the run up to “D” day. Then the “Overlord book” arrived and was guarded day and night by armed R.A.F. officers. Numbered marker pegs suddenly appeared at intervals on the main road between Ipswich and Felixstowe and a few days later army vehicles and tanks filled the entire distance and took up their allotted places. When the weather deteriorated and the invasion was delayed the long convoy was trapped and had to live on their emergency rations for over 24 hours. Eventually the convoy moved on, embarking from Felixstowe docks on June 6th.
We had been warned about the flying bomb, but it was still a shock at dawn about 10 days later when plots appeared on the plotting table and the plotter shouted “Diver, diver, diver” (the codeword) and we all shot to attention and suddenly the plots ceased and we realised what had happened. These bombs crossed the south coast heading for London, but soon they were crossing the east coast too as flying bombs were released from German aircraft over the North Sea. Over Felixstowe and then over our heads and very attractive they were too with their belching flames, that is until the engine cut out and we dived for cover. The coastal guns were very successful in shooting down the bombs, but difficult for fighter aircraft as the bombs were faster (see left: Spitfire tipping a V1). We were very busy as the battle around Caen was fierce and took longer than expected.
Ground Controlled interception (GCI)
This is air defense tactic whereby one or more radar stations or other observational stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic was pioneered during World War II by the Royal Air Force with the Luftwaffe to follow closely. Today, GCI is still important for most nations, although Airborne Early Warning and Control, with or without support from GCI, generally offers much greater range due to the much more distant horizon.
Today the term GCI refers to the style of battle direction, but during World War II it also referred to the radars themselves. Specifically, the term was used to describe a new generation of radars that spun on their vertical axis in order to provide a complete 360 degree view of the sky around the station. Previous systems, notably Chain Home (CH), could only be directed along angles in "front" of the antennas, and were unable to direct traffic once it passed behind their shore-side locations. GCI radars began to replace CH starting in 1941/42, allowing a single station to control the entire battle from early detection to directing the fighters to intercept.
In the original Dowding system of fighter control, information from the Chain Home coastal radar stations was relayed by phone to a number of operators on the ground floor of the "filter room" at Fighter Command's headquarters at RAF Bentley Priory. Here the information from the radar was combined with reports from the Royal Observer Corps and radio direction finding systems and merged to produce a single set of "tracks", identified by number. These tracks were then telephoned to the Group headquarters that would be responsible for dealing with that target. Group would assign fighter squadrons to the tracks, and phone the information to Section headquarters, who were in direct contact with the fighters.
Because the Chain Home radar stations faced out to sea, once airborne intruders had crossed the British coast they could no longer be tracked by radar; and accordingly the interception direction centres relied on visual and aural sightings of the Observer Corps for continually updated information on the location and heading of enemy aircraft formations. While this arrangement worked acceptably during the daylight raids of the Battle of Britain, subsequent bombing attacks of The Blitz demonstrated that such techniques were wholly inadequate for identifying and tracking aircraft at night.
Experiments in addressing this problem started with manually directed radars being used as a sort of radio-searchlight, but this proved too difficult to use in practice. Another attempt was made by using a height finding radar turned on its side in order to scan an arc in front of the station. This proved very workable, and was soon extended to covering a full 360 degrees by making minor changes to the support and bearing systems. Making a display system, the "Plan Position Indicator" (PPI), that displayed a 360 degree pattern proved surprisingly easy, and test systems were available by late 1940.
Starting in 1941 the RAF began deploying production models of the GCI radar, first with expedient solutions, and then permanent stations. Unlike the earlier system where radar data was forwarded by telephone and plotted on a map, GCI radars combined all of these functions into a single station. The PPI was in the form of a 2D top-down display showing both the targets and the intercepting night fighters. Interceptions could be arranged directly from the display, without any need to forward the information over telephone links or similar. This not only greatly eased the task of arranging the interception, but greatly reduced the required manpower as well.
As the system became operational the success of the RAF night fighter force began to shoot up. This was further aided by the introduction of the Bristol Beaufighter and its AI Mk. IV radar which became available in numbers at the same time. These two systems proved to be a potent combination, and interception rates doubled every month from January 1941 until the Luftwaffe campaign ended in May.
The Germans were quite slow to follow in terms of PPI and did not order operational versions of their Jagdschloss radar until late in 1943, with deliveries being relatively slow after that. Many were still under construction when the war ended in 1945.
At the going down of the sun, and in the morning we will remember them. - Laurence Binyon
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Last Modified: 08 November 2014, 11:34