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Recollections of the USAF Project

Page history last edited by Alan Hartley-Smith 1 year, 11 months ago




These are recollections by David Samways, with those of Hugh Kendall, Norman Whitehead and Bob Mountfort added. See also credits to others at the end.




The highest profile site was at Fylingdales in Yorkshire since this was the end point of the North Atlantic Radio System (NARS) linked through a series of tropospheric scatter stations to the Distant Early Warning (DEW) line system in the US.  Fylingdales was also a strategically important ballistic missile early warning system (BMEWS) site.  Later, Martlesham Heath in Suffolk was connected to Fylingdales via a tropospheric scatter link.  The ‘golf balls’ as they were known, were replaced in 1992 when the Solid State Phased Array Radar became operational.


The communication system comprised many stations; the northernmost terminal being Fylingdales, the southernmost being at Ringstead in Dorset (tropo link to Spain) with the easternmost being at Longfosse near Boulogne-sur-Mere in France.  Each of these ‘terminal’ stations - Marconi HM510s - comprised a transmitter and receiver with a baseband connection to local equipment supplied by others.  These terminal stations were interconnected via many microwave ‘repeater’ stations – Marconi HM560s - located approximately 35 miles apart line-of-sight.  Each of these comprised two receivers, two transmitters and two antennas (one for each direction) with the two interconnected at baseband level.  Repeater stations also had the ability to provide local access at the baseband level for both voice and data.




Pre-installation phase


Bob Mountfort worked in Marconi’s Installation Drawing Office (IDO) where his major responsibility was to prepare the drawings for each site.  Working from grid references supplied by the network planning people, and using the Ordnance Survey maps of the time, these could be translated to longitude and latitude.  Thus the bearing to each adjacent station could be determined taking into account the difference between magnetic and true North, necessary for compasses (GPS wasn’t available then!).


The next step was to prepare the detailed site drawings; concrete bases for the trailers (or buildings), aerial masts, feeder assembly supports and any other ‘non-standard’ bits and pieces such as brackets to hold the antenna systems. Although standard aerial masts from suppliers were used wherever possible there was always the need to make local adaptions to meet site requirements.


Another key activity of the IDO was to provide the design for the equipment trailers which were made in the UK.  The first job was to change the 5th wheel coupling to conform to US standards because the prime movers to be used were US tractor units.  The equipment racks were fitted to the floor using rubber cushion mounts and also stabilised from the top.  All wood used in the trailers had to be fire-proofed.  Hugh has commented - My definite recollection is that the trailers were taken to site by BRS (British Road Services) tractors.  Two of these were modified for the job, as the trailers had American standard air brakes, which means that air is applied to put the brakes on, which means in turn that air failure means crash.  The British standard is - or at least was - the more logical opposite.  I was told this by one of the BRS drivers, bringing one of the trailers to site.  He could have been having me on for all I would know, but I rather doubt it.  The final phase prior to delivery was to have each trailer tested in a special military approved chamber operating over a temperature range, if Bob remembers correctly, of ±40oC.



A typical site


Most stations were provided in a semi-transportable container-like vehicle, called trailers, positioned at key geographic points to maximise the line-of-sight required of a microwave system operating in the 4GHz range.  They were positioned on a bed of concrete and adjacent to an aerial mast.  These vehicles were self-contained and had an auto-start diesel generator set, located in a separate semi-transportable vehicle, in case of failure by the public GEGB grid.


Other stations would use a conventional but small building with basic facilities such as a kitchen, toilet and so on.  Fylingdales was a special case because of its security and the fact it housed much other equipment as well.  Interesting Fylingdales had its own power station using six (I think) Napier Deltics opposed-piston diesel generators and only using the CEGB as a back-up!


The aerial system used a parabolic dish mounted at the base of the tower (about ten feet from the ground) radiating upwards to a passive reflector further up the tower (refer picture) angled at approximate 45 degrees.  The advantage of this configuration was to keep the feeder cable as short as possible and for ease of servicing especially in inclement weather.  In addition the passive reflector required no power and minimal servicing.  The repeater stations had two sets of parabolic dishes and passive reflectors.


The HM500 series used two key components DET29s and Travelling Wave Tubes.


The DET29 was the last in the line of dull emitter triodes from Marconi-Osram Valve (MOV). The DET29 valve was a specialist microwave co-axial power valve.  It would produce 1.5 Watts at 3.8GHz, and gave useful output up to 5GHz.  They were pretty well proven devices because the BBC used them in their 4GHz communications systems. 


The Travelling Wave Tubes (TWTs) however were very new products from the English Electric Valve Company and formed the final output stage in the transmitter section of the HM500 series.  From memory the model was N1001 and generated 15 watts.  They were not the easiest of items to tune and also got very hot.



****  Any other major characteristics of the equipment?



My early days


I remember this well.  By the time I came on the scene all the system network and design had been completed and the installation phase had started.  There were a number of teams, three from memory, to complete the installation and commissioning.  I had just finished the HND Sandwich course at the Mid Essex Technical College having achieved a good education in electronics, engineering and other useful subjects such as thermodynamics…..I was given a car and sent out to one of the USAF sites in Hertfordshire to meet my Team Leader Norman Whitehead.  My first job, wait for it – was to mix concrete.  Well suited to my qualifications (really?) but stood me in good stead for later married life!  The concrete was to support the many legs supporting the aerial feeder assembly and each one was something like 6ft high and 18 inches square.  Now that is a lot of concrete to mix!


It became evident to me very quickly that our jobs entailed most things known to man;


  1. Project management - preparing the site, supervising construction of the building, antenna mast and diesel generator, and physical installation of same
  2. Cabling – full cabling of power and signal to and from connected equipment.  This had to be done neatly in cable trays and had to pass the keen eyes of the USAF inspectors! 
  3. Antenna system – installation of the base-mounted parabolic dish and the coaxial waveguide feed to same, and installation and alignment of the passive reflector at the appropriate height up the mast
  4. Commissioning on-site equipment - each receiver and transmitter had to conform to stringent testing regimes
  5. Commissioning link(s) – the challenging part of this activity was to align the dish and passive reflector to ensure the receiving station measured the maximum signal strength.  This was not always the best job because ‘someone’ – usually me – had to scale the mast in all weather conditions, and carrying essential tools for positioning and locking the reflector.  We had no safety harnesses then and the only way to communicate with ground was by shouting! 
  6. Diesel generator – this required a full test from simulated power failure to resumption of communication; from memory typically a couple of minutes. 
  7. Site hand-over tests – these ranged from two days to thirty days (in the case of Fylingdales 


This was typically what had to be done at each site.  As said earlier most of the stations were in semi-transportable vehicles and our ‘site office’ was typically a caravan.  Others were in more conventional buildings which spoilt us because we had access to facilities such as toilets and food preparation facilities.


In hindsight I have to say that this was brilliant on-the-job training and the Marconi Company has to be congratulated on providing the infrastructure for this to have occurred.


I clearly remember we had a visit from an entourage of USAF personnel including a 4-star General when I was told in no uncertain a manner that firstly I was a party to the Official Secrets Act and secondly that cameras were forbidden; and if found would be confiscated and destroyed on the spot.  I didn’t take any photographs – more to the pity!



Some recollections


RAF Chicksands was in Bedfordshire and was known as a secure communications base.  One was photographed going in, photographed going out and then the two compared.  It was that tight.  On one occasion soon after arriving there I wanted to go to the toilet which was in a hut a hundred yards away.  Halfway there a jeep comes tearing up, the military person got out complete with dog and gun and asked me brusquely me what I was doing.  “Going to the toilet” seemed an appropriate response only to be told that “you ain’t going nowhere bud”.  Nevertheless I was escorted to the toilet complete with dog and armed guard.


It was rumoured that at this base all remaining toilet rolls were destroyed each night.  I do not know if there was any truth in this.


RAF High Wycombe was a reasonably secure base but it appeared that illicit parking was the major security risk.  I found this out the hard way by finding a sticker about one foot by 18 inches on my windscreen straight in front of the driver.  It would not have been possible to drive with this on.  And, I couldn’t get it off.  It probably took some 30 minutes to get enough scraped off to be able to drive away.  Since that time I have always wondered what was in that glue – maybe the forerunner of Superglue?


RAF Alconbury had a delightful memory.  John Price, John Brown and I were commissioning the station and staying in the Alconbury Motel just across from the base.  During dinner John Brown decided to have apple fritters for desert.  They arrived and to our astonishment he went ballistric and exclaimed “I have had many hundreds of apple fritters in my time and never ever had any with cream on”.  During this process most of the cream sprayed from his spoon over the walls!


Near Pocklington in Yorkshire was a somewhat isolated hamlet, called Garrowby Hill on Barmby Moor, where we built a standard repeater station, one station down from Fylingdales.  The time came to connect the three phase power from the road.  It had been snowing overnight and there would have been a couple of feet of snow.  To our surprise the electricity people turned up and proceeded to dig a six foot square hole to expose the street cable.  Their job was to Tee-in the cable from the repeater station.  This they did live - one phase at a time.  Not for the faint hearted let me tell you!


In the network design phase one of the outputs is the exact location of each station.  Since many of these are repeater stations they are typically away from civilisation.  On this particular site, somewhere in Kent, after it was installed and being commissioned, it was found that the signal faded unacceptably between it and the next repeater apparently randomly.  It was subsequently found by inspection of the line-of-sight path that a gasometer was responsible.  This necessitated having to move the station a mile or so sideways.  Although time consuming that wasn’t the main repercussion.  The farmer, whose field it was in, asked for the four huge concrete blocks (**** size to be checked) that used to support the mast be removed.  This challenge was discussed in the pub that night.  The result – call in the bomb disposal unit.  This gave them an ideal opportunity to create a training program for their staff and they successfully exploded each block into smaller pieces which could then be taken away.


RAF Fylingdales has to have been the experience of the lifetime not only because the 1962 / 1963 winter was the worst in 50 years but the somewhat amusing / frustrating incidents I can clearly recall some 50 years later.


Characterised by its 3 radomes Fylingdales was a most secure location primarily because of its role in early warning.  During the commissioning phase of the radar equipment – not Marconi supplied – it was noticed that birds were flying around the radomes, from memory, in a counter-clockwise direction.  This confused all military personnel and Peter Scott (later knighted), the then expert in English wildlife, was called in for his take on it.  I believed he was as confused as others but what was quite clear was that when the radar was switched off the birds vanished.


As said earlier the weather during the 62 / 63 winter was very severe in Yorkshire.  For a number of weeks we had 15 feet or more snow and the ploughs were working full time to ensure vehicular access was maintained.  For a few days this was not possible and food was running out.  I clearly remember for two days running the only food left was baked beans but plenty of tea and coffee.  The Post Exchange (PX) had to close.  However, helicopters came to the rescue and our food chain had been resurrected.  We were also very thankful that, since we had our own power plant, we were always warm when sleeping in make-shift rooms.


At this time I was courting, and occasionally I managed to get a break to see my fiancée Doreen, who I later married and still am!  On one occasion I managed to hitch a lift on the 2.00am snow plough to have a few days off to see her – very dramatic sitting with the driver many feet above the ground with the snow being hurled out from both sides.  I remember asking how he knew were the road was and whether there were any cars stranded underneath.  His answer was brief “I just guess and pray there aren’t”!


Back to work in the snow work still had to be done.  A trench had to be dug some 50 yards in length to take power cables out to the mast area.  However, the union decided that because the snow was more than the 6 inches deep that work could not commence.  Their contract was terminated and we used local contractors from Whitby to complete the job.  By the time the court case came around I was long since gone!


Brian Bowsher, a fellow colleague, reminded me of a similar incident when the Marconi Contracts manager ticked him off for stopping the riggers climbing the mast even when the passive reflectors couldn’t be seen because of the snow storm! Hugh commented - I'll bet that manager was Gerry Seear.


Lastly, just before I finally left Fylingdales there was a somewhat informal handover dinner with representatives from the USAF and Western Electric where my education was finally completed.  It seemed in some cases that using knives and forks were optional!


The stations listed below form the total network and their interconnections are shown on the network map here.


Northern link

T  Fylingdales, Yorkshire (Northern endpoint) - for more photographs click here

R  Garrowby Hill, Barmby Moor, Yorkshire

R  Kirton Lindsey, Lincolnshire

R  Spitalgate, Lincolnshire

R  Crowland, Lincolnshire

T  Alconbury, Cambridgeshire


North East link

T  Mildenhall, Suffolk

R  Lakenheath, Suffolk

T  Martlesham Heath, Suffolk (NE endpoint)

R  Great Bromley, Essex

T  High Garrett, Essex

T  Barkway, Hertfordshire

R  Bovingdon, Hertfordshire


South East Link

T  Longfosse, France (SE endpoint) - decommissioned in 1966

R  Swingate, Kent

R  Dunkirk, Kent

T  Cold Blow, Kent

T  Botley Hill, Surrey


Southwest link

T  Ringstead Bay, Dorset (SW endpoint)

R  Portland, Dorset - refer Wikipedia entry here

R  Bulbarrow Hill, Dorset

R  Dean Hill, Wiltshire

R  Golden Pot, Hampshire - for more photographs click here

T  High Wycombe, Buckinghamshire

T  Hillingdon, Buckinghamshire – central hub for the UK


Western loop 

R  Greenham Common, Berkshire

T  Croughton, Northamptonshire

R  Daventry, Northamptonshire

R  Chelveston, Northamptonshire


Other spurs

T  Chicksands, Bedfordshire

T  Ruislip, Middlesex


     T  =  Terminal site

     R  =  Repeater site



Recollections by Hugh Kendall


Fylingdales.  Everyone who was near that place in the so-called Spring of 1963 has something to say!  I was working there with Norman Whitehead, and we eventually decided when things got too bad to 'break out'.  We started trying to walk along the road, and soon realised this was totally impossible.  The last straw was when we tripped over something which turned out to be the exhaust pipe protruding past the top of a buried bulldozer.  So we turned back, and soon bumped into a RAF Mountain Rescue Team, who were trying to assist would be escapees.  They recommended us to scramble down the slope to the west, where the Pickering to Whitby railway line still ran in the valley.  We were told that the train drivers had all been told to stop and pick up anyone who signalled for a lift!  We did this, and it was amazing how the wind dropped and the snow lessened as soon as one got below the level of the moor.  Anyway, not long after we got to the bottom, a train came along and duly stopped when we waved our thumbs at it.  A door opened and we hopped aboard, and I acn still feel the heat in that train.  It was wonderful./  That was the only time I have ever thumbed a lift on a train.


Garrowby Hill.  The only oddity I remember about that is that one of the reflectors rather embarrassingly came off in a gale, and blew quite a way down the farm track.  Fortunately nothing else got damaged.


Kirton Lindsey.  I remember late one day for some reason certainly not planned by management, several of us found ourselves gathered there.  We all decided to stay the night in Gainsborough, and booked into the same hotel there.  One of the party was Jack Martin, and by some mistake he got booked in as Martino.  We all went along more or less together, and walked into the hotel carrying our large suitcases.  Everyone had a large suitcase, as the opportunities for getting laundry done were very limited.  Anyway, seeing this crowd, the receptionist asked 'are you a band'.  Looks of slight surprise, and 'why'?  I thought you might be Martino's travelling band.  I believe Jack got called Bandmaster for quite a while.


Alconbury had the only helpful and pleasant American Serviceman I remember on the whole system, named John Bye.  The bad news about Alconbury was that on leaving one was at risk of being jumped on by Customs & Excise looking for illicit American Duty Free Cigarettes.  As if we would.  It never happened to me, but I know it did to some.


Very little to say about the Ringstead Link.  I do remember that the Page engineer in charge of building the Tropo at Ringstead was Stan Heward, who ended his career as Manager of Marconi's I & M Dept, and who died last year.


The Longfosse link again not much.  Botley Hill Farm was quite close to the BBC monitoring station at Tatsfield.  I remember them contacting me in some fear as to whether we were going to blot out their reception.  I got invited to look ound their establishment, which was most interesting.  The picture I sent of Botley Hill Farm does justify it being called a farm.  Actually I suspect the picture is of the Power container, and the straw was to keep the noise away from the cafe.  Fire risk what's that.  Swingate to Longfosse, I seem to remember that the path signal strength came and went with the tide.



Recollections by Norman Whitehead


My introduction to USAF was being dropped off alone at some repeater station in Lincolnshire on the Northern Link, I can't remember which one, prior to scheduled link commissioning tests.  It quickly became apparent that there was some fault at ‘my’ station, which I determined necessitated a DET29 change.  Never having replaced a DET29 before, it is a tribute to the clarity of the handbook instructions that I was able to carry out this somewhat complicated task successfully and restore the link in time for the tests to proceed.


At Garrowby Hill the equipment was moved from a trailer into a permanent building.  After the re-installation was complete a mysterious intermittent fault began to appear.  Sometime during the night the signal on one of the links would be lost, and then the signal would return later in the morning.  The cause of this baffled everyone on site and in Chelmsford for at least a week.  To cut the story short, someone eventually demonstrated that the problem was caused by a poorly soldered joint in an antenna feeder cable.  The feeder cable used was air-spaced (spiral PTFE insulation) with an aluminium tube outer and a copper tube inner conductor.  The inner conductor was terminated using a 'bullet' which was soldered into the tube.  This was winter, so during the night the temperature dropped, the copper tube contracted more than the aluminium tube, sufficient to pull the bullet out of the connector.  In the morning, when the sun warmed up the feeder cable, the bullet reconnected and the signal was restored!


While working at Hillingdon I witnessed a USAF 'maintenance' session.  USAF personnel removed, one by one, all the valves in the equipment and checked them in an Avo Valve Tester.  Those that met the Avo specification were put back, and the others (by far the majority) were dumped in a large bin and replaced with new valves.  Naturally, after this treatment, levels were all over the place and the entire equipment had to be re-aligned!


David mentioned escaping from Fylingdales by snow plough (leaving his Marconi car on site).  This had an unintended side effect; as he drove back to Fylingdales in his own car we now had more cars on site than there were people to drive them.  How do you get rid of a surplus car?  I can't remember how this was resolved.  I assume David must have driven his own car home at some stage and returned by public transport to pick up the Marconi car.  [Ed: David can't remember either but the girl friend probably had something to with it - as they do.  And still married to her!]


Recollections by Bob Mountfort


For my part as a young  lad in the Installation Drawing office (IDO PE&ID) I drew up many of the  mast and reflector installations on various sites. Many ZipUp Triangular towers were used. I did the siting orientation and  concrete bases for so many. I also worked on the container interior layouts for the racked equipment. Basil Francis was the IDO man in charge. Along time ago. As far as I recall there was a tropo feed from Spain through to the UK, and the final UK sites were up in Scotland where they launched across the Atlantic and maybe (odd recollection here) linked up with the DEW Line. Also a memory jog, my mind says Holy Loch, but that could have been when we were building an ELF Transmitter building for Mr. MaCarthy.

Sites near here were Lakenheath, High Garrett, Barkway?, RAF Chicksands (where I had lived as a child),  Rivenhall (I think)  




I should also like to thank Brian Bowsher, Bob Mountfort and John Price for their inputs and helping to recollect the events which occurred half a century ago.  Unfortunately, because of the time lapse we have been unable to contact any of the numerous other Marconi personnel who were very much involved in this contract’s implementation.







Comments (1)

David Samways said

at 1:32 pm on May 9, 2015

List of sites slightly revised and denoted as Terminals or Repeaters

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