Isle of Man ATC in the 1950s
Island Images
 ATC in the 1940s          ATC in the 1960s
Air Traffic Control Centres
RAF Air Traffic Control Centres
I'd mentioned the Flying Training Control Centre established by the RAF at Ramsey, Isle of Man, in the 1940s ATC section but there were others set up from the 1940s to 1950s.  The RAF seemed to operate in a very splintered way for control, with each command only interested their own aircraft, as FTK Bullmore had found out when trying to set up the Flying Control Liaison Officer positions in Fighter Command operations rooms and the Ramsey FTCC was only concerned with training aircraft from a selected ten airfields.  However, by the early 1950s a more universal approach to providing services seemed to be taking hold with five Air Traffic Control Centres set up at Prestwick, Preston, Watnall, Gloucester and Uxbridge, each with a defined area of operations, as shown on the map below.
RAF Air Traffic Control Centres
Map of areas defined for each of the
RAF ATCCs in 1951
An interesting extract from the 1951 RAF 'Radio Facilities Charts UK' handbook states the 'Aim of the Air Traffic Control Service' as follows:
'The primary objective of the Air Traffic Control Service is to promote the safe, orderly and expeditious movement of all aircraft',
achieved by:
Preventing collisions between aircraft and between aircraft and obstructions
Providing advice and information for the safe conduct of flights
Providing distress aid and diversion facilities
Alerting and assisting search and rescue authorities.
For comparison the current UK definition of Air Traffic Control Service, dating from 2012 is:
'A service provided for the purpose of preventing collisions between aircraft, and on the manoeuvring area between aircraft and obstructions; 
and expediting and maintaining an orderly flow of traffic.
The RAF ATCCs didn't provide an Air Traffic Control service as we generally think of it today, military pilots were advised to avoid Controlled Airspace is possible, but if they needed to enter it, contact the (civil) Air Traffic Control units responsible.  An interesting statement from the 1951 book is that:
'In the United Kingdom, communications with the ATCCs is not mandatory, but recommended'.
So pilots could check in with the appropriate ATCC for the area they were flying in and make regular position reports.  The ATCC would keep track of the flight and would take 'overdue action' if a position report wasn't received when expected.  They would also provide weather reports when requested and advise on diversion airfields if they were needed. Presumably they would also advise pilots on other 'known' traffic that might be deemed to be a potential hazard.  The RAF ATCC used HF and VHF radio communications, but the ATCCs were not equipped with radar sytems.
Meanwhile, after much debate between the experts and politicians, a system for controlling civil aircraft had been devised.
Civil Area Control - Start of the UK Airways System
After considerable deliberation, the UK government had decided on the future of Air Traffic Control in the UK. Corridors of controlled airspace 'Airways' would link the major airports and be defined by radio beacons at strategic locations. The first airway brought into use was 'Green One' from Strumble on the south-west Welsh coast, via Bristol to London. Intended for use by transatlantic flights it came into use on 1st August 1950. The second phase included more routes around the London area, with phase three being routes northwards to Scotland and Northern Ireland. This included airway 'Red Three' which had a segment from Wallasey on the Wirral peninsula, over the Isle of Man and onwards to Belfast. Initially the airways applied to aircraft flying under Instrument Flight Rules only, aircraft flying under Visual Flight Rules were free to fly where they wished, including across or along the airways! Subsequently, with higher performance passenger aircraft coming into use, the Airways were restricted to IFR flights only.
National Airways Plan
Phase Three
Showing Airway Red Three overhead the Isle of Man. M/F Range beacon at Cregneash with Markers at Portaferry, Dean Cross and Wallasey.
(Diagram courtesy Flight Global)
To control the new Airways, Air Traffic Control Centres were set up in three locations, Scottish Control at Prestwick, Preston Control in northern England and London Control at Uxbridge, west London.  These were co-located with some of the existing RAF ATCCs, possibly for liaison purposes between civil and military but probably more because the required teleprinter and radio facilities were already there.  In the 1951 RAF Radio Facilities book, Scottish Civil is shown having a single VHF control frequency (120.3 MHz), Preston had two (118.5 & 119.3 MHz) and London had four (118.9, 120.1, 120.3 & 122.1 MHz). 
All of the centres had backup HF radios available for communications with aircraft not fitted with VHF radios.
Redbrae House, Scottish ATCC
Preston ATCC
Uxbridge ATCC
The initial radio beacons used were Radio Ranges and Fan Markers, a proven technology used in the USA and based on the German pre-war 'Lorenz' beam principle. The Radio Ranges operated in Medium Frequency band and so could be received on the radio sets as commonly fitted to aircraft of the day. The beacon radiated on four different legs, which were aligned with the airways. They transmitted an audible morse code 'A  - .' and 'N  . -' letters, if the aircraft was left of track the pilot would here the letter 'N'  in his headphones, if right of track the letter 'A'. When on track they would merge to a continuous tone. It must have been quite tiring!  There was a development to produce a cockpit instrument to indicate visually if the aircraft was to left or right of the track, the forerunner of later radio navigation instruments. The fan markers worked on a VHF frequency of 75 Mhz and were located at a distance along the legs of the beam and transmitted a single morse letter, which also illuminated a light in the cockpit as the aircraft passed overhead, providing a position fix at that point and indicate that it was time to tune in the next beacon.  In some places Radio Ranges were also used as an approach aid to an airport. The charts below show Radio Ranges, on the left is the London Control Zone in 1951 with three ranges and eight Fan Markers.  On the right is an approach chart for Prestwick Airport using the Radio Range there.  Click the small images for a larger version with more information.
The London Control Zone in 1951
Radio Range Approach Chart for Prestwick Airport in 1954
There is a good Wikipedia article on Radio Ranges, including audio demonstrations.
Another part of the 'Airways' system was establishing reliable VHF communications to cover the routes.  A network of radio transmitters and receivers was established around the British Isles, often on high ground to increase the range of the transmissions and Snaefell in the Isle of Man was one of the sites chosen, linked into the Preston Air Traffic Control Centre which would control the routes around northern England and the Irish Sea.
The Snaefell mast in 2018
Aerial view of Snaefell Summit in 2019
There is a short BBC documentary film about the Snaefell mast and the Airways communication system available in their archives:
BBC Film
A Radio-Range was established in the Isle of Man at Cregneash, operating on 391 Khz with an identification of 'MYI'  This radiated four 'legs', towards Belfast, Wallasey, Dean Cross (Cumbria) and Dublin with associated Fan Markers at Wallasey, Dean Cross and Portaferry.  There was also an non directional beacon (NDB) at Cregneash 'GCF' on 312.5 KHz, which was designed more for marine use, operating as part of an Irish Sea network on the same frequency and transmitting according to a set timetable, although still usable for air navigation.
The Cregneash Radio Range
'MYI' 391 Khz
Showing the four 'legs' of the range, two defining 
airway Red Three. The Isle of Man Control Zone also shown. At this point the other two legs point out into uncontrolled airspace, but 'Advisory Routes' were to follow.
Link to Wikipedia Article on Radio Ranges 
Advisory Routes
By 1956 additional Advisory Routes had been added to the Airways System radiating from the Isle of Man Range. ADR 157 went from the IOM northwards to Milleur Pt and catered for the Glasgow and Prestwick flights, ADR158 went from Dublin, via the IOM to Dean Cross and Newcastle and ADR159 went from the IOM to Blackpool. An Air Traffic Control service was provided to participating traffic only. Interestingly, the map shows ADRs along airway Red Three and Green Two, was this the changeover point to banning VFR flights along airways at times?
Control Zone Change
Also published in 1956, this RAF planning chart shows the Isle of Man Control Zone has been changed to a rectangular shape, dimensions
22nm x 10nm

ATC at Ronaldsway
A fascinating black and white film of Ronaldsway ATC has come to light and you can view it on YouTube.  Uploaded by Manx National Heritage it shows the day to day operation of Air Traffic Control together with a description of how the Instrument Landing Sytem works, which dates it to the mid or late 1950s.  Unfortunately there's no sound on the film which was apparently shot by Airport Commandant Eric Cheshire.  Ronaldsway ATC Film
Whilst Ronaldsway retained the Control Zone, the rules regarding its use had changed somewhat. Instead of 'QBI' being declared by ATC, it was now up to the pilot to decide if he could fly using the Visual Flight Rules (VFR) or needed to use Instrument Flight Rules (IFR). If operating under VFR, the pilot could proceed into the zone without permission, using the Rules of the Air to keep clear of other aircraft. If operating IFR he needed to call ATC and obtain a clearance into the Control Zone and obey ATC instructions.
Control Tower and ATC Signals Square - 1953
BEA Dakota by the Control Tower - 1950s
Control was carried out from the second floor of the tower, the Navy 'Watch Office' on the roof not appearing to be used operationally, probably due to insufficient space for Controller, ATC clerks, radio operators and Direction Finder operators who required to be in close proximity due to the ATC systems in use at the start of the decade. At first Control was by either Medium Frequency or VHF radio, with ground direction finders and radio reports from aircraft being the only means of determining aircraft positions. Flight Progress strips came into use in this era showing aircraft details and having control instructions written on them, probably required with the setting up of the airways and the need to record clearances issued by Preston Centre. The M/F services including the direction finding station were withdrawn from use on March 1st 1951 as more aircraft were equipped with VHF radios. A former Royal Navy FV5 VHF Direction Finder was installed on the airfield, this gave a remote indication of aircraft bearings directly to the controller on a CRT indicator in the Control Room, although changing the radio frequency used was evidently sufficiently complicated to warrant a log book entry every time! A Pneumatic Lamson Tube system was used to connect the different sections within the tower building, ATC, the Met Office and Teleprinters.
ATC Control Room - 1950s
Former RN 'Watch Office' on the roof
Enlarged view of the Control Desk
Airfield Lighting 'Mimic' on the ceiling
1958 Floor Plan of Control Room Area
Radio Aids
Ronaldsway was equipped with Medium Frequency Non Directional Beacon (NDB)  'GJE' (the old w/t radio callsign for Ronaldsway) operating on 322 KHz and SBA 'Standard beam Approach' on runway 27, also coding 'GJE', operating on 33.3 Mhz (the chart below in fact shows 38.6 MHz, so the frequency was probably changed at some point) with an Inner Marker beacon on 38 MHz. SBA was a development of the pre-war 'Lorenz' approach aid developed in Germany and installed at Croydon Airport in the 1930s. SBA gave similar audio indications to the radio range, providing what we now know as a Localizer approach to the runway. It could also provide a rudimentary glideslope indication on a cockpit instrument, the pilot choosing which of several paths to follow down. 
Radio and Navigation aids frequencies.
From an RAF Radio Facilities book dated December 1951
Radio Telephony/Telegraphy
Ronaldsway Approach 119.7 MHz
Ronaldsway Tower 118.7 MHz 3255 KHZ.  116.1 MHz (mil emergency) 121.5 (civ emergency)
Ronaldsway Homer (VHF direction finder) 119.7, 116.1 & 121.5
Jurby Tower 104.76, 117.9.  (also 118.7 for diversions from Ronaldsway)
Jurby Homer (VHD direction finder) 104.4,116.1 & 121.5
Met broadcast (from Preston) 404.5 KHz, 3953 KHz, 8942 KHz
Navigation Aids
Ronaldsway NDB 'GJE' 322 KHz
Ronaldsway Standard Beam Approach (SBA) 'GJE' 33.3 Mhz
Ronaldsway SBA Inner Marker 38 MHz
Isle of Man Radio Range (Cregneash) 'MYI' 391 Khz (with three remote Fan Markers on 75 Khz)
Cregneash 'Z' Marker 75 MHz
Cregneash NDB 'GGF' 312.5KHZ (Marine but available to aviation)
Douglas (Carnane?) NDB 'GGP' 291.5 KHZ (Marine but available to aviation)
Area Control
Preston Airways (civil) (c/w Morse, c/s 'MYP') 3980/3985 KHz, 4415 KHz
Preston Airways (civil) (AM voice) 118.5 MHz (FIR), 119.3 MHz (airways) 3270 KHz (backup to VHF)
Preston Centre (military)  (c/w Morse, c/s 'MYP') 3165 KHz, 4415 KHz
Preston Centre (military) (AM voice) 106.02 MHz, 116.1 MHz, 121.5 MHz
The Standard Beam Approach Procedure
The initial approach to the airfield could be made using one of several aids, probably mainly the 'GJE' NDB or by bearings from the ATC Direction Finding unit, descending to a height not below 3,900 feet.  Quite possibly, the Radio range at Cregneash could also be used. On arriving overhead the airfield the pilot would fly a course of 091 degrees outbound letting down to a height of 1,555 feet and after three minutes perform a 'procedure turn' to the right, to establish on the inbound course of 271 degrees. He would maintain the centreline by listening to the Morse code from the main beacon. If he was too far to the right he would hear a Morse letter 'N' (dash dot) and if too far to the left a Morse letter 'A' (dot dash).  On the centreline the two letters would merge together to give a continuous tone. Once established inbound, descent would be commenced at a rate of 400 feet per minute, flying at 120 knots, down to a minimum height of 300 feet. This could be maintained until passing overhead the Main Beacon, an Inner Marker beacon just inside the airfield boundary indicated that the runway threshold was just ahead.  If the runway was not sighted a missed approach was flown, climbing ahead to a height of 2,700 feet.
SBA Approach Chart for Ronaldsway
1954 Ronaldsway Landing Chart
Ronaldsway Airport 1954
Non-directional Beacon and Direction Finder Approaches
 There would have also been approaches published based on the 'GJE' NDB for both runways 27 and 09. The FV5 VHF Direction Finder could be used to provide instrument approaches to aircraft not equipped to use radio navigation aids, either a pilot interpreted 'D/F Approach' or a controller interpreted 'QGH Approach'
Chart for pilot interpreted D/F Approach
Diagram of controller interpreted QGH Approach
 Ballahick Radio Station
The Ballahick Transmitting Station - 1958
Inside the Ballahick Transmitting Station
Transmitter frequencies at Ballahick in 1958 were: 
1190 Khz (Point to Point & Emergency)
126.7 MHz Approach
121.5 MHz Emergency
 Instrument Landing System Installed at Ronaldsway
ILS was an upgrade on the previously used Standard Beam Approach systems.  It had three elements, the Localizer (LLZ) that operated on VHF frequencies (100 MHz) and provided lateral guidance along the final approach path, the Glideslope (GS) which used UHF (300MHz) frequencies and provided vertical guidance along the Localizer course, usually indicating a three degree approach angle.  Marker Beacons operating on low VHF (75MHz) provided position fixes at set distances from touchdown, up to three might be provided, the Outer, Middle and Inner Markers.  When the aircraft passed over them a light illuminated in the aircraft cockpit plus an aural tone if selected.  The Outer Marker was quite important as it co-incided with the point at which the aircraft should start descending on the Glidesolope, early ILS systems in particular could produce 'false Glideslopes' so it was important for pilots to know they were intercepting the correct one.  The was usually also a Non Directional Beacon associated with the ILS, which was where the procedure started from.
Diagram of an ILS system with three Marker Beacons
 By 1955 an ILS was commissioned on runway 27 at Ronaldsway. It would appear that initially only the Localizer (LLZ) was installed and operational. This was likely due to the need for the Outer Marker, which would normally be installed directly beneath the final approach track between 4 and 5 miles from the runway, for Ronaldsway's runway 27 this would have put it in the sea! An Inner Marker beacon was however installed close to the threshold of the runway. In the 1960s a solution was found and an offset Outer Marker beacon was placed on Santon Head, allowing the Glideslope to be used.
ILS Outer Marker beacon at Santon Head
ILS Inner Marker Aerial 
The full ILS would give pilots an accurate indication of both lateral (Localizer) and vertical (Glidepath) position on final approach, displayed on a Course Deviation Indicator instrument in the cockpit. The Localizer aerial was at the far end of the runway with the Glidepath aerial by the side of the runway close to the touchdown point. With this precision system, landings could be accomplished in much poorer weather conditions than before. The SBA continued in operation for non ILS equipped aircraft.
ILS Course Deviation Indicator & Marker Beacon lights - Douglas DC3

RAF Jurby
Although RAF Jurby had closed in 1947, the airfield remained under care and maintenance and was re-opened in 1950 as No 1 Initial Training School, where prospective RAF pilots and navigators underwent an 18 week (later increased to 24 week) basic course covering such subjects as navigation, meteorology, aerodynamics and radio. Being a military unit, other important subject covered included drill, outdoor sports and leadership exercises. There was no flying training in the syllabus but some gliding experience was available using Sedburgh gliders. The 'Station Flight' operated an Avro Anson for communications purposes and possible also a DHC Chipmunk for air experience flights. Anson VM418 came to an unfortunate end on the 6th September 1953 when it crashed into Clach Ouyr, near Snaefell, killing all on board including the Jurby Commanding Officer, Group Captain Worthington and the incoming C.O. Wing Commander Fenton. In May 1953 the unit became No 1 Officer Cadet Training Unit.
RAF 1951 area chart centred on Jurby
Basic ATC services were retained at Jurby, the 1951 RAF Radio Facilities book showing that the airfield was available on Prior Permission Only Mon - Fri 0800 - 1630 and Saturday 0800 - 1200. Control was on 117.9 MHz with 104.76 MHz D/F by arrangement and Military Distress frequency 116.1 MHz available with D/F. Jurby had a light beacon available on request which would flash the letters 'JY' in red. Sodium Approach Lighting funnels were provided for all runways with electric runway lighting on 26/08 only.
Jurby entry in the Dec 1951 RAF Radio Facilities Charts Handbook
1951 Approach Chart for RAF Jurby
1951 Landing Chart for RAF Jurby
RAF Jurby was also available for diversion from Ronaldsway, in this case the NDB beacon was radiated on 358 KHz 'JY' and civil frequency 118.7 was manned for the diversions. This was the same frequency used for Ronaldsway Tower. A civil control team would be dispatched from Ronaldsway to provide the air traffic control, using the RAF control tower. Facilities were very basic, probably consisting of a radio set, flight progress strip board, clock and telephone.  In the Ronaldsway watch log of 26th July 1956 there is a note that a suggestion has been made to the ATCO i/c that radio recording facilities should be provided at Jurby as a result of the operations there on 8/7/56 as the 'written R/T log proved quite unsatisfactory'! The R/T log covering that date has also survived and backs this up, with six pages of radio messages recorded with a total of 43 aircraft movements between 0800 and 2200. It seems unlikely that the requested recorders were installed.
Enlarged section of RAF chart showing Jurby Airfield
ATC facilities in Jurby Tower
At least one airshow was held at Jurby during the 1950s, possible it was an annual event for 'Battle of Britain' Day.
I am indebted to Tim Harris for the pictures below, taken 1950 - 1952 when his father, Squadron Leader Malcolm G Harris DFC, DFM was either in command or most likely 2nd in command of the training unit.
RAF Jurby Airshow
Air Defence Radar - The Snaefell Radar Station
At the end of WW2 most of the extensive radar defence network that had been established around the United Kingdom was closed down and either dismantled or put on 'care & maintenance'. This included the stations in the Isle of Man (see 1940s pages for details). Defence planners had not anticipated another conflict for at least ten years and were somewhat take by surprise by the start of the 'Cold War' towards the end of the 1940s. It was realised that the UK was vulnerable to attack by Soviet bombers and attempts were made to resuscitate elements of the WW2 radar network, often without success, as was the case with the Dalby Chain Home station in the IOM. Technicians tried to restore operations 1949 but were unable to re-activate it.
The 'Rotor' Radar Plan
A new radar defence network code-named 'Rotor' was devised for the UK, using some WW2 vintage radar systems but also new ones then under development. The overall plan used the same principles of the WW2 Reporting and Control network with manual reporting of hostile contacts by radar stations through a 'filter' office, plotting on an operations table and fighters controlled by separate Ground Control of Interception (GCI) radar stations. Priority was given to the east and south coast of the UK as this was where the greatest threat was perceived, but 'Rotor 3' covered the west coast of the UK and this was where the Dalby station would have been used. Instead a new location was selected at Snaefell and construction commenced with an aim to have the station completed and operational with a 'Stage One' radar (WW2 type equipment) by April 1956.
It was soon realised that the old Reporting and Control system was far too slow to deal with jet bombers and that the new Type 80 'Green Garlic' radar could be used for both Early Warning and Fighter Control from the same station, cutting out the time consuming 'middle man' of the filter system. This new concept made many elements of the originally planned Rotor system redundant, including the Snaefell station. The Type 80 radar installed at Killiard Point in N. Ireland could cover the whole area on it's own and it is possible that the Snaefell station didn't even become operational. A large 'Type R11' Operations block was constructed adjacent to the Bungalow station on the Snaefell Mountain Railway, but siting the actual radar aerial here would have resulted in severe screening from the surrounding hills in most directions so the most likely location would been on the summit.
Snaefell Radar Station - 2005
 The Snaefell station was designated as a Chain Home Extra Low (CHEL) and equipment provided for these was either a Type 7 or Type 14 radar. The Type 7 operated on a frequency of around 200 Mhz and had a large square mesh aerial that probably wouldn't have survived the winds on Snaefell so most likely a Type 14 radar would have been specified, a centimetric radar operating in the 10 Cm band. 
Plinth mounted Type 14 radar
Type 14 radar mounted on a gantry
Whether the radar was actually installed remains open to question, but eventually the Operations Block was used as 'Murray's Motorcycle Museum' for a while until 2005, but is currently (2014) unoccupied. It is probably one of the best preserved above ground Cold War 'Rotor' radar stations surviving.
Type 14 Radar aerial
The Snaefell Radar station buildings as repainted in 2009
Some more recent aerial and ground level shots of the radar station.
You can step between pictures in this set by clicking on the arrows
Bungalow Radar Buildings
Bungalow Radar Buildings
Summit - Probable Radar Aerial Site
Summit - Probable Radar Aerial Site
Summit - Ground Level
Summit - Ground Level
 (Thanks to Subterrania Britannica and The Radar Pages for much of the above information)
Snaefell Rotor Radar Update (January 2020)
Researches by Chris Corkish had produced some interesting plans for the summit of Snaefell that appear to contradict my assumtions above!
The only actual radar location is identified by a 'Type 54 Special Plinth' but on the opposite side of the summit to the site with protruding ironwork as shown in the pictures just above.  I've had a quick visual look at the site on the map but couldn't see any obvious ground marks to show that anything was installed there.  There are a few possibilities,  was the radar location changed subsequent to the plan being published ot maybe there were plans for more than one radar, which was the common arrangement for most of the 'Rotor' stations as in Trimingham below.  The Type 54 radar used was circular dish type aerial and was normally mounted on a 200ft high tower, but presumably the 'Special' plinth mentioned on the plans was much lower.
There is another location on the plans quite close to the Trig pillar on the summit, but just identified as '25 foot Gantry and associated building' with a hard standing for a crane, was this a potential location for a Type 14 radar?  The plans are reproduced below, if any reader have more information, I would love to hear it!
Snaefell Summit plan for the Rotor aerials.
Plan showing potential aerial locations.
Trimingham 'Rotor' Radar Aerials

Radar for ATC?
With the establishment of the post war civil ATC system, research was being undertaken on the use of radar for controlling air traffic.  In 1952 a wartime vintage Type 14 Search Radar and Type 13 Height Finder were installed at London Heathrow airport for evaluation.  The Height FInder was not found to be particularly useful as, unlike in an Air Defence scenario, the ATC controller could always just ask the pilot for his current height!  The Ministry of Civil Aviation also had a wartime Type 11 radar on trial at Heathrow which offered some interesting possibilities for ATC.  This radar operated in the 50 Cm wavelength band at around 600 MHz and had been modified to incorporate a 'Moving Target Indicator'.  This MTI was a major advance in radar technology as it removed the ground clutter that had always been a factor in earlier radars.  With earlier equipments, this clutter could extend to a range of 20 miles from the radar aerial, obscuring aircraft returns within this area.  The choice of the 50 Cm wavelength was also inspired in that it removed a lot of the clutter produced on shorter wavelength radars by weather, particularly reflections from falling rain. 
Artist's impression of a mobile Type 11 installation
The Marconi company were asked to produce an production ATC radar based on the principles of the Type 11 and by 1954 had designed and produced the first of their S232 radars, which was installed at Heathrow for evaluation.  One snag with the S232 is that it had a horizontal beamwidth of four degrees, which could produce a very wide 'blip' on the radar display at longer ranges.
Marconi S232 Radar Aerial
Further development work was carried out by Marconi on the S232 design to incorporate a larger aerial, which reduced the beamwidth from 4 degrees to a much more acceptable 2.1 degrees.  This aerial was 52.5 ft long and 12 ft high in the form of a parabolic cylinder, which was aslo easier to manufacture. New turning gear was also produced although the electronics remained the same as in the S232.  This radar was designated the S264 and was intended to be used as a surveillance radar for larger airports.
More information of the use of radar in civil ATC is in the ATC 1960s section.

Area Control - Preston Air Traffic Control Centre
The new northern Airways were controlled from Preston Air Traffic Control Centre at Barton Hall, to the east of the town. Area Control within the airways was by 'procedural' means, with separation being either vertical or lateral, using time intervals between aircraft, proved by aircraft reports over defined 'reporting points'. 
1951 Chart of Irish Sea Airways
1951 Chart of Solway Firth Airways
Preston used VHF 119.3 KHz (with H/F 3270 KHz as backup) for all its airways, with VHF 118.5 KHz and H/F 5692 KHz available for Flight Information Service.  The Flight Information Service was the natural follow on from the old 'Communication Areas' and would provide weather and airfield details together with information on other aircraft know to be operating outside controlled airspace. The RAF had their own Control Centre at Preston for control of military aircraft. Weather reports and forecasts for Ronaldsway (and other northern airports) were broadcast from Preston on frequencies 404.4, 3953 & 8942 Khz, the forerunner of the present VOLMET and ATIS services. The pictures of the ATCC below are from a later period.  Preston Centre closed in 1975 and its functions were transferred to London and the new Manchester sub centre.
Preston Air Traffic Control Centre 1
Controllers working on the 'D' side of the Flight Progress Boards. Each flight had multiple flight progress strips, placed under designators for reporting points along the route. Colours used for area control strips were:
Blue = Westbound Flights
Buff = Eastbound Flights
Red = Airways Crossing Flights
Preston Air Traffic Control Centre 2
Assistants working on the 'A' side of the Flight Progress Boards. Data Extraction Cell where strips were produced from Flight Plan information is on the left, with Flight Information Service controllers at the back of the room.
(Preston ATCC pictures via GATCO)
1950s Flight Plan Form
Pilots would file their flight plans with the ATC Flight Clearance Office at the departure airfield. They would be transmitted via teleprinter on the Aeronautical Fixed Telecommunications Network (AFTN) to the en-route Air Traffic Control Centres and the destination airport. Flight Progress Strips would be hand written by ATC Assistants and when the flight became active, displayed on the controllers Flight Progress Boards.
A New Area Navigation Systems?
Towards the end of the decade there was international discussion to determine a new 'standard' navigation aid system for short ranges. The British proposed an area navigation system 'Decca Mk 10' which was based upon the wartime 'GEE' system and could provide for any track required anywhere within the coverage of the particular chain. Four such chains could cover the whole of the UK. It was in use with BEA and even had a 'moving map' provision within the cockpit, giving a continuous plot of the aircraft position. The USA wanted to continue with their 'point source' system of VHF Omni Directional Ranges (VOR), which required a large number of beacons and confined navigation to radials originating from each beacon. To 'fix' an aircraft position required a 'cross cut' of radials from two beacons within range, or a newly developing 'Distance Measuring Equipment' (DME) working on UHF frequencies which when co-located with a VOR would fix the position on a particular VOR radial (bearing) and DME distance. The British system had far more potential at a much lower cost, but the USA already had an extensive network of VORs and the final decision was really a forgone conclusion. The UK would start installing VORs and DMEs in the next decade and a true area navigation system would have to wait for the satellite based GPS, many years in the future.
Decca Flight Plotter
Example of an early moving map display driven by the Decca Navigator System. It used paper charts which had to be loaded for each flight, the track of the aircraft was drawn by pen on the map. This picture dates from 1950 of one installed in an Airspeed Ambassador flight test aircraft.
1958, The Winter Hill Disaster and Radio Beacon Identification
On the 27th February 1958, Silver City Bristol Wayfarer G-AJCS crashed into Winter Hill, Lancashire with the loss of 35 lives. The aircraft was on a flight from Ronaldsway to Manchester Ringway under the control Manchester Approach, having previously been working Preston Centre. It should have been navigating to the Wigan NDB (code 'MYK') on 316 Khz where it would have turned right to Manchester but the first officer had inadvertently tuned in the Oldham NDB (code 'MYL') on 344 Khz.  The beacon tuning error was not noticed by either pilot and the aircraft flew past Wigan until it eventually hit Winter Hill, close to the television transmission mast. Neither Preston Centre nor Manchester Approach had radar covering the initial track although the error was detected at the last minute by the Manchester Approach Radar controller who attempted to avert the disaster by giving an emergency turn to the aircraft, but unfortunately it was too late.  Thirty five people died and seven were injured.  Rescue attempts were hampered by deep snow on the hill.
Manchester Area Airways Chart
There are six different medium 
frequency radio beacons located 
around Manchester, all in the 300KHz frequency range and with their morse identifications all starting with 
the letter 'M'
As a result of the accident investigation it was recommended the the morse code radio identifications of navigation aids should be changed to something like the actual name of the location, all UK beacons at that time having a three letter identification starting with either 'G' or 'M'. For example the Ronaldsway NDB originally coded 'GJE' but was changed to 'RON' and then to 'RWY' The Cregneash radio beacon coded 'MYI' and was changed to 'IOM' 
Manx Airlines Bristol Wayfarer G-AIMH
Picture taken around 1958, not long before the new Control Room was added to the top of the tower
Picture by and © Rich Rimmer GD3YEO
New ATC Control Room at Ronaldsway (1959)
 At the end of the decade it was decided to build a new control room on top of the old RN Watch Office. This provided accommodation for the Aerodrome Controller, Approach Controller and the Air Traffic Control Assistant. For the first time all of the airfield and surrounding airspace could be seen from one location, without having to walk outside onto a balcony! 
CTB Front Elevation 1958
Proposed new Visual Control Room
Installation of the new Visual Control Room must have resulted in a major disruption to ATC services. Apart from the physical alterations to the buildings with the pre-fabricated room being installed on top of the former RN Watch Office, all ATC equipment, radio aerials and the Lamson Tube system needed to be re-located. Once in operation all ATC services were provided from the new location. The former Control room on the third floor became another equipment room housing radio receivers and ancillary equipment,
 ATC in the 1960s
An Island Images webpage © Jon Wornham