Site Records

Site Name: RAF Ash ('YTM') ROTOR 'R3' GCI, Kent

By David Mapley

RAF Ash is located on Marshborough Road between the villages of Woodnesborough and Ash. This site is located on a low ridge overlooking the ancient Cinque Port of Sandwich and, in the distance, the English Channel.

The radar station at Ash was built to replace the former CHL (Chain Home Low) station adjacent to the White Mill just outside Sandwich Town. The new ROTOR site made use of the RAF Sandwich domestic site located next to the River Stour and ancient Barbican Gateway (seen on the crest of RAF Sandwich). This site, still in existence, is an interesting collection of post-war and WWII buildings, some even dating back to the WWI Richborough Military Port.

Still known at this time as `A Site' RAF Sandwich, the new bunker was constructed in Phase 3 of the ROTOR plan. Construction at Ash began in 1951. The building was supposed to have been finished by 15th July 1952. However the date of completion slipped, as did the proposed delivery of the radar and other technical equipment. This was a common occurrence throughout the whole programme, due in part to the shortage of building and electrical materials in post-war austerity Britain, and in part to workers being conscripted for national service.

Nearby land was commandeered for the project. Since November 1997 the MoD has been trying to contact the former landowners to return some of the property.

The site as built was a R3 two-storey bunker. A surface generator building was situated on the west of the site. The bunker, of massive ROTOR type construction, had thick concrete walls surmounted by a sheet piling roof covered in a concrete blast slab 15 feet thick, which itself was protected by a substantial covering of earth. The prototypes of this form of construction can be seen at St Margaret's Bay near Dover (also home to another ROTOR bunker. This area is liberally covered in concrete bunkers of similar construction to ROTOR bunkers, built originally to serve the several cross-channel `big' gun batteries in the area.) Entrance to the Ash bunker was by traditional `Canberra' bungalow.

RAF Ash served quietly throughout the 1950s. It was allocated the identity letters YTM. Nearby RAF Manston during this period was used by the USAF who operated a squadron of F86D Sabre Dog all-weather fighters as part of the ADGB (Air Defence Great Britain). As already mentioned, the RAF was confined to the old RAF Sandwich domestic site. During the mid 1950s one airman was killed at Ash during a ground defence exercise between troops and RAF Regiment defenders.

The deployment of the Type 80 radar showed that the same radar could be used for both reporting and control. This allowed the number of radars to be drastically cut. This was crucial with the end of national service in sight. It also allowed the air defence radar system to be manned on a three-shift basis. The number of radar stations quickly contracted from 63 to 35. Another great blow to the C&R system was the existence of the carcinotron which allowed airborne jamming to become highly effective.

Ash survived the cuts in the 1957 Defence White Paper, becoming a satellite control station in a sub sector, with Bawdsey as its comprehensive radar and St Margarets as CHEL. However with the deployment of the new S-Band Type 85 radar, this system became redundant and by the mid-1960s Ash was placed on `care and maintenance'. In 1965 some of the site was returned to its former civilian owners and the rest of the site (some 17 acres in all) including the bunker was transferred to the Civil Aviation Authority for the princely sum of £1! The CAA built two octagonal radar receiving buildings and one transmitter building on the site. The old GCI radar was dismantled and its building left empty. The bungalow had its roof removed and new single-storey office accomodation built around it. Although nominally operated by the CAA, Ash was also a reporting radar for the Linesman/Mediator radar system and as such supplied radar information for both military and civilian purposes.

In 1979, with issue of RAF Air Staff Requirement (ASR888), Linesman was to be replaced by a new Improved Command and Communication System (ICCS) to be known as IUKADGE (Improved United Kingdom Air Defence Ground Environment). The contract to build the new system was awarded to UKADGE Systems Ltd (UKSL) - a consortium comprising Hughes Aircraft, Marconi and Plessey. The contract was formally signed in September 1981 with a planned completion date of August 1986.

With the publication of the 1981 Defence White Paper, Ash was bought from the CAA by the RAF for £250,000! This time the former radar station was renamed RAF Ash. The bunker was stripped out by the main civilian contractor Arup and two new bunkers were built on and adjacent to the ROTOR bunker to provide a protected power supply, fuel and water stores, and plant space. The rebuild of the bunker took two years and Ash was the first reconstructed R3 bunker to come on line. The building work was the subject of much local complaint, because of damage caused by vibration to buildings surrounding the site, during the installation of sheet piling around the deep excavations. Local residents wanting to complain about the building works were met with blanket denials from the MoD that the work was anything to do with them, whilst the CAA told callers that they no longer owned the site and in any case the work was being carried out by the MoD!

Although it was never declared operational, Ash became a Reserve Control and Reporting Centre. It was able to take control of the air battle in the UKADGE area in the event of any of its sister stations being rendered inoperable. To this end the bunker was fitted with full EMP protection as well as filters capable of operating in nuclear or chemical/biological mode. On the surface two microwave towers connected Ash to other microwave towers at Swingate (former CH station), Dunkirk (former CH station) and RAF Manston. The CRC bunker was also connected into the BT network using fibre optic cables. Swingate, as well as being a former CH station (its three receiving masts still in use for military communications) also housed until the late 1980s an Ace High tropospheric scatter station and also RAF Ash's UHF transmitter and datalink station. Finally in the late 80s the old Linesman/Mediator radars on RAF Ash's topside were removed. The two octangonal towers on which the radar aerials had been mounted were retained: one was converted into the new station fire section and the other became a sports pavilion for use by units from RAF Manston. The topside of the bunker became home to a football pitch.

To make more use of the station during peacetime, an OCU (Operational Conversion Unit) for IUKADGE staff was set up on site. In a search for an appropriate crest for the station, consideration was given to use of the crest of RAF Sandwich. However this was rejected because the motto for this former RAF station was `We take our toll', which was considered undesirable in view of Ash's new role as a classroom!

Like the rest of the IUKADGE systemi, the buildings were ready before the equipment to put in them was. The original finish date of August 1986 was long overshot with the system falling further and further behind schedule because of problems with both hardware and software. The originally specified DEC VAX 785 machines were replaced with the VAX 8650. Software conflicts nearly led at one point to the ditching of the specified language (reused NATO Air defence Ground Environment or NADGE software) in favour of CORAL 66. The rebuilding ground to a halt by the late 1980s owing to the reluctance of the contractors UKSL to proceed any further, alleging non-payment of sums said to be in the region of £50 million!

The MoD attempted to kick-start the project by injecting cash. By 1991 the first of the IUKADGE installations came on line for training purposes, and the entire system was handed over to RAF control on 1st July 1992. Even after this date, UKSL were still very much involved with IUKADGE. Ongoing software problems had to be fixed under warranty.

In 1993 RAF Ash became the Ground Environment Operational Evaluation Unit testing all new equipment for use in SOCs and CRCs: everything from computers, consoles and paperclips to lightstrips! RAF Ash was the RAF's smallest station until 1996 when it lost its autonomy and was downgraded to being a satellite of RAF Manston. This also signalled a gradual winding down of activities on the site. The last full year of operation was 1995.

Although the first of the new SOC/CRPs to be rebuilt and completed, RAF Ash was never an operational air control facility. Indeed the bunker was never actually finished. In the new plant extension a corridor was built with a shaft to the surface through which the bunker's four Rolls-Royce diesel generators could be lowered by crane and then moved on castors to the generator/switch room. The containerised generators duly arrived on site and were parked adjacent to the perimeter fence and there they have remained since 1984 - new and unused! The shaft was capped with a temporary corrugated tin roof. The reinforced concrete roof panels needed to cap the shaft permanently were placed alongside and, like the generators, remain unused.

Standby power to the site was provided by the old ROTOR power plant - a Lister generator set. This set was in working order until early 1997 when the starter motor broke. The set was declared unserviceable and orders were given for it not to be repaired. During October and November 1997 the site was quickly stripped of all operational electronic equipment and then placed for sale. This building also served as the officers' mess complete with bar.

Inside the Bunker

Inside the airlock a long corridor leads to another airlock, which has a blast door at its far end. Off this corridor on Level 1 on the left (west) side there is an operations room complete with empty consoles on three different floor levels. There are also two `electrically clean' rooms, which are in effect steel rooms-within-rooms built to house sensitive electrical equipment, and code and cypher equipment. They were designed to prevent electronic eavesdropping on the equipment inside. Also in one of the rooms were three radar consoles with curtains to prevent civilian maintenance staff from seeing what objects were being monitored on screen.

On the east side of the corridor is a range of offices, an officers' mess, the kitchen and other ranks' dining area. Also on this side there are stairs to the lower level. On Level 2 there is another bigger operations room complete with empty consoles, again on the three different height levels. Along the east side of this lower level is the telecommunications equipment needed to connect to the British Telecom fibre optic cable network. Also next to this section is a large plant area housing the refrigeration, heating matrix and hydraulic control equipment. Across the other side of the corridor is another operations area.

On Level 1 the north or emergency exit leads on to another bunker built on top of the old ROTOR exit. This area, although protected by blast doors, has no airlocks. It houses water tanks and the air filtration plant. From here a corridor leads to a metal staircase to the surface.

Back to the entrance vestibule: the plant area or west corridor leads to a massive new construction nearly as big as the original bunker. The plant area is in effect a large concrete box with two large two-storey corridors on two sides which act as inlet and exhausts for the generators. The inlets and exhausts are armoured louvres designed to shut if subjected to blast. As already mentioned, the generator room does not have any generators, although all the control equipment and engine beds are in place. On the exhaust corridor are the fuel oil tanks (now empty) and a very large blast door leading to the generator area. This corridor also leads to the surface shaft through which the generators were supposed to have been lowered. This area is also prone to leaking when there is heavy rainfall on the surface, the leaks being diverted away to a strategic collection of buckets by a Heath Robinson collection of tubes. Incidentally, although blast protected, the plant area was not airtight and under NBC conditions any repairs or maintenance would had to have been carried out in protective NBC clothing.

On the surface little of the old ROTOR site remains. Only the old power house (now no longer operational) and the old building on which the GCI was mounted now remain. The old GCI building was pressed back into service by the RAF as the station armoury during Ash's latest spell in service, but is now empty. All the louvred vents on the surface were built during the 1983 rebuild. Two masts stand above the site although all the microwave dishes have now been removed. Cable & Wireless Communications now leases the south mast for use as a cell site. The fate of Ash's UHF transmission site five miles to the south on the site of the former Chain Home site at Swingate near Dover has yet to be decided.

All the station's RAF personnel have now been moved to other postings. The only staff still on site are an MoD Fire Service team (to act as guides to civilian firefighters if the site were to catch light), security personnel from a local security company and the resident civilian site engineer working for the contractor Serco.

For those interested in buying a bunker the running costs (released by the estate agent acting for the MoD) for RAF Ash in 1995 (last full year of operation) were:

Southern Water £3,620
Seeboard £17,110
Power Gen £156,450
Gas £2,280
Rates £50,000
Minor Maintenance £35,300
Planned Maintenance £59,721

Update:

RAF Ash has been sold to an Internet Service Provider and a planning application submitted to Dover District Council for change of use from nuclear bunker to computer centre.

RAF Ash is now in used as a high security 'server farm' by A.L Digital, the site being marketed as 'The Bunker' Visits are not allowed. - 5/12/01

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