ACE HIGH is a tropospheric scatter/microwave link system which dates back to 1956, when SHAPE (Supreme Headquarters Allied Powers Europe) developed a plan for an exclusive communications system which would comprise the minimum essential circuits of early warning and alert and implementation of the ‘tripwire’ retaliation strike plan. The network, comprised 49 tropospheric scatter links and 40 line-of-sight microwave links, extending from northern Norway and through central Europe to eastern Turkey. The system had 570 voice, 260 telegraph and 60 data circuits.
The principle of the tropospheric forward scatter system was to beam high-frequency signals against the troposphere (5 to 10 miles above the earth), pick up part of the reflected signal with highly sensitive receivers and beam it onward by the same means. This communications technique has many advantages. Its efficiency was not marred by atmospheric conditions; it had a computed circuit reliability of 99.9 per cent and signals could be transmitted in stages of from 50 to 250 miles. Reduction of the number of required relay stations through these longer stages also meant reduced operation and maintenance costs and personnel requirements.
With the development of new microwave at satellite communications technology in the 1980’s, tropospheric scatter systems became redundant and the Ace High network was abandoned in the early 1990’s
There were five sites in Britain:
- Mossy Hill, Shetland Islands
- Mormond Hill near Fraserburgh (Aberdeenshire)
- Brizlee Wood near Alnwick (Northumberland)
- Stenigot (Lincolnshire)
- Coldblow near Detling (Kent)
The Ace High station at, Coldblow was located alongside an existing WW2 communications station on Coldblow Hill. The most prominent feature was two pairs of parabolic dish antenna, 60 feet in diameter supported on seven lattice steel girder legs. The transmitters, receivers and power supplies were located in a single storey brick building between the pairs of dishes. With the demise of the Ace High network the Coldblow station closed in the early 1980’s was sold by auction in September 1996. The dishes, a local landmark, had been removed the previous year. A microwave tower on the site was retained by the Ministry of Defence and access rights to the tower were built into the sale agreement. The mast is currently used by the USAF in conjunction with the USAF radio stations at Dunkirk and Swingate in Kent.
Although the dishes were removed, all the buildings were retained and were included in the sale. By the time the site was sold for a second time in 2001 the main transmitter building had been wrecked by local vandals with a fire destroying a large section of the roof. The new owner has renovated the large standby set house which now houses a photographic studio and workshop now trading as ‘The Radar Studio’.
Most of the remaining buildings are unused and derelict. The owner considers the transmitter building is beyond economic repair and this will eventually be demolished. There are plans to build housing on the site.
THE SITE DESCRIBED
The site, which is surrounded by a chain link fence, is located on the east side of Coldblow Lane with a short access road from it. The WW2 communications site is sited alongside the access road but outside the Ace High compound. A wooden lattice mast from this station survives and is still in use with a number of modern communications aerials mounted at the top. Three brick buildings from the 1940’s stand close by. The smallest building to the west has a door at both ends and probably housed a sub station. To the east the next building has some electrical switchgear mounted on the wall inside and would have been the power house. Both buildings are open and the power house is used as a stable. The third and largest building, adjacent to the wooden mast is locked and some modern radio equipment can be seen through the window, this would have been the communications equipment building.
Just inside the gate to the ace high compound is the guardhouse, a single storey ‘L’ shaped brick building. The building is open and internally vandalized. The Ace High sub-station and standby set house are to the right of the road with a portacabin and transmitter building to the left.
The sub-station is still in use and the standby set house has been renovated with a new roof. On the south side of the building there is a small walled enclosure with the concrete mountings for two fuel tanks. A portacabin with concrete steps for access was sited opposite the sub-station. It was used as a workshop and still retains a work bench and tool board.
Behind the portacabin is the emergency water supply stored in a large Braithwaite steel tank still clearly labeled EWS. The transmitter building is a single storey ‘L’ shaped structure. The main part of the building has a hipped roof and is similar to the transmitter building (now demolished) at the Ace High station at Stenigot. The shorter arm of the ‘L’ which is not present at Stenigot has a flat roof.
Entrance is through double doors at the west end. Just inside the door there is a toilet on the left with two cubicles one conaining a WC and the other a hand basin. There is a small shower room to the right side of the lobby. Beyond these is a short spine corridor with two rooms on the right, the first of which was the office. There is a corridor to the left into the shorter arm of the ‘L’. The room at the end of the corridor appears to have been a rest room with a small kitchen next to it.
Back in the main spine corridor the next room on the left was a workshop and still retains a workbench and tool board. The next room was the BT room with some cabling still in place. This part of the building is completely wrecked, fire damaged and roofless. There is a burnt out car sitting at one end of the spine corridor. At the end of the corridor are the three equipment rooms, each accessed from the previous room through a set of double doors. The first room, the control room, is also roofless and wrecked. On the south side of the room there are two ventilation louvre panels with a small brick ventilation stack on the outside of the building. At the back of the control room there is a large window and another set of double doors into the transmitter hall, the largest room in the building. The fire didn’t spread into this room and the roof is intact. There is some electrical switch gear in one corner and a large tool and spares board in another. There are two sets of ventilation louvre panels on the two long walls with two brick ventilation stacks on each of the outside walls of the building. There are windows at ceiling level along both long walls.
At the back of the room, double doors lead into the electrical plant room which has a tiled floor and no windows. There are two ventilation slots at ground level on each of the two long walls with metal ventilation trunking on the outside of the building. There are also four short ventilation stacks in the roof. At the side of the room a doorway leads into a small extension on the south side of the building.
Behind the transmitter building is the current MOD compound with a metal lattice mast. Communications equipment is housed in two new buildings.
Three further buildings stand at the end of the road into the site. There is a block of two buildings butting on to each other close to the western perimeter fence one building is a three bay dog kennel, the wire fencing for the dog runs at the rear of the building has been removed. The adjacent building is a preparation room for the dogs' food. The final building is a prefabricated bar/lounge and recreation room with a decorative serving area in the middle of one side. This building is in poor condition and likely to be demolished.
It should be noted that the site is alarmed with a guard dog running loose when the studio is not in use and the owner would not welcome casual visitors.
- Bob Jenner
- Andy Emmerson
- Jane’s Military Communications for 1987