Site Records

SiteName: Isle of Man Radar Stations - Bride CH

The transmitter block was constructed from reinforced concrete. Two pairs of transmission lines, probably running along the hedge boundary, carried high voltage radio frequency power to the two aerials slung between each pair of transmitter masts.

C Type transmitter block at Bride

The transmission lines were suspended from ceramic insulators on wooden poles. In order to carry the radio frequency power efficiently to the aerials, careful control of the geometry of the transmission lines was necessary. Adjacent to the blast wall entrance to the building was a bay with four glass-insulated feed-throughs for the transmission lines. To minimise danger to the operating staff from the transmission lines, transmitter blocks were built right or left handed depending on the direction of traffic to and from the building.

The building would probably have housed a transmitter type MB3 and ventilation plant. The second transmitter block is identical. It is not possible to identify the precise location of pieces of equipment because at present no drawings or photographs have been found which are known to show equipment in use in a building of this type. Each pair of steel transmitter aerial masts could support curtain wire aerials for two alternate frequencies, although it is not clear that all CH stations were equipped for dual frequency operation. A second curtain of reflector rods hung on the landward side of the main curtain. The weight of the aerial curtains was counterbalanced by a massive concrete aerial halyard balance weight and the geometry of the aerial was maintained by a series of aerial curtain balance weights. Each mast was set on a steel ball and was stabilised by steel ropes to eight massive concrete guy points.

Plan of C Type transmitter block. A. Roof vent B. Bay for feed-throughs C. Cable duct 80 cm deep D. Transmitter equipment E. Goods entrance F. Personnel entrance G. Transformer room H. Ventilation system

The concrete bases of the curtain balance weights have been removed from between the two masts and are parked at the edge of the field.

The second aerial site is better preserved and is still in much the same condition as when the station was decommissioned. The concrete bases of the curtain balance weights are still in place. It may well be the best preserved CH transmitter aerial site in the British Isles.

A three-port concrete and brick electric cable junction box is clearly visible in the gorse hedge. The box now contains brick tiles which would probably have been used originally to mark the route of the cable. They are now scattered along the hedge.

The junction box has three shielded ports, to the north and south along the hedge line and to the east at right angles to the hedge line. The shield for the eastern port is now detached from the box, possibly to make space for the new wire fence.

The cables may have been used to provide power to the aerial site, for example, to control the aerial configuration.

The advanced chain home (ACH) site was probably housed in two wooden huts, one protected by a blast wall. Today there are no physical remains, but the huts are clearly visible in an aerial photograph. The shadows indicate two masts either side of the pair of huts. By comparison with the shadow of the known 325-ft CH aerial mast on the same photograph, the ACH aerial masts are approximately 87-ft high. This is consistent with the report of an inspection party in 1942.

Little information is available on ACH systems, but it is likely that one hut housed the transmitter equipment and the other hut housed the receiver equipment. The ACH transmitter aerial was probably not in the form of a curtain array, but of rigid construction and built into one of the 87-ft masts with the receiver aerial being built into the other mast.

MK III IFF Interregator tower and cubicle

The Mk III IFF Interrogator transmitted a coded radio signal. When this signal was recognised by suitably equipped friendly aircraft, a coded response was automatically transmitted. When the interrogator received the coded response, it caused the echo of the aircraft displayed on the operator's radar screen to vary in amplitude. This indicated to the operator that it was a friendly aircraft. The entrance to the cubicle has been blocked by a large piece of concrete. It was, however, just possible to see into the cubicle which appeared to be completely empty. Three accommodation blocks have been converted into domestic houses named Brambles, Gorsebank and Seafield. These buildings may have been associated with the ACH site.

Further information and pictures about this site continues here

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