Site Name: RAF Bawdsey R7 ROTOR Radar Bunker
Sub Brit site visit: 13th April 2004
[Source: Nick Catford]
In 1950, RAF Bawdsey was chosen to participate in the ROTOR programme which should have been completed by January 1952.
All the radars were to be clustered round the R3 control centre apart
from the Type
7 which was remotely sited 2km north east of the site on Alderton
A Type 7 aerial array over an R7 bunker with an IFF on A type 14 plinth and a sub station to the rear. Note the Type 80 radar in the background with a Type 13 height finders either side. This example is at RAF Wartling.
The transmitter, receiver and motor for turning the aerial array were located underground in a bunker designated as an R7 and known as a 'well'. Because of the distance from the main site, this radar required its own IFF and an Mk 10 IFF was mounted on a Type 14 plinth, turntable and cabin. This was located a short distance to the east of the R7 bunker with a small brick built electricity sub station alongside.
Continuous tracking of targets was essential to the interception procedure and the aerial system had to provide gap-free cover. To do this an array consisting of 32 centre-fed full wave dipoles was used, mounted in four stacks, each with eight dipoles.
The antenna beam width was 15 degrees although a narrower beam width
and greater range performance was provided for the ROTOR
improvement plan by the addition of more stacks of dipoles on each end
of the aerial.
Photo:The roof of the R7 bunker. The aerial array was mounted above the fourth aperture back. The apertures on the far right and in the foreground were for personnel access.
Photo by Nick Catford
The Type 14 plinth and the adjacent sub station are located alongside the track as it runs along one side of the wooded area; both are still in good condition although stripped of any original fittings. This is now the only surviving ROTOR plinth at Bawdsey. The R7 bunker is 50 yards to the west in a clearing set back from the track. There is some evidence of the original compound fencing.
The bunker is approximately fifty feet long by fifteen feet wide. The top of it is flush with the ground with a 3' high brick wall around the west and south sides. This wall is unique to Bawdsey and may have been to stop earth erosion from the surrounding fields covering the top of the bunker. There are six rectangular apertures and one circular aperture in the roof, the largest of these was for the pedestal for the aerial array. The two smallest apertures were for personnel access using a ladder which has been removed. All the apertures have been covered by a wire mesh frame to stop animals falling into the well.
The bunker, which is divided into three rooms, appears to have been stripped of all original fittings and in places there are a few inches of water on the floor.
For further pictures of the R7 bunker at RAF Bawdsey click here
[Source: Nick Catford]
Last updated 27th April 2004
© 2004 Subterranea Britannica