Power Signalling At Bristol
So important is Bristol as a railway centre that it has been aptly described as the heart of the Great Western system. For long it had been recognised that the traffic dealt with had become far greater than could be handled efficiently with the facilities available, and that extensions and improvements were required. As far back as 1914 the Great Western Railway decided to remodel entirely the permanent way, rebuild the station, and install modern labour saving signalling apparatus, but the War intervened and it was not until 1929 that work could be commenced.
The station prior to the reconstruction dated back to 1878 when the original terminus of the Great Western Railway was joined to that of the old Bristol and Exeter Railway.
Since then modifications have been made from time to time but the inadequacy of the rail accommodation made it necessary to redesign and extend the whole layout. The work including the widening of numerous bridges in the vicinity of Temple Meads thereby facilitating improvements in the track alignment and the reconstruction to accord with modern standards of the station buildings.
The new station, which incidentally covers more than twice the ground area of the old, is situated between two large yards. The platforms, the longest of which is 1,340 feet, will comfortably accommodate the longest trains. Altogether there are 15 platforms and in addition there are through running lines. In three cases scissors crossings are provided between the platform road and the adjacent through road, by the use of which two trains can be accommodated simultaneously along the same platform face.
In order to obtain the fullest benefit from the improved accommodation, it was decided to install power signalling and interlocking, the contract, for both supply and installation being awarded to the General Railway Signal Co. Ltd.
Two main signal boxes are provided - one to control the points, crossings and signals at the Eastern end of the station, and the other the points, crossings and signals at the Western end. There is also a smaller cabin at the Western end, to control movements into and out of the Loco Yard.
The East Box is equipped with an electric interlocking frame of 368 lever spaces. It controls all traffic to and from Bristol Temple Meads, London, South Wales and the North of England together with the junction with the L.M.S. Railway. The West Box is equipped with a similar frame of 328 lever spaces. It controls all the traffic to and from Bristol Temple Meads and the West of England. The extent and complexity of the area governed by each of these boxes will be understood by referring to the plan at the back of this bulletin.
The three new boxes take the place of the mechanical boxes required to operate the old roads. Each of the new main boxes controls a much larger area containing many more operating functions.