MT 95/989

Location	National Archives
Title	Motorway signalling: emergency light signals on M4 including Severn Bridge; arrangements for supply, installation and maintenance
Date range	1966-1967
Catalogue	See entry

Context

This one should rightly be filed under "brilliant information completely mislabelled" - a bulging category at the National Archives as much as anywhere. The file title promises information on an early signalling system installed on the Severn Bridge in the mid-1960s, and indeed the Motorway Archive Trust records very early prototypes of the Mk1 VMS signals (the type usually found in the central reserve of rural motorways) being trialled there. This is what any sane person would expect to find there.

In fact the file spends most of its time talking about the emergency telephone system on the Bridge and spends page after interminable page prattling on about this. The few scant references to emergency signalling systems seem to be something to do with closing the bridge in high winds - not the purpose of those experimental Mk1's - but there is so little information that it's hard to tell what was installed to this end, if anything. The reader is left with the impression that lights were installed to halt traffic at the Aust toll booths if the bridge was closed due to high winds, but even that is very much speculative.

The real joy here is a set of photographs tucked away at the back that show the Severn Bridge under construction, some of which are breathtaking, shot from the top of one of its towers before the road deck was in place. The view of the other tower in the far distance, connected only by a pair of cables, is quite remarkable, and well worth getting the file out on its own. Heaven only knows what the photos are doing in here.

People with camera copies

Chris Marshall has a partial copy, mainly of the Severn Bridge photos.