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Automatic Train Control in the 1940s

Posted: Sun Jun 23, 2019 12:38 pm
by John Palmer
Lt Colonel Woodhouse's report upon the 1947 Gidea Park accident contains the following passage about developments towards automatic train control:

"The 'continuous' type of apparatus, providing on the engine at all times an indication of the conditions ahead by means of a miniature colour-light signal having three (or four) aspects conforming with those of the lineside signals, with a bell which sounds when the aspect shown becomes more restrictive, has been installed experimentally by the London and North Eastern Railway on a length of line between London and Hatfield; it is of the 'non-contact' type, operated by coded pulsations of current in the rails, picked up inductively by the engine. Apparatus can be added to guard against lack of response by the driver to the indications received, but has not been incorporated in the experimental installation; both engine and track equipment are much more complicated and costly than in the two 'intermittent' types mentioned."

I have not previously seen anything written about such an experiment and would be interested to hear from any contributor who can shed further light upon it. The report also comments upon the Great Western's 'contact' system and the inductive system then being trialled on the LTS section that formed the basis of BR's AWS. Relative to these, the system forming the subject of the LNER experiment evidently had the considerable advantage of discriminating between all aspects of a four-aspect colour light installation, and was thus capable of meeting the criticism that other ATC systems of the time lacked such a capability. I understand that Southern Region, in particular, had strong reservations about the BR AWS system due to its lack of this capability, given the short headways under which the Region's motormen spent so much of their time running through a succession of yellow and double yellow aspects. Why, then, was the system trialled between London and Hatfield not taken further?

Re: Automatic Train Control in the 1940s

Posted: Mon Jul 15, 2019 11:27 pm
by Eightpot
Yeadon's Register of LNER Locomotives Volume 13 (Classes C1, C2, C4 & C5 Atlantics) has at the top of Page 42 a photo of C1 No. 3293 based at Kings Cross shed at that time, fitted with this apparatus and a steam turbo-generator to power it. This was fitted when it came out of Doncaster Works in March 1946 and retained it until withdrawn for scrapping in April 1948. The text also adds that this ATC system was on trial between London and Peterborough.

Re: Automatic Train Control in the 1940s

Posted: Tue Jul 16, 2019 1:03 am
by John Palmer
Ah, that's interesting; thanks for the information. Unfortunately, that's a volume of Yeadon I don't have, but it's of interest that the apparatus drew sufficient power to require the fitting of a turbo-generator. I wonder whether that played a significant part in what seems to have been the abandonment of this trial.

As it happens, I was this afternoon reading the HMRI report on the 1978 accident just north of Patcham Tunnel on the Brighton line ( ... ks1978.pdf). This was another accident that AWS would probably gave prevented, and the report includes an interesting albeit depressing account of Southern Region's protracted struggle to implement a satisfactory form of train control.

Of particular note in the Patcham accident report is Major Rose's telling comment that "A third factor (militating against introduction of AWS on Southern Region) was the suspicion, shared at that time by the Inspectorate, that the standard British Railways AWS was not really suitable for the intensively worked, colour-light signalled sections of the Region." Regrettably those misgivings about the inadequacies of AWS were not sufficient to save the driver involved in the 1989 accident at Purley from a criminal conviction, which the Court of Appeal subsequently overturned, rightly in my view.