Automatic Train Control in the 1940s
Posted: Sun Jun 23, 2019 12:38 pm
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?
"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?