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Re: San Rafael, Novato SMART rail warning devices malfunctioning
Author: Rasputin
Date: 09-30-2016 - 11:31
Dr Zarkoff
My guess is you have it right, thin film contamination of the rail head is more complicated than most people realise.
Research done in England in the late 60's showed that sunlight was polymerising various monomers in air pollution, forming a molecularly thin plastic film on the rail head. The work back then was on the resulting increase in braking distance but this contamination mechanism could contribute to to track circuit failure.
The solution being looked at in the 60's research was to have plasma torches on the leading car / locomotive which would ablate the film from the rail head when the brakes where applied. I have not seen any further development of this approach in the intervening years.
Rasputin
My guess is you have it right, thin film contamination of the rail head is more complicated than most people realise.
Research done in England in the late 60's showed that sunlight was polymerising various monomers in air pollution, forming a molecularly thin plastic film on the rail head. The work back then was on the resulting increase in braking distance but this contamination mechanism could contribute to to track circuit failure.
The solution being looked at in the 60's research was to have plasma torches on the leading car / locomotive which would ablate the film from the rail head when the brakes where applied. I have not seen any further development of this approach in the intervening years.
Rasputin
