[LEAPSECS] No leapseconds on trains

Clive D.W. Feather clive at davros.org
Sun Nov 20 15:47:03 EST 2011

Ian Batten said:

>>> This wasn't the timetable. Its main purpose, as I understood it, was to provide a record of where trains were, or where the dispatchers thought they were, in the event of an accident.

>> Hmm, they may well be logging each track circuit transition

> Track circuits? In manually-signalled USA?

The USA had track circuits well before the UK. Read Rolt. I thought it was
fairly usual to track circuit at least sections of lines - for example, in
remote areas signals were approach-lit to save battery life, so that
implies several TCs in rear of the signal.

> Anyway, the average freight train in the USA is 6500 feet long (ie substantially over a mile) and travels at an average of around 20mph, or at most 30mph. So it takes around two minutes to pass a point. Timing that to a precision of a second seems a excessive.


Clive D.W. Feather | If you lie to the compiler,
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