[Magdalen] ATTN The Scotts !!!

[Roger Stokes]

On 31/01/2019 16:34, Scott Knitter wrote:
> I think I read that there's an actual system of gas lines to provide fire
> to the tracks near switches (where a piece of track moves to divert the
> train one way or another). The main thing is to get rid of ice and snow
> that might block the switch from switching, which would make it impossible
> for the train to take the intended route, or worst case, might derail a
> train.

I don't know if they've changed to fixed lines as I haven't seen them 
for a few years but this side of the pond they used to have propane 
heaters for the same purpose.

> I think there's also an issue with the flexibility of the rails...Normally,
> rails have some "give" to allow for shifts in weight, different train
> speeds, etc., and that's why the tracks have to be periodically measured
> and adjusted to maintain a precise width apart (I think there are devices
> that ride the rails and help do this, or at least the measurements). Some
> tracks are continuously welded, so there are no gaps, but others are bolted
> in in sections, with tiny gaps. If ultra-freezing weather happens, the
> flexibility the rails have goes away, and sections of rail can go out of
> alignment with others, with danger of derailment.

A few months ago there was a series of TV programmes about Paddington 
station in London. One section was about replacing a length of cracked 
rail and their problem was the heat last Summer. Obviously this would 
make the rail stretch and if it was too hot they were beyond the ability 
of the fastenings to keep the rail the right length without buckling. 
Nowadays we have concrete rather than wooden ties in most places but 
someone still needs to walk the lines to look for any problems, 
preferably before they become an issue for the trains.

Roger