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Leafs on the line.


woody paul
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Anglia news has just reported leafs on the line have damaged train wheels what next when high wind forecast.

 

I think someone has paraphrased that for the hard of thinking.

 

Leaves get impacted onto the line by train wheels, train wheels have little friction anyway so reduce it and the wheel locks, each time this happens a flat is worn on the wheel but worse is this flat then becomes the place where the wheel locks next time, so eventually the wheel needs changing.

 

Same happens on a car if you anchor up in a cloud of tyre smoke, flat spot on tyre makes it un usable.

 

Eventually the compressed leaf material forms a skin on the rail that increases the resistance to the track circuit signal the runs from one rail, through the axle, to the other rail and this confuses the track sensor and fouls the signalling.

 

This latter problem is one reason why signalling is moving to axle sensing, which counts the number of axles into and out of a section, a bit of a bummer when you put a trolley on one side of a sensor and take it off the other side

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I think someone has paraphrased that for the hard of thinking.

 

Leaves get impacted onto the line by train wheels, train wheels have little friction anyway so reduce it and the wheel locks, each time this happens a flat is worn on the wheel but worse is this flat then becomes the place where the wheel locks next time, so eventually the wheel needs changing.

 

Same happens on a car if you anchor up in a cloud of tyre smoke, flat spot on tyre makes it un usable.

 

Eventually the compressed leaf material forms a skin on the rail that increases the resistance to the track circuit signal the runs from one rail, through the axle, to the other rail and this confuses the track sensor and fouls the signalling.

 

This latter problem is one reason why signalling is moving to axle sensing, which counts the number of axles into and out of a section, a bit of a bummer when you put a trolley on one side of a sensor and take it off the other side

 

Every day's a school day! :thumbup1:

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It's a total joke.

 

In the summer it's too hot and the rails buckle.

In the autumn leaves fall on the rails.

In the winter the points freeze.

In the spring the tracks get flooded.

 

Trees, I'm sure you will agree, are pretty widespread across much of the planet. How do we struggle so much with these things on our tiny temperate island, when the rest of the world appears to carry regardless with far more extreme conditions.

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The problem is actually subtly different.

This was described to me by a friend who works on the signalling for railtrack.

Stick with me I'll do the best I can to recall it accurately.

 

The modern signalling system works out where the trains are based on the the resistance from a given point, along one rail, through the axle of the train then back down the other rail.

 

The naughty leaves act as an insulator so the resistance is higher, this gives the monitoring system a false reading of higher resistance - thus suggesting the train is further from the sensor than it really is.

 

The reality is that a heavy leaf fall means they dont know PRECISELY where the trains are.

 

They are just trying to be too clever.

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