Re: Cleaning Ballast - Why do they need to do this?

[cmgord@ecr.mu.oz.au (Christopher_Martin GORDON)]

: >A large section of track was removed and old ballast and ground
: >underneath the track was then dug out and placed onto the waiting works
: >train hauled by 8177/4874.
: >
: >Why do they need to do this?

The requirement for Ballast is to keep the track bed dry and the sleepers dry.
For concrete sleepers this donsn't realy matter, but you still need to keep the 
track bed dry and free of water.  Ballast is a good way of doind this, but if
the ballast is dirty then the water will not drain away.

Same thing applies to roads you need to keep the sub base dry or the road will
crack and stuff up.  

Having a wet track base will result in movement of the track base and you will
get "speed hump" tracks and do more damage to the trains and tracks.



--

Chris Gordon
http://www.ecr.mu.oz.au/~cmgord