In message , Dave Liney
writes
The train shouldn't have derailed and the fact that there was a speed
restriction is a negative thing because it shows that it happened
despite the knowledge that there was a fault in the area.

The only alternative (apart from fixing all the track faults overnight)
is to close the line. Surely a speed restricted line is only restricted
*because* you want the rather-more-likely-than-normal effect of tripping
the fault to be less serious. Isn't that why you drive a car slower in
fog?
--
Roland Perry