Rails are replaced, when they are really really causing
trouble.. Such as, a high chance of a derailment of trains.. Or a
flat head on the rails...
It could probably mean the replacement of a section of the
track, but not the whole stretch. It won't be possible for them to
replace in a few hours as current will start flowing at 5am for the
morning trains..
Sometimes, sounds that you heard on the train, aren't always
cause by the rail itself. You must understand that the wheels on
the bogies, have to got for wheel profiling, to make the wheels go
back to the round shape again.. Let say, in the wheel, there's a
part of the wheel which is flat. There will be a "thump" sound
evertime the wheel make a complete rotation. I've experienced that
before on at C751B. Reminds me of a steam locomotive instead.
Nah, you know that the sound is created by the rails because it
is created on every train which travel on the NSL, and changes back
to the normal sound when it travel back to "old" tracks.