Cant Markers (was White panels on track)

[Inversnecky]

I saw these intriguing, off centre, white panels spaced out over a few hundred metres of track on a cab view video of the Inverness Aberdeen line.

Can anyone identify what they’re for?

 

[Dunfanaghy Rd]

I think that the white patch surrounds a marking of the cant. It may be that the patches stop at the end of the curve.
Pat

 

[jj1314]

Could they be prisms for total station observation, mapping track movement over time? I know a similar method is used near Condover where there's a quarry in close proximity to the railway.

 

[Inversnecky]

Here’s an aerial view: they are evenly spaced and on a doubled stretch before Insch.

 

[civ-eng-jim]

They're usually yellow (but might just be the cab ride video quality) but I'd agree they're cant markers.

Many in a line indicate a cant transition - increasing to a constant cant (where the last marker indicates) into the long continuous curve through Insch.

Here's a photo looking in the Aberdeen direction further along the line just beyond Insch platform showing cant markers indicating cant is being reduced coming off into a straight section of track. On the adjacent line they're within the platform as you shouldn't put a cant transition through point work.

 

[Inversnecky]

Thank you Jim. I’d never noticed them anywhere before. Are they only used in particular (difficult) cases?

 

[td97]

New track installations should have cant markers on the sleepers at 5mm cant intervals along the transition length.
There should also be additional track geometry plates installed at each change in horizontal geometry

== Doublepost prevention - post automatically merged: 13 Jan 2022 ==

Quite often cant markers or geometry details are hand drawn too

 

[CEN60]

There is an NR Standard relation to the marking of track geometry / cant etc - I cant (forgive the pun) remember the number off the the top of my head.