What's this for?

[trainmania100]

The yellow thing strapped to the the crane in the bottom right of the shot. Looks like a mini tamper or something?

 

[swt_passenger]

It looks like a ballast brush. Automates the final cleaning of any excess ballast above the height of the sleepers and sitting on the railweb and clips.

Network Rail description here:

The Rexquote Ballast Brush attachment is designed for use with a road rail vehicle (RRV) using the host machines’ hydraulic power for operation.
A rotating broom sweeps and feeds excess ballast onto a lateral conveyor belt for transport to either left or right side of the tracks, as selected.
http://www.txmplant.co.uk/wp-content/uploads/2017/04/Ballast-Brush.pdf

 

[trainmania100]

It looks like a ballast brush. Automates the final cleaning of any excess ballast above the height of the sleepers and sitting on the railweb and clips.

Network Rail description here:

Thank you looks like it

 

[DarloRich]

Agreed - a ballast brush

 

[greyman42]

Agreed - a ballast brush

Where is that photo?

 

[Pigeon]

Looks like Clayton Tunnel to me.

 

[trainmania100]

Where is that photo?

It was taken at Clayton tunnel yesterday, love the castle on the end of the tunnel.