Another odd (temporary?) line side feature…

[notverydeep]

I’ve just passed Hadley Tunnel South, between Potters Bar and Finsbury Park and I have noticed a series of posts around a metre high (perhaps a bit more) with what appear to be blue or red coloured balls on the top. The ones I noticed were adjacent to the Down Slow line just South of the tunnel portal. Has anyone got any idea what they are for…?

 

[74A]

Sounds like measuring any slippage in the sides of the embankment.

ANy movement of the sticks from one week to the next can show you where the cutting sides are moving.

 

[YorkshireBear]

Sounds like measuring any slippage in the sides of the embankment.

ANy movement of the sticks from one week to the next can show you where the cutting sides are moving.

Correct.

 

[DelW]

An old discussion here:

solar panels on sticks - between Applerley Junction and Guiseley

I got the train from Ilkley into Leeds and return yesterday Coming back I sat on the left facing the front We came off the skipton line onto the branch to Ilkley Just after the junction, on the left, there were some solar panels on what looked like temporary stands, and some yellow sticks on...

www.railforums.co.uk

relates to something similar.

Just after the junction, on the left, there were some solar panels on what looked like temporary stands, and some yellow sticks on the embankment in rows.

No idea what this was for. monitoring an unstable embankment?

 

[notverydeep]

Thanks @DelW. Yes the posts did look quite similar to some of he pictures contained in a link within that thread (https://www.findlayirvine.com/rail-earthworks), though the red and blue balls are different. The slope of the cutting at Hadley Tunnel South does not look too severe, but any slope can move so it certainly seems a good explanation.

I know through Hadley Wood itself, there has been some test planting of the cutting I think to determine how vegetation management can avoid leaf fall issues, while still being noise barriers that don't create a storm of neighbour protest if removed once every two decades, so I had wondered if they were in someway connected. There was a Network Rail YouTube video about this, but I can't access that at work to create a link.

 

[YorkshireBear]

An old discussion here:

solar panels on sticks - between Applerley Junction and Guiseley

I got the train from Ilkley into Leeds and return yesterday Coming back I sat on the left facing the front We came off the skipton line onto the branch to Ilkley Just after the junction, on the left, there were some solar panels on what looked like temporary stands, and some yellow sticks on...

www.railforums.co.uk

relates to something similar.

They aren't quite the same, the yellow poles warn if they move, the red and blue balls are simply to look changes between images from cab footage.

== Doublepost prevention - post automatically merged: 13 May 2025 ==

Thanks @DelW. Yes the posts did look quite similar to some of he pictures contained in a link within that thread (https://www.findlayirvine.com/rail-earthworks), though the red and blue balls are different. The slope of the cutting at Hadley Tunnel South does not look too severe, but any slope can move so it certainly seems a good explanation.

I know through Hadley Wood itself, there has been some test planting of the cutting I think to determine how vegetation management can avoid leaf fall issues, while still being noise barriers that don't create a storm of neighbour protest if removed once every two decades, so I had wondered if they were in someway connected. There was a Network Rail YouTube video about this, but I can't access that at work to create a link.

I don't know the Geology at Hadley Wood without looking but London Clay in particular over time likes to go to a very shallow angle!

 

[notverydeep]

Thanks for the additional info @YorkshireBear. Would the footage comes from the NMT or other test trains, or is it a camera simply mounted on various service trains?

 

[YorkshireBear]

Thanks for the additional info @YorkshireBear. Would the footage comes from the NMT or other test trains, or is it a camera simply mounted on various service trains?

I'll try find out. I believe just general forward facing footage already out there on NR fleet.