GWML - OLE Alterations eastwards from Acton Main Line

[59CosG95]

I'm not sure which thread to put this in, so I started one anew.
Passing through the area on the weekend, I saw that two portal masts had gone up in the Main Cess & Relief Cess, just west of Acton ML station. The portal was boom-less on Saturday, but had gained a boom on Sunday with lots of sealing ends - which I think implies they might be trying to alter the switching arrangements.

Is this, by any chance, part of the works for Old Oak Common?

 

[WiredUp]

Possibly for a project called Faster Safer Isolations or it's ATF related... What was the structure number?

 

[59CosG95]

Possibly for a project called Faster Safer Isolations or it's ATF related... What was the structure number?

It was J/07/xxA; I can't quite make out the exact number of the new portal. Based on the cables along the top of the boom, the SFI (Safer Fast Isolations) seems most likely.

 

[WiredUp]

Cables will either be flexball drives (should really use a pear drive), possibly feeds or for the High Level Reliable Indicator devices fitted to the switches.

Probably was J/07/07A

 

[59CosG95]

Turns out it was for OOC Enabling Works:

Andrew Fleming on LinkedIn: #srsa #colasrail #teamwork #rightfirsttime #delivery

Boom Goes Old Oak Common Big milestone with the installation of the boom of this new 4-track OLE structure just outside of Acton Main Line…

www.linkedin.com

Boom Goes Old Oak Common

Big milestone with the installation of the boom of this new 4-track OLE structure just outside of Acton Main Line Station.

This mast will hold new switches key to enabling the possession and isolation regime for our HS2 Enabling Works at Old Oak Common.

A huge effort by the whole team to get this installed safely and on programme by applying the principles of PACE!

 

[WAO]

When we lament the lack of new electrification schemes, perhaps we forget the great efforts by NR in improving the existing system.

WAO

 

[bnc2018]

I wonder why they didn't put the boom on the existing masts for the headspan like they did for the ECML headspan replacements. Would have at least saved the piling, and for once the old masts actually look more substantial than the new ones

 

[pdeaves]

I wonder why they didn't put the boom on the existing masts for the headspan like they did for the ECML headspan replacements. Would have at least saved the piling, and for once the old masts actually look more substantial than the new ones

I have no inside information, but maybe later on, the old masts will be in the wrong place, either through something else needing to go there or to get the geometry/fixing points right for the contact wire.

 

[59CosG95]

I wonder why they didn't put the boom on the existing masts for the headspan like they did for the ECML headspan replacements. Would have at least saved the piling, and for once the old masts actually look more substantial than the new ones

There seems to be an unwritten rule in modern design that OLE feeding masts (like the new boom) and OLE registration masts (like the legacy headspan) are kept separate. The legacy headspan, which also has feeding arrangements, was built in a time when feeding and registration arrangements shared structures.

 

[WiredUp]

59CosG95 there is nothing in the standards that requires this; switches and feeds can use the same steelwork as those for registering wire runs.

There are some other potential upcoming changes in the area for the enabling works which may have dictated that the old headspan masts can't be reused. It also looks like the headspan in question formed an old boosted overlap (BT's since removed) which means there may have been a load of bracketry attached to the masts, and hence it wasn't worth the trouble of attempting to reuse it.

One of the other problems with the HS2P conversions on old masts is that there is a level difference between the top of the masts and the boom - not a problem if you are just registering at the location but not helpful when running operating rods/cables up and over onto it. I stole the image below from an LNER cab ride video - this is the HS2P at Connington - you get the idea.

I'm sure the designers were on the ball when it came to this configuration.