Great Western Main Line electrification - ongoing discussion

[whole diary]

[bobm]

I think I saw him. He was a new face to me.

I guess it was low key. Except the MD was on the first inbound service and the deputy MD on the first outbound....

[Electric train]

An event in Swindon by the IET^▸ (Intercity Express Train) "Electrification of the Great Western Mainline" 12 October 2016 - 18:30-21:30 at Swindon Collage.

http://www.theiet.org/events/local/241367.cfm?nxtId=239561

These are free events, registration for the event is simple

[Gordon the Blue Engine]

I notice that the OHLE on the UM and DM between Pangbourne and Tilehurst is earthed (ie cables across the insulators), so it looks like following the publicity run with the 80x on electric it’s been switched off for now so installation work can be continued. 

The system is only enegised for the test runs at the moment, the full immunisation test have not been done, also there is no full time ECR yet, so the blue leads (portable earths, technically the ones they are using are construction earths) this so safety documentation can be issued for the OLE^▸ (Overhead Line Equipment, more often "OHLE") construction teams to continue working

With test/training runs starting on 12th September between Reading Depot and Didcot (as reported on the "387's coming to the Thames Valley" page), can it be assumed that installation work (apart from AT cables!) on all 4 lines will be finished by that date and that the wires will normally be live?

[Gordon the Blue Engine]

This question has just been answered by Insider (Reply 358) on the "Class 387's coming to the Thames Valley" page.

[stuving]

Do you remember there was a discussion somewhere back in this thread about safe distances to 25 kV OLE^▸ (Overhead Line Equipment, more often "OHLE")? I wondered at the time whether 3 m was meant as the clearance from a place people stand, rather than from their closest body part.

Well, it turns out that's the case. I found this pretty comprehensive NR^» (Network Rail - home page) "electrification for dummies" (or councillors) document on BaNES website. Look at section 12 (from p 27) for safe clearances and the reasons.

This, from the introduction, explains the intended audience:

The purpose of this guide, therefore, is to help all those with an interest in the current Network Rail  electrification projects – whatever that interest may be – to understand why the line is being electrified, and  why some changes to existing structures are required.  It has been produced by Alan Baxter & Associates on  behalf of Network Rail with information supplied by, and with the assistance of, a number of the company’s  engineers.  Its contents have been reviewed and signed-off by Network Rail.   

The document has been written for the non-specialist, not the expert, and explains with the aid of diagrams  how OLE works and why it has to look the way it does.

Most importantly, it explains in ways we can all understand what is and what is not technically and legally  possible – from attaching OLE to listed stations and putting up masts on prominent viaducts, to getting wires  under historic bridges and through famous tunnels .

We hope you find this useful.  You may even find it interesting!

[SandTEngineer]

I can tell you from experience that standing on the track under the OLE^▸ (Overhead Line Equipment, more often "OHLE") on a wet day with a plastic mac on certainly gives a tingle down your neck and back......

[Electric train]

I can tell you from experience that standing on the track under the OLE^▸ (Overhead Line Equipment, more often "OHLE") on a wet day with a plastic mac on certainly gives a tingle down your neck and back......

That's because you forgot to attach the earth rod 

There certainly is discharging across insulators in the rain especially light drizzle type rain where there is a lot of pollution on the insulator; this discharges safely to earth and presents no risk.  A lot of effort is put into the design stage for touch and step potentials to keep them below the requirements of BSEN 50122

[Bmblbzzz]

You can feel the same walking under high voltage transmission pylons on a damp day.

[Adelante_CCT]

Whether as a one off or permanently I don't know but Reading Depot is being energised from 29th October.

[Electric train]

Whether as a one off or permanently I don't know but Reading Depot is being energised from 29th October.

Once the OLE^▸ (Overhead Line Equipment, more often "OHLE") has been energised once it has to be regarded as LIVE at all times and will come under the rules for a live system. 

Once it has been energised ait may well be switched out and an OLE "Form B" issued (Form B is part of the OLE isolation planning and safe working system it is the "Authority to test and apply earths" after this has been confirmed by the OLE Level A (a person authorised to issue Form C) Form C can be issued (Form C is a Permit to Work on OLE) to the person in charge of a work group.

And that is just a simplistic view  

Within the maintenance sheds a different system is used which is tied in with the Depot safety System and involves red and green lights, interlocks, padlocks and paperwork

[patch38]

Let me get this right: a Form B allows a Level A to issue a Form C? Or have I slipped into an episode of Yes Minister? 

[stuving]

Let me get this right: a Form B allows a Level A to issue a Form C? Or have I slipped into an episode of Yes Minister? 

No, this is the real world, a lot of which (called industry) is full of dangerous stuff.

If you are asked to climb up a ladder to wave your spanner at some OLE^▸ (Overhead Line Equipment, more often "OHLE"), you'll want good evidence it's off and that "off means off".  A permit to work is standard practice in much of industry, and it must come from the right person to know what control is up to - and that the back-up insurance measure (big earthing straps) is in place.

Can you think of a better way to manage safety in a big organisation?

[patch38]

I wasn't poking fun at electrical safety - I spent a lot of my younger years working on live 3-phase and the fact I'm still here is a testimony to all the health and safety that was drilled into us. No the terminology just struck me as amusing - that's why I put the smiley in!

[Electric train]

Let me get this right: a Form B allows a Level A to issue a Form C? Or have I slipped into an episode of Yes Minister? 

I wasn't poking fun at electrical safety - I spent a lot of my younger years working on live 3-phase and the fact I'm still here is a testimony to all the health and safety that was drilled into us. No the terminology just struck me as amusing - that's why I put the smiley in!

Errrrrr yes.

It sounds complex and is complex but as staving railway traction conductor systems have the dangers of electricity, the dangers of moving trains whilst ensuring the rest of the railway remains operational.

The form B and C more often than not also have to tie in with possession which are set up by a PICOP^▸ (Person In Charge Of Possession) who may have several  ES's working in his possession.

This whole safe system of work, both the possession and electrical isolation, have evolved over many many decades and I do mean many decades.   

[Bmblbzzz]

I think it's the just off alphabetical order that is amusing, rather than the existence of a comprehensive safety system.