Severn Tunnel/Golden Valley Redoubling

[ic250]

Does anyone know anything about when the Severn Tunnel is going to be wired (or even whether they will use wires) as part of the Great Western project?

I'd imagine its not until after the Golden Valley redoubling, but there has been very little news on that of late either. It seems strange that there has been so little work done on what must be one of the most complicated elements of the whole project - that of refurbishing the 7km tunnel.

 

[Flamingo]

I know that the planning is already taking place. The last thing you should see is boots on the ground, and I think that will be some time off.

The more time they spend planning, the less chance of a serious cock-up when it happens. Don't forget the six P's!

 

[joeykins82]

As for the tunnels – the big one I guess you’re interested in on GW is the Severn which in fact is really quite an electrification-friendly tunnel with quite good clearances. From the initial survey work we’ve done already, we’ve found that the room in the roof of the tunnel is capable of accommodating normal low encumbrance equipment like we put in tunnels elsewhere in the UK. And it would also be perfectly appropriate to use solid beam technology through the tunnel. We will consider both options when we move into the detail design phase.

Full article: http://www.globalrailnews.com/2011/04/28/electrification-delivering-the-transformation/
Found via: http://en.wikipedia.org/wiki/21st-century_modernisation_of_the_Great_Western_Main_Line

As far as timetable goes, electrification to Bristol is due in 2016 and Cardiff in 2017, so the Severn Tunnel will be presumably be a 2016/2017 job.

 

[LNW-GW Joint]

As far as timetable goes, electrification to Bristol is due in 2016 and Cardiff in 2017, so the Severn Tunnel will be presumably be a 2016/2017 job.

That document is 3 years old.
I have read somewhere that the Severn Tunnel wiring is proving more difficult and costly than originally thought.
There are also still the issues of how the wiring will be done in South Wales, including whether to include the slow (sorry, relief) lines between Severn Tunnel Jn and Cardiff.

I imagine diversions via Gloucester will start when the Wootton Bassett-Bristol Parkway route is being wired, which ought to be next year.

 

[fgwrich]

That document is 3 years old.
I have read somewhere that the Severn Tunnel wiring is proving more difficult and costly than originally thought.
There are also still the issues of how the wiring will be done in South Wales, including whether to include the slow (sorry, relief) lines between Severn Tunnel Jn and Cardiff.

I imagine diversions via Gloucester will start when the Wootton Bassett-Bristol Parkway route is being wired, which ought to be next year.

Do we know if NR were still considering installing OHLE via the the overhead rail system for the Severn Tunnel (ala Edinburgh's Mound Tunnels and the Thameslink Core) than overhead wires or has that yet to be decided?

 

[ic250]

There are also still the issues of how the wiring will be done in South Wales, including whether to include the slow (sorry, relief) lines between Severn Tunnel Jn and Cardiff.
.

I can't see the thinking behind not covering the slow lines as well as part of the electrification project. Can all the intercity and local services use the fast lines?

If that's the case it seems that NR are cutting some serious corners on this job.

 

[LNW-GW Joint]

I can't see the thinking behind not covering the slow lines as well as part of the electrification project. Can all the intercity and local services use the fast lines?
If that's the case it seems that NR are cutting some serious corners on this job.

Cost. They have to resolve the overspend (scope creep and roll-out costs).
Nobody wants other CP5 electrification projects cut because of GW overrun.

My perception is that the slow lines are not much used by passenger trains, certainly not STJ-Newport.
On the other hand wiring for freight is important, and is one of the strategic reasons behind the "electric spine".

 

[Michael.Y]

Cost. They have to resolve the overspend (scope creep and roll-out costs).
Nobody wants other CP5 electrification projects cut because of GW overrun.

My perception is that the slow lines are not much used by passenger trains, certainly not STJ-Newport.
On the other hand wiring for freight is important, and is one of the strategic reasons behind the "electric spine".

Still handy to have as an emergency backup mind. No reason to wire relief in Thames Valley and not relief in South Wales. Relief between NWP and CDF will have to be wired, so may as well do small part to STJ.

 

[HSTEd]

They could always wire the reliefs with trolley and accept a low-ish speed limit on it for electric traction.
(Differential 'E'?)

 

[WatcherZero]

Its fascinating to see them raise the grille and see there is basically a river running under the Severn tunnel.

 

[GRALISTAIR]

The more time they spend planning, the less chance of a serious cock-up when it happens. Don't forget the six P's!

Preparation and Planning Prevents P--- Poor Performance?

 

[Flamingo]

Preparation and Planning Prevents P--- Poor Performance?

Well done that man!

 

[BestWestern]

Still handy to have as an emergency backup mind. No reason to wire relief in Thames Valley and not relief in South Wales. Relief between NWP and CDF will have to be wired, so may as well do small part to STJ.

I agree it should be done, but surely there is no parallel with the Thames Valley - the reliefs there will be used by the electric stock on local services, which won't be the case in South Wales - unless I'm missing something?

 

[joeykins82]

I guess that's the crux of the argument. The Welsh Assembly will be saying that the relief lines should be wired with the mains because the intercity electric trains will use them during main line track possessions and other times of disruption. The Department for Transport will be saying that the GWML electrification only covers the main lines, and that the relief lines which will be used by local services should be paid for out of the valley lines electrification budget.

 

[HowardGWR]

Well done that man!

Is it that well done? Should it not be 'planning and preparation' indicating that the one follows the other?

 

[HSTfan!!!]

They could always wire the reliefs with trolley and accept a low-ish speed limit on it for electric traction.
(Differential 'E'?)

The reliefs are only 40mph between STJ and NWP with an increase to 60 after AD junction anyway.

 

[DaveHarries]

It was reported not too long ago - I can't recall where - that the line east of Bath Spa is going to be closed at some point next summer for a few days for works in connection with the electrification.

Meanwhile, where is the "Golden Valley"?

Dave

 

[LNW-GW Joint]

Meanwhile, where is the "Golden Valley"?
Dave

It's the posh name for the Stroud or Chalford valley, leading up to Sapperton tunnel, Kemble and Swindon.
Shorthand for "Swindon to Gloucester Line".

Just to confuse, there's another Golden Valley, in Herefordshire, and it also had a railway (Pontrilas to Hay on Wye) which closed in the 1950s.

 

[ic250]

The reliefs are only 40mph between STJ and NWP with an increase to 60 after AD junction anyway.

And the maximum on the fast lines is only 90mph from Severn Tunnel Junction to Cardiff (and lower thereafter), IIRC.

Presumably linespeeds will increase after the current resignalling work is complete?

 

[The Planner]

Newport area got resignalled a few years back in stages, nothing will touch that now until ERTMS comes along.

 

[HSTfan!!!]

And the maximum on the fast lines is only 90mph from Severn Tunnel Junction to Cardiff (and lower thereafter), IIRC.

Presumably linespeeds will increase after the current resignalling work is complete?

I wish, it's a bit painful running so far at 40 lol

 

[HSTEd]

You could put cheapo trolleywire up and still run at 50.
Better than a 75mph diesel line or anything like that.

 

[snowball]

It's the posh name for the Stroud or Chalford valley, leading up to Sapperton tunnel, Kemble and Swindon.
Shorthand for "Swindon to Gloucester Line".

Just to confuse, there's another Golden Valley, in Herefordshire, and it also had a railway (Pontrilas to Hay on Wye) which closed in the 1950s.

There are several Golden Valleys. Try typing "Golden Valley" into a mapping site like www.streetmap.co.uk. It appears to find 12 (including a Golden Valley Plantation). Some of those may be repeats but to judge from the counties there must be several genuinely different.

 

[Michael.Y]

I agree it should be done, but surely there is no parallel with the Thames Valley - the reliefs there will be used by the electric stock on local services, which won't be the case in South Wales - unless I'm missing something?

It would just make more sense to have the option available. No good having shiny new electric ICX trains if they're stuck at NWP while all those dirty old diesel units go chugging past. Plus it would allow more flexibility with regards to empty stock moves, rugby matchday shuttles etc.

 

[anthony263]

Dont forget the Welsh government/SEWTA have proposed these local services between Cardiff and Abergavenny etc as well as extra services to Chepstow etc so some of these most likely will have to use the relief lines especially if they serve the long proposed station at St Mellons etc.

Some freights could potentially be hauled by electric traction if the full route the service runs on is electrified

 

[ic250]

In case there is interest, the Swindon-Kemble redoubling has now been completed:

http://www.networkrail.co.uk/news/2014/aug/Swindon-Kemble-line-upgrade-complete/