South Wales Mainline Electrification

Two applications in with the planning committee this week - one to replace the bridge at the bottom of Trowbridge Road over the main line with a raised footpath/cycle way, and the other to simply remove the bridge over the mainline at the bottom of Wentloog Road (been inaccessible for years, so long in fact that I thought it had already been removed!).

As the mainline electrification continues I'd expect more of these applications to appear - particularly New Road, Brachdy Lane, Beresford Road and Splott Road. Southern Way and Central Link already have enough clearance, Beresford Road I am uncertain on...

Beresford Road bridge is scheduled to be demolished and rebuilt from June 2015. Details in the Network Rail report at http://www.networkrail.co.uk/browse%20documents/projects/great%20western/electrification%20environmental%20statements/wales/cardiff/gwml%20electrification%20-%20cardiff%20council%20-%20environmental%20statement%20vol%201b.pdf?cd=2 . Windsor Road is not listed in the document nor anything west of Canton Sheds although I gather that the Cowbridge Road West bridge will also have work done.

I'm sure I saw a planning application to rebuild Windsor Road bridge. It was probably a few months ago now.

Windsor Road bridge is definitely happening, January 2015

http://www.itv.com/news/wales/2014-11-1 ... -unveiled/

Not sure how old this is so apologies if it's not new, but if this is what we are getting then it will be worth the wait

As I understand it, this train won't be allowed to run at its full speed in the UK. So to call it a bullet train is a bit of a misnomer.

As I understand it, this train won't be allowed to run at its full speed in the UK. So to call it a bullet train is a bit of a misnomer.

Bullet-styled, maybe? I think I'm right in saying thet the top speed will still be 125mph but because of faster acceleration the journey time will be cut by 15-20 minutes. Of course if some trains ran non-stop between Newport or Bristol Parkway and London the time saving would be even greater. It will be interesting to see whether express services are required when the 2019 franchise is advertised. I should imagine the WG are pressing for some.

140mph+ running is possible - but operationally v difficult, as are express services. There are only so many pathways on the GWML. An express will quickly catch a stopping train running ahead of it - made more difficult because of 2 track section between Swindon and Bristol. When you factor in local services, freight and the commercial need to collect as many fare paying passenger as possible, the challenges become even more apparent.

There needs to be a further investment in increased pathway capacity ( eg some 4 tracking), enhanced signalling, etc and service expectations set in next franchise; then 140 running and fewer stops would be possible. As a comparison if the same average speed currently possible on WCML between Manchester and London could be replicated on GWML between Cardiff and Paddington then journey times would be less than 90 minutes.

140mph+ running is possible - but operationally v difficult, as are express services. There are only so many pathways on the GWML. An express will quickly catch a stopping train running ahead of it - made more difficult because of 2 track section between Swindon and Bristol. When you factor in local services, freight and the commercial need to collect as many fare paying passenger as possible, the challenges become even more apparent.

That's very interesting, thank you! Out of interest has the Swindon - Bristol section you mention always been two track or was it reduced as a result of Beeching or at some other period? The reason I ask is that I seem to remember that there were express services from both South Wales and Bristol at one time. I'm going back a long way, mind!

140mph+ running is possible - but operationally v difficult, as are express services. There are only so many pathways on the GWML. An express will quickly catch a stopping train running ahead of it - made more difficult because of 2 track section between Swindon and Bristol. When you factor in local services, freight and the commercial need to collect as many fare paying passenger as possible, the challenges become even more apparent.

There needs to be a further investment in increased pathway capacity ( eg some 4 tracking), enhanced signalling, etc and service expectations set in next franchise; then 140 running and fewer stops would be possible. As a comparison if the same average speed currently possible on WCML between Manchester and London could be replicated on GWML between Cardiff and Paddington then journey times would be less than 90 minutes.

It always strikes me that the Bristol to Swindon stretch is the fastest bit of the Cardiff to London journey. It is certainly far higher speed than the journey between Cardiff and the tunnel. Coming the other way, the slower speed on emerging from the tunnel into Gwent is noticeable.

I think there are long stretches of Severn Tunnel Junction to Cardiff which are effectively 2 track only, due to the feeder lines into the steel works, Freightliner and so on. Does anyone know if there is a plan to raise the speed limit to over 90mph on this bit of the line once the signalling work is complete?

It always strikes me that the Bristol to Swindon stretch is the fastest bit of the Cardiff to London journey. It is certainly far higher speed than the journey between Cardiff and the tunnel. Coming the other way, the slower speed on emerging from the tunnel into Gwent is noticeable.

I think there are long stretches of Severn Tunnel Junction to Cardiff which are effectively 2 track only, due to the feeder lines into the steel works, Freightliner and so on. Does anyone know if there is a plan to raise the speed limit to over 90mph on this bit of the line once the signalling work is complete?

I know that the relief lines will be getting a linespeed increase after the re-signalling but I don't think the main lines will be. It's really frustrating that as soon as you're in Wales the maximum speed drops down to 90.

There would certainly be a journey time improvement, maybe to 1h45m like back in the 70's!

Add this to the electric trains time saving and it could be down to 1h30m or so.