Network Rail - work on Severn Beach line, summer 2019

[whole diary]

[grahame]

From the Network Rail Media Centre

Network Rail is carrying out vital maintenance work on the Severn Beach line in Bristol during July and August with work starting this weekend to ensure the continued safe and smooth running of the railway.

The upgrade also means that any future maintenance work in the area will cause less disruption for passengers.

The work involves:

* Removing a set of redundant points near Clifton Down station. Points guide trains onto the right route at junctions, however in this case the points are no longer required and will be replaced with straight track

* Renewing the Avonmouth Dock level crossing at West Town Road by upgrading the surface and replacing the tarmac either side of the crossing

* Installing new track between St Andrews Road level crossing and Avonmouth station

The work is being completed over a mixture of weekday nights, Saturday nights and Sunday daytime shifts between Saturday 6 July and Saturday 10 August, with some follow up work in September

As a result of these upgrades, buses will replace trains on three Sundays including 7 and 28 July as well as 4 August.

To keep residents updated Network Rail will be hosting a community drop-in session from 4.30pm to 7pm on Wednesday 17 July at the Avonmouth Community Centre, BS11 9EN.

This would seem to be a good opportunity to do any work at Portway Parkway which requires a possession.

[johnneyw]

That might have been useful but I doubt the opportunity will be realised as there isn't really much time until then and there's been no announcement of any work to be started shortly at Portway.

I was curious about whether the whole line required a possession for the track replacement or only the Avonmouth to SB^▸ (Signal Box) stretch but I am guessing that a lot of the materials involved (rails, ballast etc) will be brought in/taken away by rail not road.

[Adrian]

Why the over-use of this word "upgrade" (and, for that matter, "improvement works") seemingly whenever NR^» (Network Rail - home page) do routine replacements?
An upgrade surely means that something will be made tangibly better from a user's perspective?

[johnneyw]

Why the over-use of this word "upgrade" (and, for that matter, "improvement works") seemingly whenever NR^» (Network Rail - home page) do routine replacements?
An upgrade surely means that something will be made tangibly better from a user's perspective?

The stretch between Avonmouth and St Andrews Road is still a bit bone shaking (it was worse) but I thought that was fun. Smoothing the way may make it a little more comfortable and may allow for going a little faster but I don't know if I'll treat it as an improvement. 😐

[Red Squirrel]

Very intrigued to know which set of points they plan to remove...

[JayMac]

Very intrigued to know which set of points they plan to remove...

Me too. I'm not aware of any redundant points near Clifton Down.

[martyjon]

Very intrigued to know which set of points they plan to remove...

Me too. I'm not aware of any redundant points near Clifton Down.

Might be that trap point in the tunnel which has been clipped and padlocked ever since the line was singled.

[rich0099]

I'm quite glad the sleepers are being replaced between AVN and SAR - Every evening on the way home I peer down and see them in a terrible state of disrepair.

I know all of you know far more about the rail infrastructure than I - but I'm curious - the curve/radius between AVN and the SAR Level crossing is quite tight (sorry - I don't know the technical term). When replacing the rail, would the curve of the rail be created on site - of would it be pre-shaped?

Sorry for such a noob question - I'm just interested.

[stuving]

I'm quite glad the sleepers are being replaced between AVN and SAR - Every evening on the way home I peer down and see them in a terrible state of disrepair.

I know all of you know far more about the rail infrastructure than I - but I'm curious - the curve/radius between AVN and the SAR Level crossing is quite tight (sorry - I don't know the technical term). When replacing the rail, would the curve of the rail be created on site - of would it be pre-shaped?

Sorry for such a noob question - I'm just interested.

The answer is basically that rail is a lot more bendy than it looks. Rail is made in 216 m lengths (max, on latest info I have), and several taken to their installation site on a train - and it just bends to go round the corners. OK, there's a little more to it than that, like keeping all the rails vertical, but for the curvatures involved (that curve at AVN has a radius of about 200 m) it's not even very springy. Of course it is heavy, and the forces needed to lift and bend it are correspondingly large. Note that when talking about rail expansion, and buckling in the heat, the forces involved there (which are along the rail) are are very much bigger.

[johnneyw]

I'm quite glad the sleepers are being replaced between AVN and SAR - Every evening on the way home I peer down and see them in a terrible state of disrepair.

I know all of you know far more about the rail infrastructure than I - but I'm curious - the curve/radius between AVN and the SAR Level crossing is quite tight (sorry - I don't know the technical term). When replacing the rail, would the curve of the rail be created on site - of would it be pre-shaped?

Sorry for such a noob question - I'm just interested.

I'm not a Permanent Way expert myself but while following the well blogged coverage of the rail laying on the Glos Warks Steam Railway extension, one of the noticeable things was how bendy the rails were when being unloaded on site from the flat wagons. These seemed to quite easily* fit into the pre laid sleepers just ahead, even on a bend.

*I say "quite easily" from the comfort of a sofa accompanied by a coffee and bun. Those working on the project may employ slightly different terminology.

[Bmblbzzz]

I saw the rails being laid on the Filton Four Tracking and they looked quite bendy even in a vertical plane. I think they heat them, which presumably increases their flex?

[Red Squirrel]

No heat involved in the laying process. This video shows how it's done on a modern railway: https://vimeo.com/109587564

[Bmblbzzz]

Yep, that's the machine I saw.

[paul7575]

Remember new rail is flexible enough to be delivered on specialist trains, that can take normal track curvature during the journey from the manufacturer or welding plant. 

The delivery trains carry numerous rails at the same time, (up to 32 I think), but the rails can still flex from side to side and deal with changing gradients quite happily...

New rail for renewals of existing track is often delivered and pre-positioned between the ‘other’ running tracks, and a technique called thimbling, using a road rail machine attachment, is used to lift and position the new rail into the sleepers.  The following videos show how flexible the rail is as they lift it sideways a few metres, and also how quick they can do it:

https://youtu.be/mK1d-nscTsc

https://youtu.be/SupWOAddodw

Hope they are of interest...

Paul

[rich0099]

Thanks for everyone's input - much appreciated (knowledge is a wonderful thing).