Bristol to Birmingham Corridor Strategic Rail Study - June 21

[whole diary]

[Red Squirrel]

This document is worth a read! Put the kettle on first though. There's quite a lot of interesting proposals for increasing capacity at Gloucester, Cheltenham and various other places, but my jaw dropped when I read this:

Westerleigh Junction

The recommended TSS introduces three additional services per hour (the two additional Bristol to Gloucester services and the MRH Bristol service) through Westerleigh Junction – which is already a capacity and performance constraint for services in this corridor and on the GWML^▸ (Great Western Main Line) to London and South Wales. The additional MRH service may not require intervention, but neither additional Bristol to Gloucester service can be accommodated without intervention, which would be major, complex, and costly at this location. However, any intervention would have much wider benefits (and may also be triggered by off-corridor service enhancements) and may be required to deliver acceptable performance robustness for any more trains through the junction.

One potential solution would be to introduce four-tracking west of Westerleigh Junction to allow parallel departures between services departing towards Yate and Hullavington. Again, no feasibility work has been undertaken on this option and the complexity is understood.

I feel a bit light-headed... time for another cup of tea, I think.

 https://www.gloucestershire.gov.uk/media/2108166/bristol-to-birmingham-corridor-strategic-study-final-report-v10.pdf

[Bmblbzzz]

Hang on:

Parkway to Westerleigh jnctn four-tracking with stations on the reliefs at Winterbourne and Coalpit Heath. TonyN can revert to his previous username!

Hmm. That would involve demolishing dozens of houses, and widening deep cuttings, high embankments and viaducts. It might work out cheaper to build a new alignment altogether.

Pick your jaw up but don't drop your tea!

[TonyN]

TonyN can revert to his previous username!

I had better point out that I think you mean Tony K.

Thanks to Red Squirrel for spotting the document makes Interesting reading for me regarding Improvments to services at Worcestershire parkway.

As for Bristol Parkway to Westerleigh they seem to have fogotten that the Midland did provide an alternative until someone closed it.

[Red Squirrel]

Hang on:

Parkway to Westerleigh jnctn four-tracking with stations on the reliefs at Winterbourne and Coalpit Heath. TonyN can revert to his previous username!

Hmm. That would involve demolishing dozens of houses, and widening deep cuttings, high embankments and viaducts. It might work out cheaper to build a new alignment altogether.

Pick your jaw up but don't drop your tea!

I know, I know! But to be fair, the report does say major, complex, and costly...

[Red Squirrel]

As an aside, the four-tracking of Filton Bank cost £130 million - but they had a four-track alignment to re-use. Parkway to Westerleigh could well cost three times as much; perhaps as much as £428 million. If only there was that kind of money available for a transport scheme in this area!

[Bmblbzzz]

TonyN can revert to his previous username!

I had better point out that I think you mean Tony K.

Apologies to both of you.

And if needed also to TonyL and TonyM!

[Bmblbzzz]

As an aside, the four-tracking of Filton Bank cost £130 million - but they had a four-track alignment to re-use. Parkway to Westerleigh could well cost three times as much; perhaps as much as £428 million. If only there was that kind of money available for a transport scheme in this area!

Which, to be fair, it was decided there wasn't. But, as you say, major, complex and costly – I think if I were king of Weca and had £428 million to spend on a major transport project, this probably would not be it. But I'd be open to persuasion.

[ellendune]

How much of the problem would be solved by grade separation at Westerleigh?

Couldn't the Midland line under the GW^▸ (Great Western) be used with a chord built to link it to the GW towards Parkway?

[Red Squirrel]

How much of the problem would be solved by grade separation at Westerleigh?

If I've understood correctly, then not enough. I think the path analysis in the document linked below is saying that you can't quite get 2tph from Bristol to Gloucester - and the newer study wants 4tph:

https://www.gloucestershire.gov.uk/media/1518302/metrowest-phase-2-gloucester-extensions-report-v17-final.pdf

Couldn't the Midland line under the GW^▸ (Great Western) be used with a chord built to link it to the GW towards Parkway?

I presume they will look into options like this if they get funding for a proper study.

[ChrisB]

The strategic report referenced in the originalk report addresses this problem - well worth reading all of it!

Gloucester to Westerleigh Junction

In order to accommodate the additional Bristol to Gloucester stopping services an opportunity for inter-regional passenger trains to pass local passenger trains between Gloucester and Westerleigh Junction p is required. This entails provision of major infrastructure in the form of dynamic passing loops. Two potential options have been identified:

1. Upside loop near Yate and a Down side loop near Haresfield.

2. Up and Down side loops in a four-track formation near Charfield.

[Red Squirrel]

The strategic report referenced in the originalk report addresses this problem - well worth reading all of it!

Gloucester to Westerleigh Junction

In order to accommodate the additional Bristol to Gloucester stopping services an opportunity for inter-regional passenger trains to pass local passenger trains between Gloucester and Westerleigh Junction p is required. This entails provision of major infrastructure in the form of dynamic passing loops. Two potential options have been identified:

1. Upside loop near Yate and a Down side loop near Haresfield.

2. Up and Down side loops in a four-track formation near Charfield.

That section deals with capacity between Gloucester and Westerleigh. As I read it, there would not be capacity for these trains to get beyond there to Bristol - so these interventions would be required as well as BPW^» (Bristol Parkway - next trains) - Westerleigh.

It looks like there's plenty of room for loops at Haresfield and Yate. There are already loops at Charfield, so perhaps this refers to an upgrade or extension?

[ChrisB]

On page 70 of the latest report it covers the concerns you have identified and there are detailed diagrams of the Network Rail proposed infrastructure enhancements: -

Accommodating the Recommended TSS requires a number of significant interventions.

An intervention is required between Bristol Parkway and Westerleigh Junction to accommodate all additional trains on top of the base services. Four-tracking is suggested, but more investigation would be needed to determine feasibility.

Dynamic loops in different locations on the Up and Down sides or four-tracking in the Charfield area are also needed to timetable one or two new Bristol Temple Meads-Gloucester services per hour.

More work around the different locations would be needed to identify the best opportunities for through trains to pass stopping services. These interventions in the south of the corridor are needed to deliver one additional Bristol to Gloucester service, but once undertaken they create enough capacity for two additional Bristol to Gloucester services, delivering the proposed 4tph Bristol to Gloucester metro-style service.

The 2tph Bristol-Gloucester option also improves timetabling at Gloucester as it removes the need for a shunt move to the Gloucester Curve Siding via Horton Road Junction. Instead, services have much shorter turnround times in the platform.

To make Gloucester work more efficiently and accommodate identified services a new bay platform accessible from the East is recommended. This would also reduce almost all minimum margins identified at Gloucester. In the same location, a scheme already identified to upgrade the parcels line would bring equal benefits and develop resilience of the network in the area.

[Red Squirrel]

You'll have noticed that the prospect of a third platform at Cheltenham seems to be on the cards again too:

A new bay platform is needed at Cheltenham Spa to facilitate the increased number of services
terminating or reversing direction at this station. Such a facility could also support the future extension
of any MetroWest services to/from Bristol, beyond Gloucester; and provide additional stabling in the
area.

(p63)

[jamestheredengine]

Surprised that slow crawl stopping just outside Bournville, Selly Oak, and the rest of those lovely stations on the way into Birmingham isn't considered to be a capacity constraint. That bit looks ripe for four-tracking too.

[Bmblbzzz]

Surprised that slow crawl stopping just outside Bournville, Selly Oak, and the rest of those lovely stations on the way into Birmingham isn't considered to be a capacity constraint. That bit looks ripe for four-tracking too.

I thought that bit already was four-track?