Could the Marches line be upgraded to W12 gauge?

[Liverbird 1]

Moderator note - split from:

Wrexham, Shropshire & Midlands Railway updates

An application for the "Wrexham, Shropshire & Midlands Railway" (no connection to the former Arriva company) has appeared online for a service calling at Wrexham General, Gobowen, Shrewsbury, Telford Central, Wolverhampton, Darlaston, Walsall, Coleshill Parkway, Nuneaton, Milton Keynes (set down...

www.railforums.co.uk

Is that seriously the only obstacle to doubling the line?

Have been looking at reinstating the Hereford - Ross-on-Wye - Gloucester with a Swindon Western by-pass to explore alternative ways of getting multi-modal freight from Southampton to the North West using the Marches Line - by-passing Birmingham & Bristol. Does anyone know how difficult it would be to upgrade the Marches line to W12 gauge, including the Wrexham-Shrewsbury? Was looking at a short chord connecting the Wrexham - NW mainline by-pass Lache & Saltney too and where potential mutlimodal freight terminals could be located.

 

[zwk500]

Does anyone know how difficult it would be to upgrade the Marches line to W12 gauge, including the Wrexham-Shrewsbury?

At a guess, awkward. It's currently W8 (with restrictions) according to the Sectional Appendix. There's not any great long tunnels I can remember but there are a fair few bridges over the length to do.

 

[eisenach]

I doubt whether Dinmore tunnel would be easy

 

[craigybagel]

At a guess, awkward. It's currently W8 (with restrictions) according to the Sectional Appendix. There's not any great long tunnels I can remember but there are a fair few bridges over the length to do.

I doubt whether Dinmore tunnel would be easy

Dinmore is almost a mile long and single bore. You would think that would be a challenge.

 

[Topological]

I am trying to work out what W12 for the Marches actually achieves.

If you want to avoid Colwich then trains can already by running past Bescott, a route which also avoids Birmingham.

Following HS2 Birmingham to Reading is via OOC, so you dont need two CrossCountry through Oxford. IF the one that remains is the via Solihull one then you have a path through Coventry to Stechford.

Anything that prompts a resignalling of the Marches (which more freights would require) is a good thing though.

 

[zwk500]

I am trying to work out what W12 for the Marches actually achieves.
If you want to avoid Colwich then trains can already by running past Bescott, a route which also avoids Birmingham.

To get from Southampton to Bescot requires going through some part of Birminghamceven if you avoid New Street.
King's Norton, Landor Street, and Wolves-Stafford are all rather busy areas.

However routing via Gloucester and Hereford is not the answer. Its a terribly indirect route and the Marches has some very steep sections as well as heavily constrained capacity due to short loops, limited layouts, and the legacy signalling.

Anything that prompts a resignalling of the Marches (which more freights would require) is a good thing though.

Freight wouldn't make the business case for it.

 

[Harpo]

Anything that prompts a resignalling of the Marches …….. is a good thing though.

Based on what logic?

 

[zwk500]

Based on what logic?

Tbf the presence of Absolute Block on this line leads to very inefficient capacity as the overall capacity of the line is limited by the length of the longest block. It is also staff-intensive to work and leads to limited real-time information for passengers and staff as there is no automatic train berth reporting as a general rule.

Resignalling to TCB or ETCS would be a benefit and therefore things that prompt that would be a good thing. However, the freight would not prompt resignalling on it's own.

 

[Harpo]

Tbf the presence of Absolute Block on this line leads to very inefficient capacity as the overall capacity of the line is limited by the length of the longest block. It is also staff-intensive to work and leads to limited real-time information for passengers and staff as there is no automatic train berth reporting as a general rule.

Resignalling to TCB or ETCS would be a benefit and therefore things that prompt that would be a good thing. However, the freight would not prompt resignalling on it's own.

Mechanical signalling survives because it is low cost, reliable and does what their bit of the railway needs. The (low graded) staffing cost reductions make only a small contribution to the overall scheme. I’m guessing circa £4-5m for a 10 SEU box versus four residents costing maybe £0.16m a year? Hence why life extension at around 1/3 the cost of renewals is so attractive.

Anything other than like-for-like such as splitting long blocks and increasing the SEU count is an enhancement. That involves sourcing and unlocking additional funding, never an easy task.

 

[Topological]

Tbf the presence of Absolute Block on this line leads to very inefficient capacity as the overall capacity of the line is limited by the length of the longest block. It is also staff-intensive to work and leads to limited real-time information for passengers and staff as there is no automatic train berth reporting as a general rule.

Resignalling to TCB or ETCS would be a benefit and therefore things that prompt that would be a good thing. However, the freight would not prompt resignalling on it's own.

Exactly. The longest block is something like 17 minutes (between Hereford and Abergavenny) and there are some other 10 minute plus. That is really constraining what can be done with the line.

My feeling is the freight would prompt resignalling as you would need it to get sufficient paths to make any of the other investment worthwhile. Possibly, you can find 1 path per hour north of Hereford, but south of Hereford you are already struggling.

== Doublepost prevention - post automatically merged: 6 Jan 2026 ==

Mechanical signalling survives because it is low cost, reliable and does what their bit of the railway needs. The (low graded) staffing cost reductions make only a small contribution to the overall scheme. I’m guessing circa £4-5m for a 10 SEU box versus four residents costing maybe £0.16m a year? Hence why life extension at around 1/3 the cost of renewals is so attractive.

Anything other than like-for-like such as splitting long blocks and increasing the SEU count is an enhancement. That involves sourcing and unlocking additional funding, never an easy task.

Indeed it is not an easy task. I doubt that resignalling the Marches is high on anyone's agenda.

There are so many services that would be useful. There is a huge car park at Pontypool and New Inn next to a dual carriageway. A local service could really boost railheading, but either you stop all the Holyheads and Manchesters there (which I am ok with, it is not an intercity line) or you need other services. Then you start hitting the path constraints.

Certainly there is no argument based on cost for resignalling.

 

[zwk500]

Mechanical signalling survives because it is low cost, reliable and does what their bit of the railway needs. The (low graded) staffing cost reductions make only a small contribution to the overall scheme. I’m guessing circa £4-5m for a 10 SEU box versus four residents costing maybe £0.16m a year? Hence why life extension at around 1/3 the cost of renewals is so attractive.

Anything other than like-for-like such as splitting long blocks and increasing the SEU count is an enhancement. That involves sourcing and unlocking additional funding, never an easy task.

Oh on a value-for-money basis it doesn't wash it's face, hence why legacy signalling is hanging on in there. A few IB fiddles have gone in over the years on the worst affected bits and that's probably the best that can be hoped for until the ETCS programme has done all the much busier bits.

 

[LNW-GW Joint]

What's the point of a chord bypassing Lache and Saltney on to the North Wales main line?
Three's no freight to speak of on that axis.
There's still 5 miles of single track Rossett-Wrexham to double as well.
Ken Skates talks about a similar chord at Shotton but I'm not sure if that makes any business sense.

The whole Marches network has many round-arch rural bridges which would have to be altered for a gauge enhancement.
Dinmore Tunnel was double tracked (two separate bores) last time I looked.
Marches resignalling has been postponed several times, though Crewe-Shrewsbury has been done.

 

[Harpo]

Marches resignalling has been postponed several times, though Crewe-Shrewsbury has been done.

Crewe-Shrewsbury got lucky in becoming one of the two modular signalling & MCB-OD pilots alongside Ely-Norwich.


Mechanical routes go into the renewals workbank by their notional life expiry date but because the lower cost refurb/life extension option exists for mechanical, it means that they get reviewed for funding of the preferred option. The lowest cost option usually wins. Rinse and repeat.

Even if the Marches did get re-signalled, I’d not be surprised by Shrewsbury being too difficult/expensive, forcing the survival of Sutton Bridge as a low cost fringe.

 

[craigybagel]

Anything that prompts a resignalling of the Marches (which more freights would require) is a good thing though.

Tbf the presence of Absolute Block on this line leads to very inefficient capacity as the overall capacity of the line is limited by the length of the longest block. It is also staff-intensive to work and leads to limited real-time information for passengers and staff as there is no automatic train berth reporting as a general rule.

Resignalling to TCB or ETCS would be a benefit and therefore things that prompt that would be a good thing. However, the freight would not prompt resignalling on it's own.

Exactly. The longest block is something like 17 minutes (between Hereford and Abergavenny) and there are some other 10 minute plus. That is really constraining what can be done with the line.

My feeling is the freight would prompt resignalling as you would need it to get sufficient paths to make any of the other investment worthwhile. Possibly, you can find 1 path per hour north of Hereford, but south of Hereford you are already struggling.

== Doublepost prevention - post automatically merged: 6 Jan 2026 ==


Indeed it is not an easy task. I doubt that resignalling the Marches is high on anyone's agenda.

There are so many services that would be useful. There is a huge car park at Pontypool and New Inn next to a dual carriageway. A local service could really boost railheading, but either you stop all the Holyheads and Manchesters there (which I am ok with, it is not an intercity line) or you need other services. Then you start hitting the path constraints.

Certainly there is no argument based on cost for resignalling.

When I first visited the ROC in Cardiff I was shown an empty space in the room where the panels for Marches resignalling were going to go. That was in 2013....

Crewe-Shrewsbury got lucky in becoming one of the two modular signalling & MCB-OD pilots alongside Ely-Norwich.

*Unlucky. That signalling is an absolute nightmare to deal with and 12 years after it was first commissioned it still doesn't work properly. There are so many places where the timings are incorrect for the barriers, even when the computer does know you're a fast train and hasn't defaulted to 153 all stops timings - and the signallers can't override it.

It also did next to nothing to improve capacity as they kept the block sections the same as they had been under AB after Whitchurch was closed, meaning you still have the same long ~15 minute section from Prees to Wrenbury that limits the entire line. The Marches would be the same unless they invest in changing the block sections to not just line up with the level crossings.

Even if the Marches did get re-signalled, I’d not be surprised by Shrewsbury being too difficult/expensive, forcing the survival of Sutton Bridge as a low cost fringe.

All the plans we've been told about involve keeping at least Severn Bridge Junction in place. I'm not sure what that means for Crewe Junction and Sutton Bridge Junction however. Shrewsbury's signalling is very limiting (if you lose platform 4 the whole network comes to a halt) but it very much falls into the too complicated category.

 

[Llanigraham]

Before I stop signalling on the Marches line, 11 years ago, they were quoting figures of in excess of £1m per Box to close them and modernise the signalling system. Remember that many of the Boxes also control level crossings which complicates matters.

We were told that Severn Bridge Junction Box would probably be the last mechanical box in the country to be modernised and replaced. There had been talk of transferring some of the Sutton Bridge operation to it, but fringing ERTMS to Machy complicated matters.

 

[zwk500]

It also did next to nothing to improve capacity as they kept the block sections the same as they had been under AB after Whitchurch was closed, meaning you still have the same long ~15 minute section from Prees to Wrenbury that limits the entire line. The Marches would be the same unless they invest in changing the block sections to not just line up with the level crossings.

This is a critical issue with a lot of more recent AB to TCB conversions. The Breckland line from Ely to Norwich was very similar as well.

 

[Harpo]

It also did next to nothing to improve capacity as they kept the block sections the same as they had been under AB after Whitchurch was closed,

Hence my earlier comment about additional enhancement funding. Unless somebody is willing to pay the extra for enhanced capabilities, you’re stuck with a like-for-like signalling renewal unless you can tweak spacing without adding signals.

All the plans we've been told about involve keeping at least Severn Bridge Junction in place. I'm not sure what that means for Crewe Junction and Sutton Bridge

Two choices if Severn Bridge stays.

Either, the huge expense of ‘temporary’ (insert crystal ball date here) fringe works to connect the Marches signalling and Machynlleth SC direct to the complex Severn Bridge, and re-do it all again when Shrewsbury arrives in the 20th century, or……

At far less cost, keep Sutton Bridge and its existing fringe to Machynlleth, Severn Bridge and (via less expensive new links) add the very simple two track Marches. Sutton Bridge would then go in whichever century Severn Bridge goes.

I assume Crewe Jn has similar circumstances?

 

[The Planner]

Mechanical signalling survives because it is low cost, reliable and does what their bit of the railway needs. The (low graded) staffing cost reductions make only a small contribution to the overall scheme. I’m guessing circa £4-5m for a 10 SEU box versus four residents costing maybe £0.16m a year? Hence why life extension at around 1/3 the cost of renewals is so attractive.

Anything other than like-for-like such as splitting long blocks and increasing the SEU count is an enhancement. That involves sourcing and unlocking additional funding, never an easy task.

It was designed but kicked into the long grass a good while ago. I'm sure Ive got the proposed diagrams somewhere.

*Unlucky. That signalling is an absolute nightmare to deal with and 12 years after it was first commissioned it still doesn't work properly. There are so many places where the timings are incorrect for the barriers, even when the computer does know you're a fast train and hasn't defaulted to 153 all stops timings - and the signallers can't override it.

It also did next to nothing to improve capacity as they kept the block sections the same as they had been under AB after Whitchurch was closed, meaning you still have the same long ~15 minute section from Prees to Wrenbury that limits the entire line. The Marches would be the same unless they invest in changing the block sections to not just line up with the level crossings.

One of the worst re-signallings ever that one.

 

[craigybagel]

I assume Crewe Jn has similar circumstances?

I think any decision about Crewe Junction will be tied up with what happens with the Shrewsbury - Chester line. At the moment Crewe Junction controls through to Gobowen North with TCB, which works fine (it's divided pretty evenly into two sections at Baschurch giving ~10 minute headways). Gobowen to Wrexham (Croes Newydd SB) is a long AB section that takes about 20 minutes and is a big challenge to capacity on the line. Then you have Wrexham that desperately needs something going in to allow trains from Chester to turnback without needing to shunt to Croes Newydd (and go over a busy level crossing next to a hospital twice every time).

It was designed but kicked into the long grass a good while ago. I'm sure Ive got the proposed diagrams somewhere.

We were quoted dates a few times over the years, usually only two or three years later than the current time, but it's been quiet for a long time now.

One of the worst re-signallings ever that one.

And after a brief period of calm through Crewe PSB's patch, most services over that line then need to deal with Manchester South - which must also be on that list of worst schemes of all time!

 

[HSTEd]

Mechanical signalling survives because it is low cost, reliable and does what their bit of the railway needs. The (low graded) staffing cost reductions make only a small contribution to the overall scheme. I’m guessing circa £4-5m for a 10 SEU box versus four residents costing maybe £0.16m a year? Hence why life extension at around 1/3 the cost of renewals is so attractive.

That is a rate of return of ~12.8% per annum (vs do nothing, 19% vs life extension), and increasing as rail staff pay continues to climb.

EDIT:
Misread the post, thought that was £160k each, but you aren't going to get 4 signallers for a total cost of employment of £160k per annum.

It's just shy of £140k in simple pay, according to the Network Rail website for a Grade 2 signaller. Grade 3 signaller (post training) is going to be around £193k once you include NI and pension contributions. Then pile management, training and other costs on top and it will climb rather steeply.....

EDIT #2:

To return to the topic at hand, is there any particular reason to clear the Marches line to W12?
Perhaps I lack imagination, but I can't see very much demand for running large gauge traffic on the line. As the posters above have noted, its not really a direct route for any suitable freight operations.

 

[Harpo]

That is a rate of return of ~12.8% per annum (vs do nothing, 19% vs life extension), and increasing as rail staff pay continues to climb.

Quite. It’s a useful contributor but shows why staff cost savings alone, don’t drive the elimination of mechanical boxes.

 

[Llanigraham]

That is a rate of return of ~12.8% per annum (vs do nothing, 19% vs life extension), and increasing as rail staff pay continues to climb.

EDIT:
Misread the post, thought that was £160k each, but you aren't going to get 4 signallers for a total cost of employment of £160k per annum.

It's just shy of £140k in simple pay, according to the Network Rail website for a Grade 2 signaller. Grade 3 signaller (post training) is going to be around £193k once you include NI and pension contributions. Then pile management, training and other costs on top and it will climb rather steeply....

If I remember correctly the Gr2 Boxes are Tram Inn, Moreton-on-Lugg, Leominster, Bromfield, Onibury, Marshbrook and Dorrington.
Woofferton was definitely a 3, as I think was Craven Arms. Not sure what grade Hereford is.
And what hasn't been included is the Relief staff figures.

EDIT #2:

To return to the topic at hand, is there any particular reason to clear the Marches line to W12?
Perhaps I lack imagination, but I can't see very much demand for running large gauge traffic on the line. As the posters above have noted, its not really a direct route for any suitable freight operations.

Agreed!

 

[zwk500]

EDIT #2:

To return to the topic at hand, is there any particular reason to clear the Marches line to W12?
Perhaps I lack imagination, but I can't see very much demand for running large gauge traffic on the line. As the posters above have noted, its not really a direct route for any suitable freight operations.

The only reason I could see for further gauge enhancements would be if significant container flows between North West England, North East England, or Scotland South Wales became established.

And even then the main benefit would be relieving Derby-Birmingham or Stafford-Wolves.