Issues with reducing line through Guide Bridge to two tracks from four

[yorksrob]

Mod Note: Posts #1 - #14 originally in this thread.

The real challenge is to prevent "rationalisation" turning into wholesale closure.

Rationalisation does not just mean "axe duplications" - it can involve spending significant amounts of money to enable long term savings.

The Hazel Grove chord being an obvious historical example.

Rationalisation is something that shouldn't be countenanced lightly. We all have examples rationalisations from the 1980's that are still causing problems today. My own favourite is the de-quadroupling of track between Guide Bridge and Manchester Piccadilly which must have only happened a few years before the Windsor link made it a main line, and which means that to this day trans pennine express services have to crawl along behind the Glossop stopper.

 

[Watershed]

which means that to this day trans pennine express services have to crawl along behind the Glossop stopper.

To be fair, the line speed is quite low and so it's not a great imposition. I don't think the de-quadding would have been reconsidered even if the Windsor Link had already been built at that point.

 

[yorksrob]

To be fair, the line speed is quite low and so it's not a great imposition. I don't think the de-quadding would have been reconsidered even if the Windsor Link had already been built at that point.

I can see why the line speed is quite slow for the curvy bit between Stalybridge and Guide Bridge, but the section onwards strikes me as being quite straight, so I wouldn't have thought that that was insurmountable. I would have thought that the ability to nip past the stopper would be extremely beneficial to express services (I've been caught behind it on two occasions in the recent past).

 

[Watershed]

I can see why the line speed is quite slow for the curvy bit between Stalybridge and Guide Bridge, but the section onwards strikes me as being quite straight, so I wouldn't have thought that that was insurmountable. I would have thought that the ability to nip past the stopper would be extremely beneficial to express services (I've been caught behind it on two occasions in the recent past).

Having a low linespeed means line capacity is greater. You wouldn't get a 2 minute headway west of Ashburys if it were 100mph, put it that way.

There's probably some scope for improvement between Ashburys and Guide Bridge, but I have to wonder whether the same money wouldn't be better spent on other things (eliminating single lead junctions for example).

The local service isn't really so intense as to be a major issue with the few TP services that still go via Guide Bridge.

 

[yorksrob]

Having a low linespeed means line capacity is greater. You wouldn't get a 2 minute headway west of Ashburys if it were 100mph, put it that way.

There's probably some scope for improvement between Ashburys and Guide Bridge, but I have to wonder whether the same money wouldn't be better spent on other things (eliminating single lead junctions for example).

The local service isn't really so intense as to be a major issue with the few TP services that still go via Guide Bridge.

Having four tracks also means that capacity is greater, and there are around 2 an hour TPE's that go that way, so it's not surprising some get stuck.

To be honest, this has stood out as being a bad rationalisation for the past 20+ years I've been using trans=pennine services.

 

[A0wen]

Having four tracks also means that capacity is greater, and there are around 2 an hour TPE's that go that way, so it's not surprising some get stuck.

To be honest, this has stood out as being a bad rationalisation for the past 20+ years I've been using trans=pennine services.

BIB - not necessarily - because at some point those 4 track sections have to connect to something else which may have less capacity, so whilst you can get more through a 4 track section that may cause a problem when you hit the next point where the number of tracks reduces - the ECML at Welwyn is a pretty good example of this, so too is the MML north of Kettering where it drops to 2 tracks heading towards Leicester.

 

[yorksrob]

BIB - not necessarily - because at some point those 4 track sections have to connect to something else which may have less capacity, so whilst you can get more through a 4 track section that may cause a problem when you hit the next point where the number of tracks reduces - the ECML at Welwyn is a pretty good example of this, so too is the MML north of Kettering where it drops to 2 tracks heading towards Leicester.

This is true to an extent - although in the case of Welwyn, trains do a fair amount of overtaking either side of that bottleneck, so the multiple track sections still have a lot of value.

In my example of Guide Bridge - Manchester Pic, a four track section would have slightly more value now than in previous years as more TPE services terminate at Piccadilly, rather than having to cross the throat.

 

[A0wen]

This is true to an extent - although in the case of Welwyn, trains do a fair amount of overtaking either side of that bottleneck, so the multiple track sections still have a lot of value.

In my example of Guide Bridge - Manchester Pic, a four track section would have slightly more value now than in previous years as more TPE services terminate at Piccadilly, rather than having to cross the throat.

Well with the ECML it demonstrates the problem of having a restricted capacity section in the middle of a much longer line - without it, it would be 4 track all the way from KX to Huntingdon.

The question is whether in the case you've cited it would actually add capacity - the chances are it wouldn't, all you're trying to achieve is make a couple of trains you use get to their destination a bit quicker - and it'd only be a couple of minutes at best. As @Watershed points out, you've currently got 2 min headways through that section which might not be the case with higher linespeeds, so you actually wouldn't be adding capacity, at best it would be neutral.

 

[yorksrob]

Well with the ECML it demonstrates the problem of having a restricted capacity section in the middle of a much longer line - without it, it would be 4 track all the way from KX to Huntingdon.

The question is whether in the case you've cited it would actually add capacity - the chances are it wouldn't, all you're trying to achieve is make a couple of trains you use get to their destination a bit quicker - and it'd only be a couple of minutes at best. As @Watershed points out, you've currently got 2 min headways through that section which might not be the case with higher linespeeds, so you actually wouldn't be adding capacity, at best it would be neutral.

Well, it's a very slow journey between those points.

There's nothing in the geography/gradient in that section of line that suggests it needs to be a slow journey without the need to squash a load of expresses and stoppers together. There's also often a stationary wait before guide bridge while trains come the other way over the flat junction.

In the context of overall Leeds - Manchester times, speeding up that section could have a considerable effect - more than 2 - 3 minutes.

 

[Sir Felix Pole]

Gorton to Guide Bridge was de-quadrified after Woodhead passenger services ceased, well before the diversion of TPE services into Piccadilly was a thing. If NPR is to run via Stalybridge rather than Rochdale (as recent maps seem to imply) maybe it will be reinstated, but there are encroachments in the Fairfield area, the M60 bridge at Audenshaw and Guide Bridge station itself that would need to be resolved.

 

[yorksrob]

Gorton to Guide Bridge was de-quadrified after Woodhead passenger services ceased, well before the diversion of TPE services into Piccadilly was a thing. If NPR is to run via Stalybridge rather than Rochdale (as recent maps seem to imply) maybe it will be reinstated, but there are encroachments in the Fairfield area, the M60 bridge at Audenshaw and Guide Bridge station itself that would need to be resolved.

That bridge always looks wide enough for four tracks whenever I go under it.

 

[A0wen]

Well, it's a very slow journey between those points.

There's nothing in the geography/gradient in that section of line that suggests it needs to be a slow journey without the need to squash a load of expresses and stoppers together. There's also often a stationary wait before guide bridge while trains come the other way over the flat junction.

In the context of overall Leeds - Manchester times, speeding up that section could have a considerable effect - more than 2 - 3 minutes.

BIB - I doubt it. Virtually any approach to a major terminus is slow for the final mile or so, you only need to travel into any of the major termini to see this. Ashbury's to Guide Bridge is only 3 miles - at 30 mph you'd cover it in 6 mins, at 60mph you'd cover it in 3 (assuming you were approaching it at 60mph). That's all you're realistically going to gain, because you're not going to magically turn that section into a 100mph railway.

And if you consider a 2-3 minute saving "considerable" I'm not sure about how realistic you are.

 

[yorksrob]

BIB - I doubt it. Virtually any approach to a major terminus is slow for the final mile or so, you only need to travel into any of the major termini to see this. Ashbury's to Guide Bridge is only 3 miles - at 30 mph you'd cover it in 6 mins, at 60mph you'd cover it in 3 (assuming you were approaching it at 60mph). That's all you're realistically going to gain, because you're not going to magically turn that section into a 100mph railway.

And if you consider a 2-3 minute saving "considerable" I'm not sure about how realistic you are.

And you're less likely to end up waiting around for a train coming the other way at guide bridge. Plus you're not taking account of crawling along behind the stopper.

I would suggest that you cauld save 5 - 10 minutes on some occasions.

 

[30907]

BIB - I doubt it. Virtually any approach to a major terminus is slow for the final mile or so, you only need to travel into any of the major termini to see this. Ashbury's to Guide Bridge is only 3 miles - at 30 mph you'd cover it in 6 mins, at 60mph you'd cover it in 3 (assuming you were approaching it at 60mph). That's all you're realistically going to gain, because you're not going to magically turn that section into a 100mph railway.

And if you consider a 2-3 minute saving "considerable" I'm not sure about how realistic you are.

Delays caused by a late-running Rose Hill stopper could amount to as much as 5 minutes based on current timings. Whether with a total offpeak service of 6tph this requires action is another matter.

 

[zwk500]

There's also often a stationary wait before guide bridge while trains come the other way over the flat junction.

Which 4-tracking on it's own is unlikely to do anything about, given the possibility for grade-separation being around about 0.

That bridge always looks wide enough for four tracks whenever I go under it.

It does, but with a possible penalty to linespeed.

4-tracking would be a big white elephant because Guide Bridge station would be a critical constraint. The freight yards being on both sides of the line, the bridge at the Manchester end of the station and the very constricted site means it'd be nonviable to 4-track through the station. So all the hard work done separating out the trains between Ashburys and Guide Bridge is undone by turning Guide Bridge into a worse bottleneck.

If you moved the freight sidings all to the south/east side, paired by use (fast Transpennine on the north side, slow stoppers on the south) AND rebuilt Guide Bridge for 4-track then you might be able to cope with the freight crossing on the flat with a sufficiently flexibile (i.e. complex, = expensive) junction. BUT this comes with a rather hefty price tag, and the business case would need to demonstrate not only that it will actually make it's money back but that it's a better option than converting the stopping lines to trams.

 

[Ianno87]

The more critical constraint is that 4 tracks from Guide Bridge still inevitably have to converge to the same two-track approach and 3-ish platforms at Piccadilly (4 and upwards being used for Stockport/Styal); i.e. they do not actually realise any additional capacity overall as "somewhere else" remains the constraint. The only "benefit" would be some minor TPE journey time benefit (which is irrelevant now anyway with TPE using Victoria).

I can't think of anywhere else on the network where a 4 track approach converges to so few platforms.

 

[yorksrob]

Which 4-tracking on it's own is unlikely to do anything about, given the possibility for grade-separation being around about 0.

It does, but with a possible penalty to linespeed.

4-tracking would be a big white elephant because Guide Bridge station would be a critical constraint. The freight yards being on both sides of the line, the bridge at the Manchester end of the station and the very constricted site means it'd be nonviable to 4-track through the station. So all the hard work done separating out the trains between Ashburys and Guide Bridge is undone by turning Guide Bridge into a worse bottleneck.

If you moved the freight sidings all to the south/east side, paired by use (fast Transpennine on the north side, slow stoppers on the south) AND rebuilt Guide Bridge for 4-track then you might be able to cope with the freight crossing on the flat with a sufficiently flexibile (i.e. complex, = expensive) junction. BUT this comes with a rather hefty price tag, and the business case would need to demonstrate not only that it will actually make it's money back but that it's a better option than converting the stopping lines to trams.

Grade separation would make no difference currently as you would have one set of slow lines serving Glossop etc, then the fast lines for TPE to the North of those. And since a lot of TPE services are terminating at Piccadilly now, they would have no reason to cross over the slow lines.

Guide bridge currently has a large underused area where the second set of platforms used to be, so there would be no issue providing four tracks through it.

Out of interest, why would the bridge cause a loss of line speed ? Unless it was to cause a kink in the railway, however presumably the four track width was built in line with the existing four track formation.

The more critical constraint is that 4 tracks from Guide Bridge still inevitably have to converge to the same two-track approach and 3-ish platforms at Piccadilly (4 and upwards being used for Stockport/Styal); i.e. they do not actually realise any additional capacity overall as "somewhere else" remains the constraint. The only "benefit" would be some minor TPE journey time benefit (which is irrelevant now anyway with TPE using Victoria).

I can't think of anywhere else on the network where a 4 track approach converges to so few platforms.

They tend to stack up trains in those platforms anyway, so the number belies the capacity.

 

[Snow1964]

Just out of interest why is the debate 2 track vs 4 track

I think this is one of the bits of line where a third line would be useful (in the centre as a reversible line) with some decently fast turnouts at the end.

What you really want is the ability to pass a train slowing, calling at at station and then accelerating. Not just a short platform loop. Better still if you can get past a train calling at 2 closely spaced stations as the 4-5 minutes extra justifies not slowing the fast train and making it crawl behind.

I suspect 4th track is unnecessary unless the stopping trains in both directions are timetabled to arrive about the same time.

 

[Ianno87]

They tend to stack up trains in those platforms anyway, so the number belies the capacity.

OK, so if Guide Bridge-Ardwick was 4 tracked, what extra trains could run without any other capacity intervention elsewhere?

 

[HSTEd]

I suspect 4th track is unnecessary unless the stopping trains in both directions are timetabled to arrive about the same time.

However to reach the 3rd track from both sides will require more pointwork than a four track solution.
And the line would have to be signalled bi-directionally, which in the absence of ETCS means more signal heads/proving circuits etc.

Be interesting to see how those costs stack against the fourth track.

 

[zwk500]

Grade separation would make no difference currently as you would have one set of slow lines serving Glossop etc, then the fast lines for TPE to the North of those. And since a lot of TPE services are terminating at Piccadilly now, they would have no reason to cross over the slow lines.

The freight from Denton Jn has got to get across the Slows at Guide Bridge, and given that Ardwick-Piccadilly will not be expanded, at some point Manchester-bound TPEs will need to cross outbound Glossops. There's also the conflicts at Ashburys station that would need addressing. Flat crossings of 4-tracks are by and large not good paths with service frequencies that justify 4-tracking.

Guide bridge currently has a large underused area where the second set of platforms used to be, so there would be no issue providing four tracks through it.

Does it? Looks to me like the road access, waiting room and bike shed would all need to be moved. A new accessible bridge would be required, and of course the platform would need to be built to modern standards not Victorian ones, so to get a wide enough platform with a shallow enough curve would almost certainly involve rebuilding the road bridge to a substantial amount. The fact there may have been sub-standard platforms there before, or other platforms on the network don't meet those standards, is irrelevant.

Out of interest, why would the bridge cause a loss of line speed ? Unless it was to cause a kink in the railway, however presumably the four track width was built in line with the existing four track formation.

I said possibly, it may well not make a difference. The tracks take a gentle curve through the bridge so in slueing the tracks for 2 pairs you may find there's a small penalty - tbh given the slow lines would have the penalty if it did exist it's probably the least of the problems.

 

[edwin_m]

In my example of Guide Bridge - Manchester Pic, a four track section would have slightly more value now than in previous years as more TPE services terminate at Piccadilly, rather than having to cross the throat.

But there are only half as many of them as there used to be, and as they no longer cross the throat it's slightly less critical that they present on time.

Looking at the plans for the HS2-NPR junction outside Piccadilly, this is one (of several) routes that could be used to continue it towards Leeds. In that case however it would probably turn away northwards before getting to Guide Bridge.

 

[yorksrob]

The freight from Denton Jn has got to get across the Slows at Guide Bridge, and given that Ardwick-Piccadilly will not be expanded, at some point Manchester-bound TPEs will need to cross outbound Glossops. There's also the conflicts at Ashburys station that would need addressing. Flat crossings of 4-tracks are by and large not good paths with service frequencies that justify 4-tracking.

Does it? Looks to me like the road access, waiting room and bike shed would all need to be moved. A new accessible bridge would be required, and of course the platform would need to be built to modern standards not Victorian ones, so to get a wide enough platform with a shallow enough curve would almost certainly involve rebuilding the road bridge to a substantial amount. The fact there may have been sub-standard platforms there before, or other platforms on the network don't meet those standards, is irrelevant.
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I said possibly, it may well not make a difference. The tracks take a gentle curve through the bridge so in slueing the tracks for 2 pairs you may find there's a small penalty - tbh given the slow lines would have the penalty if it did exist it's probably the least of the problems.

"Given Adwick Guide Bridge won't be expanded" isn't really relevant as this thread is about four tracks between those places. How frequent are Denton Junction freights anyway ? I'm aware that there are a lot of yards in the area, but there doesn't usually appear to be much freight moving in them.

Admittedly a flyover somewhere might sort out some conflicts between trains in opposite directions, but it wouldn't stop express trains getting caught up behind a stopper. You'd only really need it if you were going to go back to TPE using the route beyond Piccadilly, which isn't likely given through services go via Vic.

I see someone's built a waiting room on the site of the old parallel lines. I would suggest that relocating a waiting room is one of the railways lesser engineering challenges.

 

[Bletchleyite]

To take this a bit sideways, I think the only chance of this getting 4-tracked is to provide segregated lines for Metrolink if the Hadfield line is converted.

 

[yorksrob]

But there are only half as many of them as there used to be, and as they no longer cross the throat it's slightly less critical that they present on time.

Looking at the plans for the HS2-NPR junction outside Piccadilly, this is one (of several) routes that could be used to continue it towards Leeds. In that case however it would probably turn away northwards before getting to Guide Bridge.

There are only half of the TPE's going that way now, but this doesn't seem to have speeded up the journey any more, which is still painfully slow.

Just out of interest why is the debate 2 track vs 4 track

I think this is one of the bits of line where a third line would be useful (in the centre as a reversible line) with some decently fast turnouts at the end.

What you really want is the ability to pass a train slowing, calling at at station and then accelerating. Not just a short platform loop. Better still if you can get past a train calling at 2 closely spaced stations as the 4-5 minutes extra justifies not slowing the fast train and making it crawl behind.

I suspect 4th track is unnecessary unless the stopping trains in both directions are timetabled to arrive about the same time.

Interesting point - it does seem that the services are slowest going towards Piccadilly. Starting from the terminal platforms, you probably have more opportunity to flight things.

To take this a bit sideways, I think the only chance of this getting 4-tracked is to provide segregated lines for Metrolink if the Hadfield line is converted.

Typical if the only way to improve the railway is to turn it into a tram.

 

[zwk500]

but this doesn't seem to have speeded up the journey any more, which is still painfully slow.

Fundamentally, you want to have a 5 minute quicker journey every now and again. It seems that any impact on anybody else's interaction with the railway is irrelevant to you. Would you be prepared for the upgrade to be funded exclusively from additional ticket revenue from TPE passengers?

"Given Adwick Guide Bridge won't be expanded" isn't really relevant as this thread is about four tracks between those places.

I said Adwick-Picc, and it's relevant because neither the stopper nor the TPE disappear in a puff of smoke at Ashuburys.

How frequent are Denton Junction freights anyway ? I'm aware that there are a lot of yards in the area, but there doesn't usually appear to be much freight moving in them.

With a standard hour timetable, the path has to be there for all hours even if the freight only runs in one.

I see someone's built a waiting room on the site of the old parallel lines. I would suggest that relocating a waiting room is one of the railways lesser engineering challenges.

You're still likely to need the waiting room on the island platform. And my point about curvature and width is conspicuously unanswered.

To take this a bit sideways, I think the only chance of this getting 4-tracked is to provide segregated lines for Metrolink if the Hadfield line is converted.

Agreed.

 

[Journeyman]

To take this a bit sideways, I think the only chance of this getting 4-tracked is to provide segregated lines for Metrolink if the Hadfield line is converted.

Don't tell the REOPEN WOODHEAD NOW!!! brigade - it'll make it even less likely.

 

[Greybeard33]

There are only half of the TPE's going that way now, but this doesn't seem to have speeded up the journey any more, which is still painfully slow.

In pre-Covid times, only one of the five TPEs between Leeds and Manchester was routed via Guide Bridge (the Hull semi-fast). The second TPE is the Huddersfield - Manchester stopper.

When the remodelling of Miles Platting and Stalybridge Junctions is complete, the four fast trains via Victoria will become quicker, while the Guide Bridge route will have a slower turnout speed at Stalybridge.

 

[cle]

This section is incredibly slow. When it was the mainline to Leeds, it was very frustrating. 2-3 mins for 4-5tph (each way) with hundreds of people on them actually adds up to a lot of human time saved. 6 mins daily is an hour a week less on the train.

However, I was thinking that the Met is the natural evolution here, which probably leaves the lines ripe for accelerating for semi-fast services and clears up more platforms at Picc.

 

[jfollows]

Gorton to Guide Bridge was de-quadrified after Woodhead passenger services ceased, well before the diversion of TPE services into Piccadilly was a thing. If NPR is to run via Stalybridge rather than Rochdale (as recent maps seem to imply) maybe it will be reinstated, but there are encroachments in the Fairfield area, the M60 bridge at Audenshaw and Guide Bridge station itself that would need to be resolved.

Indeed, the attached were drawn by hand (by me) in about 1979 with the help of a ride in the front of a DC unit. The extra lines that did exist were "goods" and couldn't have been used by passenger trains by then (but of course there weren't appropriate crossovers anyway by then). With the exception of the up slow option through Guide Bridge station versus the crossover at Ashton Junction.
I also managed to visit Gorton box around that time. Interesting good memories. Shame I don't have a picture of the box, lots of very small levers I recall.

EDIT: https://signalbox.org/~SBdiagram.php?id= 894 shows a similar layout for Gorton in 1974, which doesn't surprise me.