What route may the HS2 Marsden spur take?

[Nottingham59]

Reopened to enable @Nottingham59 to post an update

Thanks, Yorkie.

When searching for the latest HS2 business case documentation, I found this from the DfT:
HS2 Phase 2b Western Leg Crewe - Manchester Supplement to the Update on the SOBC

HS2 Crewe to Manchester: impacts of removing the Golborne Link

Supplement to the update on the strategic outline business case.

www.gov.uk

On page 5, it has a map of the proposed route to Marsden.

I think this line is taken from an actual map, because it is not a smooth curve, but has wiggles in it like the wiggles around Warrington which correspond to the curves on the actual known alignment.

So using the stations at Piccadilly, Wigan NW and Warrington BQ to locate the map, I could overlay the proposed Marsden route onto openrailwaymap to get this:

The registration is not perfect, so the line could be easily out by 1km or so. But it seems consistent with what we know already from posts #80 and #81 above, to give the following route:

• Western portal at the aggregates site between Bessemer Street and Clayton Lane South next to the line from Ashbury to Gorton
• Ventilation shafts at Openshaw, Ashton Moss and Waterloo
• Crossing the river Tame near Dobcross
• Joining the existing railway alignment just north of Diggle
• Then paralleling the existing Standedge tunnels

The elevation of the line is purely speculative, but I would guess they will plan to run on the surface or in green tunnel across the open country between Ashton and Springhead, before re-entering bored tunnels through the high ground to the south and north of the Tame valley at Dobcross.

The furthest point on the map is suspiciously parallel to the existing Standedge tunnels, which makes me think that they plan to use one of the spare bores rather than dig a new alignment with less well understood geology.

What do others think?

If it helps, this is the same map laid over topographic-map.com to show the land forms, if that helps. Red is high ground; green is low. Note the registration is less good on this layout.

 

[YorksLad12]

Great detecting work, @Nottingham59! Having looked at the Wikipedia page on Standedge Tunnels, I think a fresh bore is more likely than reusing either or both of the exisiting bores, which are to the south-east of the in-use tunnel and the canal. That would allow an easier approach from the west past all of the existing tunnels and connect into the existing network just west (between the visitor centre and station) of Marsden, with no impact on existing rail or canal operations (or on Diggle itself).

Equally, it might be that the line stops roughly where the tunnels are because no-one knows yet how they're going to cross the Pennines...

 

[Nottingham59]

the exisiting bores, which are to the south-east of the in-use tunnel and the canal.

Or they could simply refurbish the old single bores on the SE side, slew the existing railway across to use them, leaving a double-track tunnel on the NW side available for NPR. This would be a lot cheaper than excavating a new 3-mile alignment under the pennines (2x5km@£100M/km=£1.0Bn), even if you did have to lower the floor of the older tunnels to accommodate electrification.

My estimate for the total tunnelling cost for the whole of Ashbury - Marsden is £5.4Bn, as follows:

• Portal at Ashbury: £250M
• 7km TBM-bored tunnel to past Ashton: 2x7x£100M=£1.4Bn
• 4km green tunnel to Springhead: 4x2x£50M=£0.4Bn
• 4km TBM to Tame valley: 2x4x£100M= £0.8Bn
• Tame viaduct (200m): £250M
• 2.5km TBM to Diggle: 2x2.5x£100M=£0.5Bn
• Refurbish / enlarge both single-bore tunnels at Standedge: 2x5x£50M=0.5Bn
• Portals at Tame valley, Diggle etc.: £300M (cheaper because they are on sloping ground)

These are just my guesses for the civils only: I don't have access to up-to-date cost estimates.

 

[Snow1964]

Or they could simply refurbish the old single bores on the SE side, slew the existing railway across to use them, leaving a double-track tunnel on the NW side available for NPR. This would be a lot cheaper than excavating a new 3-mile alignment under the pennines (2x5km@£100M/km=£1.0Bn), even if you did have to lower the floor of the older tunnels to accommodate electrification.

If tunnels are done in sequence, presumably it would be possible to lower the floor replacing it with slab track, and instal modern solid bar type conductors.

Appears to be room to slew tracks into old tunnels, or even add some sort of flying junction slightly further back to allow the double track tunnel to be used by all trains and allow overtaking.

 

[YorksLad12]

Or they could simply refurbish the old single bores on the SE side, slew the existing railway across to use them, leaving a double-track tunnel on the NW side available for NPR. This would be a lot cheaper than excavating a new 3-mile alignment under the pennines (2x5km@£100M/km=£1.0Bn), even if you did have to lower the floor of the older tunnels to accommodate electrification.

My estimate for the total tunnelling cost for the whole of Ashbury - Marsden is £5.4Bn, as follows:

• Portal at Ashbury: £250M
• 7km TBM-bored tunnel to past Ashton: 2x7x£100M=£1.4Bn
• 4km green tunnel to Springhead: 4x2x£50M=£0.4Bn
• 4km TBM to Tame valley: 2x4x£100M= £0.8Bn
• Tame viaduct (200m): £250M
• 2.5km TBM to Diggle: 2x2.5x£100M=£0.5Bn
• Refurbish / enlarge both single-bore tunnels at Standedge: 2x5x£50M=0.5Bn
• Portals at Tame valley, Diggle etc.: £300M (cheaper because they are on sloping ground)

These are just my guesses for the civils only: I don't have access to up-to-date cost estimates.

I think we disagree on "simply", but point taken. I was assuming that the new "fast" lines would be north of the existing tracks, but there's no reason they couldn't be south (the Sectional Appendix wasn't much help at first glance on trackwork). The canal people use one of the disused bores, and there's vehicle access as well; that's why I think a new bore would be better. You could also avoid the sharp turn tinto and out of the existing bores.

 

[LittleAH]

I think a fresh bore is more likely than reusing either or both of the exisiting bores, which are to the south-east of the in-use tunnel and the canal.

From what I heard, the NPR lines will diverge from what will be the three track section of track before Marsden. Presumably where the line curves towards Marsden station in line with where the Sparth Reservoir is.

 

[Snow1964]

From what I heard, the NPR lines will diverge from what will be the three track section of track before Marsden. Presumably where the line curves towards Marsden station in line with where the Sparth Reservoir is.

At one time (until 1966 ?) was quadruple track through Marsden from Huddersfield to Diggle Junction through Standedge tunnels.

Perhaps 3 tracks with a reversible centre line and plenty of crossovers is more flexible these days than 2 pairs of lines.

 

[LittleAH]

At one time (until 1966 ?) was quadruple track through Marsden from Huddersfield to Diggle Junction through Standedge tunnels.

Perhaps 3 tracks with a reversible centre line and plenty of crossovers is more flexible these days than 2 pairs of lines.

As part of TRU Marsden - Huddersfield is being three tracked (middle track bi-di). Four tracking isn't possible without losing line speed.

 

[Nottingham59]

The canal people use one of the disused bores, and there's vehicle access as well;

So maybe rebore one of the old single tunnels out to double track size, leaving the other disused bore for access. Without knowing the detailed costs, it's difficult to know which would be better.

the NPR lines will diverge from what will be the three track section of track before Marsden. Presumably where the line curves towards Marsden station in line with where the Sparth Reservoir is.

That's what I hope they do to avoid the tight curve at the tunnel mouth. See post #59 in this thread. I don't know the area well enough to say if they could continue the Western bore in a straight line across the Colne valley and into another tunnel in the hillside opposite, before curving round towards Sparth?

Perhaps 3 tracks with a reversible centre line and plenty of crossovers is more flexible these days than 2 pairs of lines.

I doubt it very much. I think potential traffic on the Manchester-Leeds route is so great that they will soon regret not continuing at least one tunnel bore to Huddersfield to give 4 tracks all the way.

 

[HSTEd]

Or they could simply refurbish the old single bores on the SE side, slew the existing railway across to use them, leaving a double-track tunnel on the NW side available for NPR. This would be a lot cheaper than excavating a new 3-mile alignment under the pennines (2x5km@£100M/km=£1.0Bn), even if you did have to lower the floor of the older tunnels to accommodate electrification.

You will still need a new bore for the canal access, so you don't save that much.
And from reports on the tunnels they are maintenance hogs, I can't see the railway wanting to put more critical infrastructure through them.

 

[zwk500]

You will still need a new bore for the canal access, so you don't save that much.
And from reports on the tunnels they are maintenance hogs, I can't see the railway wanting to put more critical infrastructure through them.

The canal is in it's own tunnel and is only accessible with special supervision, so you could easily not have a spare bore. However I suspect that a new twin track bore is going to be better value for money than refitting the old tunnels, especially as there would be some debate about whether or not grandfather rights apply to tunnels that have been out of use for more than 50 years.

 

[tomuk]

The canal is in it's own tunnel and is only accessible with special supervision, so you could easily not have a spare bore. However I suspect that a new twin track bore is going to be better value for money than refitting the old tunnels, especially as there would be some debate about whether or not grandfather rights apply to tunnels that have been out of use for more than 50 years.

When canal boats transit the tunnel a pilot is carried on one of the boats and an another escort travels in a pickup truck in one of the disused railway tunnels and checks on the progress of the boats from the various adits linking the tunnels.

 

[Meerkat]

Sure I read that they are currently designing the Marsden-Huddersfield section (as it is part of Transpennine upgrade), taking into account the junction for NPR at Marsden......so the site of the Eastern NPR portal must be fixed??

 

[Nottingham59]

Sure I read that they are currently designing the Marsden-Huddersfield section (as it is part of Transpennine upgrade), taking into account the junction for NPR at Marsden......so the site of the Eastern NPR portal must be fixed??

The Marsden-Huddersfield section is going to be three tracks as part of TRU, but as fas as I know, the precise details of the layout around Marsden have not been published.

Plans clearly have also been developed for the NPR route from Piccadilly to "East of Standedge", but whatever has been decided for the portal near Marsden, if has not been made public (as far as I know).

==
Speculation alert:
If I were at DfT and trying to save money, I would refurbish just one of the existing single bores through Standedge, extending the three-track running from Hudds to around Diggle. And announce an unfunded "Phase 2" which would bring the fourth tunnel back into use, but leave paying for it for the next administration.

 

[Halifaxlad]

The canal is in it's own tunnel and is only accessible with special supervision, so you could easily not have a spare bore. However I suspect that a new twin track bore is going to be better value for money than refitting the old tunnels, especially as there would be some debate about whether or not grandfather rights apply to tunnels that have been out of use for more than 50 years.

I agree!

Most seem to forget that this new tunnel isn't just a tunnel as long as the existing tunnels it's certainly much longer and a brand new alignment (probably tunneled) all the way to Picadilly!

Personally I think it would be better off heading to Victoria and comming up just West of Oldham adjacent to the tram lines.

 

[Nottingham59]

I suspect that a new twin track bore is going to be better value for money than refitting the old tunnels

If you're going to dig a new twin track bore, then surely the cheapest route would be to use a TBM to ream out one of the old tunnels to 8m internal diameter? You already have a site for launching; you know exactly what geology you're going to encounter; there is less spoil to remove; and it eliminates an ongoing maintenance cost on the old tunnel. And you still have the second old tunnel for access and evacuation.

 

[Bald Rick]

If you're going to dig a new twin track bore, then surely the cheapest route would be to use a TBM to ream out one of the old tunnels to 8m internal diameter?

Not if the tunnel isn’t going that way …

You already have a site for launching

Do you? Where?

you know exactly what geology you're going to encounter

Are you sure records have been kept from 1848? And if so, are they accurate? Would you be willing to bet the success of the rebored tunnel on those records?

there is less spoil to remove

The usual way to rebore a tunnel like this would be to fill it with foam concrete first. (As per Farnworth). So spoil would be broadly the same, but a mix of rock, masonry from the old tunnel lining, and foam concrete. Pretty difficult stuff to use for anything, unlike plain rock form a new bore.

 

[snowball]

The present layout has a quite sharp curve immediately outside the Marsden portal. Any NPR route would want to bypass that. Previous discussions in this forum have focussed on a possible NPR/TRU junction site a little further east.

 

[Nottingham59]

Not if the tunnel isn’t going that way …

I'm just going by the sketch map in the HS2 document Supplement to the Updated SOBC. See post #91. If you have any better information, then please share it with us.

Do you? Where?

Where the former tracks that led to the old tunnels used to be. There appears to be plenty of room at the Diggle end. You would have to clean cut the tunnel end to give you a vertical face for the TBM to start cutting into.

Are you sure records have been kept from 1848?

I assumed they would drill into the walls of the old tunnels to take samples. At whatever interval their geologists thought necessary. That's a bizarre notion of yours that they would depend on records from 1848. Lol.

The usual way to rebore a tunnel like this would be to fill it with foam concrete first. (As per Farnworth).

I bow to your superior knowledge. But if that's what they did at Farnworth, then it would presumably cheaper to do the same at Standedge, rather than bore a whole new tunnel, which is the point I am trying to make.

The present layout has a quite sharp curve immediately outside the Marsden portal. Any NPR route would want to bypass that. Previous discussions in this forum have focussed on a possible NPR/TRU junction site a little further east.

Agree. But if I was at the DfT tasked with delivering the NPR promises in the IRP at minimum cost, I would merge the NPR route onto the existing tight curve at the Marsden portal, for now. And then propose another unfunded "Phase 3" which continued the alignment of the Western bore of Standedge in a straight line over the canal basin and across the Colne valley into the hillside beyond, curving round inside the hill at 2000m radius to rejoin the TRU line beyond Marsden Station.

 

[Bald Rick]

Where the former tracks that led to the old tunnels used to be. There appears to be plenty of room at the Diggle end. You would have to clean cut the tunnel end to give you a vertical face for the TBM to start cutting into.

Compare the space there with the launch sites for HS2 TBMs.

I assumed they would drill into the walls of the old tunnels to take samples.

Forgive me, but you said:

you know exactly what geology you're going to encounter

by which I thought you meant you would know now exactly what the geology was, and therefore would not need to do ground investigations. As it happens, doing GIs from within a tunnel is not straightforward due to limited working space. It is probably easier to do from above.

I bow to your superior knowledge. But if that's what they did at Farnworth, then it would presumably cheaper to do the same at Standedge, rather than bore a whole new tunnel, which is the point I am trying to make.

Farnworth was / is a 270m tunnel, with the railway either side not moving or having new lines built to it. It cost £21m, 7 years ago. Re boring was the only feasible solution - you couldn’t build another tunnel there without rebuilding a whole new line, demolishing lots of houses, and relocating Farnworth station (At least), for no extra benefit.

Standedge is about 20times as long. What is proposed to be built is a whole new line, which doesn’t need to follow the existing alignment west of Marsden; indeed to deliver the benefits it is best not to follow the old alignment. Hence a tunnel from just east of central Manchester to Marsden.

I would expect that reboring the single line tunnels would be more expensive per metre than building new, and deliver a ‘new’ tunnel to somewhere you don’t want it to go.

 

[fishwomp]

Not if the tunnel isn’t going that way …
...

At this point .. and as demonstrated by the perpetual HS2 changing.. I think there is zero probability of this tunnel going anywhere in the next 20 years!

There are many criticisms of Crayons on this forum... but we have government funded teams being paid to do exactly what this forum would do for no cost - and with equal probability of becoming reality!!

 

[Nottingham59]

doing GIs from within a tunnel is not straightforward due to limited working space. It is probably easier to do from above.

The crest of the hill above Standedge is around 400m ASL. The tunnels are at 210m. Are you seriously suggesting that it will be cheaper and easier to drill down 190m to get a rock sample, than drill 2m through the brickwork of the tunnel into the bedrock to get the same sample?

Compare the space there with the launch sites for HS2 TBMs.

I have:

This is the Chiltern TBM laid over the Diggle tunnel approaches at the same scale.

You would have to slew the existing line across onto the northern edge of the alignment, but it should all fit. The cutting head is 10.26m diameter. The TBM itself is about 170m long, but no other part is more than 9m in diameter. If you needed more room, you could excavate the first 50m of hillside and assemble the TBM further to the right.

Note that most of the land area of the Chiltern launch site is taken up with the concrete segment factory and the ring storage, which can be anywhere nearby, and with the extensive excavations needed to get a flat approach, which is already available here at Diggle.

 

[Bald Rick]

The crest of the hill above Standedge is around 400m ASL. The tunnels are at 210m. Are you seriously suggesting that it will be cheaper and easier to drill down 190m to get a rock sample, than drill 2m through the brickwork of the tunnel into the bedrock to get the same sample?


I have:

This is the Chiltern TBM laid over the Diggle tunnel approaches at the same scale.
View attachment 128617
You would have to slew the existing line across onto the northern edge of the alignment, but it should all fit. The cutting head is 10.26m diameter. The TBM itself is about 170m long, but no other part is more than 9m in diameter. If you needed more room, you could excavate the first 50m of hillside and assemble the TBM further to the right.

Note that most of the land area of the Chiltern launch site is taken up with the concrete segment factory and the ring storage, which can be anywhere nearby, and with the extensive excavations needed to get a flat approach, which is already available here at Diggle.

You need a lot more space than just somewhere to drop a TBM…

 

[gimmea50anyday]

Theres probably more space available at diggle when the approaches to the micklehurst loop is taken In to account BUT you also have to bear in mind road access in the area is very poor. Granted a nearby bus turning circle may assist with road access but realistically everything will have to be shipped in via the canal or by rail and its the delivery of supplies and removal of spoil that needs the space, not the TBM itself and given the local geography space is very limited. As for the marsden end you have a new challenge getting the TBM back out once its chewed its way through owing again to poor road access, track layout and the river feeding the canal tunnel.

Reboring the old alignment may need to revert to traditional techniques such as the greathead shield and not with modern TBMs

 

[MattRat]

The cheapest option, which I'm sure the 'bean counters' are looking very deeply into. Might even scrap the whole idea, finding a 'new and inventinve' (ignore reality) way to make it work.

 

[CrossNorthPr]

No one’s going to blast new tunnels under the Pennines to marsden for six trains per hour. The BCR would ever stack up for it. Was designed to be cancelled, as unfortunate as that sounds! Same goes for Warrington.

Just my personal opinion of course!

George.

 

[Meerkat]

No one’s going to blast new tunnels under the Pennines to marsden for six trains per hour. The BCR would ever stack up for it. Was designed to be cancelled, as unfortunate as that sounds! Same goes for Warrington.

Just my personal opinion of course!

George.

The gain is the six trains through the new tunnel are faster, AND more freight and local trains being able to go the old way.

 

[CrossNorthPr]

The gain is the six trains through the new tunnel are faster, AND more freight and local trains being able to go the old way.

It still doesn’t stack up on its own, which is (unfortunately) how treasury will judge it. That’s what happened with HS2, which was designed for 18tph on a high speed alignment.

I hate to be pessimistic, but given how transport investment works in this country, it’s the reality.

George.

 

[Bald Rick]

No one’s going to blast new tunnels under the Pennines to marsden for six trains per hour. The BCR would ever stack up for it.

And yet that is the plan, and it does stack up. Rather better, incidentally, than putting massive new stations underground in Manchester.

 

[CrossNorthPr]

And yet that is the plan, and it does stack up. Rather better, incidentally, than putting massive new stations underground in Manchester.

A combined 6 platform combined underground NPR/HS2 station 650m long yes it doesn’t stack up.

For two 240m two platform (4 max) stations that absolutely stacks up. One under Piccadilly HS2 (4 platform surface) and the other in an open shallow box on a brownfield site in Salford. The core bypass is also deliverable within 12 years. With NPR as planned we’re looking at 2050

George.