What should a 'potential' underground station in Manchester be used for ?

[GJMarshy]

Bang on! West of Oldfield Road. I came up with this low-level diagram showing how the lines might interface (The intercity platforms would be in a shallow station-box with the local lines at surface level (slightly realigned to create straighter, accessible platforms) It also includes the mooted Metrolink extension by TfGM creating a nice tight interchange and hub for TOD:

 

[Howardh]

Bang on! West of Oldfield Road. I came up with this low-level diagram showing how the lines might interface (The intercity platforms would be in a shallow station-box with the local lines at surface level (slightly realigned to create straighter, accessible platforms) It also includes the mooted Metrolink extension by TfGM creating a nice tight interchange and hub for TOD:

Would the main line be underground by then? Thinking up to that point the line is pretty low anyway compared to the adjacent motorway, so would only need a slight gradient to get it properly underground by the new station.

 

[GJMarshy]

Would the main line be underground by then? Thinking up to that point the line is pretty low anyway compared to the adjacent motorway, so would only need a slight gradient to get it properly underground by the new station.

From Oldfield Rd onward to Piccadilly yes, although the station itself would be in an open shallow-box. And yes, the elevations in the area make getting to the lower-level a bit easier from the chat-moss route, with fairly gentle grades involved.

It does seem like a no-brainer to me. It'd stand to be the most connected area in the North, and potential OSD would help fund the project too, likely with interest from Peel Group, Salboy, Renaker, Select Property etc. All massive players in the Manchester/Salford property market.

 

[Howardh]

From Oldfield Rd onward to Piccadilly yes, although the station itself would be in an open shallow-box. And yes, the elevations in the area make getting to the lower-level a bit easier from the chat-moss route, with fairly gentle grades involved.

It does seem like a no-brainer to me. It'd stand to be the most connected area in the North, and potential OSD would help fund the project too, likely with interest from Peel Group, Salboy, Renaker, Select Property etc. All massive players in the Manchester/Salford property market.

If the tunnel went close to St Peter's Square that would be ideal for a station there as it's an area some distance from the nearest main-line station which I think would be Oxford Road.

 

[GJMarshy]

If the tunnel went close to St Peter's Square that would be ideal for a station there as it's an area some distance from the nearest main-line station which I think would be Oxford Road.

By all means a possibility, but in the interest of promoting the "minimum viable product" I'd argue out of the two, Salford Interchange would be far more valuable. Not to mention St Peters Sq can (and could in the case of SI) be reached within 10mins via tram from either of the two stations.

A mined station at SP Sq would likely be prohibitively expensive, and lack the space/amenities needed for mainline intercity stations. Crowd flow would also be a major issue. We need to remember this isn't metro or crossrail, it needs to accommodate existing/future intercity style rolling stock and passenger behaviour assisted with that (getting to the station way ahead of time etc)

 

[HSTEd]

With a comparatively small passenger demand and short distance the Barcelona solution of simply having a single double-deck bore with platforms in the tunnel does seem somewhat attractive.

Also means that loading gauge and platform length limitations are entirely eliminated.

The only station components dug out separately are the station access shaft/concourse

 

[Howardh]

Was HS2 to enter Piccadilly via a viaduct or tunnel? If it were a tunnel then the plans and costing are already there, so the x-Manc tunnel could carry on a bit and emerge/join on the WCML at Longsight? Looking at a map it's probably no more than 4km of tunnel, how long is the Elizabeth Line and how much did it cost per km??

 

[GJMarshy]

With a comparatively small passenger demand and short distance the Barcelona solution of simply having a single double-deck bore with platforms in the tunnel does seem somewhat attractive.

Also means that loading gauge and platform length limitations are entirely eliminated.

The only station components dug out separately are the station access shaft/concourse

A good solution for creating underground stations, and correct me if I'm wrong, but is that not for a metro type line rather than an inter-city one?

You're just not going to get the circulation space for inter-city passengers in a mined station, bearing in mind different people will be waiting for different trains, and you don't want them all waiting on the platform. You'd need to provide a large waiting area/concourse somewhere before trains are announced which risks creating a "euston dash"type situation down the escalators to platform level.

With a shallow-box design, it's much simpler. Waiting areas can be located directly above the platforms similar to the way Bologna AV works, along with a few other mainline stations on the continent. A lot of thought was put into a "central station" for the CrossNorth plan, but it was ruled out on these grounds, although that isn't to say if someone else finds a solution (aka the city council which would likely be required to fund it) that it isn't entirely impossible. Just that it isn't *required* to meet the objectives NPR set out to do.

 

[HSTEd]

A good solution for creating underground stations, and correct me if I'm wrong, but is that not for a metro type line rather than an inter-city one?

The line between such systems is kind of blurry, especially in the UK context.
There are very few "true" intercity trains calling at Manchester, indeed the only ones that might qualify are the London trains.
If NPR ever occurs it won't be a true intercity system given the very short journey times that it enables.

You're just not going to get the circulation space for inter-city passengers in a mined station, bearing in mind different people will be waiting for different trains, and you don't want them all waiting on the platform. You'd need to provide a large waiting area/concourse somewhere before trains are announced which risks creating a "euston dash"type situation down the escalators to platform level.

You can provide that on the surface if you wish and then simply shunt people downstairs in order of train arrivals. With the increases in tunnel boring machine size since the Barcelona project was committed you can provide very spacious platforms indeed.
A similar single bore tunnel for the BART (in the US) extension has gone with a 56 foot (~17m) diameter tunnel bore so they could have single level island platforms. With a tunnel that size and double deck platforms I don't think its likely they would become seriously overloaded with passengers given the comparatively low load densities of longer distance services. Platform widths would probably be something like 12m or more.

With a shallow-box design, it's much simpler. Waiting areas can be located directly above the platforms similar to the way Bologna AV works, along with a few other mainline stations on the continent. A lot of thought was put into a "central station" for the CrossNorth plan, but it was ruled out on these grounds, although that isn't to say if someone else finds a solution (aka the city council which would likely be required to fund it) that it isn't entirely impossible. Just that it isn't *required* to meet the objectives NPR set out to do.

The problem is it will cost an awful lot more to the point of materially damaging the business case! Giant box stations in urban areas are extremely expensive.

 

[GJMarshy]

The line between such systems is kind of blurry, especially in the UK context.
There are very few "true" intercity trains calling at Manchester, indeed the only ones that might qualify are the London trains.
If NPR ever occurs it won't be a true intercity system given the very short journey times that it enables.


You can provide that on the surface if you wish and then simply shunt people downstairs in order of train arrivals. With the increases in tunnel boring machine size since the Barcelona project was committed you can provide very spacious platforms indeed.
A similar single bore tunnel for the BART (in the US) extension has gone with a 56 foot (~17m) diameter tunnel bore so they could have single level island platforms. With a tunnel that size and double deck platforms I don't think its likely they would become seriously overloaded with passengers given the comparatively low load densities of longer distance services. Platform widths would probably be something like 12m or more.



The problem is it will cost an awful lot more to the point of materially damaging the business case! Giant box stations in urban areas are extremely expensive.

A box station on the proposed Salford Interchange site has the advantage of being brownfield, with only light-industrial units in the immediate vicinity of the box itself. In terms of construction, it is ideally located close to railways (Ideal for moving excavated material) as well as being at the terminus of the M602 motorway.

If you were to propose such a station in say, Piccadilly gladdens, your point would have much more weight.

 

[HSTEd]

A box station on the proposed Salford Interchange site has the advantage of being brownfield, with only light-industrial units in the immediate vicinity of the box itself. In terms of construction, it is ideally located close to railways (Ideal for moving excavated material) as well as being at the terminus of the M602 motorway.

If you were to propose such a station in say, Piccadilly gladdens, your point would have much more weight.

Whilst an interchange at Salford might be on a brownfield site, the Piccadilly station shown on 'Cross North' proposals certainly isn't!
Once you adopt a stacked platform in the tunnel arrangement for Piccadilly, not much reason not to do it for the entire route.

 

[GJMarshy]

Whilst an interchange at Salford might be on a brownfield site, the Piccadilly station shown on 'Cross North' proposals certainly isn't!
Once you adopt a stacked platform in the tunnel arrangement for Piccadilly, not much reason not to do it for the entire route.

Even on the Piccailly site there's very little other than the existing station itself in the way. The adjacent areas is mostly light industrial and car parking (which was already earmarked for demolition for the HS2 terminus on the same site)

(The below images represents a 4 platform sub-surface box with mined crossover boxes. Alternatively you could excavate the crossover boxes too if you were to move the station further east)

 

[JamesT]

Was HS2 to enter Piccadilly via a viaduct or tunnel? If it were a tunnel then the plans and costing are already there, so the x-Manc tunnel could carry on a bit and emerge/join on the WCML at Longsight? Looking at a map it's probably no more than 4km of tunnel, how long is the Elizabeth Line and how much did it cost per km??

The Piccadilly HS2 station was proposed to be above ground. The plans can be seen at https://assets.hs2.org.uk/wp-content/uploads/2020/10/06111121/MA07-Compressed.pdf
There would be a tunnel from the Airport station to around Ardwick where the North portal would be. It would then rise up onto viaducts to reach the station, including the junction with the NPR line to Leeds.