Ordsall Chord

[DynamicSpirit]

DynamicSpirit will probably conclude it wasn't worth the bother then!

I'm curious what makes you think I'd believe that, since I don't recall ever commenting in this thread apart from asking the question being discussed!

You are nevertheless correct. If it really does turn out to be only 2 or 3 tph using the chord, then that rather makes a mockery of the idea of providing a useful cross-city connection and a massive improvement in connectivity (aside from the likely slow speeds and indirect route for going cross-city in any case), and I would start to suspect that perhaps the money spent on the chord could have been spent to more useful impact elsewhere. But I'm coming from a position of relative ignorance so I could easily be mistaken.

 

[GRALISTAIR]

I'm curious what makes you think I'd believe that, since I don't recall ever commenting in this thread apart from asking the question being discussed!

You are nevertheless correct. If it really does turn out to be only 2 or 3 tph using the chord, then that rather makes a mockery of the idea of providing a useful cross-city connection and a massive improvement in connectivity (aside from the likely slow speeds and indirect route for going cross-city in any case), and I would start to suspect that perhaps the money spent on the chord could have been spent to more useful impact elsewhere. But I'm coming from a position of relative ignorance so I could easily be mistaken.

It is a step forward in planning for the future IMHO.

 

[DynamicSpirit]

I would expect to see a timetable where as every train goes through the series of junctions, it is scheduled to pass another one in the opposite direction but the same route. That way the two cannot conflict with any other train - except of course when one of them is running late - so the timetable needs to be reliable everywhere as well as scheduling most of Northern England round this particular constraint. Fortunately the travel time to the key destination of the Airport is about right for a train heading there to pass the one an hour earlier coming back again.

My bolding ... It's not often that you see so much significance in so few words If what you say is correct (and it does sound reasonable), then I'm glad I'm not one of the planners tasked with constructing the timetable!

 

[Greybeard33]

My bolding ... It's not often that you see so much significance in so few words If what you say is correct (and it does sound reasonable), then I'm glad I'm not one of the planners tasked with constructing the timetable!

You may be interested in the previous exchange between Joseph_Locke and The Planner (both knowledgeable in their respective fields) concerning the headways through Castlefield Junction post-Northern Hub. Starts at post #1209, with clarification in #1219.

 

[snowball]

In the ideal world they would be grade separated junctions but unfortunately that means £££s. The money was not available so we get what can be afforded.

It's not just the money. As Joseph Locke has stated in the past, there isn't the necessary length available for the approach ramps to the flyovers. And Metrolink passing above the existing viaduct is a further difficulty.

 

[HowardGWR]

You may be interested in the previous exchange between Joseph_Locke and The Planner (both knowledgeable in their respective fields) concerning the headways through Castlefield Junction post-Northern Hub. Starts at post #1209, with clarification in #1219.

Ah yes, I remember it now. Actually, my query in the middle of it was not about the Franglais but an explanation about 'planning' and 'technical' headway. I would be very interested if either gent could explain that please.

To answer DynamicSpirit - I'm psychic!

In fact it was pretty clear where you were heading with your post and I must say I am actually shocked at the revelation (to us both anyway) that the chord is to be so little used, initially anyway.

 

[lejog]

I don't understand quite what all these extra services that some people apparently expected to run over the Chord would be, given that it is designed to route services from Manchester Airport and Piccadilly to the lines east of Victoria which number only two - the Stalybridge and Calder Valley lines.

If you read the Manchester Hub Study, you will see the rational behind the Chord which is in briefly two fold:

- To improve capacity at Piccadilly by removing two movements across the throat by Airport TPE services.
- To meet a host of connectivity requirements within/across Manchester for major lines that Network Rail were set to solve, which the Calder Valley uniquely of the main lines failed by terminating at Victoria.

Network Rail put forward two costed options for the Hub - one with and one without the Ordsall Chord and the government chose the more expensive option (otherwise Calder Valley services would have routed to Piccadilly and the Airport by reversing at Salford Crescent!).

The 2 TPE services can run over the Chord as soon as it opens. Unfortunately it seems that Calder Valley services can't - capacity/linespeed upgrades to the line have started in the west, and apparently will work eastwards but under the latest Hendy plan are only targeted to be complete in December 2019 (heavily asterisked as date to be confirmed) with additional capacity at Leeds Station.

Of course as well as services over the Chord, there will be improved services from Chat Moss through Victoria, which will be transformed from a grotty terminus for grotty Pacers and Sprinters from Bolton, Wigan and the Calder Valley with 4tph TPE services from Liverpool and Manchester Airport to points east and 3tph Northern Connect services from Liverpool, Man Airport and Chester via the Calder Valley.

 

[HowardGWR]

I genuinely thought that a host of new journey opportunities were to be created via Manchester, with new services using the chord, the chief advantage being that of not reversing or changing trains there. I was thinking very fast Bristol / Cardiff - Brum - Manchester - Halifax /Huddersfield - Leeds/Bradford services, and so forth. I had read about the idea of services from NE cities to the airport, but have wondered just how pleased the more local airports at Leeds-Bradford and Newcastle would be about that.

Were any longer term aspirations sounded in the Northern Hub reports?

 

[Joseph_Locke]

Ah yes, I remember it now. Actually, my query in the middle of it was not about the Franglais but an explanation about 'planning' and 'technical' headway. I would be very interested if either gent could explain that please.

Technical headway is the minimum time interval that services can operate at on the basis that a driver only ever has a proceed aspect at the next signal. This is calculated in seconds and is best regarded as a thought experiment.

Planning headway is the minimum time interval that services can be planned to operate at, taking into consideration the mix of train lengths, performance, even-ness of the signal spacing (in braking space), numbers of stations, etc. This is applied between any two junctions, is always higher than the lowest technical headway and is expressed in half minutes.

As a rule of thumb (and there are many ways of doing the conversion) if there were no stations, even spaced signals and one sort of train then planning could be as low as 125% of technical, rounded up to the nearest half minute.

However it is typically 150% of the average technical headway, ish, unless other factors apply.

Summary: it's a dark art....

 

[lejog]

I genuinely thought that a host of new journey opportunities were to be created via Manchester, with new services using the chord, the chief advantage being that of not reversing or changing trains there. I was thinking very fast Bristol / Cardiff - Brum - Manchester - Halifax /Huddersfield - Leeds/Bradford services, and so forth. I had read about the idea of services from NE cities to the airport, but have wondered just how pleased the more local airports at Leeds-Bradford and Newcastle would be about that.

Were any longer term aspirations sounded in the Northern Hub reports?

The Manchester Hub (later Northern Hub) project's remit was (and whole economic case was based on) improving rail journeys between the NORTH'S major cities and towns in order to boost the economy of the North. It certainly had nothing to do with creating alternative XC routes from the South West to Yorkshire. That's why the new routes from Halifax and Bradford are to Manchester Airport, Chester and Liverpool.

 

[Greybeard33]

Technical headway is the minimum time interval that services can operate at on the basis that a driver only ever has a proceed aspect at the next signal. This is calculated in seconds and is best regarded as a thought experiment.

Planning headway is the minimum time interval that services can be planned to operate at, taking into consideration the mix of train lengths, performance, even-ness of the signal spacing (in braking space), numbers of stations, etc. This is applied between any two junctions, is always higher than the lowest technical headway and is expressed in half minutes.

As a rule of thumb (and there are many ways of doing the conversion) if there were no stations, even spaced signals and one sort of train then planning could be as low as 125% of technical, rounded up to the nearest half minute.

However it is typically 150% of the average technical headway, ish, unless other factors apply.

Summary: it's a dark art....

So a 3 minute planning headway, needed to get the planned 16tph through Castlefield Jn, implies a technical headway of 2 minutes or less? That seems rather ambitious, considering that some of the trains will be stopping in Deansgate station and that a 750m long container train will take about 1 minute to vacate a block section at 30mph....:roll:

 

[notlob.divad]

Given the restrictions around Castlefield Junction, Deansgate and the Chord. Is there a benefit in looking at converting some/all of the stopping services to Metrolink using Tram/train units.

In particular I would have thought the Warrington Central stopping service could be done. Instead of extending the Metrolink from Pomona to the Trafford Centre. Join it to the CLC after the freight terminal.
The flip side of this is you would grant Merseytravels wish of extending the Merseyrail Network to Warrington Central to cover the stops between Hunts Cross and Warrington.

Warrington Central would probably need some work to build some bay platforms facing each way. But you would free up 2 paths in each direction through Castlefield Junction.

Its not going to happen soon because of all the other electrification projects going on, but I feel it would give some significant benefits in the long run.

 

[edwin_m]

Last I heard there were going to be 2TPH of Transpennine going round the Ordsall Chord, linking Manchester Airport to Leeds and beyond, plus 1TPH or maybe 2TPH between the Airport and the Calder Valley (all TPH are doubled if you count both directions separately). Has this changed?

 

[notlob.divad]

Technical headway is the minimum time interval that services can operate at on the basis that a driver only ever has a proceed aspect at the next signal. This is calculated in seconds and is best regarded as a thought experiment.

Planning headway is the minimum time interval that services can be planned to operate at, taking into consideration the mix of train lengths, performance, even-ness of the signal spacing (in braking space), numbers of stations, etc. This is applied between any two junctions, is always higher than the lowest technical headway and is expressed in half minutes.

As a rule of thumb (and there are many ways of doing the conversion) if there were no stations, even spaced signals and one sort of train then planning could be as low as 125% of technical, rounded up to the nearest half minute.

However it is typically 150% of the average technical headway, ish, unless other factors apply.

Summary: it's a dark art....

Thank you for this, it explains a lot to me. In my language. Technical Headway sounds like the "Spherical Cow" (Or spherical Train if you want) answer.

Whereas planning headway would be the real world application of this.

 

[The Planner]

Technical headway is the minimum time interval that services can operate at on the basis that a driver only ever has a proceed aspect at the next signal. This is calculated in seconds and is best regarded as a thought experiment.

The proceed aspect has to be green (unless it is impossible for it to be, such as approaching buffers etc..) and is a the time taken for a train to clear the overlap of the signal, then the time it would take for the first possible signal to be green behind it (so the third signal back in 3 aspect, fourth in four aspect) plus the sighting distance of 7 or 8 seconds. This can vary dependent on line speed and the traction. This will give you a figure in seconds as Mr Locke esq. states. Bear in mind this assumes that the driver is only looking at the next signal and is not reading through and therefore is driving at the maximum possible speed (not always line speed) we cannot account for geography!

Planning headway is the minimum time interval that services can be planned to operate at, taking into consideration the mix of train lengths, performance, even-ness of the signal spacing (in braking space), numbers of stations, etc. This is applied between any two junctions, is always higher than the lowest technical headway and is expressed in half minutes.

As a rule of thumb (and there are many ways of doing the conversion) if there were no stations, even spaced signals and one sort of train then planning could be as low as 125% of technical, rounded up to the nearest half minute.

However it is typically 150% of the average technical headway, ish, unless other factors apply.

Summary: it's a dark art....

It is a dark art, and as much as people try to make it formulaic or add a %age uplift, it doesn't work. Planning headway's are very often single figures that apply to all traction doing the same thing ie: line speed and following each other without stopping. We are trying to move away from this as where in the past you could get away with this, it now needs to be more prescriptive for following freight, stoppers and slower traction. The amount of mandatory timing points can also hinder or help.

There is no set uplift figure, it could be as low as 120% or as high as 220%, it is what experience, knowledge and consultation with all the relevant people accept.

So a 3 minute planning headway, needed to get the planned 16tph through Castlefield Jn, implies a technical headway of 2 minutes or less? That seems rather ambitious, considering that some of the trains will be stopping in Deansgate station and that a 750m long container train will take about 1 minute to vacate a block section at 30mph....:roll:

No, you are assuming the uplift %age, the technical headway could well be 150 seconds or slightly more and you could still plan to 3 if evidence backs it up.

Thank you for this, it explains a lot to me. In my language. Technical Headway sounds like the "Spherical Cow" (Or spherical Train if you want) answer.

Whereas planning headway would be the real world application of this.

Good analogy.

 

[Joseph_Locke]

Thank you for this, it explains a lot to me. In my language. Technical Headway sounds like the "Spherical Cow" (Or spherical Train if you want) answer.

Whereas planning headway would be the real world application of this.

It was chickens when I did my degree ....

 

[Greybeard33]

Last I heard there were going to be 2TPH of Transpennine going round the Ordsall Chord, linking Manchester Airport to Leeds and beyond, plus 1TPH or maybe 2TPH between the Airport and the Calder Valley (all TPH are doubled if you count both directions separately). Has this changed?

From the service requirements in the TP and Northern franchise agreements, my best guess at the tph through Castlefield Jn remains as follows:

...if we assume that the N Wales service is to be diverted to Victoria, there will only be 15 paths used, including 2 freight, through Castlefield Junction/Deansgate after allowing for all the services required in the Northern Dec 2019 TSR (which presumably assumes all the Hub works will be complete). The 15 will comprise 4tph from the CLC line (Liverpool-Norwich, Liverpool-Airport & 2tph stoppers), 2tph from the Chat Moss line (Barrow/Windermere-Airport & Liverpool-Airport stopper), 4tph from the Bolton line (Glasgow/Edinburgh-Airport, Blackpool-Airport, 2 Hazel Grove) and 3tph from the Ordsall Chord (2 TPE Leeds-Airport, 1 Bradford-Airport), plus 2tph Trafford Park freights. If the line capacity is really to be 16tph as promised, that leaves one path spare, which could go to the Airport.

Note that the Bradford to Airport service is not due to start until Dec 2019 (presumably dependent on completion of Oxford Road and Piccadilly remodelling). An Arriva Northern rep has been reported as also promising that the Blackburn to Vic via Todmorden Curve service will be extended to the Airport, but this is not a franchise requirement. Alternatively, ATW has been arguing for a path to extend the N Wales to Manchester service to the Airport.

No, you are assuming the uplift %age, the technical headway could well be 150 seconds or slightly more and you could still plan to 3 if evidence backs it up.

Thank you for the clarification.

 

[notlob.divad]

It was chickens when I did my degree ....

Spherical Chickens work too, but only when they are considered in a vacuum.

 

[lejog]

Note that the Bradford to Airport service is not due to start until Dec 2019 (presumably dependent on completion of Oxford Road and Piccadilly remodelling).

Possibly or possibly as I posted this morning (the Franchise Specs confirm the service will run from Leeds)

The 2 TPE services can run over the Chord as soon as it opens. Unfortunately it seems that Calder Valley services can't - capacity/linespeed upgrades to the line have started in the west, and apparently will work eastwards but under the latest Hendy plan are only targeted to be complete in December 2019 (heavily asterisked as date to be confirmed) with additional capacity at Leeds Station.

And of course, I don't suppose there will be any available trains before 2019.

 

[HowardGWR]

Thanks for those technical explanations.

On the use of the chord itself, I suppose that if we are not to get through trains from Bradford or Blackburn, that go to such exotic locations such as Birmingham and Bristol, it would be useful to ensure that changing over at Piccadilly from the through platforms to the trains that will reach these far-flung outposts of the Empire, will be made as user-friendly as possible.

Clapham Junction does this, in its old-fashioned way, rather successfully. There,it helps that all trains to a destination group, always leave from the same platforms, so that the notices on the wall are actually painted on wood.

 

[Greybeard33]

Possibly or possibly as I posted this morning (the Franchise Specs confirm the service will run from Leeds)

And of course, I don't suppose there will be any available trains before 2019.

No, Northern's Northern Connect webpage says that the Airport service will terminate at Bradford, so is not dependent on capacity at Leeds. The services running through Bradford to Leeds will be the Chester, the Liverpool and the Blackpool.

The Hendy Enhancements Delivery Plan March 16 Update gives an "indicator" EIS date of 9 Dec '18 for Calder Valley East, with a footnote that the date is "currently under review". No date is given for Oxford Road and Piccadilly (Package C), with a note that the scheme is subject to a Transport and Works Act Order.

It seems unlikely that Piccadilly will be able to handle all the planned Dec 2019 services unless Platforms 15 and 16 are in service by then.

 

[QueensCurve]

On the use of the chord itself, I suppose that if we are not to get through trains from Bradford or Blackburn, that go to such exotic locations such as Birmingham and Bristol, it would be useful to ensure that changing over at Piccadilly from the through platforms to the trains that will reach these far-flung outposts of the Empire, will be made as user-friendly as possible.

Clapham Junction does this, in its old-fashioned way, rather successfully. There,it helps that all trains to a destination group, always leave from the same platforms, so that the notices on the wall are actually painted on wood.

I imagine one island (13/14) will carry southbound services and another (15/16) the Northbound. You would always go to the right island and your train would go from one face or the other.

 

[edwin_m]

Spherical Chickens work too, but only when they are considered in a vacuum.

And only if you make sure you specify whether they are fresh or frozen.

 

[snowball]

I imagine one island (13/14) will carry southbound services and another (15/16) the Northbound. You would always go to the right island and your train would go from one face or the other.

Unfortunately the same is not possible at Oxford Road as it's two side platforms and one island.

 

[Railway Dave]

Thanks lejog for link to the Manchester Hub Study. Its comparison between Ordsall Chord and Ardwick flyover is an interesting read.

It's unfortunate that Ordsall Chord is such a controversial project when it offers such great benefits that many don't understand e.g. letter in latest RAIL magazine.

Does anyone know if there is an equivalent map to this

showing services once Ordsall Chord is complete?

Something that shows how conflicts at Piccadilly are eliminated and how traffic will be taken off Castlefield corridor may help convince the doubters

 

[lejog]

The Hendy Enhancements Delivery Plan March 16 Update gives an "indicator" EIS date of 9 Dec '18 for Calder Valley East, with a footnote that the date is "currently under review". No date is given for Oxford Road and Piccadilly (Package C), with a note that the scheme is subject to a Transport and Works Act Order.

Although the Hendy Draft Version of CP5 Enhancements Plan is a very "draft" document, the "Calder Valley East" activity provides linespeed improvements not capacity improvements,

Provision of a turnback facility at Rochdale station towards Manchester and infrastructure improvements between Manchester and Bradford to provide journey time savings split into Calder Valley West and Calder Valley East.

The activities required to deliver increased Calder Valley capacity are somewhat scattered through the document but are identified as including:

• Bradford Mill Lane capacity (Complete December 2018)
• Leeds Station capacity (Complete December 2019)
• Huddersfield to Bradford Resignalling and Recontrol (Identified in a couple of places as being necessary during CP5, but I cant see where this activity is actually being done).Apparently Halifax to Bradford needs resignalling to allow Grand Central trains to run along with the new services.

Leeds Station capacity is interesting since the CP5 HLOS specified a turnback at Micklefield to allow 2 extra Calder Valley services (although West Yorkshire conveniently had a budget for an alternative with a station at East Leeds Parkway), but this seems to have disappeared with Hendy, so presumably there will have to be more spade work at Leeds.

It seems unlikely that Piccadilly will be able to handle all the planned Dec 2019 services unless Platforms 15 and 16 are in service by then.

Its not just Piccadilly that needs extra platforms, while we'll have to see what happens when Grip 3 for Leeds capacity is complete in May 2017, a Platform 0 has been mentioned to cater for the 2tph extra to Harrogate, platform lengthening for longer Airdale and Sheffield trains, now something unknown for Calder Valley services.

 

[WatcherZero]

No, theres no map of post Ordsall Chord services because they haven't been decided yet.

 

[Sox]

Thanks to lejog for posting the hub study link:

http://www.networkrail.co.uk/6485_ManchesterHubRailStudy.pdf

One thing that puzzles me is the addition of extra through platforms at Piccadilly (prospectively called 15 and 16).

The station curtilage is so tight at this point, there just does not seem to be any room.

 

[edwin_m]

One thing that puzzles me is the addition of extra through platforms at Piccadilly (prospectively called 15 and 16).

The station curtilage is so tight at this point, there just does not seem to be any room.

They would involve building another viaduct to the south of the existing one. There are some option plans on the net somewhere, all of which appear fairly tight to squeeze in with various impacts on the surroundings (Star and Garter pub, Macdonald hotel, and the rusty-looking building which I think is a major electricity substation).

 

[Elecman]

They would involve building another viaduct to the south of the existing one. There are some option plans on the net somewhere, all of which appear fairly tight to squeeze in with various impacts on the surroundings (Star and Garter pub, Macdonald hotel, and the rusty-looking building which I think is a major electricity substation).

The rusty looking building us indeed an ENWL substation, the rusty nature of the building is intentional in that it never needs any further painting /surface protection. Use quite a lot nowadays.