Heathrow: Western Link to GWML.

[Chris125]

If the money doesn't stretch to electrification then bi-modes would be a good alternative. I can see no reason why they should not be permitted to operate through the Heathrow tunnels as the diesel engines won't be running. It's not as if operating diesel engines are not permitted in current operation through long tunnels such as the Severn and Standedge which also have limited ventilation.

I was thinking of the report, possibly from Network Rail, that diesel bi-modes serving Hastings may not be allowed through HS1's London tunnels. Tunnels like the Severn and Standedge have grandfather rights.

 

[edwin_m]

I was thinking of the report, possibly from Network Rail, that diesel bi-modes serving Hastings may not be allowed through HS1's London tunnels. Tunnels like the Severn and Standedge have grandfather rights.

The safety case for the tunnels will be based on risk assessments which have provided evacuation measures appropriate to the characteristics of the tunnel. Diesel engines, even if shut down, and especially their fuel tanks, represent an increased risk because there is more energy available to feed a fire. So someone either needs to re-assess the risk and conclude it is still acceptable, or provide some more mitigating measures.

 

[eaet]

Not sure how much is new but the final consultation starts today, with two route options allowing for through running to Paddington or turnaround at Heathrow

 

[Sebastian O]

Interesting that there seems to be a large amount of earthworks already taking place on this field in Richings Park, even before the consultation has started..

 

[contractador]

How does shortening the tunnel to the west of the airport affect the ability to turnaround trains? Could someone explain how this would work and which turnarounds would be missed or lost.

 

[eaet]

How does shortening the tunnel to the west of the airport affect the ability to turnaround trains?

For anyone who's missed it, this is all it says on the matter

Option A is shown on the map by a dotted orange line. It would allow trains to turn back at Terminal 5, as well as run through to Terminals 2 and 3.

Option B is shown on the map by a dotted green line. It would allow trains to run to Terminal 5, through to Terminals 2 and 3 and on to London Paddington. This option would remove the section of track required to allow trains to turn back, shortening the tunnel by 100m. This would reduce construction time and costs, and remove the need for an access building close to Heathrow.

 

[Wirewiper]

In case anyone is unaware, Heathrow Express has sub-contracted Great Western Railway to operate the Heathrow Express from August 2018, for a ten-year period. GWR will use modified class 387s based at its Reading Depot. This means that the proposed new Heathrow Express Depot at Langley will not now be built and has been removed from the consultation.

 

[edwin_m]

How does shortening the tunnel to the west of the airport affect the ability to turnaround trains? Could someone explain how this would work and which turnarounds would be missed or lost.

For anyone else who had difficulty finding this statement, it's on page 3 of the PDF linked from the Network Rail link above (https://cdn.networkrail.co.uk/wp-content/uploads/2018/05/Western-rail-link-to-heathrow.pdf).

We are considering two possible routes for the final section of the tunnel, closest to Heathrow.


Option A is shown on the map by a dotted orange line. It would allow trains to turn back at Terminal 5, as well as run through to Terminals 2 and 3.


Option B is shown on the map by a dotted green line.It would allow trains to run to Terminal 5, through to Terminals 2 and 3 and on to London Paddington. This option would remove the section of track required to allow trains to turn back, shortening the tunnel by 100m. This would reduce construction time and costs, and remove the need for an access building close to Heathrow.

This doesn't seem very well worded. Note that option B makes no mention of turning back so I think it is saying the turnback facility is omitted so trains have to continue to Paddington. If this is so then running to Paddington would equally be possible with option A, and indeed essential unless trains terminate at T5. The difference of 100m suggests the inclusion/omission of pointwork, presumably a crossover or a scissors crossing between the portal and the T5 station.

 

[subria]

Would they put into place passive provision for the southern access route as part of the construction?

 

[GRALISTAIR]

Would they put into place passive provision for the southern access route as part of the construction?

That would seem like a good plan.

 

[cle]

Are there any ideas as to platform set up at Heathrow? And flexibility with all four NR platforms, and also with Southern access.

I imagine it would depend on how many Crossrail or other trains run through, but you'd want ideally the London platforms as a pair (one with through services from west/south, one a Crossrail terminating one) - and then a southern and a western outbound platform. But possibly it needs to be two Crossrail terminating platforms together, and the two through ones for western/southern shared - so three London-bound platforms.

 

[swt_passenger]

Are there any ideas as to platform set up at Heathrow? And flexibility with all four NR platforms, and also with Southern access.

I imagine it would depend on how many Crossrail or other trains run through, but you'd want ideally the London platforms as a pair (one with through services from west/south, one a Crossrail terminating one) - and then a southern and a western outbound platform. But possibly it needs to be two Crossrail terminating platforms together, and the two through ones for western/southern shared - so three London-bound platforms.

I remember there was a fairly detailed map of how it could been done back when Airtrack was being consulted. There are already four platforms as most people are aware, but I'm not sure what the approaches and crossovers from the T4 direction are already optimised for.

 

[contractador]

For anyone else who had difficulty finding this statement, it's on page 3 of the PDF linked from the Network Rail link above (https://cdn.networkrail.co.uk/wp-content/uploads/2018/05/Western-rail-link-to-heathrow.pdf).


This doesn't seem very well worded. Note that option B makes no mention of turning back so I think it is saying the turnback facility is omitted so trains have to continue to Paddington. If this is so then running to Paddington would equally be possible with option A, and indeed essential unless trains terminate at T5. The difference of 100m suggests the inclusion/omission of pointwork, presumably a crossover or a scissors crossing between the portal and the T5 station.

So if I understand correctly the omission of pointwork would mean turn back is impossible as effectively a train could only use the same line it entered the station on?

 

[swt_passenger]

So if I understand correctly the omission of pointwork would mean turn back is impossible as effectively a train could only use the same line it entered the station on?

Yes, that seems to be the main difference. Found another sketch towards the end of a NR report. The Orange line (as drawn above) includes a crossover west of T5, the Green line doesn't. The lines are coloured differently in the linked report here: https://consultations.networkrail.co.uk/communications/improving-rail-links-to-heathrow/supporting_documents/Consultation Overview Report.pdf Referred to as Bedfont crossover box.

 

[civ-eng-jim]

Interesting that there seems to be a large amount of earthworks already taking place on this field in Richings Park, even before the consultation has started..

That would be CEMEX extracting sand and gravel. It is hoped that the WRLTH project can tip the tunnel spoil here.

 

[civ-eng-jim]

Would they put into place passive provision for the southern access route as part of the construction?

There's no need (as part of the WRLTH scheme) as there is already a stub tunnel which was built as part of Terminal 5

On page 33 of this report you can see the outline of the stub tunnels indicated by "HAL INTERFACES" - bottom right hand corner.

https://consultations.networkrail.c...ng_documents/Consultation Overview Report.pdf

 

[The Ham]

Assuming that it is possible to run through services to Paddington in either option then I could see that having the turn back facilities should be built just so that if there's problems East of the airport there's scope to run some of the services as a shuttle. Even though they would normally do so. It could also mean that some first/last services could do so if the train depot is located at Reading.

 

[mwmbwls]

Not sure how much is new but the final consultation starts today, with two route options allowing for through running to Paddington or turnaround at Heathrow

WRATH and SWARTH - Rail access to Heathrow by Mwmbwls, on Flickr

Some subtle variations such as a link to the Waterloo to Reading route appear to have surfaced. Whilst I understand the arguments about through running via Heathrow perhaps crowding out Heathrow to the City passengers - is this inevitable given that such a route would be longer that existing routes into London? Also if there is a case for a Reading link - does not the same apply to the LSWR main line stations?

 

[civ-eng-jim]

Assuming that it is possible to run through services to Paddington in either option then I could see that having the turn back facilities should be built just so that if there's problems East of the airport there's scope to run some of the services as a shuttle. Even though they would normally do so. It could also mean that some first/last services could do so if the train depot is located at Reading.

Both options tie-in to the existing operational platforms at T5 making through running possible. There is a crossover immediately to the East of T5 which could allow turn back in an emergency.

Providing a crossover to the west is a massive capital expense and maintenance liability for something which will be used very little.

 

[kcajtam]

In Comparison, the Windsor Link Railway propose a different southern connection.

 

[civ-eng-jim]

In Comparison, the Windsor Link Railway propose a different southern connection.

I can't see how a western connection to the GWML can be achieved though.....

 

[kcajtam]

I can't see how a western connection to the GWML can be achieved though.....

They want to link up the two windsor stations, providing a straight link between staines and slough. The Heathrow southern connection would then connect to the windsor line, for southern and western access.

 

[NotATrainspott]

They want to link up the two windsor stations, providing a straight link between staines and slough. The Heathrow southern connection would then connect to the windsor line, for southern and western access.

The Windsor line junction is embedded in the middle of Slough. It might just be feasible to reopen the western chord but the bigger problem is that grade-separation in either direction is not feasible. The southern pair of tracks are the main lines for express trains and without grade-separation, trains to/from Windsor would need to cross the whole GWML to go either west or east. It works fine when the Windsor branch is just a shuttle but that's not what this link would need to be about. The whole idea of the Windsor Link Railway doesn't really stack up even if people think it just involves a small bit of new track (in a tunnel with a station underneath the town centre...).

 

[The Ham]

WRATH and SWARTH - Rail access to Heathrow by Mwmbwls, on Flickr

Some subtle variations such as a link to the Waterloo to Reading route appear to have surfaced. Whilst I understand the arguments about through running via Heathrow perhaps crowding out Heathrow to the City passengers - is this inevitable given that such a route would be longer that existing routes into London? Also if there is a case for a Reading link - does not the same apply to the LSWR main line stations?

I would suggest that given that Woking to Heathrow is going to 4tph and there's also going to be significant train frequencies on other services between Heathrow and Crossrail, that if the Woking services were to run to Paddington that wouldn't really impact on those heading from Heathrow to the city.

Likewise from Reading (or Basingstoke/Newbury) to Heathrow would likely be a longer route than to change at Reading and OOC and so wouldn't really impact on those heading to the city.

Also it's worth noting that there's going to be significant numbers of passengers getting off at Heathrow. As well as, at least for the Western Approach Trains, these are likely to be Crossrail services and if they are so busy at Heathrow that no one can get on then there's going to be some big problems in central London.

 

[Bald Rick]

In Comparison, the Windsor Link Railway propose a different southern connection.

Well yes, but that’s just bonkers.

A new railway built through the middle of Windsor? In cut and cover tunnel? Alongside the Thames?
Pffft.

 

[GRALISTAIR]

Please may I ask a silly question?

All these links southern access etc, they are all going to be 25kV AC OHLE aren’t they?

 

[swt_passenger]

Please may I ask a silly question?

All these links southern access etc, they are all going to be 25kV AC OHLE aren’t they?

Not necessarily. Airtrack was intending to have their DC/AC changeover immediately before entering the Heathrow tunnels...

 

[swt_passenger]

Well yes, but that’s just bonkers.

A new railway built through the middle of Windsor? In cut and cover tunnel? Alongside the Thames?
Pffft.

I remember this pie in the sky proposal claimed it had Network Rail support a few years ago. I suspect that was a misinterpretation of Network Rail being too polite to tell them to get lost in a formal letter...

 

[swt_passenger]

Some subtle variations such as a link to the Waterloo to Reading route appear to have surfaced.

These aren't really 'subtle variations' to this project though - they are a completely separate proposal that is at nowhere near the same level of official NR activity as western access is.

 

[The Ham]

Not necessarily. Airtrack was intending to have their DC/AC changeover immediately before entering the Heathrow tunnels...

However given the cost savings associated with OHLE over the lifetime of the system and the desire to not have any new third rail systems then I would be surprised if it were to be anything other than OHLE.

Also if they build it as OHLE then the tunnels will be big enough to be converted to third rail if needed, whilst it may not be possible to do it the other way.