Linking Thameslink to the ECML

[pethadine82]

As you head towards Kings cross there is a tunnel on the right, which I keep forgetting the name of with a pair of tracks.
I am guessing that this will connect St Pancras to the ECML.
Will this be a flat junction or will the southbound dive under the current track bed to merge in.

On another note as one heads north from kings cross there are empty tunnels on the right side and I see network rail vans parked there.
Are there any plans to lay track here and connect it all the way to Finsbury Park and beyond?

 

[swt_passenger]

As you head towards Kings cross there is a tunnel on the right, which I keep forgetting the name of with a pair of tracks.
I am guessing that this will connect St Pancras to the ECML.
Will this be a flat junction or will the southbound dive under the current track bed to merge in.

Belle Isle Junction. Leads to the Canal Tunnels. Will definitely be a flat junction - and it is nearly complete isn't it? This is why they've had so many weekends of engineering closures.

On another note as one heads north from kings cross there are empty tunnels on the right side and I see network rail vans parked there.
Are there any plans to lay track here and connect it all the way to Finsbury Park and beyond?

Nothing planned at all, to the best of my knowledge. It isn't a known pinch point or bottleneck is it?

 

[snowball]

The emptiness of the tunnels dates from the King's Cross throat remodelling of about 1976, part of the GN suburban electrification.

 

[yorkie]

On another note as one heads north from kings cross there are empty tunnels on the right side and I see network rail vans parked there.
Are there any plans to lay track here and connect it all the way to Finsbury Park and beyond?

No. St Pancras is to the West, and the slow lines at this point are also to the West. The disused tunnels are to the East.

Modernisation in the 1970s brought increased line speeds, and changed the layout so that trains on the Up Slow use a flyover to avoid conflicting moves with the Fasts.

 

[edwin_m]

I seem to recall a plan being described in Modern Railways about the same time to use the eastern tunnels as the start of a shuttle to Maplin Airport.

 

[whoosh]

The new tunnels which will connect the ECML to the St Pancras International Low Level platforms will be called 'Canal Tunnels'.

The connection to the ECML between Gas Works Tunnel and Copenhagen Tunnel, at Belle Isle is a flat junction and has just been laid.
The connection just north of St Pancras International Low Level has the northbound (Down) line towards the ECML burrowing under the two tracks to/from the MML.

 

[pethadine82]

Won't the flat junction create a bottleneck?
how come a tunnel was not built?
Another issue is that the class 700 stock is not capable of 125mph or even 110mph, how are journey's every going to become quicker?

 

[swt_passenger]

I seem to recall a plan being described in Modern Railways about the same time to use the eastern tunnels as the start of a shuttle to Maplin Airport.

That's correct, it was a point also included in the MR article that the track layout posted above comes from, published October 1977.

The idea for the airport service to Maplin was that two dedicated lines would use the eastern bore of Copenhagen tunnel, but with a branch off to the west by means of another new flyover over the other four tracks to a dedicated airport terminal built within the site of the goods yard. The eastern bore of gasworks tunnel would have remained unused.

 

[Carlisle]

I seem to recall a plan being described in Modern Railways about the same time to use the eastern tunnels as the start of a shuttle to Maplin Airport.

When does work start on that ?

 

[edwin_m]

When does work start on that ?

It's where all the flying pigs and pies in the sky will land.

 

[petersi]

Out of interest were is the neutral section or is the gradient such it does not matter

 

[AM9]

Out of interest were is the neutral section or is the gradient such it does not matter

Interesting point. There must be isolation between the MML & the GN so is a neutral section in a single bore tunnel normal practice? In addition, will the canal tunnels use an overhead conductor rail like the stretches between Kentish Town and City Thameslink?

 

[swt_passenger]

Interesting point. There must be isolation between the MML & the GN so is a neutral section in a single bore tunnel normal practice? In addition, will the canal tunnels use an overhead conductor rail like the stretches between Kentish Town and City Thameslink?

Not sure of the details of the neutral sections, which as you point out must be necessary, but the article in Rail Engineer mag back in May confirmed use of a conductor beam system by Balfour Beatty.

http://www.therailengineer.com/2014/05/01/tunnels-exercising-foresight/

 

[Mintona]

Interesting point. There must be isolation between the MML & the GN so is a neutral section in a single bore tunnel normal practice? In addition, will the canal tunnels use an overhead conductor rail like the stretches between Kentish Town and City Thameslink?

There is a neutral section about half a mile inside each bore of London Tunnel One after leaving St Pancras on HS1, which sets a precedent, so I can't imagine it being too much of an issue in the single bore Canal Tunnels either. Although trains will generally be going slower which could cause a slight issue I guess!

 

[AM9]

There is a neutral section about half a mile inside each bore of London Tunnel One after leaving St Pancras on HS1, which sets a precedent, so I can't imagine it being too much of an issue in the single bore Canal Tunnels either. Although trains will generally be going slower which could cause a slight issue I guess!

With 1 in 34 gradients at each end of the tunnel, any chance of coasting safely into STP or onto the GN slows in the event of a section outage are pretty slim. Could an 8 car 700 push a 12 car 700 clear up that slope. I suppose with a rigid conductor rail, the isolator section could be very short, as with the ceramic bead type isolators introduced in the '60s on conventional knitting.
I would also add that temperature rise could be a small issue particularly at the STP end with 3-5MW passing through 8 times per hour as well as the 16 TPH (peak) running through on Thameslink. Are there plans for enhanced ventilation on the low-level platforms?

 

[NotATrainspott]

Don't the 700s have two pantographs? If that is the case then I doubt any neutral section in these new tunnels would be long enough to gap both of them, even if the trains had to stop completely.

 

[AM9]

Don't the 700s have two pantographs? If that is the case then I doubt any neutral section in these new tunnels would be long enough to gap both of them, even if the trains had to stop completely.

Yes of course assuming that the pantograph cars are near the ends, particularly on the 8-car sets. I would imagine that the traction power bus would not be continuous throughout the train.

 

[Class377/5]

Don't the 700s have two pantographs? If that is the case then I doubt any neutral section in these new tunnels would be long enough to gap both of them, even if the trains had to stop completely.

Yes on coaches 2/7 or 2/11.

Also worth noting the Canal Tunnels support reversing trains within them with the crossover between the ECML and the tunnels.

 

[jopsuk]

I'm sure there were some in the Thameslink project planning who pushed for a total remodel of the Holloway flyover and the Kings Cross throat to avoid the flat junction, and to reflect the changes in how Kings Cross will be used. But it would have been ruinously expensive.

 

[SpacePhoenix]

The two pantographs might not necessarily both be up at the same time for example the Pendolinos (at least in clips on youtube) only ever have one pantograph raised at a time

 

[Class377/5]

The two pantographs might not necessarily both be up at the same time for example the Pendolinos (at least in clips on youtube) only ever have one pantograph raised at a time

Plan is one pan raised at a time. Sure its supposed to be the trailing end.

 

[NotATrainspott]

I presume though that if the driver were ever worried about being gapped they would be able to raise the second pan? I do think the risk of gapping in the Canal Tunnels has been overstated and that there are plenty of other things that will go wrong before that happens.

 

[Class377/5]

I presume though that if the driver were ever worried about being gapped they would be able to raise the second pan? I do think the risk of gapping in the Canal Tunnels has been overstated and that there are plenty of other things that will go wrong before that happens.

Bit difficult to become gapped when there is no gaps. Canal Tunnel is fully wired.

 

[AM9]

Bit difficult to become gapped when there is no gaps. Canal Tunnel is fully wired.

So does that mean that the TL core is not isolated from the ECML slows?

 

[NotATrainspott]

Bit difficult to become gapped when there is no gaps. Canal Tunnel is fully wired.

So does that mean that the TL core is not isolated from the ECML slows?

There is a neutral section to separate the MML and ECML wiring. I can't ever see it being much more of a problem than any other neutral section on the network though, even when it's on a gradient and there may be trains stopping in the tunnel before entering the Thameslink Core.

 

[swt_passenger]

Bit difficult to become gapped when there is no gaps. Canal Tunnel is fully wired.

Not according to the relevant NCN, which I've found subsequent to my post yesterday about the conductor beams:

1.2.3.2 Overhead Line Equipment (OLE)
The new OLE in the tunnels will be in the form of a conductor beam, to match the system that will be installed at St Pancras prior to the Canal Tunnels fit-out. The Canal Tunnels project is responsible for the integration of the two OLE sections although coordinated design has been achieved between the two
projects for the initial ‘Core’ works.
This project will also provide OLE neutral sections on both the Up and Down Canal routes to segregate the ECML and MML electrical sections.

http://www.networkrail.co.uk/browse...nels/ncg12012tlp008 ncn for canal tunnels.pdf

 

[petersi]

There is a neutral section to separate the MML and ECML wiring. I can't ever see it being much more of a problem than any other neutral section on the network though, even when it's on a gradient and there may be trains stopping in the tunnel before entering the Thameslink Core.

good to know

I was just interested in the problem

 

[Class377/5]

Not according to the relevant NCN, which I've found subsequent to my post yesterday about the conductor beams:

You can't be gapped. Gapped you your stuck in an section with no electrical power, the two section separating the GN and MML wires are designed so a train can't be in two dead sections (planned that is) at the same time meaning it will be able to take power unless you lose all three sections.

 

[swt_passenger]

You can't be gapped. Gapped you your stuck in an section with no electrical power, the two section separating the GN and MML wires are designed so a train can't be in two dead sections (planned that is) at the same time meaning it will be able to take power unless you lose all three sections.

I think you and the previous poster to yours first mentioned gapping - but we were actually discussing OHLE neutral sections. Different things surely? On the AC railway they don't talk about getting gapped...

AIUI an AC unit with a single pan can lose power if it happens to accidentally stop in a neutral section, but trackside signage is there to hopefully prevent it.

 

[Class377/5]

I think you and the previous poster to yours first mentioned gapping - but we were actually discussing OHLE neutral sections. Different things surely? On the AC railway they don't talk about getting gapped...

AIUI an AC unit with a single pan can lose power if it happens to accidentally stop in a neutral section, but trackside signage is there to hopefully prevent it.

I was simply replying to the poster over gapping but think somehow its got confused with OHLE set up. And yes they are different things, your point over gapped not being used on AC railway is my basic point I was trying to make to the other poster.

There have been occasions where AC units have stopped in a neutral section and its not great. Getting back to the Canal Tunnels, the track signage will make sure reversing units won get stuck in a dead section.