GWML ETCS

[RandomTrainFan]

Hi there, this is the first post that I've made so apologies if I got this wrong.

Does anyone know where ETCS is fitted on the GWML and where it is planned to be extended? Someone told me that there was some ETCS recently fitted but not active right now.

 

[MichaelDono]

A Level 2 Overlay in in place between around Ealing Broadway and Airport Junction and onto Heathrow, work to extend that into Paddington was meant to follow it but now seems to have been bumped into a future Control Period for some reason.

Trains to Heathrow need to use ETCS L2 as there is no AWS/TPWS through there - it was upgraded straight from GW ATP to Level 2.

 

[Benjwri]

it but now seems to have been bumped into a future Control Period for some reason.

The suggestion has always been it is because of the significant changes for Old Oak Common. Doesn’t make sense to spend the money on it just to have to do it all again for practically no benefit.

 

[Harpo]

The earliest ETCS proposals to Reading envisaged an overlay so, ETCS + lights on sticks + AWS + ATP (!). Did that ever move on?

 

[JN114]

The earliest ETCS proposals to Reading envisaged an overlay so, ETCS + lights on sticks + AWS + ATP (!). Did that ever move on?

That’s what is currently in place between Ealing and West Drayton

IETs can’t switch out of ATP on the move, so ATP will be around until it’s either risk assessed acceptable to remove it like happened on Chiltern; or ETCS replaces all of it.

 

[RandomTrainFan]

That’s what is currently in place between Ealing and West Drayton

IETs can’t switch out of ATP on the move, so ATP will be around until it’s either risk assessed acceptable to remove it like happened on Chiltern; or ETCS replaces all of it.

I thought it ended at Heathrow Airport Junction rather than West Drayton?

 

[TFN]

I thought it ended at Heathrow Airport Junction rather than West Drayton?

It ends at Stockley Junction.

 

[gravitystorm]

I thought it ended at Heathrow Airport Junction rather than West Drayton?

It ends approximately half-way between the two, immediately to the west of Stockley Bridge Junction. The sectional appendix has the precise locations for each line:



(Diagram shows an excerpt from the Sectional Appendix, and has the ERTMS Transitions as follows: Up Relief 12m 32ch, Down Relief 12m 30ch, Up Main 12m 25ch, Down Main 12m 26ch, with the Stockley Bridge Junction marked as being a notional 12m 13ch.)

Heathrow Airport Junction finishes around 11m 52ch, and West Drayton is at 13m 17ch, for context.

 

[MichaelDono]

The suggestion has always been it is because of the significant changes for Old Oak Common. Doesn’t make sense to spend the money on it just to have to do it all again for practically no benefit.

You’d think they’d plod on with getting the overlay west of Airport junction until OOC is complete. Only starting heading west after that is going to lead to some real challenges keeping ATP going in terms of maintenance, assuming ETCS needs to get all the way out to the current limits of ATP!

 

[Kentish RYS]

IETs can’t switch out of ATP on the move

I'm curious on this so have made a separate thread to not divert this one here:

IET (and other rolling stock?) can't transition from GWR ATP to ETCS on the move

From the thread on GWML ETCS the fact IETs can't transition on the move from GWR ATP to ETCS came up and am curious but it isn't 100% relevant to that thread so I thought to make one to discuss here IETs can’t switch out of ATP on the move Does anyone know why this is the case? The system...

www.railforums.co.uk

 

[RandomTrainFan]

It ends approximately half-way between the two, immediately to the west of Stockley Bridge Junction. The sectional appendix has the precise locations for each line:

View attachment 211571

(Diagram shows an excerpt from the Sectional Appendix, and has the ERTMS Transitions as follows: Up Relief 12m 32ch, Down Relief 12m 30ch, Up Main 12m 25ch, Down Main 12m 26ch, with the Stockley Bridge Junction marked as being a notional 12m 13ch.)

Heathrow Airport Junction finishes around 11m 52ch, and West Drayton is at 13m 17ch, for context.

What's the eastern bound? I know heathrow trains transition at Ealing Broadway right?

 

[JN114]

I thought it ended at Heathrow Airport Junction rather than West Drayton?

I was just picking stations as principle features

As others have said it is around the Stockley Crossovers that it truly transitions - the “Commencement of Cab Signalling” signs are erected in advance of SN310 signal on the Up Relief; and in advance of SN308 signal on the Up Main

On the Down Main they are in advance of SN203 signal on the Down Relief; and in advance of SN207 signal on the Down Main

 

[zwk500]

What's the eastern bound? I know heathrow trains transition at Ealing Broadway right?

The transition is between Acton Main Line and Ealing Broadway.

== Doublepost prevention - post automatically merged: Today at 07:43 ==

You’d think they’d plod on with getting the overlay west of Airport junction until OOC is complete. Only starting heading west after that is going to lead to some real challenges keeping ATP going in terms of maintenance, assuming ETCS needs to get all the way out to the current limits of ATP!

One issue is that Overlay setups are a lot more expensive to install and maintain as you effectively have 2 signalling systems each capable of functioning independently but they need to talk to each other to ensure ETCS doesn't issue an MA against a Red Signal and so on. So you're paying for not just the 2nd system, but the interface between them as well.

Also, the trackside infrastructure is only part of ETCS. You also need all the stock fitting. To that end I'm slightly surprised GWR didn't start a fitment programme for trains that didn't use ATP but again, money vs benefit.