‘Digital Signalling’ to be introduced on the ECML

[High Dyke]

Or, with a slower turnout, some kind of diverging distant indication using flashing yellow or splitting distant for the turnout.

That reminds me of an argument I had a few years ago, with the Local Operations Manager (at that time). He was complaining that he kept getting reports of trains being signal checked when entering the loops on the ECML in the Newark area. When we pointed out the 40mph turnouts were approach controlled he got irate and kept ranting that they weren't they had flashing aspects on the approach. How stupid he looked when he stood in the signal box one day and saw the approach control working, with his own eyes.

 

[MarkyT]

For points, it is not permitted to have discontinuity in the rail above 125mph (as at all conventional switches and crossings), so they must be replaced with Swing nose crossings, as seen on high speed lines across the world. This was actually done at Ledbury Junction for the WCML upgrade, and then later undone!

The extra complexity affects reliability. Similar concerns resulted in the formerly 90mph turnouts at Heathrow Airport Jn on the GWML main being replaced by slower units, because they needed fewer back drives and detection limit switches. At least on a newly constructed high speed line you can make the junction formation as perfectly aligned and stable as possible to manage this, and if you reduce your junction locations to the absolute minimum you can ensure there's always a maintenance team within a few minutes call out to manage performance at such a strategic site. People forget things like this when they ask for 'just another' station or junction on HS2.

BR didn’t run at 140mph in regular passenger service, at least not officially. Special dispensation was granted for each move.

And I'm sure that part of the risk mitigation would be to have a special inspection soon afterwards to make sure the track hadn't moved out of alignment too much as a result of the special run.

 

[Mordac]

Platforms passed by trains at more than 125mph will have to be confirmed clear of passengers, which probably means none on the fast lines. This probably rules out 140mph south of Peterborough, most stations further north have speed restrictions anyway but somewhere like Northallerton would need major work to avoid a restriction in the middle of a long section where (alignment-wise) 140mph would be possible.

Where did that rule come from? It's definitely not an EU one, as trains in conventional lines in the continent pass stations at 225km/h regularly. And these are low platform stations, which are much more dangerous.

 

[rf_ioliver]

Where did that rule come from? It's definitely not an EU one, as trains in conventional lines in the continent pass stations at 225km/h regularly. And these are low platform stations, which are much more dangerous.

True, at least in Portugal passing stations at 220kmh was surprising the first time I took the Alfa Pendular to Porto.

 

[Llanigraham]

Ultimately there is some loss of flexibility due to the Cambrian having to have dedicated units, but I agree due to the Cambrian already being a little segregated this hasn’t turned out to be a major issue. No doubt this is part of the rationale for the Cambrian being selected for the pilot in the first place.

Exactly.
Yes the dedicated units did cause a problem especially when TfW took over and found the lack of maintenance and up-dating hadn't been done, but other than that it has run well. And the fact that it could be a self-contained entity was exactly what it was chosen.
Unfortunately those that are against the system (and often don't understand it) try to use those plus points negatively.

 

[swt_passenger]

Where did that rule come from? It's definitely not an EU one, as trains in conventional lines in the continent pass stations at 225km/h regularly. And these are low platform stations, which are much more dangerous.

It’s been in the RSSB rail group standards for quite some years, I think section 10 of this:

https://catalogues.rssb.co.uk/rgs/standards/RIS-7016-INS%20Iss%201.1.pdf

is the current version.

But it was in a predecessor document in 2004, I haven’t looked back any further.

 

[Bald Rick]

It’s been in the RSSB rail group standards for quite some years, I think section 10 of this:

https://catalogues.rssb.co.uk/rgs/standards/RIS-7016-INS%20Iss%201.1.pdf

is the current version.

But it was in a predecessor document in 2004, I haven’t looked back any further.

It certainly applied in 1997. When 140 was being considered for the West Coast, the fast line platforms were going to be fenced and gated.

 

[HSTEd]

I'm not sure having to step abck to 125mph to go through a platform is much an inconvenience when you are only doing 140 though

Especially on large parts of the ECML that don't really have many stations.

 

[Mordac]

It’s been in the RSSB rail group standards for quite some years, I think section 10 of this:

https://catalogues.rssb.co.uk/rgs/standards/RIS-7016-INS%20Iss%201.1.pdf

is the current version.

But it was in a predecessor document in 2004, I haven’t looked back any further.

Could that be challenged?

 

[edwin_m]

I'm not sure having to step abck to 125mph to go through a platform is much an inconvenience when you are only doing 140 though

Especially on large parts of the ECML that don't really have many stations.

Getting from 125 up to 140 takes much more time (and covers even more distance) than getting from 15 up to 30.

 

[Ianno87]

Where did that rule come from? It's definitely not an EU one, as trains in conventional lines in the continent pass stations at 225km/h regularly. And these are low platform stations, which are much more dangerous.

Happens between Hamburg and Berlin. But at the intermediate stations, passengers are requested to remain behind a railing on the platform until their train has stopped.

 

[CW2]

You need to consider the increased aerodynamic effect of a train going faster through a platform. I believe that is a significant factor in 125 mph being permissible but 140 mph requiring platform screens.

 

[jyte]

Realistically, how many ECML platforms exist that also have trains on the fasts regularly stopping there that would be bordered by good 140mph territory on both the up and down direction?

I cannot think of any ECML station where 140mph running through the platform would be possible/desired that also sees a lot of trains calling at it and thus where gating the platform is either impossible or impractical. Stevenage maybe? But there's so many 100mph pathed Thameslink services I doubt they'd get any benefit from 140mph. Grantham has that big effin curve to the North that's 100, Newark has the flat crossing - again imposing a 100mph limit. Thirsk has no platforms on the fasts? Maybe Northallerton, all the way up North? Maybe Biggleswade?

Honestly I wonder what time savings you'd get on non stops building a Morpeth bypass at 100-125mph, and whether that would deliver better value for money for all services to Edinbrugh (post HS2) than trying to grab an extra 15mph or so wherever possible south of Northallerton.

 

[swt_passenger]

You need to consider the increased aerodynamic effect of a train going faster through a platform. I believe that is a significant factor in 125 mph being permissible but 140 mph requiring platform screens.

I don’t think they’re suggesting screens, but that no one is allowed on the platform. Wouldn’t screens on the platform edge be an aerodynamic issue themselves?

 

[Nym]

I don’t think they’re suggesting screens, but that no one is allowed on the platform. Wouldn’t screens on the platform edge be an aerodynamic issue themselves?

No more so than tunnels.

 

[Speed43125]

No more so than tunnels.

Are there any tunnels where doing 140 could be an issue? Thinking of Shinkansen tunnels having resulted in needing trains with very long noses.

 

[MarkyT]

Surely 140mph operation is not going to be a major priority on the south end of the ECML post HS2, when all the fastest trains from the north have been diverted onto the new line. The majority of those remaining will probably be those stopping at a selection of intermediate fast line stations such as Stevenage, St Neots area EWR interchange, Peterborough, Grantham, Newark, Retford...

 

[Bald Rick]

You need to consider the increased aerodynamic effect of a train going faster through a platform. I believe that is a significant factor in 125 mph being permissible but 140 mph requiring platform screens.

You don’t want platform screens at 140mph. They wouldn’t last two minutes!

 

[HSTEd]

Are there any tunnels where doing 140 could be an issue? Thinking of Shinkansen tunnels having resulted in needing trains with very long noses.

Well this would be a tunnel with no roof - which is a rather different proposition to actual tunnels.

You don’t want platform screens at 140mph. They wouldn’t last two minutes!

Give me a billion pounds and five years, and I will make them work!
Not sure how practical they would actually be though!

"These doors are actually composed of forged titanium..... and here we can see the huge butresses that are built over the platform to support the top edge of the doors"

EDIT:
Sometimes I wonder if I have "when all you have is a hammer" syndrome.
All my solutions involve huge amounts of concrete and steel

 

[Bald Rick]

Honestly I wonder what time savings you'd get on non stops building a Morpeth bypass at 100-125mph, and whether that would deliver better value for money for all services to Edinbrugh (post HS2) than trying to grab an extra 15mph or so wherever possible south of Northallerton.

Three minutes. See this extensive thread. https://www.railforums.co.uk/threads/morpeth-curve.179566/

 

[whoosh]

(I presume the 40 trains/hour examples is using standards for things like overlaps, dwell times and driver behaviour nowhere near comparable with today)

Yes , and also shorter 5 car trains, so were quicker to clear the signal sections.


The discussion just above about platforms being clear of people for trains to pass at over 125mph - remember that Temporary Speed Restrictions can be added and removed from the system, so could it be feasible for trains to pass through at 125mph in the morning peak, when semi- fast trains serve the fast line platforms (with a TSR of 125mph) and then 140mph be authorised (maybe after a phonecall with the Signaller or a switch is operated by station staff to confirm the platform is closed off to passengers) when the station is only served by all stations services on the slow line off peak?
Maybe that's unlikely, but you never know.

An advantage of ETCS is when you pass a single yellow and there is a curve ahead. Round you crawl, then you eventually see the next signal and it's already changed up to a green. Woolmer Green Junction (for the Welwyn bottleneck) on the Up Slow springs to mind. With ETCS you'd get a Movement Authority and target speed change in the cab when the route was set for you, and could accelerate straight away. It would save time and add capacity in those situations.

 

[HSTEd]

What are the standard overlaps for ETCS?

Do they still exist? How long are they?

I know in high density areas the length of blocks will be determined by how many axle counters you want to pay for, but overlaps are still an issue.

 

[MarkyT]

An advantage of ETCS is when you pass a single yellow and there is a curve ahead. Round you crawl, then you eventually see the next signal and it's already changed up to a green. Woolmer Green Junction (for the Welwyn bottleneck) on the Up Slow springs to mind. With ETCS you'd get a Movement Authority and target speed change in the cab when the route was set for you, and could accelerate straight away. It would save time and add capacity in those situations.

Depends on the level of fitment and the extent of fill-in for better aspect updates. Some cheap end ATP systems frustratingly wouldn't allow you to start accelerating again until you passed the next signal transponder even though you may have seen the aspect step up ages beforehand. An ETCS L1 system could plausibly be configured like that although usually, fill in Euroloops or extra active Eurobalises are added added on approach to get you on your way sooner, at least on busy lines that justify it. Of course once there are no lineside signals then there is only the onboard MA update, so you'd have no way of knowing if the system was delaying the update compared to what a notional signal might have shown. At least with L2 there is continuous radio refresh of the MA so in theory the system CAN update as soon as possible.

 

[MarkyT]

What are the standard overlaps for ETCS? Do they still exist? How long are they? I know in high density areas the length of blocks will be determined by how many axle counters you want to pay for, but overlaps are still an issue.

Overlaps exist in ETCS, just as they do in older ATP systems, and they can be variable. They work in conjunction with a concept long known in ATP systems called 'release speed' on approach to a stopping point (i.e. a block marker or signal). The supervised braking curve controls a train's speed gradually down to a specified lower value, and then the driver is able to control the train freely below that. The release speed is calculated such that on 'tripping' at the stop marker balise, the train will come to a stand within the selected overlap. Thus a custom release speed for the particular train type can be calculated onboard automatically according to the length of overlap selected, where multiple selections are available. On a particular scheme, designers can select how long they want the standard overlap to be. If there were block markers typically every 500m (say) overlaps might be one standard block length, so additional fixed train detection sections wouldn't be required just to prove shorter overlaps. For longer blocks on a quieter line, additional train detection boundaries might be justified just for the overlaps. This is definitely the case on Cambrian for example at passing loops where the extra train detection boundaries are needed for point locking and sectional release purposes anyway. I don't know what current best practice is on wholly new 'signals away' schemes such as ECML, but where ETCS is overlaid on existing colour light signals, I confidently expect the standard colour light overlaps will be used with the ETCS configured to generate appropriate release speeds to suit them.

 

[jyte]

Three minutes. See this extensive thread. https://www.railforums.co.uk/threads/morpeth-curve.179566/

Huh

Probably not worth it then!

 

[Class 170101]

Surely 140mph operation is not going to be a major priority on the south end of the ECML post HS2, when all the fastest trains from the north have been diverted onto the new line. The majority of those remaining will probably be those stopping at a selection of intermediate fast line stations such as Stevenage, St Neots area EWR interchange, Peterborough, Grantham, Newark, Retford...

125mph services will still be wanted south of York with a mix of fast and semi-fast services. I don't think the residents of stations south of York would thank you for slowing up their services. If you could get 140mph for minimal cost then it might be worthwhile on the southern section of the ECML where HS2 isn't as beneficial as compared to the WCML. Of course as has been previously noted improving your minimum speeds is more important than improving your maximum speeds.

 

[jyte]

Maybe I'm cynical, but I doubt the KGX-YRK non stops via Peterborough and Doncaster (currently timed for 1:53 iirc) will continue post HS2, doesn't seem like the best use of paths over the ECML to me, and I imagine the current 1tp2h KGX-YRK all shacks service will probably go to hourly.

That being said, 140mph would still help here and there (I'm thinking between Peterborough and Grantham where there are no booked stops and very little slow traffic on the fast lines).

HS2 is promising sub 90 minute times post Phase 2

 

[DB]

Instead we expend vast sums of public money to allow them to avoid spending that money.
They should be required to bear the full commercial cost of all trackside train detection infrastructure, for as long as they do not adopt ECP brakes, and the full cost of all signal masts, colour light signalling equipment, TPWS equipment, AWS equipment and a bunch of other things whilst they do not have ETCS equipment installed.
If they go out of business, so be it.

So what happens if they are all allowed to go bust?

Yes, all that freight ends up on the roads! Would hardly be a good move, would it?

 

[ainsworth74]

Maybe I'm cynical, but I doubt the KGX-YRK non stops via Peterborough and Doncaster (currently timed for 1:53 iirc) will continue post HS2, doesn't seem like the best use of paths over the ECML to me, and I imagine the current 1tp2h KGX-YRK all shacks service will probably go to hourly.

In theory they won't make it much beyond the next year or two. The full Azuma timetable reduces the non-stop London - York services to one every two hours with the other hour having a stop at Peterborough.

 

[HSTEd]

So what happens if they are all allowed to go bust?

Yes, all that freight ends up on the roads! Would hardly be a good move, would it?

So be it.
The taxpayer can always use some of the huge piles of money it saves from a more modern and cheaper to operate railway to start new freight operators if necessary.