HS2 Euston - number of platforms... again...

quantinghome · 10 Sep 2021

This surprisingly informative piece in NCE about the number of platforms needed at Euston is the best explanation I've seen in print to date:

Explained: Why 11 platforms are needed at HS2's Euston terminus | New Civil Engineer

The logic behind that is simple enough – trains are to take turnrounds of 25 minutes so, with 5 minutes “Run out, run in” time between trains, the 18 trains per hour for which the railway is designed (albeit the business case nominates 17 paths per hour for use with the 18th for future growth) needs nine platforms. But 25 minutes is not adequate for the longest distance trains, from Glasgow and Edinburgh, so these ‘step down’ at Euston and are given 25 minutes plus a service interval – a total of 55 minutes. That adds a platform. Then have one more platform, so as not to be working the station to 100% of its capacity, 18 trains per hour, 18 hours a day. Total number of platform = 11.

OK, let’s challenge that.

Q: Why 25 minutes?
A: Trains might be turned round in as little as 15 minutes, but the extra 10 minutes absorb small delays in arrivals. While a very high level of reliability can be expected from the Curzon Street shuttles, Manchester and Leeds train will be mixing it with NPR, and about half the specified service actually originates on the conventional network - as it should, the ability to run trains beyond the new infrastructure is a strength.

Q: Different trains could have different turnrounds, then?
A: No. To operate a terminus intensively, what matters is standardising turnrounds, with a platform occupation chart showing trains fitting together like atoms in a crystal and, crucially, allocating platforms so that when arrivals and departures of different trains coincide, they are made “in parallel” instead of conflicting. ‘Mix and match’ turnrounds make the chart more like atoms in a gas, with a few trains using a lot of platforms.

Q: Isn’t 55 minutes still excessive for the Glasgow/Edinburgh trains?
A: Yes, in isolation. But ‘25 minutes plus service interval’ preserves that crucial pattern of parallel moves in the Euston throat. Besides, due to limited platform capacity at Glasgow they’ll be taking 25-minute turnrounds there, and a bit extra at one end makes up for a deficiency at the other.

Q: But you can plan the service onto 10 platforms?
A: Agreed, but that is just a plan! On (pre-Covid) punctuality, you would expect a train to turn up more than 10 minutes late, on average, hourly. The 25-minute turnround could absorb up to 10 minutes, so the late arrival doesn’t turn into a late start. But above 10 minutes, it will start back late, which delays the next arrival, and within not many minutes the queue of arriving trains is back at Old Oak Common. And this is where the 11th platform comes in. Any train arriving much more than 10 minutes late can be pointed there instead, and all other trains run as planned.

Clearly if two trains in quick succession turn up more than 10 minutes late, the second has a problem, and here the more drastic option of terminating short at Old Oak Common and restarting from there comes into play. That is possible, but no easy matter – passengers have to be forwarded either by Crossrail which isn’t too good for those with heavy luggage, or on the next HS2 to Euston, which plays havoc with the dwell time. Unless the train crew are working back on the same set, their diagrams and breaks will be disrupted. And passengers for the departure have to be shipped to Old Oak, which means anyone turning up at Euston less than about 6 minutes before time will probably miss it.

And the point is this – without the 11th platform, when a train presents more than 10 minutes late, the choice is either knock-on delay at Euston, or terminating it at Old Oak. That’s not the only ‘event’ it protects against, of course – think of the number of ways of blocking a platform with which we are all familiar, such as technical failure of track or train, passenger taken ill on a train, waiting incoming train crew etc.

You don’t need ‘extensive modelling’ to see that running on 10 platforms with the same robustness as 11 means cutting the service. Plausibly, 16 trains per hour instead of 18 would do it, by freeing one of the 10 platforms for ‘events’. Even 17 trains per hour doesn’t do that, it just leaves one platform half-used, and unless the late arrival precisely fits the unused half, that’s no good.

Shorter turnrounds? All that means is that trains turning up less than 10 minutes late, which will happen far more often, become a problem as well. The shorter the turnrounds, the more contingency platforms you need.

Run trains on time in the first place? Well yes. So why aren’t we doing it now? And it’ll cost you, as part of the solution would be infrastructure, such as on critical mixed-use sections like Crewe – Carlisle – Scotland and York – Newcastle. To make termination at Old Oak no more frequent than daily, punctuality would need to be 99% ‘within 10 minutes’.

Add a platform at Glasgow Central so the long turnround can be there, not Euston? OK, let’s see your scheme, at a station built on a viaduct and bounded by a river bridge.

Technology? Advanced signalling such as ETCS Level 3 has benefits on plain line at full speed, and makes the proposed 18 trains per hour at 360 kph even more secure. But it offers nothing at junctions and stations. Traffic Management Systems now emerging can replan a service at short notice, but only with platforms to replan it into.

In essence, how many platforms you need depends on how often, having spent tens of billions on a new railway, you think it is acceptable to tip its passengers out in Zone 2 at short notice. The 11-platform scheme for Euston, developed over years, is a pragmatic balance between cost and the realities of running a reliable train service.

I've a few questions and thought I'd bring them here given the number of forum members who have far more knowledge about railway planning than I do. Forgive my ignorance, some of these questions may be dumb:

1. Is the assumption of a fixed, standard turnaround time compatible with the indicative service pattern, which has a mix of 400m, 2 x 200m and 200m trains?

2. Why is a 30-minute turnaround set in stone? Brand new stations and trains should be able to work quicker than this, even allowing for some minor delays. Do litter clearance between OOC and Euston; seat booking should be automated (why would you even need to have an on-train reservation system anyway? It's likely to be a reserved seat only operation and reservations will be shown on tickets); the HS2-only services are effectively long distance shuttles and may not need catering, or they can restock at the 'country end'. The Euston operation should be: train arrives > passengers off > passengers on > train departs. A quicker standard turnaround will then free up more platforms for any more heavily delayed services.

3. Can the 200m trains be flighted, allowing them to share a platform?

4. If the additional platform at Euston is going to cost billions extra, wouldn't that be better spent upgrading the classic network to make it more resilient so you don't import delay onto HS2 in the first place?

RailUK Forums

WestRiding · 10 Sep 2021

11 platforms when itvis unlikely to even go to Leeds.....? Not necessary.

Speed43125 · 10 Sep 2021

quantinghome said:
3. Can the 200m trains be flighted, allowing them to share a platform?

Presumably that would involved significant platform lengthening to fit in points. And they are not going to be building a centre road, so I think you'd be looking at at best accommodating 3x200m trains in two platforms without blocking trains in.

100andthirty · 10 Sep 2021

The article bases everything on the nominal 25 minute turnaround time. If this is set in stone, then the logic of the article makes sense. It's also necessary to allow some wriggle room somewhere and other destinations have less wriggle room than London. The author cites Glasgow Central where expansion would be tough - to put it mildly.

My contention is "what would have to change in the station design to make a noticeable reduction in standard turnaround time - say 20 minutes normally and 10 minutes when in trouble". This means getting people off and on the train and platform quickly. If the design only provided for people to exit the platform at the buffer stop like in most termini, than I'd be doubtful, but if there were a number of stairs/moving walkways/lifts along the platform to a mezzanine, then platform clearance could be quicker. So the turnaround time is partly a function of how well the station has been designed to facilitate quick turnarounds. Another factor is the train design - how many seats are served by each doorway and how easy it is to get along the gangways. As we don't yet know the train configuration except in the most general terms, nor any detail of the station design all this is difficult to judge.

The Planner · 10 Sep 2021

I think they have looked at this as a mathematical problem, not actually considering the issues of running a service. Factor in most people from Curzon St are unlikely to be lugging about luggage and large bags, further afield they will be. Look at how long it takes to empty a train now at Euston and how long it would take to load it, again factoring in type of passenger and destination. HS2 needs to be as punctual as hell so building in resilience is paramount. Spinning a late set in 10 minutes is close to the wire, it can be done and is done but you need to be on the ball.
Permissive working adds time into the schedule and spending billions on the conventional network to provide punctuality won't happen, its cheaper to have an operational strategy that puts delay into everything else and the HS2 train gets the run.

quantinghome · 10 Sep 2021

The Planner said:
I think they have looked at this as a mathematical problem, not actually considering the issues of running a service. Factor in most people from Curzon St are unlikely to be lugging about luggage and large bags, further afield they will be. Look at how long it takes to empty a train now at Euston and how long it would take to load it, again factoring in type of passenger and destination. HS2 needs to be as punctual as hell so building in resilience is paramount. Spinning a late set in 10 minutes is close to the wire, it can be done and is done but you need to be on the ball.
Permissive working adds time into the schedule and spending billions on the conventional network to provide punctuality won't happen, its cheaper to have an operational strategy that puts delay into everything else and the HS2 train gets the run.

Taking into account the different services, you could work to a 20-minute turnaround for the 8 tph HS2-only trains - 15 minutes in-platform should be enough time. Then the 9 remaining services which run on the classic network can be given an additional 20-minute step-back for a 40-minute overall turnaround, which gives a pretty generous allowance for disruption. That works out at 9 platforms in total, with the 10th giving the spare capacity.

stuu · 10 Sep 2021

WestRiding said:
11 platforms when itvis unlikely to even go to Leeds.....? Not necessary.

In the lifetime of the station it is highly likely they will, even if it is delayed in the short term

Horizon22 · 10 Sep 2021

A mathematical theory is a good start to working out platform occupancy at a terminal, but it isn't everything. Whilst in an absolutely perfect world you would have the same turnaround time everywhere, there are plenty of places where a service can be planned absolutely fine without this requirement. So as to your question 1) no, it does not necessarily have to happen, but requires a bit more "imagination".

As for point 2, this depends on a lot of things - the actual design of the train, the location of the doors, at what point you are allowing passengers to board (including cleaning / seat reservations etc.), crew diagrams and walking times, conflicts with an inward train which might lead to passenger crossfall. There's a lot to consider when how "suitable" a turnaround is, but I imagine much of this research and planning has been done. Anything less than 20-25 minutes is getting a bit edgy in terms of delays for a long-distance service. Theoretically of course in disruption or delays you can have policies to expedite the turnaround process (quick cleaning, having crew standing at the right place) but these sort of things can impact customer service a fair bit. As said above, 10 minutes is very very tight and reaches the limit of what is currently being done on the classic network with delays.

quantinghome · 10 Sep 2021

Horizon22 said:
As for point 2, this depends on a lot of things - the actual design of the train, the location of the doors, at what point you are allowing passengers to board (including cleaning / seat reservations etc.), crew diagrams and walking times, conflicts with an inward train which might lead to passenger crossfall. There's a lot to consider when how "suitable" a turnaround is, but I imagine much of this research and planning has been done.

Cleaning (litter removal) can be done during the journey surely? Cleaning crews could just shuttle between Euston and OOC all shift. And do seat reservations need to be shown on the train itself? If it's reservation-only (with an app which allows last minute bookings) then there's no need - your ticket or e-ticket will include the reservation details.

Horizon22 said:
Anything less than 20-25 minutes is getting a bit edgy in terms of delays for a long-distance service. Theoretically of course in disruption or delays you can have policies to expedite the turnaround process (quick cleaning, having crew standing at the right place) but these sort of things can impact customer service a fair bit. As said above, 10 minutes is very very tight and reaches the limit of what is currently being done on the classic network with delays.

For the 'captive' HS2 services to Birmingham, Manchester and (hopefully) Leeds, I'm not convinced they should be viewed as long-distance services in terms of train operation. They are operating on a brand new, captive line, maximum journey time around 80 minutes, which is no longer than some commuter services.

Horizon22 · 10 Sep 2021

quantinghome said:
Cleaning (litter removal) can be done during the journey surely? Cleaning crews could just shuttle between Euston and OOC all shift. And do seat reservations need to be shown on the train itself? If it's reservation-only (with an app which allows last minute bookings) then there's no need - your ticket or e-ticket will include the reservation details.

For the 'captive' HS2 services to Birmingham, Manchester and (hopefully) Leeds, I'm not convinced they should be viewed as long-distance services in terms of train operation. They are operating on a brand new, captive line, maximum journey time around 80 minutes, which is no longer than some commuter services.

Possibly, but aspects like catering (is this even going to be provided?) might need to be loaded at terminals and you can't always have the equipment available on-board if you want to do a through clean. So yes, litter removal could theoretically be done in the final stages of a journey, but that is just one part of an overall cleaning regime and there will be extra required to meet a particular standard, especially for what will be a "premium" service.

Curzon St yes that could probably be cut down to 15 minutes on a captive part of the line, but as with any service it might end up with reactionary delay caused by something joining the HS2 network from the classic with a delay - although hopefully all kept to a minimum. But one of the worst things that has impacted performance in the railway in recent history is trying to squeeze every bit of capacity possible. Assuming everything will interact HS2 / classic on time without any recovery options is a dangerous starting point.

Ianno87 · 10 Sep 2021

quantinghome said:
For the 'captive' HS2 services to Birmingham, Manchester and (hopefully) Leeds, I'm not convinced they should be viewed as long-distance services in terms of train operation. They are operating on a brand new, captive line, maximum journey time around 80 minutes, which is no longer than some commuter services.

They could almost be Javelin-esque in terms of style of operation and typical passenger make-up.

quantinghome · 10 Sep 2021

Horizon22 said:
But one of the worst things that has impacted performance in the railway in recent history is trying to squeeze every bit of capacity possible. Assuming everything will interact HS2 / classic on time without any recovery options is a dangerous starting point.

But that's precisely what you can avoid by having quicker 20 minute turnarounds for the captive services and then longer 40 minute turnarounds for the services interacting with the classic network. With 10 platforms, that arrangement still leaves you with an extra platform to take the heavily-delayed train.

Horizon22 · 10 Sep 2021

quantinghome said:
But that's precisely what you can avoid by having quicker 20 minute turnarounds for the captive services and then longer 40 minute turnarounds for the services interacting with the classic network. With 10 platforms, that arrangement still leaves you with an extra platform to take the heavily-delayed train.

Yes I don't disagree that you can have differing amounts of turnaround times and that might be practical and indeed desirable for HS2 at Euston. However, when I say squeezing capacity, that includes shorter turnaround times as platform availability is part of capacity planning.

Wilts Wanderer · 10 Sep 2021

I would be interested to know to what extent the actual paths of different service groups have been plotted out beyond the limits of HS2 infrastructure. It’s alright saying a Glasgow service will have 55 min turnarounds, but what actually dictates the turnaround is the inward path —> outward path.

In practice I’d expect Curzon Street services would be perfectly fine with 15-min turnarounds, trains from the Manchester/Liverpool/Leeds distance with 30-min and Anglo-Scots will need plenty of resilience.

No mention of the option to maintain a standby set at/near the London terminal, could one of the spare platforms at Old Oak have a crewed standby ready to pop up to Euston if required and sub onto a diagram when an inbound is heavily delayed?

edwin_m · 10 Sep 2021

quantinghome said:
3. Can the 200m trains be flighted, allowing them to share a platform?

Speed43125 said:
Presumably that would involved significant platform lengthening to fit in points. And they are not going to be building a centre road, so I think you'd be looking at at best accommodating 3x200m trains in two platforms without blocking trains in.

I agree that would be the only way of doing this. Problem there is that the first train in is the last one out, so unless you can swap diagrams around you're in trouble if one is late enough for them to arrive in reverse order. And they have to be scheduled in fairly close together, otherwise the first one ends up with a much longer turnaround time and nullifies the reason to put two in a platform in the first place.

quantinghome said:
Taking into account the different services, you could work to a 20-minute turnaround for the 8 tph HS2-only trains - 15 minutes in-platform should be enough time. Then the 9 remaining services which run on the classic network can be given an additional 20-minute step-back for a 40-minute overall turnaround, which gives a pretty generous allowance for disruption. That works out at 9 platforms in total, with the 10th giving the spare capacity.

This, and some of the other points made, are ruled out according to the article by the principle of having the same dwell time for each service (except the Scotland ones that get 30min extra). This means that, wherever possible, a train enters a platform in parallel with one leaving a platform to its right (looking into the station from Camden). Clearly this can't go on for ever, so on a simple flat layout you have a conflict when a train needs to enter the rightmost platform.

However, what the article doesn't mention is that either the arrival or the departure track (can't remember which) splits underground with branches emerging on both sides of the other track, so that conflicts of that type can be resolved by having the trains in question pass left side to left side (right hand running). My brain can't be sure, befuddled as it is by considering this exact situation a few days ago but for a country with general right hand running, but I think this might mean that the regular sequence described in the article isn't actually essential. However the article author is William Barter, who I believe wrote the timetable in question, so I'm pretty sure he's thought of that one and found a reason it doesn't work.

Robertj21a · 10 Sep 2021

Wilts Wanderer said:
I would be interested to know to what extent the actual paths of different service groups have been plotted out beyond the limits of HS2 infrastructure. It’s alright saying a Glasgow service will have 55 min turnarounds, but what actually dictates the turnaround is the inward path —> outward path.

In practice I’d expect Curzon Street services would be perfectly fine with 15-min turnarounds, trains from the Manchester/Liverpool/Leeds distance with 30-min and Anglo-Scots will need plenty of resilience.

No mention of the option to maintain a standby set at/near the London terminal, could one of the spare platforms at Old Oak have a crewed standby ready to pop up to Euston if required and sub onto a diagram when an inbound is heavily delayed?

A standby set, fully crewed, just in case ?

o_O

quantinghome · 10 Sep 2021

edwin_m said:
This, and some of the other points made, are ruled out according to the article by the principle of having the same dwell time for each service (except the Scotland ones that get 30min extra). This means that, wherever possible, a train enters a platform in parallel with one leaving a platform to its right (looking into the station from Camden). Clearly this can't go on for ever, so on a simple flat layout you have a conflict when a train needs to enter the rightmost platform.

But the 20 minute turnarounds do give you a consistent dwell time. Instead of 30 minutes for each service plus 30 mins extra for Scotland, you have 20 minutes for every captive service plus 20 mins extra for every classic-interfacing service. This then frees up an additional platform for added flexibility.

Horizon22 · 10 Sep 2021

Wilts Wanderer said:
I would be interested to know to what extent the actual paths of different service groups have been plotted out beyond the limits of HS2 infrastructure. It’s alright saying a Glasgow service will have 55 min turnarounds, but what actually dictates the turnaround is the inward path —> outward path.

In practice I’d expect Curzon Street services would be perfectly fine with 15-min turnarounds, trains from the Manchester/Liverpool/Leeds distance with 30-min and Anglo-Scots will need plenty of resilience.

No mention of the option to maintain a standby set at/near the London terminal, could one of the spare platforms at Old Oak have a crewed standby ready to pop up to Euston if required and sub onto a diagram when an inbound is heavily delayed?

I imagine the easiest option would instead be to swap sets around at Euston (providing they are a compatible length of course)

Verulamius · 10 Sep 2021

The March 2021 edition of Modern Railways provided a detailed analysis of platforming at Euston. This would appear to be consistent with the New Civil Engineer article above.

A diagram of the platforming was provided based on the original route planning for HS2.

Black – Birmingham

Mid grey – Manchester

Light grey – Leeds

Cyan – Liverpool

Cyan with white stripe – Lancaster

Cyan with black stripe – Stafford/Stoke/Macclesfield

Yellow – Glasgow and Edinburgh

Purple – Sheffield

Green – York/Newcastle

Outline only – 18th path for future growth

The Planner · 10 Sep 2021

Wilts Wanderer said:
I would be interested to know to what extent the actual paths of different service groups have been plotted out beyond the limits of HS2 infrastructure. It’s alright saying a Glasgow service will have 55 min turnarounds, but what actually dictates the turnaround is the inward path —> outward path.

In practice I’d expect Curzon Street services would be perfectly fine with 15-min turnarounds, trains from the Manchester/Liverpool/Leeds distance with 30-min and Anglo-Scots will need plenty of resilience.

No mention of the option to maintain a standby set at/near the London terminal, could one of the spare platforms at Old Oak have a crewed standby ready to pop up to Euston if required and sub onto a diagram when an inbound is heavily delayed?

Probably changed many times by now but I have seen paths and diagrams timed to the minute including ECS in the past.

6Gman · 10 Sep 2021

Wilts Wanderer said:
No mention of the option to maintain a standby set at/near the London terminal, could one of the spare platforms at Old Oak have a crewed standby ready to pop up to Euston if required and sub onto a diagram when an inbound is heavily delayed?

The crewing issue is surely how do you ensure that the crew have the available hours left if required?

DanNCL · 10 Sep 2021

Verulamius said:
The March 2021 edition of Modern Railways provided a detailed analysis of platforming at Euston. This would appear to be consistent with the New Civil Engineer article above.

A diagram of the platforming was provided based on the original route planning for HS2.

Black – Birmingham

Mid grey – Manchester

Light grey – Leeds

Cyan – Liverpool

Cyan with white stripe – Lancaster

Cyan with black stripe – Stafford/Stoke/Macclesfield

Yellow – Glasgow and Edinburgh

Purple – Sheffield

Green – York/Newcastle

Outline only – 18th path for future growth

Looking at that, if the eastern leg of phase 2 is scrapped as is expected they'd only need 8 platforms (including the spare) at Euston.

Ianno87 · 10 Sep 2021

6Gman said:
The crewing issue is surely how do you ensure that the crew have the available hours left if required?

You budget for enough crew. After all, the railway isn't even close to built yet.

Horizon22 · 10 Sep 2021

DanNCL said:
Looking at that, if the eastern leg of phase 2 is scrapped as is expected they'd only need 8 platforms (including the spare) at Euston.

Any extra capacity is a bonus. When it comes to infrastructure we have chronic issue in this country with insufficient capacity planning for long-term horizons.

6Gman · 10 Sep 2021

Ianno87 said:
You budget for enough crew. After all, the railway isn't even close to built yet.

That's going to be a fair old budget line!

edwin_m · 10 Sep 2021

Robertj21a said:
A standby set, fully crewed, just in case ?

It's been done before. XC have (or had) a standby unit at New Street for example. Though there's the question of where you keep the unit - no sidings at OOC as far as I know, and unlikely you'd put it in a platform at Euston...

6Gman said:
The crewing issue is surely how do you ensure that the crew have the available hours left if required?

If the incoming train was only modestly late then you a standby crew take the standby unit to Euston and back out to OOC in service, where hopefully by then the rostered crew would be ready to take over. A second standby crew could take the delayed train into Euston if it wasn't being turned back short. If the rostered crew were due a break then the relieving crew could start from Euston with the standby unit.

Class 170101 · 10 Sep 2021

quantinghome said:
But that's precisely what you can avoid by having quicker 20 minute turnarounds for the captive services and then longer 40 minute turnarounds for the services interacting with the classic network. With 10 platforms, that arrangement still leaves you with an extra platform to take the heavily-delayed train.

The problem is no more platforms will be built off the HS network so its difficult to see how short turnarounds in London and long turnarounds at Glasgow / Liverpool / Lancaster / Newcastle / Sheffield will work.

Bald Rick · 10 Sep 2021

This article is months old. It appeared in Modern Railways (or something similar) when the news about a reduction in platforms broke. I hope NCE didn’t pay him again.

Ianno87 · 10 Sep 2021

Class 170101 said:
The problem is no more platforms will be built off the HS network so its difficult to see how short turnarounds in London and long turnarounds at Glasgow / Liverpool / Lancaster / Newcastle / Sheffield will work.

The turnround times at the country end will be a direct outcome of the London end turnround time, the journey time each way and the frequency of that route.

HSTEd · 11 Sep 2021

Robertj21a said:
A standby set, fully crewed, just in case ?

Well "fully crewed" means "with driver" in all likelihood of

HS2 Euston - number of platforms... again...

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