Should the HS2 train order be reconfigured.

[Trainbike46]

200m doesn't work very well for Scotland either.

I wouldn't agree with that. 2tph 200m services to Glasgow would have been good, and having 2 tph to Edinburgh (split/join with the Glasgows), would have been good if there are extra services to Edinburgh to provide the needed capacity - either by extending the 2tph HS2 to Newcastle north to Edinburgh, or by running a 400m service (1tph) in addition to the 2 tph combined with the Glasgow.

We just need to do some platform extension at sensible intermediate stations (Crewe, Carlisle, etc.)

 

[HSTEd]

I wouldn't agree with that. 2tph 200m services to Glasgow would have been good, and having 2 tph to Edinburgh (split/join with the Glasgows), would have been good if there are extra services to Edinburgh to provide the needed capacity - either by extending the 2tph HS2 to Newcastle north to Edinburgh, or by running a 400m service (1tph) in addition to the 2 tph combined with the Glasgow.

We just need to do some platform extension at sensible intermediate stations (Crewe, Carlisle, etc.)

The cost of the platform extensions would far exceed the cost of simply changing the rolling stock order.

There is also not going to be a HS2 to Newcastle train.....

 

[Trainbike46]

The cost of the platform extensions would far exceed the cost of simply changing the rolling stock order.

There is also not going to be a HS2 to Newcastle train.....

I was talking in the hypothetical of the eastern leg being built (obviously not happening)

The advantage of platform extensions is that it allows for more capacity without requiring extra paths or drivers, and the cost of changing the order will depend a lot on how the contract was written, and the willingness of the manufacturers to entertain such changes.

My point, which I should have made more clearly, was that 200m trains aren't a bad idea for Scotland, especially not with the original two leg HS2 plan

 

[Bletchleyite]

With the original plan they work, yes, but without 2B there are pathing issues that prevent the 2tph. Best you'd be able to do is split at Crewe and have a fast and a slow following each other.

 

[Nottingham59]

the cost of changing the order will depend a lot on how the contract was written, and the willingness of the manufacturers to entertain such changes.

When I read the train specification, I was quite shocked by how HS2 had worded it to exclude future flexibility.

(If I remember correctly) along the lines of "we will never need lengths other than 200m"; "we will not have selective door opening"; "two units in tandem must have exit doors exactly 350m apart". So the cost of varying the contract could be eye-wateringly expensive.

 

[LNW-GW Joint]

The designers of HS2 thought they were building an extensive "world class" network, and that attitude spread to the rolling stock spec.
The only compromise made was that HS2 trains would also need to run on parts of the classic network, and so the first tranche of trains for Phase 1 would be "classic-compatible".
The intention was to add UIC-gauge trains to run on the dedicated high-speed sections to Birmingham/Manchester/Leeds later.
It was assumed that HS2 trains would dominate on the routes they operated, with classic stock filling in the regional gaps around them.
All that is now in the bin.
If the same programme managers and designers are still on the project, they now have the distasteful task of matching the trains bought (too early, as it turns out), with the WCML infrastructure they planned to avoid.
Capacity limitations mean that HS2 trains can do little else than replace existing WCML services more or less on a one-for-one basis (9tph out of Euston).
I suspect a big climb-down is going to happen when HS2 Ltd realises the funding limitations to its project.
They will have to give full consideration to Chris Gibbs' Pendolinos-on-HS2 notion versus changing the existing HS2 rolling stock design.

There was a time around 2012 when it seemed the IEP project was about to be cancelled in favour of pure DMU/EMUs, but DfT toughed it out and placed large orders with Hitachi to ensure the bi-mode option was built with all its contractual limitations.
I suspect something similar will happen this time for HS2 stock.
Too many reputations are at stake.

 

[Bletchleyite]

"two units in tandem must have exit doors exactly 350m apart"

This one is because of the spacing of the emergency exits in the tunnels.

 

[HSTEd]

When I read the train specification, I was quite shocked by how HS2 had worded it to exclude future flexibility.

(If I remember correctly) along the lines of "we will never need lengths other than 200m"; "we will not have selective door opening"; "two units in tandem must have exit doors exactly 350m apart". So the cost of varying the contract could be eye-wateringly expensive.

The project appears, from the outside, to have been very tightly specified around the service and trains they planned to operate on Day 1, with little consideration of growth margins or needs for future changes.

This one is because of the spacing of the emergency exits in the tunnels.

This restriction does not appear to appear in the tunnel safety TSIs, as far as I can tell, so it would be interesting to know where it came from.

 

[Nottingham59]

This restriction does not appear to appear in the tunnel safety TSIs, as far as I can tell, so it would be interesting to know where it came from.

It seems to be copying the layout in the Channel Tunnel, where escape passages are every 350m.

With two units in tandem, they need to align the exit doors from each unit with a cross passage.

The train spec says this is needed in an emergency stop situation, when the air temperature outside the HS2 trains is calculated to reach 50C (!). They need the ventilation from the cross passages to supply enough cold air around each exit door to allow passengers to survive an evacuation.

 

[HSTEd]

The train spec says this is needed in an emergency stop situation, when the air temperature outside the HS2 trains is calculated to reach 50C (!). They need the ventilation from the cross passages to supply enough cold air around each exit door to allow passengers to survive an evacuation.

This might have something to do with the comparatively small tunnel cross sections, which are substantially smaller than found in other schemes.

 

[LNW-GW Joint]

It seems to be copying the layout in the Channel Tunnel, where escape passages are every 350m.
With two units in tandem, they need to align the exit doors from each unit with a cross passage.

Is this just copying the spec for the London tunnels of HS1, which might derive from the Channel Tunnel itself and the existing class 373 rolling stock design.

 

[Greybeard33]

This might have something to do with the comparatively small tunnel cross sections, which are substantially smaller than found in other schemes.

Related to the small cross section, the tunnel ventilation shafts are sealed off except in emergencies. The train spec requires the HVAC system to switch to a recirculation mode through tunnels. To prevent CO2 levels in the saloon rising above a specified threshold, assuming crush loading and maximum transit time through the tunnel, the system is required increase fresh air ventilation rate before entering a tunnel, to purge CO2 from the saloon. I doubt that a Pendolino or any other "normal" train could comply.

All part of the HS2 Ltd engineering mindset that "we will do it better than the rest of the world", which also delivered the unique platform height.

 

[Nicholas Lewis]

The i running this story about the trains compatibility with the classic network

https://inews.co.uk/news/politics/hs2-trains-too-high-station-platforms-taxpayers-bill-3240475

HS2 trains too high for station platforms – leaving taxpayers with £200m bill​

The news comes days after it emerged that the trains will require a separate redesign to have extra doors added​

HS2 trains are too high for existing station platforms, i can reveal, in the latest mishap for the project that leaves taxpayers with another huge bill.

As the Chancellor Rachel Reeves mulls tax rises and spending cuts to balance the UK’s books, taxpayers will have to find another £200m to refit HS2 train carriages because their doors are too high for ordinary station platforms.

Industry sources told i that Network Rail and the Office for Rail and Road were unwilling to allow the 225mph trains to run on the existing network because of fears that the gap between the train and the platform will be too great, making them unsafe.

Wasn't there always a requirement to be able to run on the existing network so the spec should have included this requirement? Or was there to be a captive fleet on some routes?

 

[Crithylum]

The i running this story about the trains compatibility with the classic network

https://inews.co.uk/news/politics/hs2-trains-too-high-station-platforms-taxpayers-bill-3240475


Wasn't there always a requirement to be able to run on the existing network so the spec should have included this requirement? Or was there to be a captive fleet on some routes?

I heard that HS2 was planning on starting legal action against the EU to allow them to use high floor trains, and above standard height platforms, however Brexit made that (the legal action) unnecessary. I suspect this is a similar situation to Ealing Broadway, where new trains are the same height as the ones that they are replacing, however as the new trains operate in areas with level boarding, the gap is no longer acceptable.

 

[HSTEd]

The i running this story about the trains compatibility with the classic network

https://inews.co.uk/news/politics/hs2-trains-too-high-station-platforms-taxpayers-bill-3240475


Wasn't there always a requirement to be able to run on the existing network so the spec should have included this requirement? Or was there to be a captive fleet on some routes?

HS2 selected the non standard platform height and initiated a legal action against the EU to get it's way.

Brexit terminated the case as the TSIs ceased to apply.

As a result there will be level boarding at HS2 stations but never anywhere else.

 

[Energy]

HS2 selected the non standard platform height and initiated a legal action against the EU to get it's way.

Brexit terminated the case as the TSIs ceased to apply.

As a result there will be level boarding at HS2 stations but never anywhere else.

It’s a bit mad. HS2 was only planning one set of doors per carriage so sticking it in the middle and settling on 900mm would have provided level boarding everywhere.

I don’t believe the story in the i, the trains have always been planned to be classic compatible.

 

[JamesT]

The i running this story about the trains compatibility with the classic network

https://inews.co.uk/news/politics/hs2-trains-too-high-station-platforms-taxpayers-bill-3240475


Wasn't there always a requirement to be able to run on the existing network so the spec should have included this requirement? Or was there to be a captive fleet on some routes?

Although there was a plan for a future order of trains that would be captive to the HS2 network, the initial order is for the ‘classic compatibles’ which are explicitly produced to UK loading gauge.
I don’t get how they’re too tall, the floor height for level boarding on HS2 is pretty much the same as everything else currently running.

 

[HSTEd]

It’s a bit mad. HS2 was only planning one set of doors per carriage so sticking it in the middle and settling on 900mm would have provided level boarding everywhere.

I don’t believe the story in the i, the trains have always been planned to be classic compatible.

Considering that the demand for short dwell times at Old Oak Common was used a reason to force through other design decisions, one set of doors is a seemingly ludicrous decision.

 

[Energy]

Considering that the demand for short dwell times at Old Oak Common was used a reason to force through other design decisions, one set of doors is a ludicrous decision.

To be fair, I could get behind a wide class 755-style set of doors at the centre.

 

[Nottingham59]

The HS2 stations are designed with a platform height of 1115mm above the rail. This is to allow level access boarding, so I assume the HS2 trains (both captive and classic-compatible) will have a cabin floor height of 1115mm. This puts them 200m above the level of a standard BR platform at 915mm, which is quite a step.

And any platforms on the WCML which are lower than 915mm will have a bigger vertical gap.

EDIT: This is the same problem that Elizabeth Line trains are now having. EL platform height is 1110mm, with level boarding. The gap at places with low platforms like Ealing Broadway were assumed to be acceptable, but passengers are finding this gap unacceptable in practice.

 

[JamesT]

The HS2 stations are designed with a platform height of 1115mm above the rail. This is to allow level access boarding, so I assume the HS2 trains (both captive and classic-compatible) will have a cabin floor height of 1115mm. This puts them 200m above the level of a standard BR platform at 915mm, which is quite a step.

And any platforms on the WCML which are lower than 915mm will have a bigger vertical gap.

EDIT: This is the same problem that Elizabeth Line trains are now having. EL platform height is 1110mm, with level boarding. The gap at places with low platforms like Ealing Broadway were assumed to be acceptable, but passengers are finding this gap unacceptable in practice.

I’m struggling to find a reference for the floor height of the Class 390, but other models of Pendolino have a floor height of 1270mm, so the HS2 rolling stock would be an improvement.
There’s also a part of the technical specification that there will be a step automatically deployed - https://assets.hs2.org.uk/wp-conten...00007_P11_TTS_Main_Body__External_.pdf#page55 (document won’t let me copy from it to quote)

 

[HSTEd]

I’m struggling to find a reference for the floor height of the Class 390, but other models of Pendolino have a floor height of 1270mm, so the HS2 rolling stock would be an improvement.
There’s also a part of the technical specification that there will be a step automatically deployed - https://assets.hs2.org.uk/wp-conten...00007_P11_TTS_Main_Body__External_.pdf#page55 (document won’t let me copy from it to quote)

It is an improvement in the short term, but this means that there will never be level boarding at non dedicated stations.

GIven that advances of technology have made level boarding practical at 915mm at 100mph, it is only a matter of time until high speed rail can do it too.

It's a major retrograde step to permanently rule it out.

 

[LNW-GW Joint]

Although there was a plan for a future order of trains that would be captive to the HS2 network, the initial order is for the ‘classic compatibles’ which are explicitly produced to UK loading gauge.
I don’t get how they’re too tall, the floor height for level boarding on HS2 is pretty much the same as everything else currently running.

The spec for the HS2 procurement is still not finalised.
That was part of the order process, so changes are possible/likely until the point when DfT signs it off and Hitachi/Alstom start cutting metal.

 

[Peter Mugridge]

I’m struggling to find a reference for the floor height of the Class 390, but other models of Pendolino have a floor height of 1270mm, so the HS2 rolling stock would be an improvement.
There’s also a part of the technical specification that there will be a step automatically deployed - https://assets.hs2.org.uk/wp-conten...00007_P11_TTS_Main_Body__External_.pdf#page55 (document won’t let me copy from it to quote)

It lets me quote, so is this the bit you're looking at?

The Unit shall have a Moveable Step at every Exterior Door, which shall be automatically deployed (unless inhibited) when the door is released, and fully retracted whenever the Unit is in motion.

The vertical distance between the Moveable Step and the floor of the Vestibule immediately inside the Exterior Door, v2, shall not exceed: Preferred 1: The v2 threshold-step distance shall not exceed 20mm. Preferred 2: The v2 threshold-step distance shall not exceed 30mm. Mandatory: The v2 threshold-step distance shall not exceed 40mm.

 

[Trainbike46]

It is an improvement in the short term, but this means that there will never be level boarding at non dedicated stations.

GIven that advances of technology have made level boarding practical at 915mm at 100mph, it is only a matter of time until high speed rail can do it too.

It's a major retrograde step to permanently rule it out.

agreed, HS2 should have stuck with

The HS2 stations are designed with a platform height of 1115mm above the rail. This is to allow level access boarding, so I assume the HS2 trains (both captive and classic-compatible) will have a cabin floor height of 1115mm. This puts them 200m above the level of a standard BR platform at 915mm, which is quite a step.

And any platforms on the WCML which are lower than 915mm will have a bigger vertical gap.

EDIT: This is the same problem that Elizabeth Line trains are now having. EL platform height is 1110mm, with level boarding. The gap at places with low platforms like Ealing Broadway were assumed to be acceptable, but passengers are finding this gap unacceptable in practice.

Both HS2 and the Elizabeth line should have gone with 915mm platforms, and gotten trains that offered level boarding at that height. They exist - examples include the FLIRTs, the 777s, for elizabeth line style trains.

The Stadler SMILE offers level boarding as well, and it could and should have been a design criterium for the HS2 stock as well.

 

[Nottingham59]

Broadening the discussion from the OPs question about train length, should the HS2 standard platform height be changed to 915mm, and the HS2 trains re-specified to allow level boarding from this height?

I understand it would be expensive at this late stage, but would be cheaper than the overall cost of baking in a 1115mm platform height into the wider GB rail network for the next 100 years.

 

[Trainbike46]

Broadening the discussion from the OPs question about train length, should the HS2 standard platform height be changed to 915mm, and the HS2 trains re-specified to allow level boarding from this height?

I understand it would be expensive at this late stage, but would be cheaper than the overall cost of baking in a 1115mm platform height into the wider GB rail network for the next 100 years.

I'm not sure what the right answer is here - long term, ideally you'd match GB standard height, but as you say changing this late will be very expensive

 

[Bletchleyite]

Broadening the discussion from the OPs question about train length, should the HS2 standard platform height be changed to 915mm, and the HS2 trains re-specified to allow level boarding from this height?

Yes.

I understand it would be expensive at this late stage, but would be cheaper than the overall cost of baking in a 1115mm platform height into the wider GB rail network for the next 100 years.

Without any possible doubt it would be worth it. It wouldn't need to be the whole train (ideally it would be, but it doesn't *have* to be), you'd just need to drop the coaches with the wheelchair spaces between the bogies.

 

[Meerkat]

What are the procurement rules around changing the work?
How far can they go before suppliers would demand a recompeted contract?

 

[takno]

There are a few factors here. First is that the HS2 stations are already designed with higher platforms. That means that the majority of passengers will have level boarding at at least one end of their journey, a benefit that risks being lost if you start playing with the designs.

The second point is that there hasn't been some curious oversight. The original specification was built with the full knowledge that the trains would be running into existing stations. The vehicle height is lower than Pendolinos, and a step has been specified to make the process safe and completely comfortable for the vast majority of users.

The third and possibly most important point is that just because 915mm has been chosen as an arbitrary design height, the existing stations on the line don't actually have platforms at that height. Extensive work has been required to provide level boarding on East Anglia and Merseyrail. Given the range of different heights in play, it may be that the best solution is to figure out how to have differing height platforms at the stations, or to use a harrington-hump arrangement for wheelchairs.

Finally, the specification for the carriages has been designed so that they can be reasonably long and reasonably wide, can still fit within the classic loading gauges. As soon you start lowering the base you have to narrow the carriage at the bottom, which means less internal space and more need for expanding steps at the doors.

Whether it's green tunnels, floor heights or anything else, the key reason why HS2 is proving so expensive is that every single aspect of it has gone through a detailed design process, resulting in a reasonable compromise solution which is good enough for all purposes, and then at the last minute some stakeholder who is politically too important to be ignored has come along and forced a redesign so that their narrow interests take primacy. Let's just get something built