Should the HS2 train order be reconfigured.

[Crithylum]

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.

This strategy has not worked with Ealing Broadway, so why would it work for HS2? The point of "playing with the designs" is to get (as close to) level boarding at all stations. A rolling stock adjustment would also come with a platform adjustment at new stations.

Extensive work has been required to provide level boarding on East Anglia and Merseyrail.

An important part of which was ordering low floor trains, so that platforms wouldn't foul freight.

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.

Valid point. From Wikipedia the 755s are 5cm narrower than the 720s, roughly 2%. However, personally I think a 2% longer train is a better than making universal level boarding impossible without a "super-duper pendolino" that can raise and lower itself.

 

[HSTEd]

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.

There are precisely three stations designed with higher platforms. Old Oak Common, Curzon Street and Birmingham International with 17 total platforms. It is a tiny portion of the railway system.
The majority of passengers will get level boarding at one end of their journey using rolling stock, but only a small portion will ever have level boarding at both ends.
915mm boarding height hgih speed trains will be developed, and will never provide this benefit on HS2 because of this.

EDIT: Recent reports indicate that only some of the platforms at Curzon Street will actually be fitted out, so the number that actually need modification works will likely be smaller than 17 in total.

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.

No it's not a curious oversight, it is simply a terrible decision.
A decision so bad that HS2 had to initiate an unwinnable legal action and only got its way because of Brexit.

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.

Harrington Humps are unworkable above 915mm, because they will rip the sides out of other legacy rolling stock.
The cost of providing national level boarding at 915mm is far lower than at any other platform height.

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

I must be very careful with how I phrase this, but I think it is more likely that a major reason that HS2 is so expensive is because they appear to have repeatedly thrown best practice in the bin in exchange for some bespoke solution that they believe is superior.

The non standard platform heights, the very small diameter tunnels (in direct opposition to all practice abroad), the extremely high operational speeds (again in direct opposition to operational experience abroad).
The list goes on and on and on.

EDIT: Edited to make it somewhat more succinct.

 

[Elecman]

As non platforms or trains have actually been built HS2 should bd instructed to re specify the platforms and trains for 915mm and a more usable length for existing network platforms where these trains will call

 

[Halifaxlad]

As non platforms or trains have actually been built HS2 should bd instructed to re specify the platforms and trains for 915mm and a more usable length for existing network platforms where these trains will call

Im sure someone will be like

'Well its been designed like this'

But yes the platforms should be built to conventional platform height!

The whole situation is just ridiculous!

 

[Nottingham59]

The whole situation is just ridiculous!

Yes.

It stems from the original brief for HS2 to build a new high speed line between London and the West Midlands, rather than design a GB rail network fit for the twenty-first century, that incorporated high-speed running between London and the West Midlands.

 

[Halifaxlad]

How much would it cost to scrap the entire order ?