Train v platform heights

[DanNCL]

Am I correct that this means that other "standard" rolling stock cannot use the line because they would be foul of the higher platforms?

A 90 ventured down there during the early stages of testing so it’s definitely possible from a gauging point of view for stock not specifically designed for Heathrow to go down there.
The bigger limitation to stock accessing Heathrow is the lack of AWS/TPWS on the branch, anything that goes there now needs ETCS.

I actually had no idea that was even a thing. Is this all Hitachi units or just the 802s specifically?

All the diesel-powered 800s have higher floors in the vehicles that have engines

I never would've noticed, and now I'm curious to see if the electric ones have a similar design seeing as some of them are equipped with backup diesel generators in the even of an electrical failure.

They're probably all the same to avoid having different tooling, parts, etc for different bodies

Classes 800/801/802/803/805/807 all have it. The floor is lower in the driving vehicles to accommodate the pantograph, whereas it needs to be higher in other vehicles to accommodate the engines. It’s higher in all intermediate vehicles regardless if they have an engine or not both for commonality and also because the 80x range is a modular platform; though unlikely to happen, hypothetically you could convert an 803 or an 807 into a bi mode unit.
Unsure how it’ll work on the 810s as they have engines in the driving vehicles.

 

[david1212]

..... On a newly built line, that is only served by newly built trains, will never see any freight services and where all trains stop at every station these issues can be managed. For a new platform on an existing line served by a wide mix of trains, only some of which stop it's more difficult.

The low floor Stadlers mitigate the gap with pop-out gap fillers. Which works for a new design of rolling stock, but isn't really an option for existing stock.

Unless a new fleet is designed for the line there are engineering trains, recovery trains, snowploughs etc. that have to be considered which rules out platforms that are either higher or closer to the train / running line. The new fleet of trains has to get to a suitable facility for major exams and refurbishment so can not be wider unless the depot on the line is equipped to do everything expect accident damage where they would have to be transported by road. Hence the best practical option is platforms at a standard height and distance from the rails then a train design similar to the Stadler Flirt with the floor by the doors at or just above platform level and the slideout gap filler.

The Elizabeth Line has been discussed on other threads. If it was only intended to be self contained then the higher platforms would be fine. However it was always intended to serve existing stations but not to add dedicated platforms. Hence choosing the 1100mm height for platforms along new line then making the new fleet of trains have nominally level boarding to these but a big step to/from existing platforms has always seemed odd rather than the platform height being 915mm and the new trains low floor even if smaller wheels had to be used.

 

[JamesT]

Unless a new fleet is designed for the line there are engineering trains, recovery trains, snowploughs etc. that have to be considered which rules out platforms that are either higher or closer to the train / running line. The new fleet of trains has to get to a suitable facility for major exams and refurbishment so can not be wider unless the depot on the line is equipped to do everything expect accident damage where they would have to be transported by road. Hence the best practical option is platforms at a standard height and distance from the rails then a train design similar to the Stadler Flirt with the floor by the doors at or just above platform level and the slideout gap filler.

The Elizabeth Line has been discussed on other threads. If it was only intended to be self contained then the higher platforms would be fine. However it was always intended to serve existing stations but not to add dedicated platforms. Hence choosing the 1100mm height for platforms along new line then making the new fleet of trains have nominally level boarding to these but a big step to/from existing platforms has always seemed odd rather than the platform height being 915mm and the new trains low floor even if smaller wheels had to be used.

1100mm is around the level of most current stock. So the 345s aren’t really any worse than the stock previously used. However, what do you then do with the existing 1100mm platforms at Paddington and Heathrow? Rebuild to 915mm to match new stock? Do you also replace the HEX rolling stock to match?

 

[YorksLad12]

Thanks for the comments everyone. I hadn't considered freight profiles as being a/the sticking point, I'd assumed that the platform edge was the limit and everything had to be inside that.

I guess we'll be sticking with on-train and platform ramps, and friendly fellow passengers helping people on and off with pushchairs for now.

 

[zwk500]

Thanks for the comments everyone. I hadn't considered freight profiles as being a/the sticking point, I'd assumed that the platform edge was the limit and everything had to be inside that.

I guess we'll be sticking with on-train and platform ramps, and friendly fellow passengers helping people on and off with pushchairs for now.

A useful image that has appeared on these threads before is this:

[image of BR W6 gauge profile compared to a typical BR platform and UIC Gauge profiles]

 

[InkyScrolls]

Leeds to Ilkley (currently class 333, going to be class 331)

Currently also 331s and that combination will remain. There is no plan to withdraw the 333s from Triangle services.

 

[david1212]

1100mm is around the level of most current stock. So the 345s aren’t really any worse than the stock previously used.

True but all of the railway, other public transport and buildings / facilities that have public access are supposed to be working towards access-for-all which is not just those with disabilities but also with buggies/strollers and similar preferably without intervention e.g. manually placed train <> platform ramps.

Look back to this thread.

However, what do you then do with the existing 1100mm platforms at Paddington and Heathrow? Rebuild to 915mm to match new stock? Do you also replace the HEX rolling stock to match?

HEX certainly 'muddied-the-waters' but as built was stand-alone. Heathrow Connect and the approval for Crossrail, renamed to Elizabeth Line, which included services to Heathrow serving existing stations both came later.
While disruptive and complicated by the underground locations rebuilding the Heathrow platforms and using stock with the same bodyshell as would have been built if all the new Crossrail / Elizabeth Line platforms had been 915mm would have been the ideal long term path.

 

[zwk500]

HEX certainly 'muddied-the-waters' but as built was stand-alone.

It's worth pointing out that AIUI Heathrow Airport stations were built to the standards then in force, which required the gap between train and platform to be minimised and did NOT mention 915mm.

To quote myself in post #302 of that linked thread:

Heathrow opened in 1998. The Standard then in force appears to be GC/RT5161 Issue 1 (Issued 1995) - which says:

5.2.3 The edge of the platform shall be located such that the distance from the top edge of the platform to the top edge of the step board or floor of passenger rolling stock using the platform is kept to a minimum necessary to maintain structural clearance. Stepping distances shall not exceed the following nominal dimensions without the dispensation of the HMRI: • horizontal 275mm; • vertical 250mm; • diagonal 350mm.

It does not specifically say 915mm. Issue 2, from 2000, does specify 915mm.

So Heathrow was built to minimise the stepping distance to the conventional floor height of 1,100mm and is grandfathered in. Leading to the present mess. Rail Vehicles Accessibility Requirements was only passed into law in 2010, so there's lots of relatively recent schemes that didn't need to meet it, and thus the same problem exists.

 

[Indigo Soup]

Hence choosing the 1100mm height for platforms along new line then making the new fleet of trains have nominally level boarding to these but a big step to/from existing platforms has always seemed odd rather than the platform height being 915mm and the new trains low floor even if smaller wheels had to be used.

IIRC, at the time the decisions were being made, either only no train manufacturer, or else only one, could offer stock compatible with level boarding and a 915mm platform height.

If it was none, then the manufacturers would have had to develop new rolling stock for Crossrail at high cost. If it was only one, then setting that as a requirement was perceived as handing them the contract without fair competition, since everyone else would have to incur the aforesaid cost.

Unfortunately, I can't remember which of the two applied.

 

[Griffin Park]

Clapham Junction is lethal.The higher-numbered platforms in particular.

Wasn’t there something in the agreement when SWR took over in 2017 to do something about Clapham Junction platform heights. Since then nothing. A bit like the new trains we were promised, but that is another subject.

 

[Spartacus]

As a side-note I noted something interesting online today with the Manchester Metrolink M5000s, where they're meant to be level boarding were actually below platform height, with the doors struggling top open against the platform! They looked to be heavily loaded at the time so may have been a suspension issue? Not something I'd hope would be an issue for trains, but worth noting nonetheless to ensure it isn't an issue.

 

[swt_passenger]

Wasn’t there something in the agreement when SWR took over in 2017 to do something about Clapham Junction platform heights. Since then nothing. A bit like the new trains we were promised, but that is another subject.

Yes, but not all platforms, only 3,4 and 10,11 were in scope. So was that supposed to mean suburban services only?

No idea what the detail was, but isn’t Clapham Junction now NR’s responsibility since 2018 - or did that not happen either?