High speed trains with level boarding from 915mm platforms

[MarkyT]

Well, given the failure of the HS2 programme, it seems a very large fraction of passengers will have to deal with a step, forever.

This whole thing just seems to be another example of hubris.
What they decided makes sense if they assume that the entire programme will suceed and cannot fail, but otherwise it was a huge unnecessary risk.

I've said it before but I think the whole industry has been caught out badly by level boarding. 20+ years ago, raising platforms to around the traditional train floor height was seen as the only solution which is how we got the first deviations from 915mm platforms such as the Heathrow Express outlier that drove the eventual Crossrail decisions. The CAF and Bombardier new UK bodyshells were developed for traditional floor height over conventional bogies, locking in non-level boarding on vast fleets at most stations for decades, while the same companies were delivering genuine low floor solutions for mainland Europe, albeit not yet for the highest speeds which stubbornly retained their 1m+ floors often with many steps up from lower platforms in rural areas and even at large stations in the south of the continent.

 

[Trainbike46]

I agree, but specifications required a level floor throughout the train. Perhaps, with retrospect, some steps or ramps internally would have been better than big steps at all doors at most stations served, for safe and efficient boarding with much lower risk of minor incidents at the interface and consequent disruption.

People in this thread are saying that the specification for HS2 trains should have been different, so that's really not an argument

 

[AM9]

Well, given the failure of the HS2 programme, it seems a very large fraction of passengers will have to deal with a step, forever.

This whole thing just seems to be another example of hubris.
What they decided makes sense if they assume that the entire programme will suceed and cannot fail, but otherwise it was a huge unnecessary risk.

I was actuallly referring specifically to the Lizzie, where the total number of boardings/alights at PED equipped platforms in the new sections (core plus Abbey Wood) probably far exceeds the total of all boardings/alights at the other lower height platforms that the trains use. The sort of numbers in the Passenger Usage Insight (see here) show annual figures of 50-75k per annum rivalling all but the largest London terminii, and I would hazard a guess that the majority of passengers carried start, finish or interchange at one of those stations.

 

[renegademaster]

I was actuallly referring specifically to the Lizzie, where the total number of boardings/alights at PED equipped platforms in the new sections (core plus Abbey Wood) probably far exceeds the total of all boardings/alights at the other lower height platforms that the trains use. The sort of numbers in the Passenger Usage Insight (see here) show annual figures of 50-75k per annum rivalling all but the largest London terminii, and I would hazard a guess that the majority of passengers carried start, finish or interchange at one of those stations.

Lizzie line is unique also in that its highish speed (90mph) but with a metro core, 3 doors per car per side and longitudal seating. Its an S Bahn , but most of the german speaking world either picks lower speed captive metropolitan line style stock (Like Hamburg and Berlin), or just typical regional commuter stock like Flirts and Desiros (Vienna).

 

[zwk500]

I've said it before but I think the whole industry has been caught out badly by level boarding. 20+ years ago, raising platforms to around the traditional train floor height was seen as the only solution which is how we got the first deviations from 915mm platforms such as the Heathrow Express outlier that drove the eventual Crossrail decisions.

I think it was mentioned in the Ealing Broadway thread, the standard then in force when HEX was built didn't specify 915mm, but instead that the difference between platform and train floor height should be minimised.

My feeling on this is that the platform and floor should be harmonised at 950/960mm, with gap fillers/ramps to cover small adjustments. I'd also take advantage of the gap fillers to have a programme of rebuilding platforms to UIC profile widths, but I do accept that's very high level fantasy.

 

[MarkyT]

I think it was mentioned in the Ealing Broadway thread, the standard then in force when HEX was built didn't specify 915mm, but instead that the difference between platform and train floor height should be minimised.

The idea and benefits of level or near-thereabouts boarding have been appreciated for decades, as evidenced by its adoption on modern metros and some light rail, coupled with the near universality of low floors on UK buses today. T&W Metro and Manchester Metrolink went for ~3ft floor height which no doubt minimised work required on the former national network platforms they adopted. That was facilitated by both vehicles being derived from European light rail designs with smaller bogies and wheels than is common for heavy rail. TfL adopted the same plan with the S stock for subsurface lines built with mainline standard platforms; they'd had much experience of smaller bogies on deep tube stock, some of which can run just as fast (100km/h) as the subsurface, and South Wales Metro has recently followed suite for tram-trains and FLIRTs on its technically still heavy rail, but locally administered network. For a wholly or partly isolated heavy rail operation such as HEX, initially the sole user of all 8 platforms served - all but 2 of which were new-build, it was practical to simply use a standard UK vehicle floor height of the time with a platform raised to suit, a solution also used on UK engineered self contained railways built overseas, such as Gautrain in South Africa, using Bombardier UK Electrostars with pointy noses bolted on. Unfortunately that set a precedent that seemed to take away the focus from any notion of trying to match floors better to the thousands of existing platforms elsewhere on the national network and new generations of trains and vast recent stock orders have locked in that vertical step at the vast majority of the network for decades. I believe this was a monumental generational mistake, especially for regional routes and for high-density metro-like operations. At least on long distance high speed there are fewer less frequent and longer stops at bigger stations where assistance is more likely to be available. All this while the continent has been rolling out level boarding steadily on urban and regional networks for decades, often facing difficulties such as the lack of a local standard over an entire nation or even a local network for instance. The same manufacturers delivering level boarding solutions through lower train floors all across Europe were simultaneously designing and delivering 'stepper uppers' for the UK with its already 'quite high' platfroms. We still have a standard in 3ft, and while not all platforms meet it exactly, it is far more achievable at most than nearly a foot higher. HEX and subsequent related decisions and technical choices screwed that up. The more we raise to 1m+ the more we create difficulties for future generation lower floor trains where they interwork as it's generally considered very bad to have a 250mm step down into a train at the platform interface (although its still a thing at certain TfL stations where subsurface or LO and tube stock interwork).

My feeling on this is that the platform and floor should be harmonised at 950/960mm, with gap fillers/ramps to cover small adjustments. I'd also take advantage of the gap fillers to have a programme of rebuilding platforms to UIC profile widths, but I do accept that's very high level fantasy.

Maybe useful on selected freight routes if continental flatbed sets could be accepted over a core trunk UK network. Load size restrictions above would still apply clearly. With more width for the lower saloon available, it might allow development of some UK-compatible double-deck passenger rolling stock. While platforms are solvable thereby once all passenger vehicles have the gap filler, some structures like underbridge girders are very close to the width-limited area below the platform face and might be foul of a UIC gauge. Signal equipment may need moving too, particularly ground signals.

 

[zwk500]

The more we raise to 1m+ the more we create difficulties for future generation lower floor trains where they interwork as it's generally considered very bad to have a 250mm step down into a train at the platform interface (although its still a thing at certain TfL stations where subsurface or LO and tube stock interwork).

Thanks for the post. Interestingly this year I have been to Italy (Rimini) and Germany (Berlin) where both railways had relatively new stock (possibly of the same family, it certainly felt alike) on regional trains with a distinct step down from the platform into the train. It certainly wasn't 250mm though!

Maybe useful on selected freight routes if continental flatbed sets could be accepted over a core trunk UK network. Load size restrictions above would still apply clearly. With more width for the lower saloon available, it might allow development of some UK-compatible double-deck passenger rolling stock. While platforms are solvable thereby once all passenger vehicles have the gap filler, some structures like underbridge girders are very close to the width-limited area below the platform face and might be foul of a UIC gauge. Signal equipment may need moving too, particularly ground signals.

As mentioned, I do accept its high fantasy. You'd need to widen track centres for UIC clearances, and good luck doing that at anywhere worthwhile!