UK Platform Height Question

[43021HST]

From what I understand UK railway platforms according to Wikipedia and a few other sources are 915mm high, aka 3ft.

However I was wondering if this height was measured from the top of the rail or from the bottom of the sleepers, or is it some sort of average between the railtop and the bottom of the sleepers?

Any help would be much appreciated.

 

[Bald Rick]

From what I understand UK railway platforms according to Wikipedia and a few other sources are 915mm high, aka 3ft.

However I was wondering if this height was measured from the top of the rail or from the bottom of the sleepers, or is it some sort of average between the railtop and the bottom of the sleepers?

Any help would be much appreciated.

All such heights are ARL - Above Rail Level, which is the top of the rail.

 

[thenorthern]

What Bald Rick has said is correct.

There are a small number of exceptions to this however such as Salford Central has lower platforms than normal, High Speed 1 also has a lower platform height at some stations while Heathrow Express has a slightly higher platform height.

 

[AM9]

What Bald Rick has said is correct.

There are a small number of exceptions to this however such as Salford Central has lower platforms than normal, High Speed 1 also has a lower platform height at some stations while Heathrow Express has a slightly higher platform height.

HS1 has platform heights of 760mm on platforms used by Eurostar trains and 915mm on those that class 395 trains stop at. Thus all stations have both heights.
Some existing uK stations have lower platforms where the original infrastructure has been unchanged since the lines were built with what was a lower standard.
A few stations have platform heights considerably higher than 915mm, particularly where tracks under adjacent bridges have been lowered during electrification but it was not demmed practicable to lower the platform level, e.g. Ilford on the GEML.

 

[kevjs]

Are all new trains designed with this in mind to facilitate (near) level boarding?

It seems daft all our buses have extended dwell times to kneel down to kerb height (where raised kerbs aren't installed) yet the step onto trains seems to vary a fair old bit and even for me at 194cm it can be a bit of a stretch at times. That being said the oldest buses are less than a decade old round here where as the newest trains are even older and many are over 30 or 40 years old.

 

[edwin_m]

Are all new trains designed with this in mind to facilitate (near) level boarding?

It seems daft all our buses have extended dwell times to kneel down to kerb height (where raised kerbs aren't installed) yet the step onto trains seems to vary a fair old bit and even for me at 194cm it can be a bit of a stretch at times. That being said the oldest buses are less than a decade old round here where as the newest trains are even older and many are over 30 or 40 years old.

The Stadler units for Merseyrail and East Anglia will have entrances at 914mm for level boarding to a standard platform, although this may result in a wider horizontal gap at some curved platforms and the train floors may not be level. The 1100mm platforms on HEX, East London Line, Crossrail central section and a few other places are level with a typical EMU floor height but not compatible with passing freight trains so can't be adopted universally. HS2 would like 1100mm platforms on their dedicated infrastructure, but these would have to be further back from the track than the ones already in use on conventional lines (as indeed they would if at any other height).

So counting HS1 we could be heading for three standard platform heights in the future.

 

[NotATrainspott]

The Stadler units for Merseyrail and East Anglia will have entrances at 914mm for level boarding to a standard platform, although this may result in a wider horizontal gap at some curved platforms and the train floors may not be level. The 1100mm platforms on HEX, East London Line, Crossrail central section and a few other places are level with a typical EMU floor height but not compatible with passing freight trains so can't be adopted universally. HS2 would like 1100mm platforms on their dedicated infrastructure, but these would have to be further back from the track than the ones already in use on conventional lines (as indeed they would if at any other height).

So counting HS1 we could be heading for three standard platform heights in the future.

It is now confirmed that HS2 captive platforms will be built at 1115mm above rail level, allowing for step-free access. Gap-filling devices will be fitted to trains, and for classic-compatibles this will even oversail the 915mm classic platform height to remove all gaps entirely. The joy of European gauging is that platforms can be at any height as the side profile is straight, not stepped just above platform level as it is in Britain. Step-free high platforms aren't unprecedented on European rail networks, being found primarily on semi-captive networks like S-Bahns and airport express shuttles (e.g. the Arlanda Express in Stockholm).

As an added benefit of this, it effectively creates room for a 'captive-compatible' type of rolling stock. While a classic-compatible set is a standard HS2 train which is capable of running on the classic rail network, a 'captive-compatible' would be a classic train which sometimes runs on tracks built by HS2 for its own services. This is particularly important for regional services, most notably any future Northern Powerhouse Rail/HS3 services, which would have no reason to run faster than 230km/h but would benefit from being able to share HS2 stations. For instance, the Manchester Airport station is planned to have only two platforms, which would need to be built for captive trains to call. Unless the station were to be expensively expanded just for the sake of providing a different platform interface for NPR/HS3 trains (like what the Channel Tunnel Rail Link designers had to do for HS1 Javelin domestic services), the NPR sets would need to have special steps and gap-fillers for the lower TSI platform heights that were previously planned. These gap-fillers would have no use whatsoever beyond the few captive platforms they would call at. With the gap fillers now designed for a 1115mm platform height, they can now be used to fill up the gaps at the many classic stations they'll also call at. The utility of the gap fillers for classic platforms will probably be such that most new trains will be fitted with them by default, meaning that they could call at captive platforms with no real effort at all.

 

[Adlington]

HS2 captive platforms

What are they?

 

[NotATrainspott]

What are they?

HS2 will be a standard gauge, 25kV-electrified railway just like is the case for our major mainlines and most other mainlines and high speed lines around the world. However, in addition to the speed the other major difference compared to the domestic rail network is that it is built to a larger loading gauge. The loading gauge is the allowable height and width of the train bodies - theoretically an American double-stack ISO container train can run on the same rails as a Piccadilly line train but you can see there's quite a loading gauge difference. The GB network loading gauge is slightly more restrictive than on the continent, especially for width. Our loading gauge is narrower in general and then becomes even narrower at about 950mm above rail level. Platforms built on HS2 dedicated infrastructure are being built for the wider loading gauge, meaning that they're at a different position than a normal GB network one would be.

It's always been known that they would be further away from the centre of the rails so that wider trains may pass, but more recently it has been confirmed that they'll be built slightly higher as well so that they're at the same height as the interior floor of the train. Until then, the presumption had to be that the platforms would be at one of the two allowable heights (540mm and 760mm) of the EU Technical Standards for Interoperability regulations for new high speed rail lines. Eurostar trains on HS1 currently use platforms built to the 760mm height, so there is a noticeable step up from the platform onto the train. HS2 Ltd are in a position to build a new network from scratch in a time when accessibility and passenger friendliness is a key concern, so they've chosen a different standard. It seems entirely possible that the TSIs will also be updated, if they haven't been already, to permit this flat-access platform height.

 

[paul1609]

HS1 has platform heights of 760mm on platforms used by Eurostar trains and 915mm on those that class 395 trains stop at. Thus all stations have both heights.
Some existing uK stations have lower platforms where the original infrastructure has been unchanged since the lines were built with what was a lower standard.
A few stations have platform heights considerably higher than 915mm, particularly where tracks under adjacent bridges have been lowered during electrification but it was not demmed practicable to lower the platform level, e.g. Ilford on the GEML.

Indeed when the international platforms were used by 395s at stratford during the olympics they were fitted with wooden panelling to raise the height.

 

[kevjs]

HS2 Ltd are in a position to build a new network from scratch in a time when accessibility and passenger friendliness is a key concern, so they've chosen a different standard. It seems entirely possible that the TSIs will also be updated, if they haven't been already, to permit this flat-access platform height.

Why does that remind me of this comic strip?

https://xkcd.com/927/

So basically, no realistic chance of 100% fixed step free and gap free access on the rail network in our lifetimes through rolling stock/platform changes - unlike some (all?) tram networks where there is a small but in practice non-existent gap?


Source: https://polishrail.wordpress.com/tag/nottingham-express-transit/

Newer networks like Cross Rail and HS2/HS3 would be similar to tram style networks with a level entrance and little gap although the floor of the train might be like a low floor bus where it ramps up away from the door? Merseyrail and Anglia will be achieving something similar at many stations through there new rolling stock too?

However Gap-filling devices could potentially be on all "non-captive" networks in the future to effectively give a ramp between train and platform?

RE the comments on 'captive-compatible' rolling stock - if I've understood this correctly - on straight platforms on the legacy network this form of rolling stock would offer level and gap free access to the trains - but when calling at a HS2/HS3 station there would be a ramp from the platform to the train effectively offering the same sort of access? Presumably the Gap-filler could be used on most (all?) curved platforms at the classic height?

Are any new platforms being built on curved track or are we just left with ones from times past?

Out of interest - what is the height above the rail for both the step level and vestibule floor level of a HST and Meridian? Both have quite high steps up from the platform (although it always seems worse at Nottingham than St Pancras)?

 

[NotATrainspott]

Why does that remind me of this comic strip?

https://xkcd.com/927/

So basically, no realistic chance of 100% fixed step free and gap free access on the rail network in our lifetimes through rolling stock/platform changes - unlike some (all?) tram networks where there is a small but in practice non-existent gap?


Source: https://polishrail.wordpress.com/tag/nottingham-express-transit/

Newer networks like Cross Rail and HS2/HS3 would be similar to tram style networks with a level entrance and little gap although the floor of the train might be like a low floor bus where it ramps up away from the door? Merseyrail and Anglia will be achieving something similar at many stations through there new rolling stock too?

However Gap-filling devices could potentially be on all "non-captive" networks in the future to effectively give a ramp between train and platform?

RE the comments on 'captive-compatible' rolling stock - if I've understood this correctly - on straight platforms on the legacy network this form of rolling stock would offer level and gap free access to the trains - but when calling at a HS2/HS3 station there would be a ramp from the platform to the train effectively offering the same sort of access? Presumably the Gap-filler could be used on most (all?) curved platforms at the classic height?

Are any new platforms being built on curved track or are we just left with ones from times past?

Out of interest - what is the height above the rail for both the step level and vestibule floor level of a HST and Meridian? Both have quite high steps up from the platform (although it always seems worse at Nottingham than St Pancras)?

The main problem for universal step-free, gap-free access on the classic rail network is the amount of curvature allowed. Curved platforms mean that the heights get very wonky, and there's not a lot that can be done really about it unless we set about rebuilding vast swathes of rail infrastructure. For these, I think the HS2 Ltd idea of a gap-filling device which actively extends out and over the edge of the platform is a good idea. Gaps and steps are hazardous when a misplaced foot could mean falling down between the train and the platform, and the degree of difference makes it hard for certain groups to use the train. With the gap-filler adding a proper solid step, it'll be much easier and safer for everyone to use the train at these low platforms.

One possibility which I think we'll see explored for HS2 is if the gap-fillers at the accessible entrances to the train can indeed ramp down as well as fill the gap. I can imagine the gap being filled like normal, and then a bus-style ramp automatically extending down over the deployed steps and the platform surface to provide a standards-compliant ramp. Passengers needing the ramp would then not need the help of train or platform staff to board and alight trains, which will make an enormous difference compared to today.

Remember that classic trains have their floor at a ~1100mm height internally anyway, which is what leads to the step existing from our 915mm platforms. Classic-compatible and captive trains would have the same floor height, and at captive platforms the classic-compatibles would just need to extend their gap fillers out by a few centimetres more. The gap filler would be at 1115mm height so at 915mm platforms, it would extend out over the top of the platform. There's little point having a gap filler at the 915mm height, as people will need to step up anyway and doing that step on top of the platform is safer than at the edge of the train. A requirement for these gap-fillers is that they will provide a proper step that people can stand on, so they'll oversail the classic platforms by a not insignificant amount.

New platforms have to be built much straighter than they were in the past. Ideally, platforms are located on flat and level track, and only if that is not possible are they put on gentle curves. The curvature is low enough that the platform height difference should come under little more than just the normal variation allowed due to wheels wearing away and the track moving around at renewals.

I've only just come up with this 'captive-compatible' idea. Essentially, my point is that the NPR/HS3 services could be run by non-high-speed trains like a 125mph version of the Bombardier Aventra sets for Anglia. The oversailing gap-fillers would be useful for accessibility even if they never went on the captive tracks at all, but their existence means that they could share platforms with HS2 captive trains.

 

[jopsuk]

a further issue is that if a platform has non-stop services through that causes problems- trains do hunt and sway. This is not typically such an issue for metro/light rail!

 

[NotATrainspott]

a further issue is that if a platform has non-stop services through that causes problems- trains do hunt and sway. This is not typically such an issue for metro/light rail!

Yes, and this is why gap fillers are the preferred solution. The trains can have an entirely standard kinematic envelope and the platforms can allow any arbitrary GB rolling stock to pass. Only when the train comes to a halt do the gap fillers deploy and take the train out of gauge.

 

[Essan]

Kingussie has 2 platforms at different heights ....

 

[NotATrainspott]

Kingussie has 2 platforms at different heights ....

There are plenty of legacy issues like that on the railways. However, when the time comes to repair or rebuild the platforms, they will be built at the proper height.

 

[SpacePhoenix]

Don't know what the situation is like now but a good few years ago, getting the Central Line in London, there was a good step upto the platform, it always seemed strange as the 92 stock would have been the only stock using it.

Have any units/coaches ever had anything like "kneeling suspension", kinda like the "kneeling" suspension on modern buses?

 

[NotATrainspott]

Don't know what the situation is like now but a good few years ago, getting the Central Line in London, there was a good step upto the platform, it always seemed strange as the 92 stock would have been the only stock using it.

Have any units/coaches ever had anything like "kneeling suspension", kinda like the "kneeling" suspension on modern buses?

I think there are quite a few cases of Tube lines having platforms too high for the trains. It's a problem wherever the same platform is used by both subsurface and tube trains, and it'll happen when a deep level line has taken over a pre-existing surface railway. I don't think it'll last forever though, since the works to enable UTO for the NTfL will encompass platform level works in the core stations.

 

[edwin_m]

I think there are quite a few cases of Tube lines having platforms too high for the trains. It's a problem wherever the same platform is used by both subsurface and tube trains, and it'll happen when a deep level line has taken over a pre-existing surface railway. I don't think it'll last forever though, since the works to enable UTO for the NTfL will encompass platform level works in the core stations.

Quite a few LU platforms have been re-built in recent years to line up with the stock that uses them. So I think the historic ability to, for example, run District stock to Hounslow and Metropolitan stock to Stanmore has now vanished.

 

[Greybeard33]

a further issue is that if a platform has non-stop services through that causes problems- trains do hunt and sway. This is not typically such an issue for metro/light rail!

Yes, and this is why gap fillers are the preferred solution. The trains can have an entirely standard kinematic envelope and the platforms can allow any arbitrary GB rolling stock to pass. Only when the train comes to a halt do the gap fillers deploy and take the train out of gauge.

Another situation where gap fillers may be needed is if TfGM's Metrolink tram-train proposals eventually come to fruition. Metrolink has the standard 915mm platform height, unlike the lower platforms of other British tram networks, with the tram floors also at 915mm, so providing level boarding. But the vehicle width is the tramway standard of 265mm, with a straight side profile down to door sill height. This means that, to give a minimal gap to the tram door sill, the Metrolink platform edges extend closer to the centreline of the rails than allowed by the National Rail structure gauge.

Metrolink tram-trains would need to have 915mm floor height and 265mm body width for compatibility with the tramway infrastructure, but this would leave dangerous gaps when stopped at a National Rail platform, unless bridged by automatic gap fillers.

The classic British loading gauge, wider at the ~1100mm door sill height than at the 915mm platform height, avoided the need for gap fillers. Except on sharply curved platforms, the fixed door sill oversails the platform edge, so reducing the risk of falling into the gap. The drawback is, of course, the necessity of providing manually deployed ramps for wheelchair access.

 

[3141]

Don't know what the situation is like now but a good few years ago, getting the Central Line in London, there was a good step upto the platform, it always seemed strange as the 92 stock would have been the only stock using it.

Was that at the eastern end of the line? There are stations there that previously had LNER services from Liverpool Street.

 

[SpacePhoenix]

Was that at the eastern end of the line? There are stations there that previously had LNER services from Liverpool Street.

It was at Leytonstone station.

 

[30907]

It was at Leytonstone station.

The Epping branch retained some BR services (freight, excursion, staff trains) after transfer to LU, so they weren't in a hurry to alter the track.

 

[Taunton]

There are plenty of legacy issues like that on the railways. However, when the time comes to repair or rebuild the platforms, they will be built at the proper height.

You have to wonder though how after all these years there are still some oddball platforms which are far lower than standard.

I recently had to travel for the first time to Hackbridge, South London, where the platforms are extraordinarily low, and would be quite a challenge to some. On the return I looked at other platform heights, which were more straightforward, but you have to wonder how a longstanding station, and indeed one with a new station building, can have been allowed to retain such non-standard platform heights.

The warning "please mind the gap between the train and the platform edge" is completely useless, because it is given as a General Blah rather than a necessary caution in such circumstances - on that return journey, it was given at Mitcham Eastfields, a brand new station, on the straight, which appears perfectly up to modern standards.