London Bridge Train/Platform Step/Gap

[Deepgreen]

Now that the new platforms (14 and 15) are in use at London Bridge, it has struck me that the gap and step between the train and the platform is at least as bad as it used to be before rebuilding (and possibly a little worse), and is certainly far worse than new platforms at other stations (London Overground's Canada Water, for example). Given that the stock using both stations is to the same outline, why has the once-in-a-lifetime opportunity to provide virtually step-free train access been missed at London Bridge?

 

[swt_passenger]

The stock isn't standardised at London Bridge though. Canada Water, like other core ELL stations, will be tailored to the 378, but that's not the case on the overground generally, where platforms will be arranged to the general standard to allow use by any stock that uses the route.

 

[Deepgreen]

Yes, that's what I thought at first, but the profiles of the 455, 442, 377 and 170 classes (i.e. all those that regularly use London Bridge) are essentially the same as the 378s, so I still believe that the opportunity could and should have been taken to provide a proper interface between train and platform. We are now going to have the step-free access problem at this much-touted 'new' key station for another several decades. The attached photo is of the interface on the new platform 14. Given the large step/gap I find it hard to believe that this couldn't have been improved greatly.

 

[philjo]

The new platforms at Blackfriars also have a large step/gap, especially platform 1. It is a larger gap than that at City Thameslink, used by the same trains. Odd as the platforms at Blackfriars were completely rebuilt.

 

[swt_passenger]

I think the bottom line is that the Network Rail infrastructure 'standard' platform edge is at 915 mm (3 foot) and that's the standard gap you get. Network Rail follow Railway Group Standards - and these may not be designed around full step free access to trains, just step free to platform and then ramp to train.

In the relevant Railway Group Standard, this paragraph shows the designed maximum stepping distances:

3.3 Footsteps of new trains relative to standard platform position
3.3.1 GM/RT2149 sets out the requirements for footsteps for passenger use on new trains relative to a platform positioned in accordance with sections 3.1 and 3.2. Appendix A of GM/RT2149 requires that the footstep be designed so that the stepping distance between the footstep and the edge of the standard platform does not exceed the following maximum static dimensions for platforms on curves with radii down to 160 m:
a) Horizontal 275 mm
b) Vertical 250 mm
c) Diagonal 350 mm

http://www.rgsonline.co.uk/Railway_...re/Railway Group Standards/GIRT7016 Iss 4.pdf

I don't think they intend to provide level access - and what TfL have done at Canada Water may not be to the same standards?

 

[Deepgreen]

Absolutely - but my point is that surely the opportunity should have been taken to improve the situation, bearing in mind that the standard from which you quote (thanks, by the way) is for the maximum dimensions (i.e. there is nothing to stop the step/gap being reduced from those dimensions). The step/gap is not just an issue for wheelchair users, of course, but for all passengers, and the smaller the gap, the more the risk of boarding/alighting accidents is reduced.

 

[philjo]

The new island platforms 7/8 at Cambridge also have much larger step up to the train than the old platforms.

 

[westcoaster]

The new platforms at Blackfriars also have a large step/gap, especially platform 1. It is a larger gap than that at City Thameslink, used by the same trains. Odd as the platforms at Blackfriars were completely rebuilt.

Not 100% sure is that to do with networkers! as networkers and 375's are now banned from going past Blackfriars due to clearance issues.

 

[asylumxl]

Not 100% sure is that to do with networkers! as networkers and 375's are now banned from going past Blackfriars due to clearance issues.

Any chance that could be due to the fact City Thameslink now has OHLE? Genuine question.

 

[Bald Rick]

Any chance that could be due to the fact City Thameslink now has OHLE? Genuine question.

Certainly for the networkers, not sure about 375s but likely.

 

[Timothy Turtle]

Network Rail standards may not be designed around step free access to trains, just step free to platform and then ramp to train.

In the relevant group standard, this paragraph shows the designed maximum stepping distances:

Just to be pedantic - they are Railway Group Standards, not Network Rail Standards.

Railway Group Standards are "owned" by the Rail Safety and Standards Board Limited. Decisions about Standards are made by a cross-industry committee which includes Network Rail, TOCs, FOCs, rolling stock owners/leasing companies/manufacturers, contractors etc.

 

[Class377/5]

Certainly for the networkers, not sure about 375s but likely.

Curious is the Networkers were banned along with 375 but 376's were permitted as far as Smithfield.

 

[westcoaster]

Curious is the Networkers were banned along with375 but 376's were permitted as far as Smithfield.

Believe that to be the case, they have put up a big red cross, no 465/466/375 sign up on both platforms at blackfriars.

 

[swt_passenger]

Just to be pedantic - they are Railway Group Standards, not Network Rail Standards.

Railway Group Standards are "owned" by the Rail Safety and Standards Board Limited. Decisions about Standards are made by a cross-industry committee which includes Network Rail, TOCs, FOCs, rolling stock owners/leasing companies/manufacturers, contractors etc.

Happy with that - I was simply using 'Network Rail' to differentiate the responsibility for the relevant infrastructure - the original post was comparing with the situation at Canary Wharf - which is not Network Rail infrastructure.

I'll go back and tweak the post to be more accurate.

 

[civ-eng-jim]

Absolutely - but my point is that surely the opportunity should have been taken to improve the situation, bearing in mind that the standard from which you quote (thanks, by the way) is for the maximum dimensions (i.e. there is nothing to stop the step/gap being reduced from those dimensions). The step/gap is not just an issue for wheelchair users, of course, but for all passengers, and the smaller the gap, the more the risk of boarding/alighting accidents is reduced.

The standard height and offset is somewhat irrelevant when designing the train/platform interface. A safe clearance and a compliant stepping distance "trump" the standard height/offset values.

The step height on different types of rolling stock can be wildly different. (100s of mm)

The platform/train interface is a compromise between making the track far enough away to provide compliant clearance and close enough to minimise the gap between the step and platform.

A 50mm clearance is required between the platform and the kinematic envelope of the train. This 50mm clearance takes into account many scenarios such as suspension failure, wheel wear, track shift (25mm for ballast track) cross level errors, rail wear et cetera which will explain why some stepping distances from certain trains will be excessive but not non-compliant.

Level access can only be achieved where a single type of rolling stock uses the line and often where the 50mm minimum is compromised somewhat.

A straight platform with no cant on the track is by far the easiest place to achieve level access, provided one rolling stock type uses the line. Bank Station on the Central Line is a good example where level, step-free access is impossible to achieve due to the curvature and cant of the track.

Interesting document on acceptable stepping distances ca be found here

http://assets.dft.gov.uk/publications/rvar-significant-steps/significant-steps-research.pdf

 

[Tio Terry]

Does anybody know if the works being undertaken at London Bridge are classed as Interoperable?

If they are then EU TSI's are applicable and, from the photograph, do not comply. Also, what's been done does not appear to be DDA Compliant. Is it the finished article or will the track be lowered as part of the on-going works?

 

[Bald Rick]

AIUI NR has a permanent derogation from EU TSIs (conventional) for platform height in order that it complies with the Railway Group Standard of 915mm platform height.

The 2 new platforms are at 915mm.

 

[Tio Terry]

AIUI NR has a permanent derogation from EU TSIs (conventional) for platform height in order that it complies with the Railway Group Standard of 915mm platform height.

The 2 new platforms are at 915mm.

Only for existing platforms, any new works or major alterations must comply. (Assuming it is classed as Interoperable)

 

[swt_passenger]

Only for existing platforms, any new works or major alterations must comply. (Assuming it is classed as Interoperable)

The Railway Group Standard I quoted earlier in the thread:

http://www.rgsonline.co.uk/Railway_...re/Railway Group Standards/GIRT7016 Iss 4.pdf

Is the 'Notified National Technical Rule' for the purposes of the TSI for interoperable routes.

Notified national technical rules (NNTR) are a technical standard used to ensure the rail industry is safe, efficient and sustainable. NNTRs can perform a number of functions, such as:

making a provision to deal with specific cases for particular circumstances prevailing in a member state
filling in where gaps have been identified in the technical specifications for interoperability (TSI)
setting requirements to maintain technical compatibility with existing assets that do not conform to the requirements of TSIs
https://www.gov.uk/government/publi...ity-current-notified-national-technical-rules

I also found this section in an RSSB Guidance Note on platform design. For conventional interoperable routes, the 'TSI Persons of Reduced Mobility' (TSI/PRM) has replaced references to DDA, RVAR etc etc:

TSI - Persons with Reduced Mobility
4.1.2.18.1. Platform height
For platforms on the Conventional Rail Network, two nominal values are permissible for platform height: 550 mm and 760 mm above the running surface. The tolerances on these dimensions shall be within –35 mm/+ 0 mm.
For platforms on the Conventional Rail Network where tramways (e.g. Stadtbahn or Tram-Train) are intended to stop, a nominal height of platform between 300 mm and 380 mm is permitted. The tolerances on these dimensions shall be within +/–20 mm.
In curves with a radius of less than 500 m, it is permitted for the platform height to be greater or less than those specified provided that the first useable step of the vehicle complies with figure 11 in clause 4.2.2.12.1.
7.4. Specific cases [part]
7.4.1.1. Platform height [part]
Great Britain, Northern Ireland and Eire ‘P’
It is permitted for the height of the platform to be 915 mm above the running surface.

http://www.rgsonline.co.uk/Railway_Group_Standards/Infrastructure/Guidance Notes/GIGN7616 Iss 1.pdf

Whichever way you look at it, 915mm platforms appear to be the current standard. A question then. How does making platforms lower, at 'European levels' of either 550mm or 760mm, make them more accessible?

 

[455driver]

Whichever way you look at it, 915mm platforms appear to be the current standard. A question then. How does making platforms lower, at 'European levels' of either 550mm or 760mm, make them more accessible?

It wouldnt, it would have the opposite effect.

The heights you quote are from the top of the railhead so if you want a smaller step into the train then you would need to increase the height from the running line, not reduce it.

The Continent has much lower platforms and so much higher steps from the platform to the train hence their smaller values.

 

[swt_passenger]

It wouldnt, it would have the opposite effect.

The heights you quote are from the top of the railhead so if you want a smaller step into the train then you would need to increase the height from the running line, not reduce it.

The Continent has much lower platforms and so much higher steps from the platform to the train hence their smaller values.

We're in agreement I think - I'm trying to emphasise that calling for European style rules makes things worse, with a higher stepping distance - even with their sort of rolling stock. Back in post #16 it was suggested that the tracks should be lowered, presumably to make the platform higher to meet TSIs (although he wrote DDA) - whereas in reality the tracks would have to be raised even further to meet the TSIs...

As I suggested earlier in the thread - level access doesn't seem to be a requirement of anyone's rules, yet.

 

[Tio Terry]

We're in agreement I think - I'm trying to emphasise that calling for European style rules makes things worse, with a higher stepping distance - even with their sort of rolling stock. Back in post #16 it was suggested that the tracks should be lowered, presumably to make the platform higher to meet TSIs (although he wrote DDA) - whereas in reality the tracks would have to be raised even further to meet the TSIs...

As I suggested earlier in the thread - level access doesn't seem to be a requirement of anyone's rules, yet.

Just remember that the Disabled Discrimination Act is British Law, if you look at a lot of LU platforms (LU is not subject to the EU TSI requirements as it's not classed as a Mainline Railway) you will find there are now raised sections of platform to comply with the DDA requirements for step free access.

European Trains have lower access steps, that's why they have lower platforms than the UK.

I don't know if the works at London Bridge are considered Interoperable and I'm not so sure you are right about that NNTR being valid anymore. A lot of NR Standards are well out of date because for about 18 months there's been a ban on updating and re-issuing them. I would take more notice of what the RSSB have to say but I do know of instances when the ORR have also disagreed with their interpretations. The whole subject is currently a minefield with the change over from ROGS to CSM thrown in on top!

 

[swt_passenger]

...A lot of NR Standards are well out of date because for about 18 months there's been a ban on updating and re-issuing them. I would take more notice of what the RSSB have to say but I do know of instances when the ORR have also disagreed with their interpretations. The whole subject is currently a minefield with the change over from ROGS to CSM thrown in on top!

Possibly as a result of which there's updated versions of both the linked Rail Group Standard and the RSSB Guidance note above that come into force next month. They both still allow for 915 mm platforms.

 

[edwin_m]

The industry, both across Europe and specifically in the UK, is getting itself into a pickle on platform height and offset.

Heathrow Express platforms (including theirs at Paddington) are at about 1100mm above rail level to give level boarding to the 332 units, which is obviously an advantage given the number of wheeled suitcases being taken on board. Some Overground stations have the same for 378s, and I believe Crossrail central section will do the same (and will also serve the Heathrow platforms). However these high platforms would foul passing freight trains, unless they were set so far back that the lateral gap to the vehicle steps would be dangerous, so they can't be used on mixed traffic sections. There's a study on the RSSB website that concludes that 1100mm platforms are unacceptable at many stations.

Just to confuse things I believe the floor height of S Stock is different again and LU are modifiying sub-surface platforms to match these.

The two Europe-wide platform heights mandated by the TSIs are simply the standard heights for the high speed networks in France and Germany. Having two values represents a typical Euro-compromise, and as stated the step up is generally greater than in the UK. At least one German S-Bahn (but I can't remember which) has level boarding and therefore higher platforms on some at least of its stations (probably onliy where not shared with other trains). There is also at least one train design with a 760mm floor height for level boarding from these platforms.

According to a recent article in Modern Railways, HS2 is exploring the option of getting a higher platform written into the high-speed TSIs and using it on the dedicated lines. If so it would be set much further back to clear GC gauge, with the classic compatible trains needing some sort of moving step arrangement to give a reasonable stepping distance.

 

[Chrisgr31]

Whilst platforms level with the train are obviously the best outcome is it possible that where it cant be achieved it is better to have a definite step? Is it possible that a step of say 10 cm would just be a trip hazard as it wouldn't be seen?

I did hear recently that there was an issue with the Class 171s of Southern, in that there were issues connecting the original delivered units with the ones that had been in service for some time. The reason being that the weight of the units had settled the older ones down on their suspension meaning they were at different heights.

That issue on a level platform would mean a small step which under my theory would be a trip hazard.

Having said all this I did ask why they weren't level platforms on the London Bridge works thread!

 

[edwin_m]

Whilst platforms level with the train are obviously the best outcome is it possible that where it cant be achieved it is better to have a definite step? Is it possible that a step of say 10 cm would just be a trip hazard as it wouldn't be seen?

That's an interesting point but none of the standards include any suggestion that this is necessary, as they just define maximum gaps horizontally and/or vertically. The ideal maximum vertical step, required for tram systems which aren't constrained by historic structure gauges, is 50mm. This allows for wheelchairs to get on and off without having to deploy a ramp, is very helpful to people with luggage and small children, and therefore has an effect on reducing dwell times.

Trams usually don't have air suspension, so they go down a bit on the springs when fully loaded and this has to be taken into account to stay within the 50mm tolerance under all circumstances. Turning (on a lathe) or replacing the wheels changes the step height and trams are usually shimmed at this time. I don't think this happens for trains, as the air suspension provides some self-adjustment to loading.