Steepest Gradient in New Stations?

[00crashtest]

What is the maximum gradient allowed for the tracks at new platforms of stations in the UK or located elsewhere serving the UK? I've heard multiple numbers, including 1 in 500, 1 in 280, 1 in 264, 1 in 260, and 1 in 200. So, which is it? Also, at what points of the station are those measured/applicable for? Is it that the gradient limit should not be exceeded for the average of the station (chord connecting the tracks at the ends of the platforms), at the steepest point within the station, etc.?

Edited April 15, 2022 by 00crashtest

[jim.snowdon]

These days, anything so long as you can satisfy the ORR (more specifically HM Railway Inspectorate) that the gradient does not introduce any unacceptable safety risks. It's a change that goes back to the late 1990s when railway safety started to become more formalised in a legal sense and railway operators were required to assess and manage their risks, essentially becoming aligned with the H&S principle of 'as safe as reasonably practicable'.

 

Before that, when the 'requirements' of the Ministry of Transport Blue(?) book were still regarded as the 'bible', the expectation was that stations should be as near level as practicable, and anything flatter than 1:400 was generally accepted as being level for practical purposes. Trains would not generally roll away on 1:400. The 'requirements' were not requirements in the legal sense, but defined the parameters that, if followed, would generally allow approval of new construction to be granted. They weren't binding, but to deviate from them and still expect approval from HMRI required a very good argument for what was proposed.

 

Jim

[stivesnick]

Here is the link to the new document setting basic railway safety principles:

 

https://www.orr.gov.uk/sites/default/files/om/principles-for-health-and-safety-on-the-railway.pdf

 

No obvious mention of gradients. A straight platform is also part of the risk assessment which is proving more of a problem for people wanting to reopen their local station which is on a curve.

 

Regards 

 

Nick 

 

[Wheatley]

The maximum permitted gradient and curvature limits are in the relevant RIS (RIS-7016-TOM I think but don't quote me)  available from RSSB's standards catalogue. You need an account to read it though and I'm away from my laptop until Tuesday. I'll have a look then if no-one beats me to it. 

 

You can get a derogation for a new station (or re-opened station) provided it isn't too far out of the RIS standards, and provided you can convince ORR that the risks are controlled. What those controls need to be depend on which bit you want a derogation for ...

 

The RIS is far more prescriptive in places than the Blue Book was. The stepping distance limits of 230mm vertical 275mm horizontal are quite tightly enforced for new build stations, whereas as the Blue Book merely stated that the gap was to be as small as practicable or words to that effect  without specifying what that should be. Consequently what constituted an acceptable gap often varied between Inspecting Officers.  The 1996 standards were a godsend in that respect. 

Edited April 15, 2022 by Wheatley

[jim.snowdon]

1 hour ago, stivesnick said:

A straight platform is also part of the risk assessment which is proving more of a problem for people wanting to reopen their local station which is on a curve.

And a cause of considerable expenditure as there is no one who will challenge the principle of 'as far as is reasonably practicable' early enough in the design process to make a difference. In an environment where money is thought of as limitless and no-one is prepared to take the risk, it is always either easier to increase the costs or can the project.

[kevinlms]

Surely gradients in most station platforms ought not be a major issue, UNLESS carriages are intended to be uncoupled. That would normally only be at end platforms or places where trains terminate.

Sure, risk has to be accessed, but if stock isn't being uncoupled and/or left unattended, then the risk is low.

[stivesnick]

1 hour ago, kevinlms said:

Surely gradients in most station platforms ought not be a major issue, UNLESS carriages are intended to be uncoupled. That would normally only be at end platforms or places where trains terminate.

Sure, risk has to be accessed, but if stock isn't being uncoupled and/or left unattended, then the risk is low.

 

As mentioned above, the railway industry has become very risk adverse. A railway station has a similar risk profile to say a shopping centre or a sports stadium. In reality the amount of paper work that is required on the railway to get something approved is many time greater.

 

Nick  

[DY444]

15 hours ago, jim.snowdon said:

And a cause of considerable expenditure as there is no one who will challenge the principle of 'as far as is reasonably practicable' early enough in the design process to make a difference. In an environment where money is thought of as limitless and no-one is prepared to take the risk, it is always either easier to increase the costs or can the project.

 

Indeed and that will never change until the ORR is forced to treat the cost benefit of its pronouncements as a fundamental component of its decision making.  There are plenty of problems with the GBR proposals but one of the biggest imo is the failure to recognise the insidious impact of the ORR on the the cost of infrastructure projects.  There is a very long list of things wrong with the railways but the ORR's aloof attitude to ALARP is right up there and yet nobody in Government can see it or is too scared to address it.

[JimC]

Trouble is it's hard to make a rational evaluation of risk and cost/benefit look good in the newspapers or at a public enquiry if something bad happens. 

[bécasse]

2 hours ago, DY444 said:

 

Indeed and that will never change until the ORR is forced to treat the cost benefit of its pronouncements as a fundamental component of its decision making.  There are plenty of problems with the GBR proposals but one of the biggest imo is the failure to recognise the insidious impact of the ORR on the the cost of infrastructure projects.  There is a very long list of things wrong with the railways but the ORR's aloof attitude to ALARP is right up there and yet nobody in Government can see it or is too scared to address it.

Actually there is a far simpler way of making ORR more "realistic". Make them responsible for overseeing safety on British roads - and targets that they have to attain.

[Wheatley]

I think the reason for the gradient limit was to reduce the risk of station overruns and passengers getting off at an unplatformed door, it happens more often than you might think. Nothing to do with loose vehicles rolling about. 

 

Having said that it's also remarkably easy to make a 2nd gen DMU roll with the doors open whilst people are boarding and alighting. 

Edited April 16, 2022 by Wheatley

[Rivercider]

18 minutes ago, Wheatley said:

I think the reason for the gradient limit was to reduce the risk of station overruns and passengers getting off at an unplatformed door, it happens more often than you might think. Nothing to do with loose vehicles rolling about. 

 

Having said that it's also remarkably easy to make a 2nd gen DMU roll with the doors open whilst people are boarding and alighting. 

In my 30 years of commuting by rail the station that had the most overruns was Nailsea and Backwell, always in the down direction from Bristol on the falling gradient from Flax Bourton tunnel, about three or four instances of mis-judgement (often with loco and coaches) and one where the driver seemingly forgot the stop and made an emergency brake application at the start of the platform, then thought better of it and went through to Yatton.

 

cheers 

[DY444]

4 hours ago, JimC said:

Trouble is it's hard to make a rational evaluation of risk and cost/benefit look good in the newspapers or at a public enquiry if something bad happens. 

 

"If something bad happens".  If.  The true art is assessing the realistic probability of it happening and balancing it against the cost.  It is always possible to reduce real or imagined risk if you don't care how much it costs.  For instance ... 

 

The ole clearances agreed in the 1950s and applied to the early phases of the modernisation plan AC schemes were very conservative and required the provision of 6.25KV in some areas to minimise structure rebuilding costs.  Through a combination of better insulating materials, service experience and empirical data derived from various specially arranged flashover tests those clearances were refined; so much so that the financial need for 6.25KV sections disappeared.  Those clearances have not, so far as I can establish, resulted in a single death or injury of a passenger on a station platform.  That's in the 60 plus years across the entirety of the route mileage electrified before the most recent schemes.  

 

Despite that the justification from the ORR for the increase in clearances imposed recently was people have got taller and now use selfie sticks.  Statistically these supposedly taller people with selfie sticks are more likely to be on a platform at a station electrified to the old clearance standards as there are vastly more of those and yet there hasn't been a single incident.  And nobody has yet provided a satisfactory explanation as to how the very common sight in the 60s, 70s and 80s of people on station platforms in the morning peak holding umbrellas above their heads on wet days is materially different to someone holding a selfie stick above their head now.  In short the new clearances are attempting, at huge cost, to mitigate against a risk that there is no evidence is actually anything other than theoretical. 

 

I am aware of the supposed cock-up which allowed the EU TSI on clearances to be rubber stamped instead of challenged.  However if the ORR was properly assessing reasonably practicable in its truest sense they would have realised this new standard was disproportionately expensive for its supposed benefits and been proactive in ensuring it was challenged.  Instead they did what they always do which is ignore "reasonably" and blindly impose it so we now have the situation where a dispensation has to be sought on new schemes for clearances which have been standard and safe on large parts of the network for decades.  In other words pointless bureaucracy and its associated cost for zero practical benefit - words which are a fitting motto for the ORR in fact.  The great HMRI inspectors of the past who did so much to improve railway safety whilst at the same time being empathetic with what made sense and what didn't must be spinning in their graves.      

Edited April 16, 2022 by DY444

[JimC]

43 minutes ago, DY444 said:

"If something bad happens".  If. 

I don't dispute a word of your comments. But the problem is that society in general and press and pundits in particular have a very poor appreciation of relative risk, and some industries are held up to much higher standards than others. And has often been said, "fools are so very ingenious". 
 

[luckymucklebackit]

I asked this question on another forum as the electrification of the East Kilbride branch includes the relocation of Hairmyers Station as part of the project, and the planned new site adjacent to the St James Retail Park is on a gradient of 1:72!

 

Jim

[Edwin_m]

These days it's probably relatively easy to get agreement to a station on a gradient provided it's not somewhere trains reverse - if the driver is in the cab then they should be able to stop any runaway.  On modern multiple units parking brakes are applied automatically, so it's very unlikely they would be left unbraked due to driver forgetting to apply the parking brake and unit running out of air.  

[JimC]

You know I wouldn't be surprised if runaway pushchairs and wheelchairs on the platform were as great a concern as runaway trains these days.

[Grovenor]

2 hours ago, JimC said:

You know I wouldn't be surprised if runaway pushchairs and wheelchairs on the platform were as great a concern as runaway trains these days.

Certainly are.

[Michael Hodgson]

3 hours ago, JimC said:

You know I wouldn't be surprised if runaway pushchairs and wheelchairs on the platform were as great a concern as runaway trains these days.

Not just pushchairs and wheelchairs   https://en.wikipedia.org/wiki/Wellingborough_rail_accident

 

That platform still wasnt level and I have seen BRUTE trolleys parked where they could roll into the path of a train.

[jim.snowdon]

14 hours ago, DY444 said:

 

Indeed and that will never change until the ORR is forced to treat the cost benefit of its pronouncements as a fundamental component of its decision making.  There are plenty of problems with the GBR proposals but one of the biggest imo is the failure to recognise the insidious impact of the ORR on the the cost of infrastructure projects.  There is a very long list of things wrong with the railways but the ORR's aloof attitude to ALARP is right up there and yet nobody in Government can see it or is too scared to address it.

The problem lies, not with the ORR, but with the unwillingness of both the Train Operators and NR to challenge the 'safety at all costs attitude' that actually originates from the RAIB.

 

The underlying problem is that the RAIB, at its creation, was given a remit of making safety recommendations without any accountability for the cost. At first sight, this ought to be a good thing because their conclusions should not be coloured by financial considerations. The ORR (HMRI) is the safety authority, and as such is the first filter for whether 'as safe as is reasonably practicable' has been observed. Ultimately, if a decision is required, it has to go before the judiciary. In the days of BR, there were sufficient senior people with real practical experience to make proper assessments of the practicability of safety measures, and the Inspectorate could, and did, operate a very gentlemanly arrangement of quiet pokes and prods, with the Law kept in the background for use only if necessary.

 

We are now in a much more commercially cutthroat age, where train operators, many of whom have links to the bus industry, are notoriously risk-averse. They will positively resist raising any challenge against authority. For some of us with more familiarity with the UK tramway sector, one only has to look at the way in which UK tramway safety is now diverging from European practice, expensively.

 

[Pandora]

City Thameslink Station which replaced Holborn Viaduct Station  has steep gradients at each end, the platforms are affected by the gradients,  the climb out of City Thameslink  towards Blackfriars is between 1 in 30 and 1 in 35,  main-line OTM machines such as Tampers and Tramms if required to pass through City Thameslink  are subject to controls such as one-off  written authority signed by a  Senior Engineer, the OTMs tend to stall 2/3rds up the gradient,  the gradient is so severe the OTMs   cannot be depended upon  to make the summit

[kevinlms]

16 minutes ago, Pandora said:

City Thameslink Station which replaced Holborn Viaduct Station  has steep gradients at each end, the platforms are affected by the gradients,  the climb out of City Thameslink  towards Blackfriars is between 1 in 30 and 1 in 35,  main-line OTM machines such as Tampers and Tramms if required to pass through City Thameslink  are subject to controls such as one-off  written authority signed by a  Senior Engineer, the OTMs tend to stall 2/3rds up the gradient,  the gradient is so severe the OTMs   cannot be depended upon  to make the summit

So it's possible to have platforms on a grade, you just need agreement - easy!