Station platforms on gradient?

[TheSignalEngineer]

Stations on gradients are quite common. Nowadays the Authorities will expect no steeper than 1 in 500 if trains are to change ends or be left unattended at any time. 

 

When Phase 1 of the Robin Hood line was done in 1993 the Inspecting Officer would not let us change ends at the temporary terminus at Newstead because of the gradient, which IIRC was about 1 in 77. We had to drop the last bit of the line so that after arrival the train could draw forward and stand on an almost level track for the driver to change ends.

 

At Birmingham Snow Hill there is a bit of steep gradient falling away from the station at both ends. It starts within the platform so the Inspecting Officer insisted on self-normalising trap points being provided to catch any runaway.

[BR60103]

1 in 264 - what a nice round number!

264 times 20 is 5280, so 20' in a mile.

[jamie92208]

Yes I love those scales.  the standard railway plans at 2 chains to 1 inch is a good one.

 

Jamie

[Donw]

The chain was such a practical measure. Two persons with a chain can measure any distance. Much longer and it would be too heavy.

Don

[avonside1563]

Hence why BCB was based on chains, although it did cause headaches with the baseboard dimensions!

[Gwiwer]

 

Kings Cross Hotel Curve platform. 1 in 52 I seem to recall.

 

 

Along its full length that was certainly one of the steepest.

 

Ian might correct me on this but IIRC the high level island platform at Portsmouth & Southsea (which was 6 and 7 and is now 2 and 1) is on a gradient riding to the south throughout its sinuous length but which commences at the Fratton end on the steepest part of the gradient which memory suggests is 1:37 up from the former canal bed the tracks use between those stations.

 

The present requirements are far more proscriptive than in days long gone.  Thus when a site for a new Ivybridge station was sought the former location was no longer acceptable and the current (and arguably much less convenient) location was the only one acceptable on account of a combination of curvature and gradient.

 

London Underground also has some ferocious gradients including a number through platform roads.

[Pete 75C]

Ah yes... Portsmouth & Southsea. I'd forgotten about that which is odd bearing in mind I signed Portsmouth Harbour from Horsham and drove through Southsea often enough! Late middle age memory loss, I think! I do now remember a Horsham turn was to work 12VEP empties back from the Harbour in the evening. We'd usually get signal checked at Southsea almost to a complete stand. Just a couple of seconds in "shunt" to get moving, and we'd quite happily coast all the way down, usually needing to brake for the curve before Fratton.

 

[jamie92208]

Hence why BCB was based on chains, although it did cause headaches with the baseboard dimensions!

Yes Lancaster Green Ayre is based on the rating plan and the 2 chain plan.  The rating plan is 1 in 500  so everything is multiplied by 11.63 and from the 2 chain plan it's multiply by 33.somehting IIRC.  That's to get up to 7mm  to the foot but I wonb't go into british scale/gauge relationships.

 

Jamie

[Edwin_m]

Stations on gradients are quite common. Nowadays the Authorities will expect no steeper than 1 in 500 if trains are to change ends or be left unattended at any time. 

 

When Phase 1 of the Robin Hood line was done in 1993 the Inspecting Officer would not let us change ends at the temporary terminus at Newstead because of the gradient, which IIRC was about 1 in 77. We had to drop the last bit of the line so that after arrival the train could draw forward and stand on an almost level track for the driver to change ends.

 

At Birmingham Snow Hill there is a bit of steep gradient falling away from the station at both ends. It starts within the platform so the Inspecting Officer insisted on self-normalising trap points being provided to catch any runaway.

I believe this requirement is now on its way out.  There was a RSSB study a few years ago which found no increased risk from platforms on gradients (and incidentally included a long list of such platforms).  Current practice seems to be moving towards just assessing the risk of runaways in the light of the parking brakes provided on the trains. 

[Gwiwer]

An outbreak of common sense on the railways???  Surely not?  

On the other hand there is a finite number of locations where platforms can be provided both straight and near-level and which would restrict the potential for opening / reopening stations in some cases.

[Oldddudders]

Having, more than a decade ago, done some very preliminary work on a proposed new station where gradient would certainly have been an issue, I think the matters that most concerned us were about affairs on the platform, rather than the track. In an era of increased requirements for disabled access, and parallel increase in accessibility by buggies etc., sloping platforms, and the scope for a runaway by such devices, become more important.

[Pete 75C]

Having, more than a decade ago, done some very preliminary work on a proposed new station where gradient would certainly have been an issue, I think the matters that most concerned us were about affairs on the platform, rather than the track. In an era of increased requirements for disabled access, and parallel increase in accessibility by buggies etc., sloping platforms, and the scope for a runaway by such devices, become more important.

 

Totally understandable after reading this page from the RAIB website:

 

http://www.raib.gov.uk/publications/current_investigations_register/130828_southend_and_whyteleafe_stations.cfm

[Donw]

Totally understandable after reading this page from the RAIB website:

 

http://www.raib.gov.uk/publications/current_investigations_register/130828_southend_and_whyteleafe_stations.cfm

Yet more circumstances where everyone else has to make special provision for others lack of care. Even if a platform is dead level a child playing or someone tripping over could then accidently push a wheelchair over the edge.

Don

[Edwin_m]

The gradient along the platform is a limiting factor in tramstop design, where the track can be at gradients of 6% or more.  It is unlikely to be an issue at the gradients found on heavy rail.  The incidents mentioned by RAIB appear to be down to the gradient across the platform, which should always be sloping away from the track but apparently wasn't in these cases. Although in one of the incidents the pushchair started rolling along the platform, this woudn't have been a problem until it turned towards the track. 

[Pete 75C]

Sadly, just another example of having to engineer something as a reaction to the limited abilities of some people when it comes to comprehending danger.

I well remember the years I spent pushing my two around in a buggy. Not once did I leave them without the brake applied.

I still have palpitations every time I see that level crossing footage of a young mother dodging the barriers and running across just in front of the train with a young child in a pushchair...