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Post by Deleted on Jan 31, 2006 23:53:21 GMT
Does anyone happen to know what the maximum permissible track gradient for sidings is?
I know that there are strict limits of the gradients in stations, but does this apply to sidings as well?
Thanks.
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Post by ttran on Feb 11, 2006 3:01:09 GMT
You would assume there would be, due to safety considerations incase the parking brakes suddenly decide to pack it in. Anyway, imagine if there were no limits anywhere. Could ya' just imagine a 1 in 40 platform or something!  |
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Phil
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RIP 23-Oct-2018
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Post by Phil on Feb 11, 2006 11:01:41 GMT
Does anyone happen to know what the maximum permissible track gradient for sidings is? I know that there are strict limits of the gradients in stations, but does this apply to sidings as well? Thanks. Are you talking new or existing (i.e. grandfather rights)? On NR I believe it is something like 1/100 towards a buffer stop and 1/150 towards a running line/junction for new build (perhaps StanmoreK can confirm or vary this) but of course much steeper gradients were used in the past and these can still be used. As for LU I don't know if the rules are the same or different. |
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Post by trainopd78 on Feb 11, 2006 15:09:45 GMT
When I was a guard, there were certain sidings that required the use of extension bars to the handbrakes, rail anchors and scotch blocks. The use of spring applied parking brakes has stopped the need for such items today.
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Post by Deleted on Feb 11, 2006 18:13:02 GMT
Scotch blocks? I assume those were the wedges placed in front of the wheels to stop the train rolling?
Sam
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Post by Deleted on Feb 11, 2006 18:42:50 GMT
Scotch blocks? I assume those were the wedges placed in front of the wheels to stop the train rolling? Sam Exactly  |
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Post by Deleted on Feb 11, 2006 18:46:24 GMT
That's what I thought.  Thanks for the pic too! ;D Sam |
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Post by ttran on Feb 12, 2006 6:24:51 GMT
Hmm, we call 'em chocks over 'ere. Crushed a few of 'em out at Zig Zag Railway I tells ya! Although the worst thing you could ever do is leave the handbrake on accidentally when your trains trying to lift itself up a 1 in 42. Not nice!
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Post by stanmorek on Feb 15, 2006 23:11:14 GMT
Quoting the horse's mouth (track engineers):
Max allowable gradient on SSL running lines:
Desirably 1.25% (1 in 80)
Absolute 2% (1 in 50)
Max allowable gradient on SSL depot tracks and sidings:
Desirably LEVEL
Absolute 0.38% (1 in 260)
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Post by setttt on Feb 15, 2006 23:19:45 GMT
Max allowable gradient on SSL running lines: Desirably 1.25% (1 in 80) Absolute 2% (1 in 50) Max allowable gradient on SSL depot tracks and sidings: Desirably LEVEL Absolute 0.38% (1 in 260) An ATM demostrated to me at NFDS depot that you can release the brakes in the car sheds, and the train will quite happily roll all the way across the Boston stabling roads and out into the neck at Boston Manor, accumulating quite some speed in the process! It certainly seemed like the gradient was more than 1 in 260 - I guess different rules apply to tube line depots? |
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Post by Deleted on Feb 15, 2006 23:26:49 GMT
Quoting the horse's mouth (track engineers): Max allowable gradient on SSL running lines: Desirably 1.25% (1 in 80) Absolute 2% (1 in 50) So the gradient from Bow Rd to Bromley is only 1 in 50? It seems steeper! |
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Post by stanmorek on Feb 16, 2006 0:13:06 GMT
I think the figures quoted are standards for new design. As civils we just lay whatever the specs say.
Besides standards may say one thing but track is difficult is get to conform to everything as Phil said grandfather rights. If there's a good reason the standard can't be applied then we go for a concession against the standard. Non-conformances on District line track ran into the thousands pre-PPP and a programme was started a couple of years ago to address these.
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Post by Dmitri on Feb 16, 2006 12:24:30 GMT
Quoting the horse's mouth (track engineers): Max allowable gradient on SSL running lines: Desirably 1.25% (1 in 80) Absolute 2% (1 in 50) Just in case, here are maximum and minimum allowable gradients for the xUSSR metros: Max allowable gradient on the running lines: Desirably: 4% (1/25) Absolute: 4.5% (1/22) When unavoidable: 6% (1/17) Min allowable gradient on the running lines: 0.3% (1/333) Max allowable gradient on the stations: Desirably: 0.3% (1/333) Absolute: 0.5% (1/200) Min allowable gradient on the stations: level (adequate drainage should be provided) (Note: we usually express gradients on the railways in thousandths). |
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Post by stanmorek on Feb 16, 2006 12:24:34 GMT
On examination of an 1885 ICE paper on the construction of the Metropolitan & Metropolitan District Railways which has a chart of the gradients of the inner circle, the steepest I can find is 1 in 70 between Notting Hill Gate and High Street Ken. Unfortunately it doesn't cover Bow Road.
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Post by CSLR on Feb 16, 2006 12:42:38 GMT
On examination of an 1885 ICE paper on the construction of the Metropolitan & Metropolitan District Railways which has a chart of the gradients of the inner circle, the steepest I can find is 1 in 70 between Notting Hill Gate and High Street Ken. Unfortunately it doesn't cover Bow Road. The notorious down line into the former King William Street station had a staggering 1 in 14 gradient and a 1.51 chain curve ! |
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Phil
In memoriam
RIP 23-Oct-2018
Posts: 9,473
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Post by Phil on Feb 16, 2006 12:48:38 GMT
And of course the original gradient from station to Depot at Stockwell was 1/3.5 ! Trains were rope hauled by a stationary engine until the runaway.........
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Post by CSLR on Feb 16, 2006 12:57:09 GMT
And of course the original gradient from station to Depot at Stockwell was 1/3.5 ! Trains were rope hauled by a stationary engine until the runaway......... Yes, yes, yes and No! After extensive research, I can confirm that I found no contemporary documentary evidence of a run-away at Stockwell. Some years ago I traced this often repeated story back to the earliest record that I could find in a published book and spoke to the rather elderly author. When I asked him for a reference source he said that he could not remember. Everyone seems to have used his book as a subsequent reference. |
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