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Post by roboverground on Nov 30, 2017 20:32:54 GMT
At Farringdon, the Up Snow Hill/Down Moorgate has a falling gradient of 1 in 30 over concrete 'slab track', I believe before electrification by overhead line with ballasted track this was 1 in 35. Gradient sign hidden under platform bed-pan.homestead.com/FarringdonGradient.JPGhas any member got a gradient profile prior to electrification ?? Most sinalboxes of the day has a wall mounted copy (mainline network) More generally whilst much fuss is made of steepest mainline gradients - what are the stats for steepest LU gradient ?? |
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Post by superteacher on Nov 30, 2017 21:25:51 GMT
I’m sure that the District line just east of Bow Road is one of the steepest.
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Post by Dstock7080 on Nov 30, 2017 21:44:05 GMT
I’m sure that the District line just east of Bow Road is one of the steepest. The District Line, Driving Technique Diagrams has this as 1 in 38. Ravenscourt Park-Hammersmith EB District, listed as 1 in 35. |
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Post by bassmike on Dec 1, 2017 12:45:34 GMT
Anyone know what the gradient from EC depot down to Acton is?
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rincew1nd
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Post by rincew1nd on Dec 1, 2017 21:09:21 GMT
I’m sure that the District line just east of Bow Road is one of the steepest. The District Line, Driving Technique Diagrams has this as 1 in 38. Ravenscourt Park-Hammersmith EB District, listed as 1 in 35. I'm sure we've discussed this before, isn't there a crossover somewhere in that area with about six inches of 1 in 6 or something similarly acute? |
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Post by Chris M on Dec 2, 2017 0:45:47 GMT
I'm sure we've discussed this before, isn't there a crossover somewhere in that area with about six inches of 1 in 6 or something similarly acute? Now you mention that, I remember a thread from many years ago (almost certainly when Dave was still with us) in which someone mentioned that, I think on the south side of the Circle (maybe near Blackfriars or Mansion House?), where there is (or maybe was now) a set of trap points with no flange gap for a derailing train to cross the running rail but a ramp with a few inches of 1 in single-digit gradient. Edit: In This post North End comments: Edit 2: In a couple of very old threads CSLR notes that the incline into King William Street Station was 1 in 14! |
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Post by melikepie on Dec 2, 2017 8:06:59 GMT
We're probably going slightly off topic here but from my experience in remember the Piccadilly Line just north of Southgate and also between Arnos Grove and Bounds Green as pretty steep. And how about the Northern Line between East Finchley and Highgate and the Victoria Line rising to Northumberland Park depot?
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Post by brigham on Dec 2, 2017 8:43:38 GMT
The incline into King William Street was designed for cable traction, where wheelslip isn't a factor.
A similar legacy are the steep gradients on the South Devon Railway, originally designed for atmospheric working.
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Post by jetblast787 on Dec 2, 2017 12:12:05 GMT
What about the district WB from Hammersmith to Ravenscourt Pk? I have a very fond memory of riding a battery loco getting support from the rear battery loco going up that gradient and the driving hoping the sticks were green XD
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Post by Dstock7080 on Dec 2, 2017 17:39:30 GMT
What about the district WB from Hammersmith to Ravenscourt Pk? I have a very fond memory of riding a battery loco getting support from the rear battery loco going up that gradient and the driving hoping the sticks were green XD Initially starts as 1 in 43 rise, changing to 1 in 50 around halfway up. (initial dip from Earl's Court towards West Kensington; 1 in 39 (going under eastbound track from West Brompton) |
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Tom
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Post by Tom on Dec 3, 2017 15:55:19 GMT
I thought that dip at Earl's Court was somewhat steeper!
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Post by Tom on Dec 3, 2017 15:56:50 GMT
The District Line, Driving Technique Diagrams has this as 1 in 38. Ravenscourt Park-Hammersmith EB District, listed as 1 in 35. I'm sure we've discussed this before, isn't there a crossover somewhere in that area with about six inches of 1 in 6 or something similarly acute? That's just a badly dipped couple of beds in terms of gradient - and would in all likelihood be shown as a vertical curve. Ifn terms of crossover angles 1 in 6 would mean the angle of divergence in the z axis. |
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Post by londonstuff on Dec 3, 2017 22:25:46 GMT
I thought that dip at Earl's Court was somewhat steeper! On an S Stock looking right down the train you can really see how steep heading out of Earl’s Court to West Ken is. I’m with Tom on this one  |
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Post by philthetube on Dec 4, 2017 9:39:34 GMT
I would have thought that approaching East Finchley Northbound would have been as steep as anywhere. I always wondered what provision was made on the big hills to the north of London on the Northern in the event of a power failure, The brakes would bleed off on a 59 stock train within a couple of hours and I would not have expected the handbrakes to hold, on much lesser gradients in depots/sidings scotch blocks or/and rail anchors were used
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Post by Dstock7080 on Dec 4, 2017 9:45:25 GMT
We're probably going slightly off topic here but from my experience in remember the Piccadilly Line just north of Southgate and also between Arnos Grove and Bounds Green as pretty steep. And how about the Northern Line between East Finchley and Highgate and the Victoria Line rising to Northumberland Park depot? Definitely off-topic but to answer specific points: Bounds Green-Arnos Grove: 1 in 60 Southgate-Oakwood: 1 in 60 |
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Post by norbitonflyer on Dec 4, 2017 9:46:34 GMT
, The brakes would bleed off on a 59 stock train within a couple of hours and I would not have expected the handbrakes to hold, Aren't brakes designed to fail safe? (They need compressed air to be released, and are "on" at atmospheric pressure) |
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Post by programmes1 on Dec 4, 2017 10:07:54 GMT
, The brakes would bleed off on a 59 stock train within a couple of hours and I would not have expected the handbrakes to hold, Aren't brakes designed to fail safe? (They need compressed air to be released, and are "on" at atmospheric pressure) Not on the CWL but some years ago a train rolled from Queens Park after the brakes leaked off and the train was not secured correctly. I think it nearly made Oxford Circus. |
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Post by Dstock7080 on Dec 4, 2017 10:49:44 GMT
Aren't brakes designed to fail safe? (They need compressed air to be released, and are "on" at atmospheric pressure) A fully charged Westinghouse brake system will have a charged Train line and auxiliary (brake cylinder) reservoirs, the dissipation of train line air allows auxiliary (brake cylinder) reservoirs to empty into the brake cylinders; thus applying brake. The triple valve being a key element . If system is not recharged, eventually brake cylinder pressure will be released to atmosphere, causing brake to release. Therefore handbrakes were fitted for manual operation. (Westinghouse fitted LT trains) |
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Post by superteacher on Dec 4, 2017 20:06:28 GMT
As this has morphed into a general discussion about gradients, I’ve changed the thread title to reflect this. It warms my heart that people at so worried about going off topic! 
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Post by philthetube on Dec 5, 2017 2:24:28 GMT
Aren't brakes designed to fail safe? (They need compressed air to be released, and are "on" at atmospheric pressure) A fully charged Westinghouse brake system will have a charged Train line and auxiliary (brake cylinder) reservoirs, the dissipation of train line air allows auxiliary (brake cylinder) reservoirs to empty into the brake cylinders; thus applying brake. The triple valve being a key element . If system is not recharged, eventually brake cylinder pressure will be released to atmosphere, causing brake to release. Therefore handbrakes were fitted for manual operation. (Westinghouse fitted LT trains) however even on relatively flat depot roads additional braking was used, wooden blocks, (scotch blocks) under a wheel,and (rail anchors), which fastened onto the track and the train. 59 stock brakes would always bleed off overnight, I can think of two derailments of stabled trains on the Northern between 1995 and the end of 59 stock, one at High barnet, on new roads which no one had realised were sloping, and one at Finchley Central when a train was stabled overnight due to engineering works, on both occasions the crew took off the Handbrakes, (which they shouldn't have, before opening up the train. There was also a famous incident at Highgate sidings where a train rolled away into a dip and all anyone could do was stand and watch as it rolled up one side and back down the other like a pendulum. |
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Post by philthetube on Dec 5, 2017 2:25:26 GMT
As this has morphed into a general discussion about gradients, I’ve changed the thread title to reflect this. It warms my heart that people at so worried about going off topic! At least it is an interesting Underground related stroll form the topic. |
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Post by Dstock7080 on Dec 5, 2017 6:36:04 GMT
A famous incident on the District Line, before OPO was the R Stock at High Street Kensington pfm.4, which remained as a hot-spare all weekend, the relieving crew neglected to check the handbrakes and compressors correctly and the air brakes leaked off while they were in the newsroom.
Luckily a passing driver saw the train moving without a driver and managed to climb aboard and apply the brakes while it passed.
Under investigative testing in the following days it was found an unbraked train would roll out of High Street, past Triangle sidings, down the dip, through Earl’s Court pfm.4, through West Brompton, down that dip, through Fulham Broadway and finally end up trying to get up the hill into Parsons Green, before rolling back!
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Post by slugabed on Dec 5, 2017 8:59:22 GMT
"Investigative testing"?
Does that mean they waited till after hours and tried it,to see what would happen?
This all,I suppose,depends on the route being clear....what would happen to a runaway train that hit a tripcock?
What would happen with trains on those ATO lines without tripcocks?
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Post by Dstock7080 on Dec 5, 2017 9:40:07 GMT
"Investigative testing"? Does that mean they waited till after hours and tried it, to see what would happen? Exactly! its the best way to test for conclusions. (tripcocks - mounted on train; trainstop - mounted at track level)
yes, the route was pre-arranged and set.
in this instance the train had no air to stop it, so the trip arm would operate but the air would already have been exhausted.
Modern trains and signalling systems operate in a different way to the discussion in this thread. Trains are now fitted with SAPBs Spring Applied Parking Brakes, which are held OFF by the presence of air pressure.
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