Steep Gradients

[roboverground]

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.JPG
has 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 ??

[superteacher]

I’m sure that the District line just east of Bow Road is one of the steepest.

[Dstock7080]

Nov 30, 2017 21:25:51 GMT superteacher said:

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.

[bassmike]

Anyone know what the gradient from EC depot down to Acton is?

[rincew1nd]

Nov 30, 2017 21:44:05 GMT Dstock7080 said:

Nov 30, 2017 21:25:51 GMT superteacher said:

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?

[Chris M]

Dec 1, 2017 21:09:21 GMT rincew1nd said:

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:

The Northern and Central lines offer some more extreme gradients, including:

- Leaving Kennington NB City - 1 in 20 fall
- Approaching Old Street SB - 1 in 20 fall
- Leaving Borough SB - 1 in 24 fall
- Central Line WB leaving British Museum - 1 in 25 fall
- Leaving Oxford Circus EB - 1 in 25 fall
- Leaving Notting Hill Gate WB - 1 in 25 fall
- Leaving Marble Arch EB - 1 in 26 fall
- Leaving Bank WB - 1 in 26 fall
- Leaving Bank SB - 1 in 27 fall
- Leaving Bond Street both roads - 1 in 27 fall
- Leaving Queensway WB - 1 in 27 fall
- Leaving Chancery Lane EB - 1 in 28 fall
- Leaving Oxford Circus WB - 1 in 28 fall
- Leaving TCR WB - 1 in 29 fall
- At 3x locations between Angel and King's Cross NB - 1 in 29 fall

Most of these last only for a very short distance however, typically around 50 metres or less.


The JLE also get close, with numerous sections of 1 in 33 both rising and falling, including some sections extending over a sustained distance, in particular a length of over 500m rising at 1 in 33 approaching Bermondsey EB.

I haven't managed to find any rising gradients steeper than in 1 in 32 however.

Edit 2: In a couple of very old threads CSLR notes that the incline into King William Street Station was 1 in 14!

[melikepie]

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?

[brigham]

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.

[jetblast787]

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

[Dstock7080]

Dec 2, 2017 12:12:05 GMT jetblast787 said:

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)

[Tom]

I thought that dip at Earl's Court was somewhat steeper!

[Tom]

Dec 1, 2017 21:09:21 GMT rincew1nd said:

Nov 30, 2017 21:44:05 GMT Dstock7080 said:

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.

[londonstuff]

Dec 3, 2017 15:55:19 GMT Tom said:

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

[philthetube]

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

[Dstock7080]

Dec 2, 2017 8:06:59 GMT melikepie said:

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

[norbitonflyer]

Dec 4, 2017 9:39:34 GMT philthetube said:

, 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)

[programmes1]

Dec 4, 2017 9:46:34 GMT norbitonflyer said:

Dec 4, 2017 9:39:34 GMT philthetube said:

, 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.

[Dstock7080]

Dec 4, 2017 9:46:34 GMT norbitonflyer said:

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)

[superteacher]

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!

[philthetube]

Dec 4, 2017 10:49:44 GMT Dstock7080 said:

Dec 4, 2017 9:46:34 GMT norbitonflyer said:

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.

[philthetube]

Dec 4, 2017 20:06:28 GMT superteacher said:

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.

[Dstock7080]

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!

[slugabed]

"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?

[Dstock7080]

Dec 5, 2017 8:59:22 GMT slugabed said:

"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.

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?

(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.