The Gradient down to Acton Wells Junction

[Questaware]

Can anybody tell me how I can find out the gradient down to Acton Wells Junction on the Dudding Hill line?

I estimate it at 1 in 70. Am I corrrect?

https://ehq-production-europe.s3.eu-west-1.amazonaws.com/86f5f59ddb2d7f72d572e5fa4379824ad934db79/original/1788769835/d44dc0403bac4da72c5914ec86e150a3_WLO%20Old%20Oak%20Common%20Lane_cons_FINAL.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA4KKNQAKIPIPQP5NM%2F20260925%2Feu-west-1%2Fs3%2Faws4_request&X-Amz-Date=20260925T030322Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=acb09b98cc7c1eb9e06415aa9ec77e468dae64de5ebf8e2aeacce855aa2b2032

I understand that the maximum gradient on a new station platform is 1 in 400 !!!

 

[35B]

Can anybody tell me how I can find out the gradient down to Acton Wells Junction on the Dudding Hill line?

I estimate it at 1 in 70. Am I corrrect?

https://ehq-production-europe.s3.eu-west-1.amazonaws.com/86f5f59ddb2d7f72d572e5fa4379824ad934db79/original/1788769835/d44dc0403bac4da72c5914ec86e150a3_WLO%20Old%20Oak%20Common%20Lane_cons_FINAL.pdf?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIA4KKNQAKIPIPQP5NM%2F20260925%2Feu-west-1%2Fs3%2Faws4_request&X-Amz-Date=20260925T030322Z&X-Amz-Expires=300&X-Amz-SignedHeaders=host&X-Amz-Signature=acb09b98cc7c1eb9e06415aa9ec77e468dae64de5ebf8e2aeacce855aa2b2032

I understand that the maximum gradient on a new station platform is 1 in 400 !!!

https://www.railwaydata.co.uk/linefiles/route/?ELR=AWL gives a gradient of up to 1:85.

The comparison with a new station is irrelevant - that is about ensuring that trains won't roll away, not about performance.

 

[John Webb]

I can't get any sense out of the two links above.
But looking at Gough's "Chronology of the Midland Railway" the gradient diagram from LMS days shows, as you approach from Cricklewood, sections of 1:194, 280, 480 at the junction, 270, level and then 1:100 for about half the distance down to Acton.

 

[Questaware]

https://www.railwaydata.co.uk/linefiles/route/?ELR=AWL gives a gradient of up to 1:85.

The comparison with a new station is irrelevant - that is about ensuring that trains won't roll away, not about performance.

A new station is proposed south of Victoria Road on the West London Orbital route.
Tfl have in in their new project proposal.
This proves that it would never be allowed.

West London Orbital

Find out about proposals for the West London Orbital, a new London Overground service designed to improve connections across west and northwest London. View plans for new and upgraded stations, understand the potential benefits and impacts, and share your feedback.

haveyoursay.tfl.gov.uk

The sayings "What a tangled web we weave ... " and "When you are in a hole stop digging" come to mind.

 

[greatkingrat]

https://www.railwaydata.co.uk/linefiles/route/?ELR=AWL gives a gradient of up to 1:85.

The comparison with a new station is irrelevant - that is about ensuring that trains won't roll away, not about performance.

That's the wrong route - that is the connection from Acton Wells to the GWML.

https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW is the Dudding Hill line.

 

[zwk500]

A new station is proposed south of Victoria Road on the West London Orbital route.
Tfl have in in their new project proposal.
This proves that it would never be allowed.

West London Orbital

Find out about proposals for the West London Orbital, a new London Overground service designed to improve connections across west and northwest London. View plans for new and upgraded stations, understand the potential benefits and impacts, and share your feedback.

haveyoursay.tfl.gov.uk

The sayings "What a tangled web we weave ... " and "When you are in a hole stop digging" come to mind.

The gradient from Acton Canal Wharf Jn to Acton Wells Jn is 1:226 down towards AW151 signal and then 1:92 down to the junction with the Mildmay line itself. Any new platforms would presumably be on the 1:226 section (where the Victoria Road underbridge is.

RIS-7016-INS (iss.2.2) States:

The mandatory requirement for vertical track alignment through station platforms was withdrawn in issue four of GIRT7016, based on work carried out to support deviations against issue two of GIRT7016 for specific stations and the findings of RSSB Research Report T815 (2009)
For many years it had been considered good practice in GB to locate platforms on gradients not steeper than 1:260, except where geographic constraints made this unavoidable. This requirement was later changed to refer to a gradient of 1:500, possibly because of a shift from plain bearings to roller bearings across all rolling stock.

Issue 2 of the Infrastructure National Technical Specification Notice (INF NTSN) requires tracks through passenger platforms where vehicles are intended to be regularly attached or detached and in sidings to be not more than 2.5mm/m (1:400) to prevent vehicles running away. This requirement would almost certainly not be relevant for station platforms at Victoria Road on the WLO.

So, there is no specific maximum limit, but the site would be subject to a safety assessment and part of that would include the suitability of a 1:226 gradient, which would give a vertical difference of about 0.5m from one end to the other of a platform sized for Overground trains (about 125m).

For reference: The maximum gradient permitted on new lines according to GC/RT5021 (iss. 6) is 12.5mm/m, which (if my maths is correct) is 1.25% or 1:80. Exceptional limits of 20mm/m are permitted with no restriction (1:50), or 35mm/m (slightly steeper than 1:29) with restrictions about how long and if trains would normally stop there.

And, of course, all of these standards can have derogations issues for new builds.

Spoiler: Maths:

% = Rise/Run
1 in X = Run/Rise

Rise	Run	%	1 in X
2.5	1000mm	0.25	400
12.5mm	1000mm	1.25	80
20mm	1000mm	2	50
35mm	1000mm	3.5	28.57

 

[Questaware]

The gradient from Acton Main Line to Acton Wells junction is 1:100 rising, then 1:85 rising, then 1:100 rising to AW146 signal. After AW146 signal it is 1:450 *falling* and then briefly 1:600 rising to the junction.

The maximum gradient permitted on new lines according to GC/RT5021 (iss. 6) is 12.5mm/m, which (if my maths is correct) is 1.25% or 1:80

Exceptional limits of 20mm/m are permitted with no restriction (1:50), or 35mm/m (slightly steeper than 1:29) with restrictions about how long and if trains would normally stop there.

Issue 2 of the Infrastructure National Technical Specification Notice (INF NTSN) requires tracks through passenger platforms where vehicles are intended to be regularly attached or detached and in sidings to be not more than 2.5mm/m (1:400) to prevent vehicles running away.

RIS-7016-INS (iss.2.2) States:


And, of course, all of these standards can have derogations issues for new builds.

However, The Poplar lines do not exceed the normal acceptable gradient limits for new build track today. You just wouldn't be allowed to put a platform on them.

Spoiler: Maths:

% = Rise/Run
1 in X = Run/Rise

Rise	Run	%	1 in X
2.5	1000mm	0.25	400
12.5mm	1000mm	1.25	80
20mm	1000mm	2	50
35mm	1000mm	3.5	28.57

News to me. This will be three new platforms at 1:85 where trains will call and terminate (but not reformed) WILL THIS BE ALLOWED?

 

[sh24]

News to me. This will be three new platforms at 1:85 where trains will call and terminate (but not reformed) WILL THIS BE ALLOWED?

Assuming the new station isn't going to be used for coupling or uncoupling, it looks like it is allowed (based on those links) albeit not considered best practice.

 

[JN114]

WILL THIS BE ALLOWED?

Yes, in short

 

[zwk500]

News to me. This will be three new platforms at 1:85 where trains will call and terminate (but not reformed) WILL THIS BE ALLOWED?

Apologies, my first attempt at that post had the wrong branch from Acton Wells (the Acton Main Line GWML link). I now understand you were asking about the link from Dudding Hill line/Acton Canal Wharf and specifically the proposed Victoria Road station.

This would be on a 1:226 gradient so would be very dependent on the safety assessment and any subsequent mitigations. A terminating/bay platform (which is AIUI the latest plan for the 3rd platform) could level off/rise slightly towards the buffers so that's probably the least difficult part of the proposal.

However, there's absolutely no need to shout/use caps lock.

 

[Questaware]

Assuming the new station isn't going to be used for coupling or uncoupling, it looks like it is allowed (based on those links) albeit not considered best practice.

https://foi.tfl.gov.uk/FOI-1450-2425/rspg-2b-stations.pdf?utm_source=chatgpt.com

>> Stations should be constructed with straight platforms and on the level or on a gradient not steeper than 1 in 500. Minor stations, at which trains do not terminate or reverse, may be built on steeper gradients where suitable arrangements can be made to ensure safety, subject to the agreement of the Inspectorate.

I guess that the terminating platform could be level and on the side.

Does anybody know the highest gradient station on Tfl?

== Doublepost prevention - post automatically merged: Yesterday at 12:18 ==

Apologies, my first attempt at that post had the wrong branch from Acton Wells (the Acton Main Line GWML link). I now understand you were asking about the link from Dudding Hill line/Acton Canal Wharf and specifically the proposed Victoria Road station.

This would be on a 1:226 gradient so would be very dependent on the safety assessment and any subsequent mitigations. A terminating/bay platform (which is AIUI the latest plan for the 3rd platform) could level off/rise slightly towards the buffers so that's probably the least difficult part of the proposal.

However, there's absolutely no need to shout/use caps lock.

I am absolutely clear that the gradient is at least 1:85. See posts here. At Midlands Terrace the Dudding Hill line is at 3m above pavement and Mildmay is at 1m below. 4m over 280m to the junction is 1 in 70!

The approval of this station at 1:85 is essential to the viability of the WLO project.

== Doublepost prevention - post automatically merged: Yesterday at 12:31 ==

There is a risk of strollers and suitcases rolling away!

 

[zwk500]

I am absolutely clear that the gradient is at least 1:85. See posts here.

All posts here I can see relating to 1:85 are talking about the Acton Main Line - Acton Wells Line (the Poplars), not the Dudding hill line. No station is proposed on that section.

At Midlands Terrace the Dudding Hill line is at 3m above pavement and Mildmay is at 1m below. 4m over 280m to the junction is 1 in 70!

My figure of 1 in 226 is from a rail industry diagram. While errors are not unknown, that would be serious margin of error. The link in Post #5 agrees with this figure.

Looking on google street view suggests Midlands Terrace is not perfectly flat. The houses step up slightly (but noticeably) between each pair. Is this accounted for to get your 1:70?

 

[greatkingrat]

I wonder why TfL spent large amounts of money on feasability studies when they could have just got Questaware to do a back of the envelope calculation and tell them it wouldn't work?

 

[Questaware]

All posts here I can see relating to 1:85 are talking about the Acton Main Line - Acton Wells Line (the Poplars), not the Dudding hill line. No station is proposed on that section.

My figure of 1 in 226 is from a rail industry diagram. While errors are not unknown, that would be serious margin of error. The link in Post #5 agrees with this figure.

Looking on google street view suggests Midlands Terrace is not perfectly flat. The houses step up slightly (but noticeably) between each pair. Is this accounted for to get your 1:70?

Background: Arup did a detailed design of a station north of Victoria Road and this may have been at 1 in 226. The posts here correct my 1:70 to 1:85.

See

== Doublepost prevention - post automatically merged: Yesterday at 12:44 ==

I wonder why TfL spent large amounts of money on feasability studies when they could have just got Questaware to do a back of the envelope calculation and tell them it wouldn't work?

The feasabilty study by Arup stated:
A station south of Victoria Road is not possible.
They or Tfl also spent lots of money for a detailed design of a station north of Victoria Road. Detailed down to the lifts, gate line etc.

 

[zwk500]

The posts here correct my 1:70 to 1:85.

Can you share your surveys so we can get NR's records corrected from 1:226 and 1:92.

I've pointed out before, the 1:85 is for the gradient rising from Acton Main Line station towards Acton Wells.

 

[35B]

I am absolutely clear that the gradient is at least 1:85. See posts here. At Midlands Terrace the Dudding Hill line is at 3m above pavement and Mildmay is at 1m below. 4m over 280m to the junction is 1 in 70!

As @zwk500 makes clear, you are citing my post about the line down from the North London Line to GWML which I had misunderstood you to be referring to. The link to https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW posted by @greatkingrat is the correct line. Looking at the detailed data, that shows a gradient of 1:226 under Victoria Road, steepening 240m after Victoria road to 1:92 before the junction at Acton Wells.

That may or may not be feasible to build a platform on with derogations, but is far from the extreme you cite. Where you quote the standard, it uses the word "should" which is a clue that what is written there is advisory rather than compulsory.

 

[edwin_m]

All trains have a means of holding them indefinitely on the maximum gradient they are likely to encounter. With freight and older passenger trains this involves manually applying a brake, but modern units have parking brakes that automatically apply if the main braking system is lost, for example after the unit is shut down. So there is very little risk associated with modern passenger trains stopping at stations on significant gradients.

From RSSB project T815 (access requires registration so won't link):

Although there has been a requirement not to exceed the 1 in 500 gradient for 60 years, the research has shown that there are over 600 existing stations with gradients of 1 in 400. There have recently been seven stations constructed with platforms on gradients steeper than 1 in 500, where a derogation from GI/RT7016 has been granted. As part of the research, several train operators were consulted to establish their views and what they considered to be the greatest risk at stations with steep gradients. The outcome was that it was not seen as high risk and no more so than starting/stopping at a gradient elsewhere such as a signal. A review of incidents over the last 15 years has shown that there have been five incidents reported through The Safety Management Information System (SMIS), at stations with gradients of 1 in 500 and nine National Incident Reports (NIRs) where a train has rolled on a gradient at a platform. In the majority of cases these can be attributed to driver error or faulty brakes. The research concluded that removing the 1 in 500 requirement from GI/RT7016 would not present an unacceptable risk.

It is worthwhile noting that twenty four of the stations on the Western route have been opened (or reopened) since 1980 and five of these stations are on gradients steeper tha n 1 in 100. Ebbw Vale station is on a 1 in 73 gradient, falling away from the buffer stops and is a turn -back station at the end of the line.

Disappointingly this doesn't say which is the steepest station on the network, and the data doesn't seem to be fully comprehensive. The steepest one I found on a quick skim was Pontlottyn at 1 in 50.

 

[Questaware]

Can you share your surveys so we can get NR's records corrected from 1:226 and 1:92.

I've pointed out before, the 1:85 is for the gradient rising from Acton Main Line station towards Acton Wells.

I dont have NR records.

That's the wrong route - that is the connection from Acton Wells to the GWML.

https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW is the Dudding Hill line.

This is northwards from Victoria Road. We want southwards.

 

[zwk500]

I dont have NR records.

The 1:226 comes from NR's records.

This is northwards from Victoria Road. We want southwards.

'We want' is quite different to 'the entire project is unviable without'.

 

[Questaware]

All posts here I can see relating to 1:85 are talking about the Acton Main Line - Acton Wells Line (the Poplars), not the Dudding hill line. No station is proposed on that section.

My figure of 1 in 226 is from a rail industry diagram. While errors are not unknown, that would be serious margin of error. The link in Post #5 agrees with this figure.

Looking on google street view suggests Midlands Terrace is not perfectly flat. The houses step up slightly (but noticeably) between each pair. Is this accounted for to get your 1:70?

Finally I have found the RailwayData table: (Check gradients and bridges)

https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW

(going South Victoria Road Bridge 14.10km
14.26km Gradient 1 in 92 down for 80 metres
14.34km Gradient 1 in 510 down for

https://www.railwaydata.co.uk/linefiles/route/?ELR=AWL gives a gradient of up to 1:85.

The comparison with a new station is irrelevant - that is about ensuring that trains won't roll away, not about performance.

This is south of Acton Wells Junction not north of it.

 

[zwk500]

Finally I have found the RailwayData table: (Check gradients and bridges)

https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW

(going South Victoria Road Bridge 14.10km
14.26km Gradient 1 in 92 down for 80 metres
14.34km Gradient 1 in 510 down for

Indeed you have, note the entry above Victoria Road Bridge at 13.78 KM saying 1 in 226 down for 482.8m, meaning that from Victoria Bridge south there is a gradient of 1 in 226 down for c.160m.

 

[Questaware]

All posts here I can see relating to 1:85 are talking about the Acton Main Line - Acton Wells Line (the Poplars), not the Dudding hill line. No station is proposed on that section.

My figure of 1 in 226 is from a rail industry diagram. While errors are not unknown, that would be serious margin of error. The link in Post #5 agrees with this figure.

Looking on google street view suggests Midlands Terrace is not perfectly flat. The houses step up slightly (but noticeably) between each pair. Is this accounted for to get your 1:70?

https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW

Southbound the 1 in 226 figure runs to 160m south of Victoria Road (north side presumably) (falling 0.3 metres)
then 80 metres at 1 in 92 (falling 1.5 metres)
It is then 50 metres to AWJ. (Total fall 2m).

The turnout to the terminating platform would start at 40 metres and the platforms at 50 metres leaving 110m at 1 in 226.
Just about fits
I guess Midlands terrace plus Mildmay rises 2m !

 

[Mr. SW]

[I think the western end of Farringdon Thameslink is something like 1 in 30 (3.33%). About. Sort of.]

Transport for London would have certainly taken advice, but adding a bay platform on the western side of the proposed station would probably involve some modification to the roadbridge as well as the existing infrastructure: See screenshot from personal notes (below)

So it may mean that when they've got their toys out, they may tweak gradients slightly, and shift the platforms slightly northwards from what I've shown here. I've taken the platform length as 120m but that may be inadequate. The southern end of the proposed structure is more-or-less at ground level, by the way. The houses are thoroughly overlooked, too.

 

[DelW]

Southbound the 1 in 226 figure runs to 160m south of Victoria Road (north side presumably) (falling 0.3 metres)
then 80 metres at 1 in 92 (falling 1.5 metres)
It is then 50 metres to AWJ. (Total fall 2m).

I can't see where those figures for the level difference have come from.

160m at 1:226, fall = 160÷226 = 0.708m
80m at 1:92, fall = 80÷92 = 0.87m
Total = 0.708 + 0.87 = 1.578m for those sections.

(Edited to add)
The final section seems to be 113m at 1:510 = 0.222m fall, combined total 1.80m

No idea whether this is good or bad for your argument.

 

[35B]

Finally I have found the RailwayData table: (Check gradients and bridges)

https://www.railwaydata.co.uk/linefiles/route/?ELR=CAW

(going South Victoria Road Bridge 14.10km
14.26km Gradient 1 in 92 down for 80 metres
14.34km Gradient 1 in 510 down for

This is south of Acton Wells Junction not north of it.

As I've acknowledged - and corrected in a subsequent post