Distance of Structures on a Line

[Andy873]

I talked about this briefly a while ago and wanted to re-visit the question of mileages.

Looking at the railway data site and comparing the distances with my working timetables from the 1950's and '60s there's a difference of around 11 chains (11 less on the newer mileage).

Now I make 11 chains roughly the distance from what was Rose Grove West box to the West junction itself.
Looking at the railway data site, Station Road bridge just before what was Padiham station is marked at 1 mile 40 chains. From this bridge to the station's platform is 2 chains giving the station at 1 mile 42 chains.

If we add on the 11 chains it marks the station at 1 mile 53 chains, exactly as my WTT's state.

I can only think that the modern mileage is from when the area was re-signalled as part of the Preston power box upgrade in 1973, and that the newer milage then actually starts from the physical junction as the signal box has gone, in other words the difference of 11 chains fewer? Do you think that's right?

And as for my list of bridges on my old branch, what distances would be best to use? those from say the '50s and '60s or the newer ones?

And there's one other thing, the railway data site shows Padiham viaduct (west of the former station) at 1 mile 55 chains which I know is correct from the 1960's - the thing is - why has this distance not been changed to 1 mile 44 chains? any ideas?

We also have something similar on the East Lancs line, I was trying to find out where bridge 56 was, it's the railway bridge that spans the Leeds & Liverpool canal just to the west of Rose Grove station. In 1986 this was referenced as being between 20 and 20 and a quarter mile posts, however when you look on the old OS maps it's actually between mile posts Manchester 26 and 27. Did BR put in place the newer miles posts?

 

[Mr. SW]

Check, check, and check again. The railway data site does have errors, but there are errors in original documents as well. One thing I've found useful is cab ride videos. You can see the mileposts (most of the time) and these can be matched up to maps, plans and Google Maps, but beware of mileage changes caused by diversions, rebuilds and historical company boundaries. I was recently watching a cab ride video from Aylesbury up to Claydon LNE junction (before the changes) and the mileages were all over the place due to old company ownerships: Metropolitan/Joint/Great Central/Wartime Spur/LNWR. Further Example: Distances on the LSW mainline from Waterloo appear to be measured from the historical boundary with the SER on the bridge crossing Waterloo Bridge Road and not the modern platform ends.

 

[zwk500]

It would be quite rare to remile a line, especially after the 60s. If a junction was moved by 11 chains, normally it'd just have the new chainage listed and the nominal 'zero' left where it was. Stations like Euston even have negative mileages.
However, confusion can occur if minor realignments take place - there's lots of 'short miles' around, or if a line had connections at both ends to different zeros, especially where divisional/company boundaries changed.

 

[Bevan Price]

It would be quite rare to remile a line, especially after the 60s. If a junction was moved by 11 chains, normally it'd just have the new chainage listed and the nominal 'zero' left where it was. Stations like Euston even have negative mileages.
However, confusion can occur if minor realignments take place - there's lots of 'short miles' around, or if a line had connections at both ends to different zeros, especially where divisional/company boundaries changed.

The question of mileages can be very complicated. The whole mileage in "North / Central" Lancashire area has seen several changes. Currently I think the zero point is at Farington Curve Jn. for Preston to Blackburn, Rose Grove and Burnley Manchester Road / Colne, etc.

Until the Marples/Beeching closures, several other mileage series applied. For example Accrington to Rose Grove and Gannow Jn had a zerp point at Manchester Victoria (via Bury), whilst Gannow Jn to Todmorden had a zero point at Manchester Victoria via Rochdale. Blackburn To Accrington had a zero point at Manchester Victoria via Bolton, whilst parts in the Lostock Hall / Bamber Bridge area had a zero point at Liverpool Exchange. I am not sure when things changed to the current arrangement.

Also, when platforms are shortened, that can move the centre point of a station by a few chains. In addition, some Working Timetables do not always make it clear if the listed mileages apply to stations, signal boxes, or the actual junction points.

 

[Andy873]

Check, check, and check again. The railway data site does have errors, but there are errors in original documents as well.

Wise words indeed, I even re-check my own facts about the branch line.

It would be quite rare to remile a line, especially after the 60s. If a junction was moved by 11 chains, normally it'd just have the new chainage listed and the nominal 'zero' left where it was. Stations like Euston even have negative mileages.

Until the Marples/Beeching closures, several other mileage series applied. For example Accrington to Rose Grove and Gannow Jn had a zerp point at Manchester Victoria (via Bury), whilst Gannow Jn to Todmorden had a zero point at Manchester Victoria via Rochdale. Blackburn To Accrington had a zero point at Manchester Victoria via Bolton, whilst parts in the Lostock Hall / Bamber Bridge area had a zero point at Liverpool Exchange. I am not sure when things changed to the current arrangement.

The zero point, and a great point (no pun intended!).

Unlike many lines around Lancashire who's zero point was Manchester Victoria, this line being a later one was actually measured from Rose Grove. I assumed that the zero point was probably Rose Grove West box, but decided to revisit that idea.

From mile post 1 (on the branch line) I measured back and found that bridge No. 56 on the East Lancs line (between Padiham junction and West signal box) was the zero point. This bridge carries the lines over the Leeds & Liverpool canal. I get the zero point to be the western side (Accrington side) of that bridge.

There seems to be three different measuring points for different reasons...

The sectional appendix measures box to box.
The mileage for the mile posts run from the canal bridge (No. 56).
And then there's the structures on the branch such as bridges.

I measured from bridge No 1 (Molly wood overbridge) back towards the junction and I came out roughly 100 or so feet short of the outer home signal that guarded the junction?

I know one bridge mileage on the railway data site is correct. Bridge No. 13 (Padiham viaduct). Back during the closure meeting from 1964 BR management explain the down line was to be removed from the Blackburn end all the way to 1 mile and 55 chains of Rose Grove. That location was Padiham viaduct.

As this line had to climb up a 1 in 40 gradient to the junction, is it possible that originally the outer home signal was further back than I can see on the 1909 map and for operational reasons it was moved closer to the junction?

Why wouldn't you simply use the mile posts to measure a bridge's location?

 

[zwk500]

Also, when platforms are shortened, that can move the centre point of a station by a few chains. In addition, some Working Timetables do not always make it clear if the listed mileages apply to stations, signal boxes, or the actual junction points.

It can, but the station's mileage will often not be updated

I measured from bridge No 1 (Molly wood overbridge) back towards the junction and I came out roughly 100 or so feet short of the outer home signal that guarded the junction?

Remember that when 1 Chain = 22 yards = 66 feet, so when rounding to the nearest chain there's a reasonable amount of margin of error.

Why wouldn't you simply use the mile posts to measure a bridge's location?

Typical Bridge numbers are quoted with a mileage. I suspect for monitoring purposes it was easier to have an indexed list of how many bridges there were, and the actual position was a separate concern. A bridge being located at mile 10 might be the first bridge on a line or the 20th.

 

[Andy873]

Remember that when 1 Chain = 22 yards = 66 feet, so when rounding to the nearest chain there's a reasonable amount of margin of error.

With that in mind, I decided to try to measure a different way.

Going west along the branch I found MP1, from there I measured to the next bridge along (No. 5). The distance recorded from the data and my measurements concur at around 1 mile 2 chains.

The next bridge going west was very close to bridge 5, the data says it's 12 chains away but I measure it at 6.5 chains - clearly there's something wrong with the data.
I could be out a few feet but not nearly 400, surely not?

Maybe I might have to measure each bridge distance based on the mile posts.

 

[zwk500]

With that in mind, I decided to try to measure a different way.

Going west along the branch I found MP1, from there I measured to the next bridge along (No. 5). The distance recorded from the data and my measurements concur at around 1 mile 2 chains.

The next bridge going west was very close to bridge 5, the data says it's 12 chains away but I measure it at 6.5 chains - clearly there's something wrong with the data.
I could be out a few feet but not nearly 400, surely not?

Maybe I might have to measure each bridge distance based on the mile posts.

It does seem there might be an error in either the recorded distances or the original surveying. 400ft is too much to account for anything like the nominal centreline, I'd have thought.

 

[etr221]

An interesting thing I read was regarding rhe surveying being done for HS2, and their use of a new 'snake' projection tailored for the line for drawings - which reduced the distance (as measured off them) from London to Birmingham by (IIRC) about 20m - certainly a noticeable amount, compared with those using a national projection.

 

[Andy873]

An interesting thing I read was regarding rhe surveying being done for HS2, and their use of a new 'snake' projection tailored for the line for drawings - which reduced the distance (as measured off them) from London to Birmingham by (IIRC) about 20m - certainly a noticeable amount, compared with those using a national projection.

Interesting, so even now there are differences when it comes to measuring.

Speaking of measuring, I decided to measure the "structures" (mainly bridges) on the branch line. Although it's laborious it does show the railway data is wrong, I could only concur with two bridge distances.

It did bring up one thing, the actual point where the down line was lifted to. It's the Padiham station home signal on the other side of the viaduct. I've always know it was somewhere close to the viaduct - a logical place to stop at?

You can see the signal position here:

Georeferenced Maps - Map images - National Library of Scotland

 

[Bevan Price]

Within Network Rail, historic records are knwn to exist for assorted closed railways, showing the locations / distances .of just about every feature - bridges, crossings, culverts, stations, signal boxes, etc. I have seen some such information from Scotland and it is very detailed. Presumably similar information exists amongst Civil Engineering records for North & Central Lancashire. All you need to do is try and locate those records (if they have not been destroyed) - and get permission from Network Rail to copy them.

 

[edwin_m]

Within Network Rail, historic records are knwn to exist for assorted closed railways, showing the locations / distances .of just about every feature - bridges, crossings, culverts, stations, signal boxes, etc. I have seen some such information from Scotland and it is very detailed. Presumably similar information exists amongst Civil Engineering records for North & Central Lancashire. All you need to do is try and locate those records (if they have not been destroyed) - and get permission from Network Rail to copy them.

Possibly now transferred to National Highways, who inherited the non-operational rail assets of British Rail.

 

[Andy873]

Within Network Rail, historic records are knwn to exist for assorted closed railways, showing the locations / distances .of just about every feature - bridges, crossings, culverts, stations, signal boxes, etc. I have seen some such information from Scotland and it is very detailed. Presumably similar information exists amongst Civil Engineering records for North & Central Lancashire. All you need to do is try and locate those records (if they have not been destroyed) - and get permission from Network Rail to copy them.

Possibly now transferred to National Highways, who inherited the non-operational rail assets of British Rail.

Thanks for the possible sources regarding the structures on the line, I may ask them.

Question - Could a mile post be wrongly placed on an OS map?

All my measurements (regarding the station locations) come out exactly as I expected them, that is 11 chains less than the working timetables - except for Great Harwood station! The mile posts are well defined except for MP 4, the dot is missing, and Great Harwood is on the 5 mile post section.

Between MP 4 & 5 the track goes on a long left hand curve.

Is it possible MP 5 is out by two or three chains? as that's what I'm getting for Harwood station based on MP 5's map location.

 

[edwin_m]

Thanks for the possible sources regarding the structures on the line, I may ask them.

Question - Could a mile post be wrongly placed on an OS map?

All my measurements (regarding the station locations) come out exactly as I expected them, that is 11 chains less than the working timetables - except for Great Harwood station! The mile posts are well defined except for MP 4, the dot is missing, and Great Harwood is on the 5 mile post section.

Between MP 4 & 5 the track goes on a long left hand curve.

Is it possible MP 5 is out by two or three chains? as that's what I'm getting for Harwood station based on MP 5's map location.

Not unknown for mileposts to be out. The easy way to check would be to measure the distance between them on the map!

If any of the bridges survive, they may have the Engineers' Line Reference (three letters sometimes followed by a digit) and the structure number and/or miles and chains stencilled on them.

 

[Andy873]

If any of the bridges survive, they may have the Engineers' Line Reference (three letters sometimes followed by a digit) and the structure number and/or miles and chains stencilled on them.

Sadly all the bridges on the five mile section have long since gone.

The only possible suggestion as to why I'm 2 chains out is that around 1905 the second station on the line going East (Simonstone) had its platform length increased by 2 chains (at the eastern end). Now if you're measuring east to west that would make Great Harwood station that bit further away.

The working timetables seem to be more concerned about distances from junction to junction and the station distances in between.

Do you think the lengthening of two chains at Simonstone is the reason why I'm 2 chains out at Harwood station?

 

[Bevan Price]

Possibly now transferred to National Highways, who inherited the non-operational rail assets of British Rail.

Found some of this data is actually on line at the Railway Data site, but for the North Lancashire Loop, it only covers Rose Grove to Padiham

https://www.railwaydata.co.uk/linefiles/route/?ELR=PRG&filter=Crossings

 

[Andy873]

Found some of this data is actually on line at the Railway Data site, but for the North Lancashire Loop, it only covers Rose Grove to Padiham

Thanks Bevan, that's the data which in most cases is clearly wrong.

Question please, That site covers Rose Grove to Padiham under line code PRG, the rest of the branch is under code NLC - Before the NLC section closed, would the PRG part have been under the NLC line code?

 

[edwin_m]

Thanks Bevan, that's the data which in most cases is clearly wrong.

Question please, That site covers Rose Grove to Padiham under line code PRG, the rest of the branch is under code NLC - Before the NLC section closed, would the PRG part have been under the NLC line code?

Usually the ELRs don't change, because that would make it very difficult to track back historic records to a specific location (and the historic records may relate to infrastructure that is still present). You see changes of ELR apparently in the middle of nowhere, simply because there was once a junction there and one of the ELRs continued on the route that is now closed. There are also ELRs that disappear and reappear somewhere else because the section in betwen is closed.

Having said that, Rail Map Online only shows a short freight branch at Padiham, so I can't see any obvious reason the ELR should change here. And often the way the ELRs are assigned is down to the whim of whoever is doing it for that time and place, so it's possible someone might have decided to change it for no particular reason.

 

[zwk500]

Having said that, Rail Map Online only shows a short freight branch at Padiham, so I can't see any obvious reason the ELR should change here. And often the way the ELRs are assigned is down to the whim of whoever is doing it for that time and place, so it's possible someone might have decided to change it for no particular reason.

When did ELRs start to be allocated to this part of the network? If the line had closed beyond the power station by then it would be possible a second ELR was included to denote the closed section of line.

 

[Bevan Price]

Thanks Bevan, that's the data which in most cases is clearly wrong.

Question please, That site covers Rose Grove to Padiham under line code PRG, the rest of the branch is under code NLC - Before the NLC section closed, would the PRG part have been under the NLC line code?

Sorry, do not know the answer
Have you visited the excellent sites by Phil Deaves:

ELR-N

Engineers' Line References (ELR) in range NAA to NZZ.

www.s-r-s.org.uk

or the Signalling Record Society

RailRef LY

RailRef information for company line LY, Lancashire & Yorkshire Railway.

www.s-r-s.org.uk

They both contain information about ELRs

 

[bramling]

Within Network Rail, historic records are knwn to exist for assorted closed railways, showing the locations / distances .of just about every feature - bridges, crossings, culverts, stations, signal boxes, etc. I have seen some such information from Scotland and it is very detailed.

Out of interest, would you be able to give a bit more detail on the latter? I have bridge registers for much of Britain, but pretty much nothing for Scotland, and have been hunting same or similar for some while. My interest lies mainly with closed lines.

 

[Bevan Price]

Out of interest, would you be able to give a bit more detail on the latter? I have bridge registers for much of Britain, but pretty much nothing for Scotland, and have been hunting same or similar for some while. My interest lies mainly with closed lines.

I will have to seek permission from the source.

 

[Andy873]

Have you visited the excellent sites by Phil Deaves:

Thanks Bevan, no I didn't know about those sites. I note it lists all the signal boxes that were extant at one time or another, that is, pre 1913.

 

[bramling]

I will have to seek permission from the source.

Okay thanks for that.

 

[Bevan Price]

Okay thanks for that.

Please send me an email address to which I can send you the files.

[email protected]

I will send the files in batches; my email gets overloaded if i try to include too many attachments in a single message.
They mostly cover only the GNSR lines in Scotland including closed branch lines.

 

[Andy873]

I will send the files in batches

This is why I like this forum so much, many of you are willing to help!

With regards to my original questions:

Compare these two maps, the first one is from 1909:

Georeferenced Maps - Map images - National Library of Scotland

And this one from 1891 - look for the railway at the top of the sheet:

View map: Ordnance Survey, Lancashire LXIV.5 (Burnley; Habergham Eaves; Hapton) - Ordnance Survey 25 inch England and Wales, 1841-1952

Both show Padiham junction connecting to the East Lancs line. You will note that on the 1891 map, the signal box is between the physical junction and the Leeds & Liverpool canal railway bridge. The later maps shows a newer signal box and it has been moved further East on the other side of the canal bridge.

The signal box from the 1891 map is half way between the junction and the Western end of the canal bridge - which I judge to be the branch line's zero point. Fortunately for me, this branch did have its own zero point rather the being measured from Manchester Victoria, which helps in measuring structure differences.

As mentioned to me, boxes can be moved, junctions change and stations altered...

Now let's compare different measurements for different purposes:

1. Station to station - Rose Grove to Blackburn is 10 miles.
2. The physical length of the branch was 9 miles, 00 chains.
3. The sectional appendix measures signal box to signal box - by the late 1890's both signal boxes guarding the two junctions either end have moved further apart giving 9 miles 13 chains.
4. Finally, Simonstone station's platforms were extended East by two chains. This means Simonstone is now closer to the East junction.

Conclusion:
With the newer Rose Grove West box being further East and technically a "new" starting point further East away from this box I can quite easily account for the 11 chains difference between my measurements and the later official ones.

With the platform extension of 2 chains at Simonstone, it puts the distance of Great Harwood station up to 13 chains more, which is what I get it to be.

Milestones - comparing the location of MP 2 and 9 on both the 1890's map and the 1909 one, they haven't moved. These MP's are what I've based my structure distances on.

It simply comes down to how you want to measure a line.