Zero point for mileage on the Ungerground.

[chrisb]

The Wikipedia article for Ongar station says that "the eastern buffers remain the point from which all distances on the London Underground are measured.". link

Is it true ? If so, how does the mileage (or kilometerage) on lines other than the Central get calculated ?

[Colin]

Shockingly for a Wikipedia article, it is actually true!

Not sure how other lines are worked out from Ongar though....

[Chris M]

I think for the District it is worked out such that Mile End has the same value as Mile End on the Central. The south side of the Circle shares the same values as the District, the Picc the same values on the shared section with the District. The Met will then take the same values as the Circle, the Jubilee the same values as the parallel part of the Met, the Bakerloo will have Baker Street as the same value as the Jubilee from when it had the Stanmore branch. I guess the Victoria will have the same values as the Picc at Finsbury Park, and teh Northern the same values as the Picc around King's Cross. The Waterloo & City will not have originally used Ongar-based distances, but I don't know if it does now (if it does, I guess it will take the Central's value at Bank as its datum).
The East London will have taken values from the District at St Mary's Curve, but I don't know if it still does?

[gantshill]

I know that I have seen online somewhere details of how the kilometre figures transfer from one line to another.
I think it was on Clive's Underground Lines Guide.
From recollection it is mainly where there are physical connections between lines. Although the transfer to the District at Mile End is an exception to that rule.

[Chris L]

There is a point of origin sign on the wall on the platform beside the ticket office door at Ongar.

[castlebar]

@ Chris L

I remember services from Marylebone were measured from Sheffield (still might be), even though all the track through Loughborough etc, is long gone

[littlejohn]

I think there is a reference to this in the LT Museum (maybe in the current 'Hidden London' exhibition?) together with a '0.o' plate. It also gives the distance from Ongar to Amersham/Chesham.

[PiccNT]

Diamond Geezer reported on this a while ago.

diamondgeezer.blogspot.com/2018/07/look-back-from-ongar.html

[Chris M]

According to the information on CULG, it seems I was slightly wrong. Mileage transfers from the Central to the District at Mile End, to the Picc at Barons Court, then to the Met at Rayers Lane. The Circle and H&C then takes their mileage from the Met at Baker Street junction, which seems an odd way of doing it to me. I don't know how authoritative a source that is though.

On the Waterloo and City the mileage is measured from the stops in Waterloo depot. The DLR doesn't use Ongar-based distances either, but it doesn't say what datum is used (or indeed whether there is only one).

[chrisb]

To answer my own question, the kilometerage map is here.  The transfer points for each line are underlined.

Obviously, there is no real significance to the distances other than on the Central.  For example Morden Depot is 'closer' to Ongar than Woodford is.

[John Tuthill]

Dec 19, 2019 19:27:26 GMT chrisb said:

To answer my own question, the kilometerage map is here.  The transfer points for each line are underlined.

Obviously, there is no real significance to the distances other than on the Central.  For example Morden Depot is 'closer' to Ongar than Woodford is.

[spsmiler]

Where was the zero point before Ongar had this honour bestowed upon it?

oh and why Ongar?

[Chris M]

Why Ongar? Probably because it was unambiguously easternmost and with less likely prospects of an extension to any line taking that crown from it. Extensions north and west (and northwest) are/were certainly more likely than extensions east and while southern extensions were not massively likely, the southern terminus of LU's lines are all firmly within the urban area unlike Ongar.

[norbitonflyer]

Dec 20, 2019 0:05:07 GMT spsmiler said:

Where was the zero point before Ongar had this honour bestowed upon it?

oh and why Ongar?

As I understand it, there was no common zero point before it was standardised across the network on Ongar.

Once the transfer points are established, there could only be two places that could be chosen as the zero point if negative numbers were to be avoided - one was Ongar and the other was (I think) Chesham. The latter, with distances measured in the opposite direction to that chosen, might have been a problem if extension beyond Amersham towards Aylesbury were ever contemplated, as indeed it was as part of an earlier plan for Crossrail.

[35b]

Dec 20, 2019 7:44:02 GMT norbitonflyer said:

Dec 20, 2019 0:05:07 GMT spsmiler said:

Where was the zero point before Ongar had this honour bestowed upon it?

oh and why Ongar?

As I understand it, there was no common zero point before it was standardised across the network on Ongar.

Once the transfer points are established, there could only be two places that could be chosen as the zero point if negative numbers were to be avoided - one was Ongar and the other was (I think) Chesham. The latter, with distances measured in the opposite direction to that chosen, might have been a problem if extension beyond Amersham towards Aylesbury were ever contemplated, as indeed it was as part of an earlier plan for Crossrail.

...especially as the Met used to go beyond Amersham, whereas Ongar was always a terminus.

[roythebus]

And the District used to go to Sarfend!

[countryman]

Jan 3, 2020 10:13:03 GMT roythebus said:

And the District used to go to Sarfend!

Although there were through trains from Ealing Broadway powered by District locomotives, weren't these essentially LTSR trains?