The Signalling Record Society
Railway Mileposts & Mileages
This page should be regarded as “Work in Progress”. The webmaster will welcome additional information for this page.
Signal Fact 15
E A Cowper invented the railway detonator in 1841. Used to protect trains that had come to a stand unexpectedly.
First adopted by the Great Western Railway, the other companies soon followed suit.
Detonators are still used today.
Locations and mileages shown in the RailRef listings on this web site are intended to give an overall guide to the scope of each Line Code and allow identification of the lines in published railway atlases. They are not guaranteed to be a complete list! Mileages given in the lists are generally to the nearest chain and the datum (zero point) used is quoted where it is not immediately obvious within the Line Code.
Within each of our RailRef Line Codes, the mile post mileage is given for the locations listed where it is known or can be reliably calculated. Official sources have been used as the basis where available but it must be appreciated that official records are sometimes in error. Some instances of “error of mileage” quoted in railway industry documentation are not correctly that but represent historic positions that have been forgotten with the passage of time.
Quoted mileages at a location may vary a little over the years as junctions are remodelled or a different average position is taken within more complex junctions or errors are corrected. Some junctions have 'upped sticks' and moved quite some way from their original position when major alterations have occurred or an older junction name has been reused.
Datum (Zero) Points
Zero points are often taken from a company boundary or a junction with a 'main' line.
Terminal station mileages are usually calculated from the buffer stops at the concourse end of the platforms or from the back of the concourse. In some instances they are calculated from the railway company's boundary beyond the concourse. Station reconstructions have led to several terminals no longer having a zero point on the present day railway.
Intermediate stations are usually calculated at the “mid point” and thus can appear to move when platforms are lengthened (or shortened) and a new mid point is calculated. Bear in mind that a BR Mark 1 carriage at 63 feet over buffers is almost 1 chain in length so a four coach platform extension at one end will move the calculated point by 2 chains!
Changes Over Time
During the construction of these pages it has become increasingly clear that many milepost mileages have altered over the years and not just because of a change of ownership. The latter part of the 20th century saw great reduction in the frequency of this.
Sections of railway have been 'remiled' either when substantially altered or following the discovery of errors in the distances set out. The Midland Railway undertook a major 'remiling' exercise affecting most of their lines early in the 20th century and John Gough's notes about this can be read here. Other railways that have carried out similar or major remiling exercises at some stage include the Great Northern Railway, North Eastern Railway and the South Eastern Railway.
Evidence of early 'remiling' can often be found by comparing 19th century Ordnance Survey maps against modern records although it does seem that the Ordnance Survey may have taken some time to catch up with changes. Perhaps this is why they later dropped quoting the actual mileage and origin on their maps. Notes about milepost policy and large scale changes appear in the preamble to each company page where appropriate and a note is placed under each Line Code where a more localised change of milepost mileages is known to have taken place.
Parliament was clearly minded to bring the railways into the same general situation that applied to Turnpike Roads and Canals, namely that they should display distance markers that would allow their customers to verify that they were being charged correctly. Clauses were included in the sections of the various Acts authorising the railway to charge Tolls that required the erection of markers at quarter mile intervals. This requirement was enforced by only allowing Tolls to be collected if the markers were present and visible. Each company was left free to decide preisely how this was to be done and where it measured from with the result that practices varied.
The requirement to erect mile posts then appeared in the Railways Clauses Consolidation Act 1845 and Railways Clauses Consolidation (Scotland) Act 1845. These required that:
“The Company shall cause the Length of the Railway to be measured, and Milestones, Posts, or other conspicuous Objects to be set up and maintained along the whole Line thereof, at the Distance of One Quarter of a Mile from each other, with Numbers or Marks inscribed thereon denoting such Distances.”A further provision was:
“No Tolls shall be demanded or taken by the Company for the Use of the Railway during any Time at which the Boards hereinbefore directed to be exhibited shall not be so exhibited, or at which the Milestones herein-before directed to be set up and maintained shall not be so set up and maintained”.
The passing of the 1845 Act allowed subsequent acts authorising new and extended railways to refer to the 1845 Act rather than simply repeating the clauses ad nauseum.