These geographically-accurate diagrams were prepared by the Midland Railway for internal purposes, with the original paper documents printed on 370 x 500mm sheets (nearly the same as the modern B3 size).. Alterations and amendments were recorded continuously, and the diagrams were updated at regular intervals.
There are no known documents by British railway companies that are as comprehensive, detailed , or long-lived as these MR diagrams.
This collection is scanned from the originals, and contains detailed diagrams for a selection of dates over the 1873 - 1923 period, and also many of the handwritten Alterations sheets, from 1875 to 1926, which sometimes include sketch plans to further explain the alteration or addition concerned.
Index Plans, covering the whole of the Midland Railway's network, are provided for 1895, 1909, and 1920. They indicate the areas covered by each of the numbered detailed diagrams, of which there are a total of 593 grouped in albums by Sheet number, for convenience. The geographical area covered by each numbered distance diagram changes slightly over time, in line with the development of the Midland Railway's wholly- and jointly-owned network, and those lines over which it had running powers.
The Midland Railway also became the owner of the Ashby, Cromford, and Pinxton Canals. Accordingly, these also have their Distance Diagrams.