Coal Seam Plans

Scope and Content

Coal seam plans showing historic mining information and underground workings at various collieries across the south Wales coalfield.

Administrative / Biographical History

The creation of seam plans is described by Bob Bradley, retired surveyor, on the Healey Hero website:

"Continual rolling and unrolling usually took its toll, with the paper cracking and flaking, ultimately with the loss of accuracy and maybe some detail of the plan. Sometimes thin wooden slats were fastened to the ends of the plan to assist with the rolling up and as an added protection. In addition quite a few lead weights, usually covered with leather and seam stitched were necessary to hold the plan reasonably flat when unrolled. When a new plan required making, it was a colossal task, as everything from the surface features, including copyhold areas etc, and the mine workings of the past were delineated on it. This lead to much of the old work being left off, when a new plan was made in order to save time. Unfortunately this also lead to other bits of valuable information being left off as well, such as levels, gradients, faults with throw, old staple pits, boreholes etc. These old plans were very cumbersome and large drawing tables were necessary to allow work to be carried out on them. The old plans would generally have different coloured inks to depict each quarter of a year’s work and would also have the area worked coloured. Also designated would be the surface boundaries of freehold or copyhold areas, both using a watery colour wash, which again did not help for accuracy, as the paper and linen would tend to stretch, buckle or shrink depending upon the material."

(Source:, accessed 25 Feb 2019)


An artificial arrangement has been imposed on the collection, with plans arranged by the valley/area that they depict. The valleys/areas have been arranged alphabetically.