| Reference | Title | Date |
| RHP146000 | National Coal Board Inspectorate plans of workings | 1957- |
| RHP146000/577 | Plans of workings at Ordnance Survey National Grid Reference NS 26/9266 Harthill Colliery, Hartrigg Colliery, Polkemmet Colliery and Cappers No.2 Pit noted on these plans. | 1958-1966 |