| Reference Number | TPC/5/7/40 |
| Title | Wiring Diagram - National Upper Hoist System - Masking Screen |
| Level | Item |
| Date | 05 April 1974 |
| Description | Evershed Power-Optics Ltd drawing number W6922 issue A. Drawn by C A W. |
| Extent | 1 drawing |
| Series | Evershed Power-Optics Ltd Drawings |