| Reference Number | TPC/3/13/3 |
| Title | Quadruple Up-Down Detector with Dead Space ~CD245 |
| Level | Item |
| Date | c 1980 |
| Description | Evershed Power-Optics Ltd drawing number V4506. |
| Extent | 1 drawing |
| Series | The National Theatre Point Hoists in the Olivier and Lyttelton Theatres: Operating and Maintenance Instructions |