| Description | The file contains correspondence and enclosures, file notes and drawings and operating manuals mainly relating to making and installing power flying equipment and specifically mentions rope brake micro switches, patchboards, isolator switches, thermistors, emergency stops, Upper Theatre hoisting / scenery hoists, a control cubicle for the Lower Theatre, the Upper Theatre grid, point hoists and masking screens, wagons and wagon drives, revolve control perch, fly tower grid, control console, cabling for upper scene hoists, hoist wiring, hoist motors, resetter gears for Lower Theatre, power flying panel, hoist control pot assembly, hoist / wagon parameters, drive equipment, drum and hoist control systems, communication panels, the colour of the control desks, Lower Theatre windlasses, scenery hoist desk, curtain position indicator, external cabling, control room windows and additional electrical wiring. The Evershed Power Optics contract and sub-contracts placed with Hall Stage Equipment Ltd are also covered, as are tests, delays and extra costs. Correspondents include Theatre Projects Consultants Ltd, Evershed Power Optics Ltd, Hall Stage Equipment Ltd, Mole-Richardson (Stage & Studio Engineering) Ltd, Flint & Neill Ltd, Sir Robert McAlpine & Sons, Molynx Ltd, British Ropes Ltd and Reynolds Ltd. Items include a schematic 'Lower Theatre: Power Flying Major EPO Routes', drawing number Y26703 'Control Cublic Room - Lower Theatre National Theatre'; a blown up section of a drawing 'Patchboard - Power Flying - Lower Theatre - National Theatre' showing full sized controls and fonts [possibly from Everdshed Power Optics Ltd drawing number X12617]; two copies of drawing number X 12617 'Diagram of Patchboard Showing Numbers Lower Theatre - National'; sketches 'Fig 1: Diagram of Expected Interconnections in Lighting Hoists' and 'Fig 2: G.A. of Three Point Hoists for Lower Theatre to Assist HSE Tie Up External Details'; a chart titled 'National Theatre Hoist Control Data'; a list / chart of completed drawings by Hall Stage Equipment Ltd; a photocopy of an instruction manual 'Lower Theatre Panel operation'; sketches and calculations by Hall Stage Equipment Ltd - 'National (Lower) Theatre Point Hoists - Resetter Gearing', 'National (Lower) Theatre Power Flying Resetter Gearing' and 'National (Lower) Theatre Wagon Drives - Resetter Gearing'; sketch number L0901/SK 'National (Lower) Theatre - Power Flying Proposed Modification to Head Pulley Mounting', a list of control panel functions for the Lyttelton Theatre and a report on hoist stopping tests. Original card folder disposed of. '2 Power Flying Nov 73-Sept 75' was written on the front, and 'National Theatre File 904/5B5 1-11-73 Powered Flying Equipment' was written on the spine. |