From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Specification sheet for a single core electric cable.
| Identifier | ExFiles\Box 168b\2\ img095 | |
| Date | 30th November 1922 | |
| ROLLS ROYCE LIMITED AERO/GEN/SPEC/SHEET No. 493/1 MATERIAL: Electric Cable. SPECIFICATION NUMBER: 26C TYPE OF CORE: Single. CORE SIZE: 40/36 OUTSIDE DIAMETER: Maximum .187 CONDUCTOR: High Conductivity Tinned Copper Wire DI ELECTRIC: One layer pure rubber, one layer white vulcanising rubber, and one layer black vulcanising rubber, all to be equal in quality to First Grade Plantation Rubber. Vulcanising Rubber to contain at least 40% pure Rubber. Mineral fillers only to be used. Proportion of sulphur by weight not to exceed 2.5%. Total radial thickness of rubber .035". Radial thickness of pure rubber .006". PROTECTIVE COVERING: Single cotton lapped directly over the V.I.R. and soft coloured cotton braiding paraffined overall so that the braiding material will not fray or slip when the cable is cut. Colour of the braid to be as specified on our orders. | ||