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 for a twin core, metal braided electric cable.
| Identifier | ExFiles\Box 168b\2\ img079 | |
| Date | 27th September 1922 guessed | |
| ROLLS ROYCE LIMITED. MATERIAL. Electric Cable. 600 Megohm Grade. SPECIFICATION NUMBER. 254. Metal Braided. TYPE OF CORE Twin CORE SIZE. 2 - 90/36 OUTSIDE DIAMETER .422 CONDUCTOR High Conductivity Tinned Copper Wire DI ELECTRIC One layer pure and two layers vulcanizing rubber both to be equal in quality to First Grade Plantation Rubber. Vulcanizing Rubber to contain at least 40% Pure Rubber. Mineral fillers only to be used. Proportion by weight of sulphur not to exceed 2.5% PROTECTIVE COVERING. Each core taped. One core coloured red and the other white. Cores twisted together and wormed circular with cotton. Taped and protected overall with a braid of 36 SWG. Tinned Copper Wire. | ||