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 4-core, Ferflex braided electric cable.
| Identifier | ExFiles\Box 168b\2\ img094 | |
| Date | 30th November 1927 | |
| ROLLS ROYCE LIMITED. MATERIAL: Electric Cable. 600 Megohm Grade. SPECIFICATION NUMBER: 256. Ferflex Braided. TYPE OF CORE: 4 core CORE SIZE: 2 - 70/36 2 - 40/36 OUTSIDE DIAMETER: .470 Maximum CONDUCTOR: High Conductivity Tinned Copper Wire DI ELECTRIC: One layer pure rubber and two layers Vulcanizing Rubber. Both to be equal in quality to first Grade Plantation Rubber. The vulcanizing rubber shall contain at least 40% Pure Rubber. Mineral fillers only to be used. Proportion by weight of sulphur not to exceed 2.5%. The radial thickness of the pure rubber shall be at least .006 and the total thickness of the dielectric must be .035 minimum. PROTECTIVE COVERING: Each core to be taped. One 70/36 coloured Red and the other White. One 40/36 coloured Black and the other Green. Cores twisted together and wormed circular with cotton. Taped and protected overall with a Ferflex braid of 36 SWG. Tinned Copper Wire. | ||