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 single and twin core electric cables.
| Identifier | ExFiles\Box 168b\2\ img112 | |
| Date | 14th September 1923 | |
| Revised 14.9.23. SPECIFICATION NUMBER 252. MATERIAL. Electric cable. 600 megohm grade. TYPE OF CORE. Single. CORE SIZE. 84/25. OUTSIDE DIA. .425" Maximum. CONDUCTOR. High Conductivity Tinned Copper Wire. DIELECTRIC. One layer pure rubber and two layers vulcanizing rubber. Total thickness of dielectric not less than .050". The thickness of pure rubber must be at least .007". PROTECTIVE COVERING. Oil-resisting varnished cable cloth applied spirally. Cotton braided, and compounded black. Workshop finish. SPECIFICATION NUMBER 253. MATERIAL. Electric Cable. 600 megohm grade. TYPE OF CORE. Twin. CORE SIZE. 2-40/36. OUTSIDE DIA. .375 Maximum. CONDUCTOR. High Conductivity Tinned Copper Wire. DIELECTRIC. One layer pure and two layers vulcanizing rubber. The radial thickness of the pure rubber shall be at least .005 and the total thickness of the dielectric must be .035 minimum. PROTECTIVE COVERING. Both cores to be taped. One coloured red and the other white. Cores twisted together and wormed circular with cotton. Taped and protected overall with a Ferflex braid of 36 S.W.G., tinned copper wire. | ||