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).
Test report on St Helens Cable & Rubber Co's high-tension and wiring cables, detailing high voltage breakdown and chemical effects.
| Identifier | ExFiles\Box 168\1\ img112 | |
| Date | 23th May 1932 | |
| RR 238 (150 BKS.) (DB{Donald Bastow - Suspensions} 451-8-12 24) MP 306975 Copy for file. X6117 (varnished covered L.T. cables) ROLLS-ROYCE LTD. INSTRUCTIONS. To: H.E.W Order No. Customer's No. Tests of Messrs St Helens Cable & Rubber Co's HT & Wiring Cables High Voltage Breakdown Test. 23/0076. Single conductor, varnished cambric taped, cotton braided, special black polished. Breakdown Voltage 20,700 peak. 70/0076. Single conductor thin V.I.R varnished, cambric taped, cotton braided, special black polished. Breakdown Voltage 20,530 peak. 40/0076. Single conductor, thin V.I.R varnished cambric taped cotton braided, special black polished. Breakdown voltage 20,530 peak. 4D/0076. Round, three core. Thin V.I.R varnished cambric taped. cotton braided, special black polished. Wire to wire breakdown voltage 13,800 peak. H.T. Flex. Failed at breakdown. Chemical Effects. 100 Hours in Petrol. 2D/0076. Finish good. Covering slightly hardened but not cracked. The covering was not penetrated. 4D/0076. (Three core). Finish good. The covering was penetrated & the rubber insulation slightly swollen. The external covering was very hard & cracked when bent. 4D/0076 (Single core). Finish good. Covering slightly hardened, but not penetrated. 70/0076. Finish good. Covering hardened & penetrated. HT Flex. Covering not penetrated, the diameter of the covering increased by .160 after 6 hours, but did not increase further. The Petrol absorbed was 8.86 grams. Signed: Cant'd This Sheet must be filed on completion of the work. | ||