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).
The investigation and testing of high tension cables for standardization.
| Identifier | ExFiles\Box 167\3\ img141 | |
| Date | 25th January 1939 | |
| To By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to By/RD. re High Tension Cables. Owing to the comparatively short running life to be obtained from the B.I. grade 6/3 High Tension Cable, an improved type, made by Messrs. Johnson & Phillips, was standardised for the Bentley and Phantom III cars on the 2.6.37, this was followed by a sheet for the 25/30 H.P. type car on the 8.7.37. Examination of the first five reels of the new cable proved the outside diameter over the rubber cover to be oversize, varying from .004" to .016". On taking the matter up with Johnson & Phillips they admitted that they could not work inside the limits of our specification, namely .266 to .276 inches. They had of course in the first place, agreed to work to our specification. By ordering oversized Ernoid ferrules the cable was made usable on the Bentley and Wraith. It is however, impossible to thread oversized wire through the P.III tubes. We then approached the B.I. and they promised to supply a cable similar in quality to the Johnson & Phillips and to work to our limits. We have subjected samples of this cable, called B.I. Neoprene, to all our tests and we find it to be in every way as good as the Johnson and Phillips. The following running tests have been carried out with excellent results :- Two samples each completed 250 hours on the ionization rig, without any signs of cracking. 156 hours in W.III No.4.No.5 (Test Bed). Unit No.5 in 8.B.V. (France) 4,242 miles Unit No.7 in 8.B.V. (France) 11,000 miles. Unit No.5 in 28.G.VI. 600 miles. From the above, we have no hesitation in starting a standardisation sheet for B.I. Neoprene (Taped Finish) | ||