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).
Letter discussing the pros and cons of different insulation materials like bakelite and micanite for various components.
| Identifier | ExFiles\Box 180\M6\ img038 | |
| Date | 10th July 1928 | |
| REG. TELEGRAPHIC ADDRESS: "ROYCE, WEST WITTERINGHenry Royce's home town" TWO WORDS ONLY TELEPHONE: CHICHESTER 210. STATION: CHICHESTER—7 MILES. PASSENGER & GOODS: L. B. & S. C. RLY. "ELMSTEADHenry Royce's home in West Wittering," WEST WITTERINGHenry Royce's home town, NR. CHICHESTER. Copy to Mr. Claremont. " Mr. Hulley. " Mr. Allcock. Dear Mr. Bentley, INSULATION. I thought you said bakelite did not give satisfaction because it tracked, and that micanite was better. We find bakelite does nearly all our RR. work, although we agree it tracks. I am pleased to hear you prefer bakelite as made up with paper and woven cotton sheets. I am quite agreed that for your voltages bushes and washers of the earlier times are not satisfactory in any materials. You would have to use very thick washers with bushes passing right through the washers, but this type of insulation should be avoided. We are therefore left with the bakelite carrying bodily the part to be insulated, or the square tube and clamp scheme. Both of these you are using extensively, and perhaps only the details and proportions of each carefully allotted to its own sphere. COMMUTATORS - ~~exclusively~~ use mica or micanite. BRUSH HOLDERS - I think should be square tube and clamp. CONNECTOR TERMINALS - should be carried bodily in micanite paper or cotton sheets. LINES - should be insulated with stoneware, such as Bullers. Let us hammer at all of these until we have some good standard ways of working, which we only depart from in fear and trembling that something will go wrong. Yours faithfully, F.H. Royce | ||