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).
Blueprint for an outdoor insulator designed to support grooved trolley wires.
| Identifier | ExFiles\Box 180\M6\ img084 | |
| Date | 2nd January 1927 guessed | |
| Malleable Iron Casting. Insulator, for outdoor use, to be exactly the same as for indoor except Malleable iron hood to be used, in place of top filling No N26, as shown. INSULATOR for supporting grooved trolley wire. (OUTDOOR TYPE) | ||