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 specifications and wiring for 'Goshawk II' lamps.
| Identifier | ExFiles\Box 180\M1\1\ img046 | |
| Date | 13th August 1921 | |
| TO FH. FROM R.{Sir Henry Royce} Copy to Mr. * EPC. Mr Hives. Mr Wormald. Mr Halden. Mr Whacker. ORIGINAL X.4090. RE LAMPS FOR "GOSHAWK II". We seem to have got the "Goshawk" lamps now which we require from the Lucas, and these people seem to have the only lamp which thoroughly suits our job. We are arranging for internal wiring and for the head lamps and side lamps both to be carried on the front mudguards. Regarding c.p. of the lamps, we should assume that the head lamp is not larger than the 48 c.p. ½ watt gas filled lamp which we are using here for the drawing boards. This in the Osram make has lasted very well. The side lamp we presume would be about 6 c.p. i.e. ½ amp. It is highly desirable that all lamps should be of the high efficiency type, but we believe that these are not made in the lower c.p. (than 48) suitable for the side and rear lamps. We are allowing for the dynamo to give 8 amperes, so that assuming that the ignition will take 1½ amperes there would be 6½ amperes available for the whole lighting of the car, including the internal body lighting. This should be ample, and leave something over for the starter and Klaxon. You will remember in purchasing lamps for these cars, and lamp holders, that we have an earthed system, and therefore the central contact single wire lamp holders and lamps will be needed, and as there will be only one insulation to be provided this can be carried out much more reliably than in the case of two insulated conductors which necessarily cuts down the thicknesses and spaces to less than half. R.{Sir Henry Royce} | ||