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).
Testing headlamp dipping arrangements for English and Continental driving conditions.
| Identifier | ExFiles\Box 167\1\ img231 | |
| Date | 12th January 1938 | |
| W/S. Cx.{Major Len W. Cox - Advertising Manager} from Rm.{William Robotham - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} c. Hs.{Lord Ernest Hives - Chair} c. Ey. File RC.{R. Childs} 6116. Headlamp Rm{William Robotham - Chief Engineer}6/R.12.1.38. DIPPING ARRANGEMENTS TO SUIT ENGLISH & CONTINENTAL CONDITIONS. We tried your P.III car with its arrangement of double filament headlamps and centre lamp. We tried the headlamps with both yellow and white bulbs. The three essentials which have to be catered for on our car are:- (1) A good driving light. (2) A good dimming light suitable for both English and Continental conditions. (3) A good light for driving in fog. In our test we treated each of these items separately, and compared your car with a scheme suggested by Waller. Taking them in order:- (1) Driving Light. We do not consider that the flat top beam is as good a driving light as the ordinary P.100 headlamp. We do not find it so easy to drive with on level straight stretches, and on undulating roads the restriction of visibility due to the reduction in vertical spread of the beam was noticeable. We would qualify these remarks by saying that the driving light with the R.100 fitted with double filament bulbs was quite good. We only criticise it in comparison with the efficiency of the light given by the single filament bulbs. (2) Dimming, Dipping or Passing Light. There is little to choose between the scheme we recommend and the scheme on the P.III. under these conditions. Personally, we prefer the light concentrated on the curb as is obtained by the dipping reflector, because it facilitates cyclists being observed. Neither scheme is objectionable to on-coming cars in the dipped position. | ||