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).
Optimal angle for dipping headlights, comparing the Barker scheme with tests on Lucas lamps.
| Identifier | ExFiles\Box 61a\1\ scan0203 | |
| Date | 14th February 1924 | |
| X4555 To DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} from Hs.{Lord Ernest Hives - Chair} c. to LHS.{Lord Herbert Scott} c. to E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} c. to RG.{Mr Rowledge} Hs{Lord Ernest Hives - Chair}2/LG14.2.24. RE. DIPPING HEAD LIGHTS. We suggest that before we adopt the angle of dipping used on the Barker scheme, we should consider whether the angle they give is the most desirable. The angle of dipping required depends to a considerable extent upon the type of lamp which is fitted. Tests made at Derby prove that with the Lucas RB.{R. Bowen}65 lamp, the lamps dipped 9º. It is possible to walk straight up to the car without any glare. In order to make it sufficient for undulated roads, we consider 10º ample. We have driven behind several cars fitted with Barker dipping head lights and consider they have too much range. The virtue of the dipping is lost unless the driver is left with reasonable light on the road. Hs.{Lord Ernest Hives - Chair} | ||