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).
Performance of different headlamp dipping schemes after testing.
| Identifier | ExFiles\Box 61a\2\ scan0013 | |
| Date | 28th January 1929 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} O+ TO BJ. SG.{Arthur F. Sidgreaves - MD} c. to WOr.{Arthur Wormald - General Works Manager} E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} DA.{Bernard Day - Chassis Design} X4477 Hs{Lord Ernest Hives - Chair}3/LG28.1.29. HEAD LAMPS. X4555 X4520 We have not had much success with the Lucas Magnetic dipping reflectors. A set of these lamps were fitted to the 20 HP. 14-G-4 which has recently run 10,000 miles in France. During the preliminary test in England, we had cases when the reflectors got into a state of maintained oscillation. Also they would sometimes dip when going over a bad road. When the car got to France, these lamps were hopeless, and they had to be wedged into position. We have now tried the following schemes of lamps: (1) Barkers dippers. } 4555 (2) RR. dippers. (3) Lucas Magnetic dippers. ✓ (4) 3-lamp scheme using spot light. 4520 ✓ (5) Lucas Bi-focal lamps. 4477 (6) Lucas lamps with two bulbs as fitted to 19-EX. The schemes which we have had the best results from are either the Bi-focal or 3-lamp scheme. We consider whatever scheme [word crossed out] is used the foot operated switch is by far the best way of operating. The Bi-focal is the simplest scheme but the 3-lamp scheme is excellent for fog. Hs.{Lord Ernest Hives - Chair} | ||