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).
Proposing the use of slow-motion cinema to investigate high-speed steering wobbles.
| Identifier | ExFiles\Box 29\1\ Scan070 | |
| Date | 21th September 1925 | |
| X457 To Hs.{Lord Ernest Hives - Chair} PNS/EH 21.9.25. HIGH SPEED STEERING WOBBLES. In reference to your memo HS{Lord Ernest Hives - Chair}/RML/LG 18.9.25., I am not surprised to hear that pouring water on the drums instantly stopped the wobbles, as obviously when the front wheels are being driven in that way, the only source of energy for maintaining the oscillation which has started is derived from the revolving drums, and pouring on water would appear to be equivalent to lifting the front wheels off the drums, reducing the co-efficient of friction to a negligible quantity. I should think that slow motion Cinema pictures would demonstrate what is happening quite usefully. It should be remembered that these would be taken at ten times the normal rate of speed, i.e. 160 exposures would be made each second, instead of 16. 10 feet of film would be exposed in each second, there being 16 pictures per foot. I have ascertained from Messrs. Pathe Freres that the cost of taking a negative would come out at 1/6d. per foot, plus £10. for the hire of the two projection arcs necessary, and the man. They would require current for supplying these two arcs, which take 150 amperes each at 110 volts, or, say, 150 amperes with a second lamp in series at 220 volts. Are you able to lay a cable to supply this amount of direct current ? I gave this firm a useful idea as to what the conditions were likely to be. It should be noted that the longest run of film in one go is 350 feet, consequently in taking 600 feet there would have to be two separate operations. If you are interested further in this matter, would you communicate direct with Mr. Watts of Messrs. Pathe Freres in Wardour Street, who is the individual dealing with this matter. P.N. PN.{Mr Northey} | ||