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).
Photographs from a road test concerning braking, wheel bumping, and skidding at 55 MPH.
| Identifier | ExFiles\Box 49\1\ Scan161 | |
| Date | 6th August 1919 | |
| R.H. 235A (100 T) (S.T. 848 6-8-19) C. 2469 Pencil Note. None of these have been sent to the works, please do it if you consider it necessary and interesting I am sending you at the same time the negatives in case you wish to do enlargements. COPY. RE 3X SPRINGS. I am sending you some photographs & lantern slides also negatives which we have taken after test on the road. No. 1 & 1-A show wheel tracks when brakes were applied at 55 MPH No. 1-B. Photograph showing close view of pot-hole in road where bumping first began No. 2 & No. 2A. show wheel tracks when brakes were applied and car bumping on the road. Please notice that it appears that the left near side wheel is bumping more than the right and consequently the right has more grip on the road, but in some places you will notice bumps also. No.3. show wheel tracks of car skidding when pulling up. No.3-A.{Mr Adams} simply show the car skidding when apply brakes. Also note on 3-A pothole where car begins to bump. No.4. Please note faint mark on photograph where brakes were released and car driven to the side of the road. No. 5,6,7,8 Photographs show the wheel tracks of other test which also show bumping etc We have measured the bumps on the road which are as follows:- SPEED OF CAR 55 MPH. 1st. bump - 2.60 2nd. " - 2.40 3rd. " - 2.25 4th. " - 2.23 5th. " - 2.37 6th. " - 2.32 7th. " - 2.21 Contd | ||