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).
Progress report on the 'Spectre' model, detailing issues and developments with its steering, suspension, and brakes.
| Identifier | ExFiles\Box 4\1\ 01-page183 | |
| Date | 12th December 1934 | |
| X4694 To R.{Sir Henry Royce} From Ha/Rm.{William Robotham - Chief Engineer} c. to Sur. c. to By.{R.W. Bailey - Chief Engineer} Ha/Rm{William Robotham - Chief Engineer};14/MW.12.12.34. SpectreCodename for Phantom III Progress. The following is a brief summary of the present position of the SpectreCodename for Phantom III :- (1) Steering. We have proved that with correct geometry and parallel arms we can run with 3" or 9" deflection and little damping and yet be almost entirely free from road shocks even with a reversible worm and nut steering. On the whole under these conditions the steerability of the car is not so good as with the Cadillac set up of unequal suspension links. We therefore feel at the moment that for the final scheme we shall want a compromise between the parallel links and the Cadillac links. We hope to receive a Cadillac steering from America very shortly, which should enable us to reproduce the results which we shall get with a steering of our own design. (2) Suspension. For the best ride we require little or no damping on the front of the car. Unfortunately this causes the car to throw the passengers in the rear seats into the air when negotiating a hump-backed bridge. This actually is so violent that it cannot be tolerated. We are trying out the inertia controlled type of damper as used by the Americans to see if this will overcome the trouble. It may be that this feature will ultimately determine the softness of the ride which is permissible. (3) Brakes. With the existing SpectreCodename for Phantom III brakes it is almost unsafe to drive the car. We hope that the semi-servo scheme is progressing, also the simplification of the linkage. | ||