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).
Development of steering suspension and comparing Cadillac's steering gear with a Marles type for the Spectre.
| Identifier | ExFiles\Box 125\1\ scan0172 | |
| Date | 6th February 1935 | |
| Handwritten: Rm{William Robotham - Chief Engineer}, x1729a W/S. SECRET. To Sg.{Arthur F. Sidgreaves - MD} from E.{Mr Elliott - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Cx.{Major Len W. Cox - Advertising Manager} Da.{Bernard Day - Chassis Design} Hn.{F. C. Honeyman - Retail orders} re CADILLAC. Replying to your memo Sg.{Arthur F. Sidgreaves - MD}2/E.5.2.35, I was about to let you know what the position is. Our experience with the Cadillac geometry up to now is that road shocks are fundamentally present and can only be eliminated with it by using a steering box sufficiently irreversible to prevent these shocks from reaching the driver. You will no doubt recollect that we obtained a fairly good result on the first SpectreCodename for Phantom III by fitting a Marles steering in place of the RR, but as time went on it was found that the insulating properties of this steering box deteriorated and that the result is not so good now as when we first tried the car. Whether this deterioration would continue to increase or not we cannot say. Personally I think it would not, and that the box having arrived at a certain standard of freedom would remain fairly consistent. In the case of the Cadillac as we are aware a steering gear of very low ratio is fitted, much too low for English standards, but a degree of irreversibility has been obtained and the absence of road shocks seems to have been maintained. In our development of the SpectreCodename for Phantom III suspension of steering we have been working along two lines of policy so as to have two strings to our bow and to be in a position to choose either. We have the original suspension with the Cadillac geometry for which we have instructed a Marles type of steering box to our own design of a ratio suitable for English conditions and fitted with a large diameter worm having a helix angle which should provide a maintained irreversibility for dealing with the road shocks. This has | ||