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).
The causes of rattles in a Peregrine Park Ward Saloon body, referencing shock dampers and chassis rigidity.
| Identifier | ExFiles\Box 12\6\ 06-page094 | |
| Date | 13th October 1932 | |
| 7830 HS.{Lord Ernest Hives - Chair} FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} DA{Bernard Day - Chassis Design}/EV{Ivan Evernden - coachwork}/1/ 13.10.32. C. to SG.{Arthur F. Sidgreaves - MD} WCR. HS.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} PEREGRINE BODIES. X4027 x 5830 We note from your memo, that the first Peregrine body, a 4 light, Park Ward Saloon, has developed very bad rattles. This body was built with the same constructional details, and materials, as one of our stock 25HP. Saloon, which has given every satisfaction in customers' hands. We note that you attribute the cause of the failure in a large measure to the use of controllable hydraulic shock dampers, making it possible to almost lock the axles to the frame and body, so giving good riding and stability at high speeds. We should imagine that this would seriously damage the body, and do not therefore consider the problem one of how to make Peregrine bodies durable, but a greater one - how shall we make the bodies in general to be durable! - because these shock dampers will no doubt be fitted to P.2. and 25HP. simultaneously with, if not prior to, being fitted to Peregrine. Balloon tyres and low rating springs have relieved the chassis and body of much of the violence of the forces from the axles, and today our body troubles are few, but if we are going to make it possible for the driver, at his will, to couple the axle to the chassis by a powerful shock damper, we shall certainly be in trouble, and we see no way out. You will not let us increase the chassis frame torsional rigidity to relieve the body, because that involves you in jellying. We cannot isolate the body on rubber supports with or without a subframe because you say you want the body rigidity to give the chassis torsional stiffness. This you can tolerate, because while chassis crossmembers give rigidity without damping, the body gives rigidity with damping friction. You quote the case of American chassis with frames of little or no torsional rigidity, but with pressed steel panelled bodies, either all steel or composite, such as the Chrysler, which are extremely good and durable cars as far as the coachwork is concerned. We can understand this being so, but regret that we cannot do likewise. The all-steel body is hopelessly beyond our reach due to the enormous die costs, and even pressed steel panels we cannot have because our qualities are so low. Even on Peregrine we shall not | ||