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).
Investigations into a 'booming' noise complaint on Phantom II cars.
| Identifier | ExFiles\Box 182\M19\ img151 | |
| Date | 18th March 1931 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to SE. MOR. c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to EY. ORIGINAL K634 PHANTOM II BOOMS. We do not know whether we have made it clear that on the production tests of Phantom II cars there is no distinct boom, although all cars were tested with covered bodies. These bodies are clamped to the frame. It is very difficult to distinguish with the covered body test kits the difference between Phantom I and Phantom II chassis. On the other hand, the fact that the booming which causes the chief complaint is always at approximately the same speed shows that it has some relation to the chassis. Another feature we have found is that on one of our experimental cars (25-EX) which was a very bad example of this complaint, we found that after we had run the car with the body bolted in different ways, which most probably strained the body, booms were very considerably reduced. Although so far most of our results have been negative, we believe that we are getting nearer a satisfactory solution of this annoying complaint. Hs.{Lord Ernest Hives - Chair} | ||