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).
Disagreeable booming periods in a 20-HP chassis fitted with Thrupp & Maberly bodies.
| Identifier | ExFiles\Box 47\2\ Scan328 | |
| Date | 30th September 1930 | |
| W/S C. c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Hy{Tom Haldenby - Plant Engineer}/Cav. c. J.L.R.Liddle Hall. X4117 EP{G. Eric Platford - Chief Quality Engineer}14/HS.{Lord Ernest Hives - Chair}9.30. re. 20-HP. CHASSIS FITTED WITH THRUPP & MABERLY BODIES. With reference to the trouble we had with disagreeable boom periods on a recent 20-HP. chassis used as a trials car by Mr. Reginald Roote, i.e. GDP-36. On the 2nd. inst. Messrs. Thrupp & Maberly again brought to my attention a complete new finished car, GLR-21 on which they had fitted a similar type of body as GDP-36, but considerable expense had been incurred with the body to obtain freedom from booms, and as the complete car was still disappointing in this respect, they considered that possibly the chassis required attention. In trying the car I was certainly more than ever convinced that in this case the chassis was particularly good for general vibration periods, yet at the same time as a complete car it was distinctly disagreeable for boom periods etc. I was able to discuss the matter with Mr. Heath Junr. of Messrs. Thrupp & Maberly and was emphatic on the fact that the chassis was quite a good one and we could not give him any encouragement in regard to improvement in this respect. I was able to demonstrate to him that the body was a particularly bad boomer and nearly all features when touched, even lightly, set up a boom. It was also possible to demonstrate that the car on the road, even with the engine stopped had disagreeable booming when the car went over pot-holes or over road setts. It does not seem that Messrs. Thrupp and Maberly have been able to achieve much success in their cures for booms. I went over the various body features with Mr. Heath, pointing out the importance of various parts being stretched and damped. He proposed trying various alterations, also dismantling various parts to see if possible what effect, if any, could be made on the booming periods. I am sending you this report, as I certainly feel you should be aware of the position, as a very firm stand will have to be made with Coachbuilders in producing boomy bodies, as GLR-21 as it was certainly was not fit to put into the hands of a customer. EP.{G. Eric Platford - Chief Quality Engineer} | ||