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).
Letter to Vortex Silencer Co. Ltd. discussing the results of testing two sample silencers and requesting a quotation.
| Identifier | ExFiles\Box 152\3\ scan0053 | |
| Date | 21th January 1931 | |
| X44 V Expl. Dept. Hs{Lord Ernest Hives - Chair}/Lid.{A. J. Lidsey}3/KT. January 21st. 1931. Vortex Silencer Co. Ltd., Vortex House, Wembley Hill Estate, Wembley, Middlesex. For the attention of L.R. Halford Esq. Dear Sir, Thank you for your letter of the 20th. inst. I much regret that I was not available to see you when you called last week. We have carried out a considerable amount of testing on the two sample silencers which you submitted to us for our 20/25 HP. model. The best results were obtained with the silencer fitted with silencing units similar to the small model which you sent us ( 'A' silencer on the enclosed print ). We find that the second type (Vortex 'B') absorbs a considerable quantity of power in back pressure and is not so efficient as regards freedom from booms. The former type is quite good for power loss, it absorbs only very slightly more B.H.P. than our own standard silencer and is extremely good for absence of exhaust booms both on forward and overrun conditions, while at the same time the exhaust is effectively silenced; generally the results given by this type of silencer are very good. Our chief engineer, Sir Henry Royce, has received reports of our investigations on your sample silencer and any further developments will be entirely governed by his decisions. As a further matter of interest, could you let us have your price quotation for the supply of 'A' type silencers suitable for both our 20/25 HP. and Phantom II models? Yours truly, | ||