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).
Silencer experiments showing performance figures after system alterations.
| Identifier | ExFiles\Box 66\2\ scan0023 | |
| Date | 7th February 1925 guessed | |
| (5) SILENCER EXPTS. CONTD :- FIGURES OBTAINED SINCE ALTERATION OF SYSTEM. Alterations :- (1) 50% increase in No. of holes in Inter: pipe. (2) 9" wide fish tail instead of 6" wide. | R.P.M. | Loss to swan neck fish tail. | Loss to silencer & baffles. | Loss to holes in Inter: Pipe. | Loss when C.O. is closed rel. to cutout open. | |---|---|---|---|---| | 2500 | 3.6 | 5.3 | 5.7 | 13 | | 2250 | 3.7 | 3.3 | 4.7 | 11.85 | | 2000 | 3.6 | 2.1 | 5.3 | 10.75 | | 1750 | 2.5 | 2.4 | 1.0 | 7.85 | | 1500 | 1.7 | 1.5 | 2.0 | 6.3 | | 1250 | O | 1.6 | 0.5 | 2.1 | Hs{Lord Ernest Hives - Chair}/ACL. | ||