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).
Comparative report on different silencer designs and baffle configurations for the New Phantom.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan198 | |
| Date | 27th November 1925 | |
| Expl: Report. Expl: NO. _____ Ref. Hs{Lord Ernest Hives - Chair}/AJL1/LG27.11.25 ORIGINAL y 8230 To R.{Sir Henry Royce} from HS{Lord Ernest Hives - Chair}/WW. c. [REDACTED] c. to [REDACTED] c. to [REDACTED] c. [REDACTED] COMPARATIVE SILENCER TESTS (NEW PHANTOMCodename for PHANTOM I). Silencer under consideration - Standard silencer as compared with :- (1) Concentric tube silencer fitted with three baffles E.74332. (2) Concentric tube silencer fitted with three baffles E.74339. (3) Concentric tube silencer fitted with four baffles E.74339. The concentric tube silencer was evolved by WW. as the result of experiments carried out by us on this type of silencer. The silencer was slightly modified when compared with the Derby one with a view to lowering the weight, facilitating manufacture and decreasing the H.P. lost in silencing the exhaust gases. The two baffles mentioned above are made as follows :- E.74332. This baffle is similar to that fitted to the standard silencer, the only difference being that the baffle holes are smaller (.312" dia.) E.74339. This baffle is drilled with two more holes than E.74332 but the holes are all spaced out in one half of the baffle. The baffles are placed in the silencer so that the baffle holes come alternatively at the top and at the lower half of the silencer. The exhaust gases, therefore, do not have a straight passage through the silencer, but contd :- | ||