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).
Solutions for S.S. Exhaust noise and cracking issues, suggesting design modifications.
| Identifier | ExFiles\Box 14\6\ Scan086 | |
| Date | 1st July 1929 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} X7220 SECRET. R4/M1.7.29. X7230. C. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} S.S. EXHAUST. We are very definitely against wrapping the exhaust in asbestos, and sheeting it. If the upper piece (on engine) is silent in thick metal (cast iron), then the lower piece should be. We are sending a design for a cast aluminium first expansion box with outside ribs to help silence and cool the exhaust. Cracking noises probably come from expansion motion, deep Y exhaust should have been OK, and one cannot believe with equally thick pipes that there should have been much, if any, difference in noise. We, and others, have used sliding joints on the first pipe instead of trusting sliding faces, we are sending a few modifications. The booming of the exhaust we think cannot come through the metal of the pipes, but must depend on exit noises, hence cooling the exhaust is very desirable, as well as for the life and expansion of the parts. If the exhaust exit is too noisy we ought to work at the diaphragms. Have you tried the suggested grading of the perforations? The internal pipes in the silencer should avoid the necessity of asbestos jacket. If not, try an aluminium box at the front, and where noise may occur - see drawing. contd. | ||