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).
Collection of press clippings from June 1936 reporting on demonstrations of a new 'straight-through' silencer by Servais Services, Ltd.
| Identifier | ExFiles\Box 152\3\ scan0213 | |
| Date | 11th June 1936 | |
| The Times SILENCING ENGINES AND FIREARMS DEMONSTRATION OF NEW DEVICE A new silencer, which may be applied to motor engines, machine-guns, and other forms of explosive machinery, was shown yesterday by the firm of Servais Services, Limited, which has produced it. Attached to the exhaust of a small petrol engine it smothered all the explosion noise and left the rattle of the valve gear clearly audible. Set in prolongation of a pistol barrel, it reduced the sharp crack of the shot to the level of noise appropriate to popping corn. It may be applied in such cases because it has no baffle plates and affords free passage to the bullet. News Chronicle THE SUPER SILENCER A remarkable invention to eliminate street traffic noise was demonstrated in London yesterday. It is a super silencer which can be fitted to motor-cars, motor-cycles, commercial vehicles, buses, "road-breakers" and aeroplanes. The Servais silencer, devised by Mr. H. {Arthur M. Hanbury - Head Complaints} Dare Lea in co-operation with Mr. F. {Mr Friese} Servais, contains cells vibrating within the casing, which, by synchronising with the sound vibrations of the exhaust gases, entirely absorb them. Motor Boat A Straight-through Silencer. We recently attended a demonstration of a new British silencer, which has been developed during the past 12 months and is now available for two-cycle and four-cycle petrol-paraffin and Diesel marine engines. It is made by Servais Services, Ltd., Westminster, S.W.1, the prices ranging from 27s. 6d. upwards. The silencer is of the straight-through type. It is of normal dimensions and in it are three layers of packing, designed to absorb different sound frequencies. One is of metal wool, one of asbestos and the third of some material the nature of which the makers will not divulge. No tests have yet been carried out with the silencer on a marine motor, although it is claimed that on a Servais-equipped Diesel engine the manifold temperature was decreased 15 per cent. and the fuel consumption 2 per cent. Morning Post QUIETER CARS—AND GUNS CLAIMS FOR A NEW SILENCER (BY OUR MOTORING CORRESPONDENT) In a room full of people at the Savoy Hotel yesterday a small pistol was loaded with a blank cartridge and fired. Everybody jumped. A few moments later the same pistol was loaded with the same kind of cartridge and fired. But this time a new form of silencer, about ten inches long, had been screwed to the muzzle. Nobody in the room moved, and even those who had been standing three or four feet away from the experimenter failed to hear anything. This was one of the methods chosen by the inventors of a new form of silencer to demonstrate its qualities. The silencer, in larger form, was also fitted to a Standard motor-car, and demonstrations were given with this. Judging by ear alone I am of the opinion that a greater noise reduction is secured with this silencer than with the types in ordinary use in motor-cars. It has the advantage of being of the "straight-through" type without baffle plates, and in consequence it is claimed that the loss of power is much less than with the baffle-plate types. The principle is that of a spiral-wound blanket of porous material encased in a large diameter tube. A free hole of the same diameter as the car exhaust pipe is left in the middle of the filling and the exhaust gases pass along this. The inventors, Mr. H. {Arthur M. Hanbury - Head Complaints} Dare Lea, and Mr. F. {Mr Friese} Servais, claim that the silencer is suitable for the silencing of the pneumatic picks used for road breaking. It can also be used for silencing machine-guns or the exhaust gases of aero-engines. | ||