NOISE ABATEMENT ON DIESEL LOCOMOTIVES. THE DIESEL ENGINE AS A NOISE SOURCE. INVESTIGATION INTO THE NOISE PRODUCED BY VARIOUS MECHANICAL MOVING PARTS

The noise produced by a diesel is due partly to the moving mechanical parts and partly to combustion and its mechanical effects. The tests described in the report are mainly concerned with the noise produced by the various constituent parts of the engine in the absence of combustion. The engine used was a 16-cylinder supercharged 4-stroke diesel V-form engine with direct injection and a rated output of 1,030 kW (1,400 hp) at a speed of 1,500 rpm; it was driven by its main generator functioning as a motor. The sound measurements, taken with the various parts working separately, enabled the part played by each in the overall noise to be evaluated. The results of these measurements show that the sound energy radiated by the different mechanical moving parts increases considerably with the speed of the engine. In the prevailing test conditions, the overall noise at the nominal rating of 1,500 rpm was as high as 98 dB (A), by far the greater part of which was due to the piston and connecting rod assemblies (94 dB (A)); on the other hand, the overall noise level drops sharply (80.5 dB (A)) when the engine is idling (550 rpm), and then the noise of the injector pumps, although reduced from 86.5 to 78.5 dB (A), becomes predominant, that of the piston and connecting rod assemblies dropping to 71.5 dB (A). The results of these tests indicate that any effort to reduce the noise produced by the mechanical components should be focussed first on the piston and connecting rod assemblies, then on the injection system and lubricating-oil pumps. The supplementary tests have shown that, at nominal rating, the combustion would produce a noise of the same order as that recorded for the individual piston and connecting rod assemblies, and somewhat quieter than that of the complete motored engine.

• Supplemental Notes:
  • Restrictions on the use of this document are contained in the explanatory material.
• Corporate Authors:

  International Union of Railways

  Office of Research and Experiments
  Utrecht,   Netherlands 
• Publication Date: 1968-4

Media Info

• Features: Figures;
• Pagination: 27 p.

Subject/Index Terms

• TRT Terms: Acoustic measuring instruments; Acoustics; Diesel engines; Diesel locomotives; Noise; Noise control; Noise sources; Sound level; Tests
• Old TRIS Terms: Acoustic measurement; Diesel engine noise; Question b104
• Subject Areas: Environment; Railroads;

Filing Info

• Accession Number: 00052999
• Record Type: Publication
• Source Agency: International Union of Railways
• Report/Paper Numbers: B104/RP 3/E
• Files: TRIS
• Created Date: Oct 26 1976 12:00AM