Rail and wheel dynamic vibration absorbers have been proposed as noise reductionrnmeasures for rail transit systems in Europe and the United States. These absorbers arernessentially tuned spring-mass systems that damp the rail or wheel, and can effectivelyrncontrol wheel squeal. Their noise reduction effectiveness for rolling noise and railrncorrugation noise is less clear. The results of on-board and wayside noise reductions arernpresented and discussed for extensive testing conducted at the San Francisco Bay ArearnRapid Transit system (BART) for operations on bonded resilient direct fixation railrnfasteners. The tests included noise reductions for both tangent and curved track onrnconcrete aerial structure and within subway for speeds up to about 120KPH. The testsrnresults indicated limited effectiveness of the order of one decibel for tangent track rollingrnnoise and corrugation noise.
展开▼
