63 巻 (1997) 612 号 p. 2679-2686
High-speed railway noise comes from vibration and aerodynamic noises. Rolling noise from rail and wheel vibration and aerodynamic noise generated under the car body can be minimized with noise barriers constructed along the rails. Thus. noise radiated from current collectors becomes the dominant noise source, and it must be controlled to reduce noise emission from high-speed railways. A pantograph cover is a useful and effective apparatus that reduces aerodynamic noise from a conventional pantograph when the operating speed does not exceed 300 km/h. At speeds over 300 km/h. however, the cover does not reduce aerodynamic noise enough to meet Japanese noise regulations, and its lift also becomes quite large. A new concept for a low-noise current collector has been developed. This current collector uses a delta-wing shape for the collector and has a pair of insulators on a hydraulic mechanism covered by a streamlined dome. The noise level of the new collector is expected to be 19 dB lower than that of the present pantograph.