Abstract

Operators of mobile shredders used to reduce tree waste are at risk of being dragged into the cutting system and hit by pieces of wood that are ejected. Furthermore, shredders generate high noise levels and operators experience handling problems. Concern about these hazards, which were identified in previous research, has led to the development of minimum corrective measures for certain machines. This project was undertaken to design a new machine, as recommended by the advisory committee established at the beginning of the research. The project adopted concurrent engineering methods, which allowed users' expectations concerning technical, production, marketing, and occupational health and safety considerations to be taken into account at the design stage. Work focussed on the cutting unit, which is a source of both noise and safety hazards. Noise levels were reduced by 15 dB(A) while maintaining acceptable productivity under normal usage conditions. Criteria for the design of a safer feeder system, which is the main machine-operator interface, were defined.