An examination of the dret model and the influence of payload, haul grade and truck type on earthmoving emissions

Earthmoving equipment is a large generator of emissions. Accordingly, it is important to understand the underlying parameters affecting performance, in order to operate the equipment in the most emissions-efficient way. The paper aims to provide an original examination of the truck-oriented earthmoving parameters of haul grade, payload and truck type and their little known influence on fuel use and emissions. Observed field data ‒ on fuel use, payloads and cycle times from four different earthmoving operations ‒ are compared with theoretical estimates. The assumptions behind the DRET (Department of Resources, Energy and Tourism ‒ Australia) energy model for truck fuel use and hence emissions estimation, are examined and improvements suggested. Conclusions are given on haul grade, payload and truck type usage that lead to least emissions. Suggestions for overcoming some limitations of the DRET model are given, and a modified DRET model is introduced.