Investigations into a differential charging system for harvesting

The method of charging for harvesting cane in New South Wales has traditionally been on a flat-ratc pcr tonne basis. In 1992, steps were taken by the Brushgrove-Lawrcnce Harvesting Co-operative to investigate a differential charging system. Vi be-recorders were installcd in harvesters owned by the Co-operative to measure engine working time. Pour rates for individual farms were determincd from this data, highlighting large variations from farm to farm. The results from this work indicated considerable variations involved in the cost of harvesting that were not reflected in the flat-rate charging method. Investigations were continued through the design and installation of a more sophisticatcd system using a data logger to record working time of various harvester components. By measuring the chargc timc for each job, the basis for a variable-rate charging system was put in place. The system involves the use of a "palm top" computcr for the down loading of data obtained from sensors installed to measure the opcration time of the engine, basecutter, tracks and the elevator. The system produced a number of reports including a differential charge for harvesting of each block and an equivalent flat"rate charge. Other reports allow comparisons of the performance of individual harvesters over any required time period. This information was relayed to harvester crews on a regular basis in an effort to maximise efficiency. Work with the system during the past two seasons has demonstrated its potential for implementing a differential charging system for harvesting. It was thought that up to $1.00 per tOnne could be saved on overall Co-operativc harvesting costs. During this pcriod, several problems requiring software changcs were encountered as well as difficulties with operator data input. Barricrs to adoption of the technology within the Co-operative are also discussed.