Measuring the utilisation of winch-assist machine

The introduction of winch-assist for felling machines over the last decade to support felling and shovel logging has allowed ground-based harvesting machinery to work safely on significantly steeper slopes than unsupported machines. This has promoted increased mechanisation of tree felling in cable operations, reduced the reliance on motor-manual felling and opened up opportunities for grapples to replace choker-setters during the extraction phase. However, winchassist units incur a significant capital cost, and increasing the machine utilisation is a typical way of reducing operating costs by spreading fixed costs over more working hours. As winch-assist is only used to support felling machinery when required, it was expected that machine utilisation would be highly variable, and lower than that of machinery used full-time. This report presents the findings of two studies to evaluate the utilisation of winch-assist machines. The first study was a survey of existing machinery and their operating hours. Utilisation of the 12 machines surveyed averaged 45% of scheduled time, ranging from a low of less than 20% up to 80%. The second study gathered more detailed information on delays through the use of GPS navigation devices on two machines operated by a contractor in Hawkes Bay