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Table 7.4 Fuel burn rates
harvester fuel burnt rate at idle 29 Litres per hour
harvester fuel burnt rate at work 86 Litres per hour
haulout fuel burnt rate at idle 8 Litres per hour
haulout fuel burnt rate at work 24 Litres per hour
vehicle fuel use per day 15 Litres per day
Wages are calculated at $50.00 per hour flat rate with a 30% on-cost. This is to reflect the typical rate
for this area where operators will typically travel from Perth and work on a three or four day shift.
Feed mills and processing plants typically operate for around 8,000 hours per year. This equates to
334 days per year of operation at 24 hours per day. Some harvest scenarios return a few hours of
harvest per day. In reality, one would operate on a roster of one day on and two off, for example, to
bring the harvest hours per day to a more realistic number of hours per day. The model, for the sake
of comparison, has assumed that harvest activity occurs each of the 334 days per year and has allowed
the harvest hours per day to vary. Some scenarios return at around seventeen hours per day.
Obviously this would occur in two shifts plus a rostered day off as appropriate and again this has
remained as one shift for 334 days per year. Varying the rostered days on and off will have no effect
on costs. Some of the largest group sizes at very low pour rates return a harvest duration of more than
twenty-four hours per day. Clearly two harvesters would be required for this. Again, harvest hours
per day has been allowed to vary for the sake of comparison.
7.3.4 Road Transport Assumptions
Road transport costs are in addition to harvest costs. Previous modelling has suggested two prices for
road transport: $0.13 per tonne per kilometre and $0.17 per tonne per kilometre. Both rates assume
that trailers are hauled in pairs.
Bulk density trials are currently underway. The modelling has assumed that bulk density is adequate
to achieve legal axle loads, which seems likely from work to date and from experience in the wood
chip industry. Scenarios One and Three are more likely to achieve higher bulk density as the bins are
filled directly by the harvester so that packing of the wood chip occurs during filling. Scenario Two,
where infield tipper bins tip into road transport, is more likely to be affected by bulk density issues
and assumes that the wood chip can be tipped from bin to bin without decrease in bulk density.
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