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contractors and growers, and the fact that most harvesters operate within a short time window each
day.
Prestwidge et al. (2006) investigated the opportunities for adding cane loading pads for road transport
to reduce haulout distance and consequently the costs of harvesting across three mills regions in
NSW. They adapted two existing modelling tools to the NSW sugar region, namely the Siding
Optimisation Model (Higgins and Laredo 2006) and the Harvest Haul Model (Sandell and Prestwidge
2004). The Siding Optimisation Model, originally used for locating sidings on a cane railway system,
was adapted to the road transport system in NSW and was named the Pad Optimisation Model. They
suggested harvesting cost savings of $786 000 over 5 years (across the three mills) could be realised
from investing in additional loading pads at optimal locations. The outcome of this study was the
expansion of existing pads and the construction of new pads to reduce haul distance. This is an
essential component of the whole-of-crop harvesting system adopted by NSW Sugar Milling Co-op
(NSWSMC). Further discussion on supply chain management tools and capacity planning is given in
Chapter 6 of the report.
Mallee System
A high level of coordination between harvesters, infield haulouts, shunt trucks (where required) and
road trucks will be required for an efficient harvest and transport system. The logistics will depend on
the harvester delivery capacity and harvester delivery capacity will be defined by the logistics.
The location of loading points to provide optimal haul distances will require careful consideration.
The paddock landings (pads in sugar cane) will be used for periods of a few hours every few years to
handle modest tonnages of biomass, which precludes the cost of significant site preparation.
Therefore vehicles using these points will need to be paddock-capable. Road transport landings will
be used for larger tonnages and better site preparation will be required to accommodate all weather
access for road train trucks. It is hoped that the flexibility introduced by the use of a shunt transport
stage will permit these road transport landings to be located opportunistically, such as at disused
railway sidings, where costs of access and site preparation can be minimised.
The structure of harvester “groups” can be optimised in mallee with appropriate coordinated industry
development. If the number of harvesters and the composition of each harvesting unit is optimised
from the outset, the new industry can avoid many of the inefficiencies that have evolved in sugar,
such as the large number of harvesters supplying each mill, with some harvesters operating for short
periods each day. Industry development planning, informed by the wide range of experience in the
sugar industry, will be one of the significant results of this project.
2.5.4 Harvest to process delays
Sugar System
Sugarcane is a perishable commodity and must be processed into sugar quickly after it is harvested
otherwise its commercial value deteriorates.
Most of the sugar mills operate under continuous crushing arrangements, 24 hours a day, seven days
a week, during the crushing season. Continuous crushing proves a better utilisation of transport and
milling capital.
Cane deteriorates after burning or harvesting. Rapid deterioration of cane is caused by a bacterium
that enters the cane pieces at the instant of cutting and produces a sugar polymer, dextran. Dextran is
formed by the action of bacteria on sucrose.
The deterioration of chopped cane is accompanied by a rapid increase in dextran. When processed,
deteriorated cane causes process liquids to increase in viscosity, with a decrease in factory capacity.
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