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• The harvester will not have any on-board storage capacity or tow its own bin. A commercial
harvester will be a large machine on its own and adding a large volume bin would make it a very
cumbersome machine. Also the time required to transfer a bin-full of biomass to a haulout will
significantly reduce upon the field efficiency of the harvester.
• With relatively long infield haul distances, haulouts will need to have high payloads and relatively
high speeds.
• Whole-tree biomass is difficult material to transfer from vehicle to vehicle. It is most similar to
silage, so it does not flow or auger from the bottom of a bin like grain, and conveyors themselves
can be difficult to load from a bulk mass. The mass has to be torn apart and fed incrementally onto
the conveyor to avoid blockages.
• It is unlikely that whole tree biomass will be readily tipped from one bin to the next. Tipping is
feasible in itself, but as discussed previously in Section 2.3.3, tipping is expected to lead to
significant losses in bulk density.
• Short term surge buffers in bins or on trailers will be required between the infield transport and
the road transport stages to enable maximum field efficiency for the harvester. The problems of
limited surge capacity between stages were identified by McCormack et al (2009) as one of the
most significant weaknesses of the supply chain.
• Road transport will be in multi-trailer truck configurations and terminal time (loading and
unloading time) must be minimised. This makes loading and unloading over the side of road
trailers necessary, and to avoid the need for another machine in the supply chain, the road trailers
need to be able to load themselves, or be loaded by the haulouts.
Not all the key parameters have been tested at this point, and most importantly the effect of tipping
bin-to-bin is yet to be quantified. If as expected tipping causes unacceptable loss of bulk density, then
a system based upon containers is most likely to be adopted. This will place additional requirements
upon system design:
• Containers will be filled at the harvester and passed along the supply chain undisturbed until
emptied at the processor’s receival point.
• Containers must be matched to the size of the road trailers as there is no practical method of selfloading
two containers over the side of one road trailer.
• A road trailer has a payload of 25 - 28 tonnes, depending upon tare weight, so bins of about 70 m3
volumetric capacity will be required. This indicates larger haulouts will be necessary than are
currently employed in the sugar industry. A conceptual haulout configuration is presented in
Figure 3.6.
• Haulouts matched to side-loading trailers (similar to the swing-lift loaders used for shipping
containers) will also need to be self-loading and unloading.
4.2m
18m
Figure 3.6 Conceptual haulout configuration with a 70 m 3 bin
3
In the introduction to Section 3.2 the option of using shunt trucks was raised as a way of introducing
operational flexibility into the system and allowing infield transport to focus upon short hauls to the
field edge. If shunt trucks are employed, they will be similar to road truck configurations, with a prime
mover suitable for operations in most paddock conditions, but without the whole-of-paddock
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