Additional costs
are a part of the cost calculation. They occur when the work is necessary
for the production, but is not productive in a sense that there is an output of
any products.
Very often
it happens that workers are working hard, but do not produce any single product.
As an
extreme example, take the work with a cable yarder. Before the yarder can be
installed, an engineer must explore the terrain and trace a ground profile with
distance and inclination. Based on that profile, he can select the best path
for the cable corridor, selecting suitable spar trees, anchors and intermediate
supports. Then he’ll go back to the forest and mark the corridor. Now a troop
of specialists installs the yarding system. The end-mast and the intermediate
supports must be prepared: they are stabilized with guylines, some pulleys are
fixed, saddles are mounted…
Finally,
the skyline is laid out, lifted and tightened. This takes the work of several
persons and the basic machine over hours. Now the productive work begins.
When all
logs in the area have been extracted, the yarder system needs to be dismantled.
Also here, a troop of persons takes down the skyline, frees the end-mast and
the intermediate supports, collects all materials (cables, pulleys, strops
etc.) and stores all, ready for transport to the next site.
All these
additional costs must be regarded when the costs per m3 are calculated. With
yarder systems, they can be so high that the extraction with yarders will be achievable
only under conditions of small clear-cuts.
