Q2 Z2,(Q2) Z2(Q2) - Institute for Water Resources - U.S. Army

would tend to be slightly higher cost barges than those without the
covers.
As a result each of the barges in the sample has been classified
into nine types (see Table 14).- In the statistical model each type is
identified by a dummy variable. Thus, it will be possible to determine
the relative cost of operating barges with different physical character-
istics.
Two additional aspects af barge freight operations should be
significant elements in barge cost determination. The two aspects can
be seen as different ways of partitioning total output into types of
special services produced by the firm.
The first way of partitioning total output is by commodity shipped.
Barge cost should be quite sensitive to the commodity being shipped for
several reasons. One reason is found in the way commodities are loaded
and unloaded. Coal, for example, is generally unloaded by bucket clam-
shells which are dropped into the barge. Even when reasonable care is
exercised the buckets frequently damage the sides and bottom of the
barge. 'Eventually, the hull damage will require that the barge spend
time in dry-dock to be patched. Occasionally, the buckets will drop
through the bottom or side of the barge requiring substantial structural
repair.
Grain, on the other hand, is loaded and unloaded by more "gentle"
equipment. However, grain shipments require special handling in that
barges used for shipping grain must be cleaned of other bulk materials
and also must be covered to prevent mildew of the grain.
Bulk commodities, including coal, generally tend to be more
abrasive than, for example, grain. In addition, some bulk commodities
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