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

come in large size pieces, such as coal and some ores, whereas others,
such as sand or grain, come in small particles. As bulk commodities,
are loaded into a barge, generally by dumping, the large size corn-
modities can inflict additional damage on the hull.
As mentioned earlier, -liquid commodities are shipped in tank
barges. Some tanks are used to ship more than a single commodity.
To prevent contamination when this occurs, tank barges must be clean-
ed. In addition, some liquid commodities are corrosive, thus tanks
may have to be occasionally relined.
To capture the effect of commodity shipped on cost, information .
has been obtained. Commodities are classified in the barge industry
according to one of several standard commodity classifications. The
classification used by the firm in this sample is the ICC "Standard
Commodity Classification for Transportation." This commodity code is
an extremely disaggregate taxonomy of bulk, agricultural, and manu-
factured products. The sample firm carried an average of 60 commodi-
ties, as listed in the commodity code, in each of the three years in
the sample.
. To reduce the problem to manageable proportions the sixty de-
tailed commodities were combined into six commodity groups. A two-fold
classification is frequently used in the barge industry: general cargo
and bulk commodities. However, there are important commodity differences
which this classification would obscure. Bulk commodities were classi-
fied into five types, general cargo becoming the sixth type, as follows:
1. grain
2. coal
•
on the number of ton-miles of each commodity shipped by each barge
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