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

ing is quite consistent with a priori expectations. Standard barges
tend to be lower cost than the larger jumbos with covered standards
being slightly more expensive. Jumbo open hopper barges are very
slightly more expensive than jumbo covered barges. There might be a
tendency for this to occur since covered barges carry mostly grain
and general cargo whichprobably contribute less to barge maintenance
problems than coal, for example, which often moves in the open hopper
barges.
Gulf barges, a jumbo size barge with higher sides to allow deep
water operations in the Gulf of Mexico,are higher cost barges. This
is to be expected since gulf barges operate almost entirely in salt
water areas where the corrosive environment requires frequent pre-
ventative maintenance.
Tank barges, with the exception of the acid barges, are high cost
barges. This is certainly a reflection of the additional cost required
to maintain the more sophisticated design of such barges.
Acid barges present a problem, in that their coefficient is the
lowest, by an order of magnitude, than the coefficient for the other
types and has a t-value significant at the .9995 level of probability.
In checking the records for these barges it is apparent that little
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maintenance is performed on them. However, all of the acid barges are
operated under a long term lease. A possible explanation is that any
maintenance is performed by the leasing agency. .
Tables 15 and 16 present rankings for the river district and com-
modity.variables respectively. These two sets of variables, it should
be recalled, represent alternative ways of dis-aggregating total output.
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