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

exclusive of delays, is begun in the next section. To the extent
that linehaul delays are related to variables which also enter.the
train speed function and train cargo function, the productivity re-
lationships and input tradeoffs derived below will be biased. How-
ever, until a reliable linehaul delay analysis is available, little
can be done about this problem.
Rail Productivity Relationships
It is interesting at this point to investigate the rail line-
haul process function, ignoring route segmentation, acceleration,
deceleration, and linehaul delays. Route segmentation, by its very
nature, is specific to a given trip. Ignoring it in the following
analysis does not preclude examination of the effects of route char-
acteristics on the output of a train. It was argued above, that, in
most cases, acceleration and deceleration may be safely ignored. •
Delays en route are important, as was indicated above, but will be
omitted nevertheless. The form of the linehaul process function .
which omits acceleration, deceleration, route segmentation, Equa-
tion (3.10) above, reduces to the folloWing when delays are ignored:
Q = VC ,
where Q = output of the train, in ton-miles per hour
V f - cruising speed of the train, in miles per hour
C = cargo weight of train, in tons.
(5.33)
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