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Hi all----The
size of the car fleets generated in mergers make it easier to use "merger"
reporting marks instead of having to shuffle cars around to create full blocks
of cars in the reporting mark of the absorbing line. That is a central reason CR
used the PC car numbering scheme as the core of its car-numbering plan, the
fewer cars that have to be renumbered and relettered the better, so using the
largest fleet as the core set of numbers simply makes sense. When the core
groups is very large and the number series do not allow for simple "insertion"
of newly remarked cars, you run into problems like CSX has. The large car fleet
picked up from Conrail simply could not be "folded" into the CSX numbering
system without a cascade effect of other pre-existing CSX car groups then in
turn having to be renumbered to make room for the new X-CR cars.It is more cost
effective for CSX to use the NYC reporting marks on former Conrail cars that to
have to entirely re-do their rolling stock fleet numbering system to accommodate
them. CSX, in fact, used a common numbering system for locomotive
purchases from 1983-1986 (when Seaboard System and Chessie had not yet been
merged together) in anticipation of the coming CSX combination. C&O and
B&O did the same under the Chessie regime for locos, but continued to letter
the cars for B&O, C&O, and WM. Loco fleets are tough enough to make
common, but car fleets approaching 100,000 are VERY difficult to remark into a
common plan without massive errors or overlaps among series, things that will
make computers choke.
UP, for
example, not only has continued to use WP, MP, SP, CNW reporting marks, but
has used subsidiary reporting marks for specific purposes. My understanding is
that the CHTT (Chicago Heights Terminal and Transfer) reporting mark, formerly a
subsidiary of the MP, is now used by the UP to designate leased cars.
NS did the same
thing, leaving most X-Southern and X-NW cars in original reporting marks. As
they purchased or leased new cars, they went into a common NS reporting mark
scheme. As the older Southern and NW cars were either sold off or retired, the
number of cars requiring renumbering slowly became smaller. Further, rebuilds of
hoppers allowed them to be moved into new series indicating their new capacity
and service. As those things went on, the NS renumbering scheme became a
smaller, simpler task.
Decisions like
this are driven by cost and the effectiveness of the simplest
solution.
I also wrote an
article about roster construction for proto/freelanced lines. It can be found
here:
Patrick
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