the requisite seniority districts. The coordination covers only
one assignment, i.e., Trains 316/317. The other difference in this
dispute is that the component runs of the coordinated assignment
involve two different types of runs constituting Trains 316/317.
One component is a straight away, or a terminal to terminal, road
operation, i.e., Parkersburg to Huntington. The other component
is a turn around run, i.e., Russell to Huntington, wherein the crew
making this run, can and does perform other work during their tour
because of the short distance traversed.