The advantage that railroads accrue from using ‘Heavy’ locomotives works it’s way too standard bulk commodity train sizes.
“…On my carrier when the GE Dash-8 was the primary heavy haul locomotive, coal trains over a particular territory were 80 cars. With the Dash-8’s it was always problematical if the trains would successfully handle the multiple grades on the territory I was responsible for. With the introduction of the original AC’s, the 80 car trains became no problem and subsequently experiments were undertaken to increase the normal train size - with the AC’s as standard power, normal train size became 90 cars. With the introduction of the ‘Heavy’ locomotives, train size has been increased again to 105 cars…” [ qutes: BaltACD ]
“…Same number of locomotives used, same crew costs, same or increased speed over the territory, more payload = more money to the carriers bottom line. …”
Improvements of fractional percents in a railroad operation add up to big bucks over time - Improvement in the whole number percent range equal even bigger bucks over a shorter span of time.
Sometime back I started a Thread referencing the TRAINS Forum
Linked @ http://cs.trains.com/trn/f/741/t/160437.aspx
“CSX’s Heavily Ballasted, CW44AH Locomotives”<