From what I've read, UP's steam motive power philosophy focused on more and more powerful locomotives due to its long grades and desire to eliminate the costs of helper service. In contrast was ATSF's policy of developing big, but not giant articulated steam power, and using helpers due to ostensibly shorter graded sections. Does anyone here know why UP's philosophy of power continued after the advent of MU capable diesels? It seems that having two SD40's would be better than one less flexible DDA40X, and probably cheaper, too. Please let me know, thanks. Kevin
Kevin - Here are two good articles by Don Strack explaining why UP was looking for extra-high horsepower locomotives: http://utahrails.net/articles/up-dd35.php http://utahrails.net/articles/up-dda40x.php Hope this helps answer your question.
Thanks Bob, that's exactly what I was looking for. I hadn't realized there was a cost-per-locomotive maintenance factor involved. I assumed that if you had two motors and 8 traction motors on one loco, it would cost as much to service as two separate locomotives with 4 motors each. I guess there are some economies of scale involved.
