At the suggestion in another thread will start a thread about the minimum motive power needs of various AMTRAK trains.
A. Congress meddled into AMTRAK by requiring a certain on time performance ( 80% ? ) from it and the host RRs. This requirement makes AMTRAK do everything possible to shave minutes off its trains times whenever there are delays.
B. There is a preception by potential passengers that any mode of transportation that can operate on time is doing a good job.
C. Along with “B” is any public awareness that as scheduled times are decreased an increase of passengers all out of proportion to the actual decreases of travel time.
D. On time trains make their turns to an outbound trip more likely.
E. There are several constraints at present that limit the number of locos or motors on various trains.
A finite number of both
2 Most units still use DC traction motors. Exceptions are about 29 AEM-7s that were converted to AC traction, The 15 HHP-8s are AC traction with many common components to present ACELA train sets which are all AC. There are a few diesel locos ( 10 ? ) that were bought or converted.
DC traction motors seem to have several disadvantages that will probably see their demise.
a. Fine snow gets into traction motors and causes the motor to ground out thereby loosing 700 HP for each grounded motor ( P-42 ) . Have heard of some locos grounding out all their motors in a 25 mile streach.
b. Salt spray although only occasionally can ground out a motor.
c. For what ever reason DC seems to be limited more at design max speed than AC there by slowing acceleration to max speed ( 110 for P-42s & modified P-40s ).
Blue Streak, you have missed couple of major factors for the power used by Amtrak. First and foremost, the host railroads don’t want a passenger train fouling their tracks…if one breaks down, the other should be able to haul it rather than Amtrak sending another loco a thousand miles or the host railroad having to find something and crew to do it. Second, Amtrak does’t want to have to go a thousand miles for a back up locomotive and doesn’t want to pay the host road for the use of a locomotive and for the rescue crew. Third, Amtrak itself has to move power around and much better to do in in a train going that way rather than sending it light with crew (which they might or might not have nor want to pay the host road for). Fourth, no turning facilities…if it ain’t push pull, then they can at least run the power around the train…providing the units are back to back and not elephant coupled. I think these are probably more the reasons for two locos than what you have proposed.
Henry thanks for the jab. That is what happens when there was no proof reading. Have added item #16 & 25 and will add in any others that any poster notes.
As one railroad passenger I would not reduce transportation success to simply operating on time. However, when there is significant and repeated lateness then I would conclude the operator is no doing a good job.