Your right Tony, the figure I quoted was maximum, with 12 cars the amount would be about 3/4 of maximum, the diner and the lounge are the biggest power draws.
Another reason might be that one or more of the units was recenty outshopped and is being tested under load conditions so as to ascertain that the unit is functioning properly. If the outshopped unit continues to have problems, then the train still has two good units to use. Or perhaps one of the units has been experiencing intermittent problems, and is being operated in order to identify the problem under actual load conditions. In either case, there might be a diesel technician riding the ailing unit to observe its operation.
Me thinks it is not a power movement as the Cheif routinely has 3 engines. 4 units would consitute a power move. The answer is a combination of previous answers. They have to provide enough power for the most demanding grade on there route. There must be adequate hotel power to power all the cars in the middle of the dessert with a full load of passengers. While the train is usually not full the power is dispatched as if it were. Most importantly there must be adequate power if they lose one unit for the train to both proceed and maintain a certian level of “hotel power”. Amtrak does not have the luxurary of assingning extra power to there trains. As an example the Cheif requires 3 units to complete its journey with adequate power for all eventualities.[2c]
For the record, the eastbound Chief today had three units coming into Chicago and the westbound Zephyr had two. What is describe above is very normal in and our of Chicago. Once in a great while the Chief will have four and hte Zephyr three but that is very unusual.
The P42 is only equiped with a HEP generator rated at a maximum output of 800 kW (1000 HP), so there is no way to divert 2000 HP from traction. Actually, the 800 kW is overkill. Long distance AMTRAK trains generally only use 225 kW to 375 kW HEP (300 to 500 HP) with everything running.
Even with everything running on the train pictured, the 3 P42s would still have over 12,000 traction HP for 12-13 cars. That is an absurd waste of power from a freight railroading prospective. Of course, since AMTRAK uses tax payer money to run their operation, it really doesn’t matter to them…
I HATE TITLE 24! By the way, Title 24 applies to more than just lighting. Soon it will apply to all aspects of everybody’s life.
since amtrak is rarely on time adding another engine will reduce tartiness simple answer