Marc,
Thanks for the information regarding the 710 series Prime Movers!
I have not seen any of the new 265 Series Prime Movers in person, but I have a Magazine Article about it.
Nice looking Motor!
SD-90 MAC Locomotives use the 265 Series.
The Prime Mover is 16V265H7, rated at 6,300 HP - but after figuring in all the Parasitic Loads on the Motor, it ends up as 6,000 BHP.
It (the "265") has dual Turbochargers, which are "Exhaust Gas Driven Only".
The Turbocharger on prior Models were Mechanically driven at lower Engine speeds (like a Supercharger would be), then when Engine speed became high enough, the Turbocharger was driven by Exhaust Gases (normal operation).
As to Traction Motors, the SD-90 MAC (and SD-70 MAC + SD-75 MAC) use AC Traction Motors, and the remainder of production still use DC Traction Motors - typical to the D77X3 Traction Motor
my freind works on a railroad with new AC traction system, and he really likes them alot.
and he says its hard to stall the AC, compared to the DC traction motors - espcally on " drag " lines; aka heavy coal trains typically about 10-15K tons loads
I have heard the same from friends in the railroads - and more specifically, when Coal Drags are involved.
Another thing that is mentioned relates to loading Hoppers, and the way the Locomotive Control System has been designed very well around AC Traction.
There is a mode which the AC type Locomotive may be placed in, which will automatically compensate speed control, while dragging empty Hoppers through Coal and Grain loaders.
You pretty much just need to set a desired speed, place the Controls into a certain mode, and wait until someone radios you to stop!
Let me see what other information I can find / get regarding this AC Traction - Applications stuff.
I will post it here later (actually, I think a new thread would be best!)
Thanks again for the reply message, Marc!
Scott35