04-27-2011, 12:40 AM
Don,
As I understand it from my reading of TRAINS and elsewhere, when units are reasigned from road service to switching duties, they have their turbos removed to make them normally aspirated units which is also refered to as de-rating the units. The reason for de-rating the turbos is to reduce maintenance costs as the units seldom notch out into turbo mode while switching.
You could also use this premise as the reason your road chose to take the option of re-engining the units with 645's instead of sticking with the 710 units with turbos.
Someone here in another thread gave the example of the speeds used while switching as less than 10 mph and coupling as 4 mph or less.
I hope this helps with the decision making process.
Mark
As I understand it from my reading of TRAINS and elsewhere, when units are reasigned from road service to switching duties, they have their turbos removed to make them normally aspirated units which is also refered to as de-rating the units. The reason for de-rating the turbos is to reduce maintenance costs as the units seldom notch out into turbo mode while switching.
You could also use this premise as the reason your road chose to take the option of re-engining the units with 645's instead of sticking with the 710 units with turbos.
Someone here in another thread gave the example of the speeds used while switching as less than 10 mph and coupling as 4 mph or less.
I hope this helps with the decision making process.
Mark
Fake It till you Make It, then Fake It some More