NS units

[da_kraut]

Hello everybody

Why is it that the NS only orders 4000 hp road units when everybody else orders 4400 hp road units from GE?  Is it that the reliability of the diesel engines increases dramatically if they produce 400 hp less?

Thank you for your replies.

Frank

[cairosbd]

This is what I have heard:  Being the cost optimizing company that Norfolk Southern is, it buys the 4000hp units because of the greater fuel economy.  It doesn't have anything to do with reliability.

[WSOR 3801]

The NS units use the same prime mover as everybody else.  They feel that by using them at 4000 hp instead of 4300, or 4380, that the engines will run longer between overhauls.  Some have a switch that will allow use of the extra 400 hp.  Using something below its rated capacity usually increases the service life.

[Dakguy201]

If there is a simple switch that allows the crew to re-rate the engine to its original power, what is to prevent the NS's crews (or the crew of some other railroad) from defeating the purpose of the derating?

[Anonymous]

I think what the other person was saying is that back in the engine room, or something is s switch.  You are correct though, if there was a switch in the cab compartment then yes, it would be defeating the purpose.  But I would think it is in the engine comartment, and probably locked out and tagged by mechanical. 

[BigJim]

I think that there is a key that you have to have to make to swap over.

[Randy Stahl]

I think that there is a key that you have to have to make to swap over.

Yes , it resembles a diagonal wire cutter .

[BigJim]

I've had a couple of units that must have slipped by the person that derates them. I pulled up the Loco Monitor and the unit was indicating 4500 - 4600HP!

Sometimes I wonder just how accurate those readouts are. I have stopped waiting on a meet and let the unit auto shut down. I had the monitor on watching the temps on the water, oil and Traction Motors. We sat there for at least a couple of hours and the TM temp went down to about the ambient air temp. As soon as the unit started again and before loading, the TM temp was showing something way up there, like well over 150. The reading took a long time to come down. I asked an electrican about this and he said it was just a guess by the onboard computer in the offbeat way it monitors things like that.

[NS SD70M-2]

Because a large amount of the ns units are DC instead of AC?

[trainfan1221]

NS does things differently.  After all they had conventional cabs a long time (wish they had kept them) and are formed from two railroads that specialized in long hood forward.  And they do seem to prefer DC traction.  Can't argue with what works.

[Lord Atmo]

the spartan cab stuff was also because of costs. at the time of their introduction, safety cabs cost more. so NS stuck with spartan cabs. then after safety cabs became the only cab offered, the price was dropped to the same as the spartan cabs originally cost. hence NS went crazy with C40-9Ws.

although i never did understand why they weren't all over that safety cab design when it first came out. they were notorious for high hoods and running units backwards all for the sake of crew protection. so it would seem like this new design with collision posts is a godsend to that purpose