Model Railroading > Low idle feature for Scale Trains SD40T-2

Found out if you select F4 while stopped will reduce engine sound to “low idle”. Simulates correct RPM sound when the reverser is centered.

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Edited 1 time(s). Last edit at 03/31/19 12:43 by Ozolian.

Ozolian Wrote:
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> Simulates correct RPM sound when the reverser is centered.
>

Had to look that one up...

Here is what I found:
One of the engineer's controls is a "reverser".  When it is "centered", it is in Neutral. 

If the engineer radios the crew that "the reverser is centered, the brakes are set, and the generator field is turned off", then the crew knows the train is not going to move so it is safe to move in and under the equipment. 

Since the prime mover is not under load, it goes to low idle.



Edited 1 time(s). Last edit at 04/01/19 22:47 by tmotor.

Yes. I’m pretty picky about sounds since I use to run them. With the reverser in forward or reverse position, the engine would go to a higher rpm and stay there even in run 1 throttle position. Then the RPM would increase when the throttle was advanced to throttle 2 position. Just love DCC sound!!

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All the second generation EMDs I've known had the engine RPM set the same for "Idle" and "Run 1."  When they loaded up in Run 1, the idle would briefly drop while the governor responded and similarly, it would rise slightly until the governor caught up when they shut off.   Do any rails here know of any exceptions to this?
D F W

tmotor Wrote:
-------------------------------------------------------
> Ozolian Wrote:
> --------------------------------------------------
>
> If the engineer radios the crew that "the reverser
> is centered, the brakes and set, and the generator
> field is turned off", then the crew knows the
> train is not going to move so it is safe to move
> in and under the equipment. 
>

I think this is what Conrail used to call "Three-Step Protection"....  maybe other railroads used that same terminology too.  I used to hear "Three-Step Applied" quite often on the scanner when railfanning in the Altoona, PA area...  

Bob

alto_towerbob Wrote:
-------------------------------------------------------
> tmotor Wrote:
> --------------------------------------------------
> -----
> > Ozolian Wrote:
> >
> --------------------------------------------------
>
> >
> > If the engineer radios the crew that "the
> reverser
> > is centered, the brakes and set, and the
> generator
> > field is turned off", then the crew knows the
> > train is not going to move so it is safe to
> move
> > in and under the equipment. 
> >
>
> I think this is what Conrail used to call
> "Three-Step Protection"....  maybe other
> railroads used that same terminology too.  I used
> to hear "Three-Step Applied" quite often on the
> scanner when railfanning in the Altoona, PA
> area...  
>
> Bob

Have also heard it referred to as the Red Zone and also hear the phrase "set and centered" a lot too.

Normal idle for a 645 powered locomotive is 235 rpm.  If requested as an option or modified with a "low idle panel" when the reverser is centered the "Low Idle Relay" picks up dropping the engine idle speed to 200 rpm.  When the reverser is thrown "Normal Idle Relay" picks up and egine idle speed goes to 235 rpm.  First notch speed is also 235 with locomotive set to load.  One exception is locomotives equipped with electronic cooling controls have a feature to keep the NIR picked up when engine cooling water temp drops below a set point.

Thanks for the information.

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