Re: NR locos

[Ben Armstrong <ba13@uow.edu.au>]

Just to clarify- is the HP in an NR limited by changing the maximum
notch that the engine revs to, or some other means?

I thought that the variable horsepower control would have worked by
changing the maximum amount of fuel the governor could let the engine
use in each notch.

ie- The engine still responds to all notches the same way rev wise, but
the fuel used and hence power output is restricted by the setting of the
HP control.

This would have the advantage of still giving 8 evenly graduated
notches. (both powerwise and rev wise) 


On Sun, 16 Apr 2000, The Narc wrote:

> 
> Sorry to disappoint but it is a simple as limiting notch settings IE
> 2750 HP =notch six that is you can place the throttle lever in notch 8
> but it will be exactly the same as putting it in notch 8 
> 3200 HP = notch 7 same as above 
> 4000 HP = notch 8
> >Yes Rod, I think it might be something along these lines. If the method
> >was to simply leave all cylinders running but not allow them to develop
> >full power you will lose efficiency as engines of this size need to be run
> >in their most fuel efficient range, which afaik is about 75% of their
> >maximum
> >power. I am guessing that it would be far more efficient to run 2/3 of the
> >cylinders
> >at 75% than all of them at 50% but have had little success in finding out
> >the actual
> >mechanism used. Potentially it could be viable to use a 6 and a 10 cylinder
> >unit
> >so you could run 6, 10 or 16 cylinders, that way you wouldn't be having to
> >throw
> >all that dead weight around when some were shut down.
> >Rod Gayford <rjaygee@eisa.net.au> wrote in message
> >news:8dbgia$3p3$1@news.eisa.net.au...
> >> I am sure it is a little more complex than notch settings. I understand
> >they
> >> can be set 2500, 3000 or 4000 HP by cutting out banks of cylinders. I have
> >> seen a couple of articles on this feature of the NR Class in the recent
> >pass
> >> but I cannot remember which magazine etc.
> >> Cheers
> >> Rod Gayford
> >>
> >> "David Johnson" <trainman@ozemail.com.au> wrote in message
> >> 38F87C3D.4A416EF4@ozemail.com.au">news:38F87C3D.4A416EF4@ozemail.com.au...
> >> > deano wrote:
> >> >
> >> > > I read somewhere that NR class locos had three HP ratings, can someone
> >> fill
> >> > > me in(briefly) on how this
> >> > > is achieved or point me to a site with further information please.
> >> >
> >> > I think all it does is limits the maximum throttle notch for the loco.
> >For
> >> > example, it could be notch limited at 4, 6 or 8 notch (or something) and
> >> when
> >> > the throttle is placed in 8, the limited loco will only go up to its
> >> maximum
> >> > setting, saving fuel.
> >> >
> >> >
> >> > --
> >> > David Johnson
> >> > trainman@ozemail.com.au
> >> > http://www.ozemail.com.au/~trainman/
> >> > ------------------------------------
> >> > These comments are made in a private
> >> > capacity and do not represent the
> >> > official view of State Rail.
> >> > C.O.W.S. Page 11.
> 
> Regards Paul Johnston (MNRC)
> 
> 

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