Re: NR locos

[The Narc <gonoNOCRAP@bigpond.com>]

On Mon, 17 Apr 2000 11:45:49 +1000, Ben Armstrong <ba13@uow.edu.au>
wrote:
Ok i just reread what i posted and note a TYPO they are definitely
notch limited IE when set to notch 6 IE 2750 HP  you can place the
throttle in notch 6,7 or 8 and the net result is the same IE notch 6
revs and notch 6 excitation =2750 HP in all three notches
when set to notch 7=3200 HP whether you have the throttle in 7 or 8
so you can achieve exactly the same result on a single unit by not
going past notch 6 or 7.
PS the GE locos only increase revs in notch 3 and notch 6  
>
>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)
>> 
>> 
>
>---
>                           ______________________________________
>Ben Armstrong                                         /
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Regards Paul Johnston (MNRC)