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diesel notch power settings

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Posted by Overmod on Friday, August 21, 2020 12:07 PM

I of course would like to see these listed 'in one place' to take them down for reference.  Others may differ in their interest.  Perhaps you could list them in something like a word-processing file to be sent by e-mail in response to a PM or other request if it is a problem to get it in posts here.

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Posted by caldreamer on Friday, August 21, 2020 8:24 AM

I have the fuel usage for each notch setting for a number of locomotives from just about all of the manufacturers and models.

     Caldreamer

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Posted by Overmod on Friday, August 21, 2020 6:07 AM

M636C
This is shown in a diagram in Eugene Kettering's ASME paper on the development of the 567 engine, which I think is available on the Utah Rails website.

https://utahrails.net/pdf/EMD_567_History_and_Development_1951.pdf

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Posted by M636C on Friday, August 21, 2020 1:10 AM

Lithonia Operator

Why 8 levels? Why not, say, 10?

Do/did all diesels have 8 settings? EMD, GE, Alco, etc.

Are these 8 levels available in a switch engine, say an SE type?

 

One reason for eight notches was the need to avoid engine speeds where torsional vibration in the crankshaft would become a problem.

This is shown in a diagram in Eugene Kettering's ASME paper on the development of the 567 engine, which I think is available on the Utah Rails website.

This seems to be more of a problem on the EMD two stroke engine than on the four stroke engines used by GE and Alco.

The firing order was changed on the 8-567C (becoming the 8-567CR) and on the 12-710G3A (becoming the 12N-710G3B) to avoid these problems.

Peter

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Posted by MMLDelete on Friday, August 21, 2020 12:37 AM

Thanks, OM.

I mistyped; should be SW.

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Posted by Overmod on Friday, August 21, 2020 12:16 AM

Lithonia Operator
Why 8 levels? Why not, say, 10?

It is actually binary, the result of combinations of four relays on the engine governor.  Read up on the Woodward governor for more on how the MU system is designed.

Do/did all diesels have 8 settings? EMD, GE, Alco, etc.

In order to use electric MU a locomotive had to share the relay control structure and some proportional power at each combination of relay action.  [EDIT: note carefully what M636C says about avoiding engine critical or resonance speeds, or at least transitioning through them, up or down, quickly]

There were other approaches to engine control, Baldwin for example using stepless air control; there were some late examples where Baldwins were explicitly built with electric MU capability.  Alco had very different control over how the electrical generation was done and regulated, but kept notches for Diesel engine control -- again, for compatibility.

GE at one point developed a 'half notch' system, where there were eight compatibility notches but also some 'in between' positions (of course available only to other 15-notch controllers) for finer control.

Are these 8 levels available in a switch engine...

Any GM engine with a Woodward governor could have the 8-notch control as it saved considerable complexity and opportunities for failure.  (Just what is an SE switcher, though?)

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Posted by MMLDelete on Thursday, August 20, 2020 10:32 PM

Why 8 levels? Why not, say, 10?

Do/did all diesels have 8 settings? EMD, GE, Alco, etc.

Are these 8 levels available in a switch engine, say an SE type?

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Posted by Overmod on Thursday, August 20, 2020 9:19 PM

blue streak 1
wonder how the NS practice that limited the MAX HP allowed was less than published HP on some of their units ? Did that change the schedule or not ? Is that still a practice in today's PSR operation? /

NS notoriously ordered a bunch of GEs intentionally derated to 'save fuel and wear'.  It would not make sense to rate those to take a train with any higher resistance than appropriate for their nominal performance profile (which would be interesting to compare with one producing 'stock' horsepower level in the running notches).  

Of course you then have notch restriction exercises on top of such derating, probably with the intended result more of slower peak speed rather than increasing the risk of stalling or doubling --which is more likely from derating than voluntary throttle use.

Rather famously, although I don't have firsthand knowledge, NS turned up many of the D9-40s to higher horsepower.  I would surmise that the result -- full availability, but operating notch restriction -- gave them the real-world fuel management they found best.

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Posted by blue streak 1 on Thursday, August 20, 2020 7:46 PM

wonder how the NS practice that limited the MAX HP allowed was less than published HP on some of their units ? Did that change the schedule or not ? Is that still a practice in today's PSR operation? /

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Posted by gregc on Thursday, August 20, 2020 2:50 PM

the curve of paul's fuel data is comparable to the values i posted last

it think the answer to my question is that each notch step provides a higher change in power than from the previous step (mildly exponential).

greg - Philadelphia & Reading / Reading

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Posted by Paul Milenkovic on Thursday, August 20, 2020 2:03 PM

W J White, How Diesel-Electric Locomotives Operate: The Last 25 Years, Including ACs (Second Professional Edition), p 3-10.

 

Fuel Consumption of B36-7

Notch  Gross HP

 

1        125

2        370

3        770

4      1245

5      1875

6      2465

7      3190

8      3845

The power appears to step up in 600 HP increments in the higher notches, smaller increments in the lower notches, with notch 1 being below the smallest increment.  This helps give finer control at the lower power settings used in low-speed "creeping." 

This GE unit is rated at 3600 HP, which is at the input to the traction alternator after powering auxiliaries.  The power at the wheel rims is 20% less given an 80% efficient drive for DC traction motors; the peak gross power of 3845 is presumable at the crank shaft of the diesel engine.

The notches on the GE unit appear to be more even than on an EMD unit.  Although this source lists only fuel consumption and not HP with throttle notch, turbocharged EMDs have a big jump in fuel consumption between notch 5 and notch 6.  This is the result of the turbocharger switching from direct drive to power the scavenging of the 2-stroke diesel unique to the EMD to a true turbocharger mode where the exhaust gas is able to power the turbine portion of the turbocharger. 

The turbo "cutting in" has a big boost in fuel usage but an even bigger boost in horsepower as the engine operates more efficiently in turbo mode.

It was interesting that some unnamed railroads in pursuing fuel and cost economy ask their crews to not exceed notch 5 or 6.  Running in notch 6 rather than notch 5 offers substantial fuel savings with EMD units, assuming, of course, that the trailing load is sized so that notch 6 gives the desired train speed.  Notch 7 actually gives the best fuel economy on a per-HP basis, with notch 8 only slightly higher in in fuel burn per HP-hour followed by notches 6 on down.

 

 

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by Overmod on Thursday, August 20, 2020 1:06 PM

I am staying out of the discussion on this side (it matches a more involved topic in the MR forum) because I don't have quick access to the sort of EMD technical material available through RyPN or some of the online technical resources on Woodward governors and the evolution of MU systems.  I have seen 'hard' discussions of governed speed and main-generator excitation for locomotives with 567s and 645s and have seen a number of very detailed discussions of Alco and GE practice from the Amplidyne days forward, but I don't want to discuss them without references at hand.  

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Posted by gregc on Thursday, August 20, 2020 10:45 AM

how about?

   1     70.0   3 %
   2    150.0   7 %
   3    335.0  17 %
   4    595.0  30 %
   5    875.0  45 %
   6   1200.0  61 %
   7   1565.0  80 %
   8   1940.0 100 %

 

greg - Philadelphia & Reading / Reading

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Posted by timz on Thursday, August 20, 2020 10:35 AM

Notch 1 isn't zero power-- Idle is.

In the 1970s, Run 5 was around 50% power.

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diesel notch power settings
Posted by gregc on Wednesday, August 19, 2020 10:43 AM

how much nominal power does each notch correspond to?     

are they proportional to max power

   1   0.0 %
   2  14.3 %
   3  28.6 %
   4  42.9 %
   5  57.1 %
   6  71.4 %
   7  85.7 %
   8 100.0 %

or perhaps something where the difference for each notch is a little more than the previous one and the 2nd notch is small enough to move the loco without any cars

   1   0.0 %
   2   5.4 %
   3  15.3 %
   4  28.1 %
   5  43.2 %
   6  60.4 %
   7  79.4 %
   8 100.0 %

 

greg - Philadelphia & Reading / Reading

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