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diesel notch power settings

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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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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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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 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 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 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 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 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 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 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 Friday, August 21, 2020 12:37 AM

Thanks, OM.

I mistyped; should be SW.

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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 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 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 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 Overmod on Friday, August 21, 2020 12:16 PM

As a perhaps relevant point in this discussion: the principles of 'doubleheading' apply to MUed consists just as they do for individual control.  So it is not technically necessary for all locomotives to produce equivalent horsepower at the same notch, or turn at the same rpm, or even have the same rate of electrical loading or transition when power is changed OTHER than to preclude 'hunting' under conditions like particular ranges of balancing speed under particular conditions.

We have remarked from time to time that mixed consists can 'bump' each other when faster-loading power is coupled in with slower-loading, this being independent of actual horsepower rating when settled in at a commanded notch.  With loose buffers on given locomotives this might be noticeable in the cab, and I suspect at least some of the engineers here will be familiar with it.

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Posted by timz on Friday, August 21, 2020 12:42 PM

Lithonia Operator
Do/did all diesels have 8 settings?

Until dunno-when, GEs had 16-notch throttles -- the engine speed increased at alternate notches, with just an excitation increase in the in-between notches.

In the 1970s, GE (trying to save fuel) tried running with three (?) engine speeds instead of eight -- the engine was at 1050 RPM in notches 6, 7 and 8, or some such thing. And everyone remembers UP's rebuilt SD24 with its constant-speed engine -- don't recall how long that lasted.

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Posted by Overmod on Friday, August 21, 2020 12:55 PM

timz
Until dunno-when, GEs had 16-notch throttles -- the engine speed increased at alternate notches, with just an excitation increase in the in-between notches.

Fifteen-notch, Tim... it's the math of intermediate spaces between eight steps with the first representing idle.
In the 1970s, GE (trying to save fuel) tried running with three (?) engine speeds instead of eight -- the engine was at 1050 RPM in notches 6, 7 and 8, or some such thing.
I have to wonder at the sense of this, 1050 already representing substantial 'overclocking' of the prime mover for competitive horsepower-rating numbers and a known reliability reducer in practice.  Not saying they didn't, just that it would be goofy.  
And everyone remembers UP's rebuilt SD24 with its constant-speed engine -- don't recall how long that lasted.
Perhaps the less said the better; it makes only slightly more marginal sense to run HEP that way.  And this purely on economical grounds, leaving the noise and other issues for crews out of it.  Those who are familiar with the effects of extreme 'thermodynamic optimization' attempts on big recip steam will be smiling inside as they read the story of that UP project...

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Posted by caldreamer on Friday, August 21, 2020 3:11 PM

Overmod:

  I have them in an Excel spreadsheet.  If you emiil me off list I will attach the file and send it to you.

    Caldreamer

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Posted by bogie_engineer on Friday, August 21, 2020 3:24 PM

Overmod

 

 
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

 

 

Fascinating story to me, I liked the line about the dipstick being the only thing that didn't give a problem. It puts into focus the difficulty in designing a new engine or any other complex system perfect out of the box.

Dave

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Posted by oltmannd on Friday, August 21, 2020 4:36 PM

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?

 

The short answer is there are 8 notches because the governor has 3 solenoids it uses to set engine speed from the throttle and that's how many combinations you can make from 3.  2^3 = 8

It actually has a fourth solenoid that is used to signal the govenor to shut down the engine, and that solenoid gets exercised in the speed schedule so it won't get stuck in place.

The Woodward governor - which is the standard on all locomotives, is a flyball governor that controls engine speed.  Each solenoid acts against a lopsided triangular plate.  The plate pushes against a spring that works against the flyball mechanism.  The harder the spring pushes, the faster the flyballs have to spin to balance.

The plate's geometry gives each solenoid a different length from the spring such that solendoid A is worth 1 increment of engine speed, B is worth 4 and C is worth 2.  (D, the shutdown solenoid, is worth -2)

So, and engine speed schedule from the solenoid's perspective looks like this:

Low idle AD (added circa 1980 - so there are actually 9 speed settings, and on units with low, low idle, 10)

 

Idle and Notch 1  no solenoids energized

Notch 2 A

Notch 3 C

Notch 4 AC

Notch 5 BCD (would be B if you didn't have to "exercise" D)

Notch 6 ABCD (would be AB..."...)

Notch 7 BC

Notch 8 ABC

Each of these solenoids is controlled by throttle switches on a cam on the throttle and is assigned a pin on the 27 pin trainline.  

Eight became the standard and fit the 27 pin MU scheme.  There are all sorts of games that have been played with this speed schedule where the locomotive "interperets" the throttle setting and does something different.  GE, in their effort to control smoke, had a 1-5-8 speed schedule where the diesel engine would run in notch 5 engines speed anytime you asked anything over notch one and in notch 8 speed when you were in 6 or above.  Later, they had a "skip 3, double 6" speed schedule, and some of the more recent entries have an 8 high and 8 low, where the locomotive makes notch 8 tractive HP, but varies engine speed between notch 7 and 8 depending on conditions - to save a few drops of fuel.

But, they all use the basic Woodward governor with it's four solenoids to control engine speed.

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by oltmannd on Friday, August 21, 2020 4:40 PM

In the very early days, there were some strange variants.  Some Baldwins used pneumatic controls for the governor and some locomotives (switchers, mostly) had straight mechanical throttles where the control stand  lever moved against the flyball governor spring directly giving "infinite" notches.  This stuff is all before my time, so I don't know the details.

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by SD70Dude on Friday, August 21, 2020 7:00 PM

This guy has a bunch of videos of load tests on various locomotives.  The computer screens on newer units show the engine rpm and horsepower output in each throttle notch. 

https://www.youtube.com/user/SnowX51/videos

The SD70M-2 putting out over 4600 HP at 950 rpm impressed me, though that may have been total brake horsepower instead of traction output (or perhaps a bad sensor). 

Greetings from Alberta

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Posted by M636C on Sunday, August 23, 2020 11:12 PM

bogie_engineer

 

 
Overmod

 

 
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

 

 

 

 

Fascinating story to me, I liked the line about the dipstick being the only thing that didn't give a problem. It puts into focus the difficulty in designing a new engine or any other complex system perfect out of the box.

Dave

 

I was given a copy of the paper when I started my career as a railway mechanical engineer. I've read it and re-read it many times.

One thing that struck me much later was the comment that the 201A was limited by requirements from the US Navy. When I checked, the USN used the 201A in only one submarine, and later relied on Cleveland built engines that shared some 567 features. But the funding from the USN was probably vital in getting the engine built in a reasonable time....

The other things that stood out were the attention to detail in all areas, and the ability to recognise unexpected results (such as the good performance of cast iron pistons using only basic grey cast iron rather than the proposed special alloy.)

Peter

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Posted by CSSHEGEWISCH on Monday, August 24, 2020 10:07 AM

The US Navy had 567 engines in their LST's.

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Posted by bogie_engineer on Monday, August 24, 2020 11:27 AM

Throughout the paper Kettering stresses listening to what the parts are telling you, I think that's critical in any development program.

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Posted by Overmod on Monday, August 24, 2020 12:18 PM

Moreover, he implicitly stresses watch for what the parts are telling you... and learn from it and from 'all that that implies' for your future work.

It occurs to me that Mr. Goding, or people he knows how to contact, would be able to write a comparable account of the H-block 265 engine, including a reasonably conclusive account of ultrasonic concentration in thin-wall cast blocks at high power and any remediation strategies GM tried.  As I tried to point out during the British steam LSR challenge -- unsuccessfully -- documenting even blind alleys or mistaken designs can be highly valuable, to advancing the state of the art and its understanding as well as staying ahead of the edge of history.

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Posted by oltmannd on Monday, August 24, 2020 6:48 PM

M636C

 

 
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

 

As the HP increased, EMD eventually had to go to visous crankshaft dampers.  The spring-pack ones didn't have enough oomph.  Engines speed schedule had to be worked around the "peaks", for sure, but the governor design gives lots of leeway for setting the speed schedule.

That 567 paper is very interesting!  The 567C engine was pretty bullet-proof and lots of the older A and B engines had some of the improvement incorporated when rebuilt.  The GP9, with that 567C engine and battery field excitation might have been the most dirt simple, reliable locomotive ever made. 

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by oltmannd on Monday, August 24, 2020 6:50 PM

bogie_engineer

Throughout the paper Kettering stresses listening to what the parts are telling you, I think that's critical in any development program.

 

Oh, my yes!  EMD heads went through more evolutions than anything.  Circles, Diamonds, numbers.  Hard to keep track of...

-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/

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Posted by jeffhergert on Monday, August 24, 2020 8:55 PM

timz

 

 
Lithonia Operator
Do/did all diesels have 8 settings?

 

Until dunno-when, GEs had 16-notch throttles -- the engine speed increased at alternate notches, with just an excitation increase in the in-between notches.

 

In the 1970s, GE (trying to save fuel) tried running with three (?) engine speeds instead of eight -- the engine was at 1050 RPM in notches 6, 7 and 8, or some such thing. And everyone remembers UP's rebuilt SD24 with its constant-speed engine -- don't recall how long that lasted.

 

The current GE's still have half notches.  The engineer can't access them, only have the 8 notch throttle, but GE's Trip Optimizer Auto Throttle can.  

Jeff

 

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