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diesel notch power settings

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Posted by jeffhergert on Thursday, August 27, 2020 3:50 PM

For us, they only consider it stretch/power braking if you release the air above a certain notch.  I think they raised it back to notch 5, it was notch 3 before.  It's one of those items they like to change every so often, as the mood strikes them.

The managers always want to see "stair steps" on the tapes as one opens or closes the throttle.  One coworker was telling me his manager was riding with him.  He went to engage one of the energy management systems, which once you push the button you move the throttle to notch 8.  It doesn't engage until the thottle is in 8 and moving the throttle doesn't register anything.  The computer holds it in whatever position it was in until fully engaged.  So you can just move the throttle to 8.  So my coworker just swiped the throttle to 8.  His manager asked him, "WHAT DID YOU JUST DO!"  The MOP started reading him the riot act when my coworker informed him about initiating EMS. 

Now, the last time this manager worked as an engineer was before EMS and PTC.  You would still think he would be up on how things work.

Jeff 

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Posted by zugmann on Thursday, August 27, 2020 3:23 PM

oltmannd
Do you get summarily shot for stretch braking?

Oh yeah.. it's like a game of BINGO. All sorts of stuff they tell you they don't like.

It's a whole new railroad.  

 

   The opinions expressed here represent my own and not those of my employer or any other railroad, company, or person.

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Posted by oltmannd on Thursday, August 27, 2020 3:11 PM

zugmann

 

 
oltmannd
If you have a train all stretched out and you are in a position where you can't possibly generate enough TE to get a knuckle...wiping the throttle will just get you where you're going faster

 

Not according to the tattle-tales that live in teh magic PTC box. 

 

okay.  They'll just get you to your trial faster.

Do you get summarily shot for stretch braking?

 

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

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Posted by zugmann on Thursday, August 27, 2020 2:58 PM

oltmannd
If you have a train all stretched out and you are in a position where you can't possibly generate enough TE to get a knuckle...wiping the throttle will just get you where you're going faster

Not according to the tattle-tales that live in teh magic PTC box. 

   The opinions expressed here represent my own and not those of my employer or any other railroad, company, or person.

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Posted by oltmannd on Thursday, August 27, 2020 2:36 PM

zugmann

 

 
oltmannd
The speed changes were fast.  The loading was slow.  If you wipe the throttle on a GE Dash 7 or 8, it's 80 seconds to full load, and more than half of it occurs in the last 20 seconds.  

 

"Train handling exception: throttle modulation."  

[acknowledge]

 

If you have a train all stretched out and you are in a position where you can't possibly generate enough TE to get a knuckle...wiping the throttle will just get you where you're going faster

An EMD (pre-AC) - wiping the throttle would get you to full load inside of  25 seconds, nearly linearly.

GE CHEC had "three slope curve". 

God bless you if you had to start a train on the grade with a B36 leading and GP40s trailing...and you needed all three to get rolling.

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

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Posted by zugmann on Thursday, August 27, 2020 10:54 AM

oltmannd
The speed changes were fast.  The loading was slow.  If you wipe the throttle on a GE Dash 7 or 8, it's 80 seconds to full load, and more than half of it occurs in the last 20 seconds.  

"Train handling exception: throttle modulation."  

[acknowledge]

   The opinions expressed here represent my own and not those of my employer or any other railroad, company, or person.

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Posted by oltmannd on Thursday, August 27, 2020 8:24 AM

Overmod
.  If I remember correctly the engine speed changes were artificially dashpotted to avoid smoke shows due to turbo lag, and the purely loading transitions of the intermediate notches might not have had a comparable long 'time constant' -- as a feature, of course.

The speed changes were fast.  The loading was slow.  If you wipe the throttle on a GE Dash 7 or 8, it's 80 seconds to full load, and more than half of it occurs in the last 20 seconds.  

 

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

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Posted by Overmod on Wednesday, August 26, 2020 5:33 PM

Paul Milenkovic
Is this anything like those placebo walk light buttons that apparently have not effect on the scheduling of the cross walk light?

Only if the buttons were originally working but were then quietly disconnected as being an annoyance to vehicle operations...

Remember that these would result in weird loading mismatch with ordinary 8-notch units if more aggressive excitation is what the half-notches control and the engineer isn't careful to count if he is engaging a half or whole notch in a one-notch throttle lever transition.  If I remember correctly the engine speed changes were artificially dashpotted to avoid smoke shows due to turbo lag, and the purely loading transitions of the intermediate notches might not have had a comparable long 'time constant' -- as a feature, of course.

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Posted by Paul Milenkovic on Wednesday, August 26, 2020 3:06 PM

oltmannd

 

By the time the U25s with their half notches got to Conrail, all of that nonsense had been removed but the throttle still moved in half notch increments.  There were still engineers who had all sorts of theories on how to use the half notches, even though they didn't work anymore!

 

 

Is this anything like those placebo walk light buttons that apparently have not effect on the scheduling of the cross walk light?

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 oltmannd on Tuesday, August 25, 2020 9:23 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.

By the time the U25s with their half notches got to Conrail, all of that nonsense had been removed but the throttle still moved in half notch increments.  There were still engineers who had all sorts of theories on how to use the half notches, even though they didn't work anymore!

timz
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.

The 1-5-8 speed schedule. Trying to get the darned things to load a bit quicker. Notch 5 engine speed in notches 2-5, Notch 8 after that.  A good chunk of PC U23Bs had this silliness.  It was superceded with "skip 3, double 6".

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

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Posted by BigJim on Tuesday, August 25, 2020 6:10 PM

Overmod

 

 
timz
When a current GE is in Run 8, the engine isn't always at maximum RPM? At low locomotive speed, prime mover RPMs might drop while the locomotive continues to produce maximum TE in Run 8?

 

That is a good question.  In the days before FADEC EFI the governed maximum speed is what would be commanded in Run 8 (with the governor of course apportioning fuel to keep the engine at that rpm regardless of load).  It would make sense for a computer to drop the rpm as noted for physical deloading, both for the significant aggregate fuel saving and reduction of wear and tear. 

 

I suggest that the immediate path to a practical answer involves a BatLight call to Randy Stahl...

 

When operating in notch 8 for extended periods of time and additional traction motor cooling is needed, GE units will increase rpm to 1050, with no increase in HP.

And yes, if a GE loco is in the lead with an EMD trailing, under the right circumstances, when the throttle is increased the EMD will bump the GE telling it to quit picking its nose and start loading!!!

.

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Posted by Overmod on Tuesday, August 25, 2020 10:52 AM

timz
When a current GE is in Run 8, the engine isn't always at maximum RPM? At low locomotive speed, prime mover RPMs might drop while the locomotive continues to produce maximum TE in Run 8?

That is a good question.  In the days before FADEC EFI the governed maximum speed is what would be commanded in Run 8 (with the governor of course apportioning fuel to keep the engine at that rpm regardless of load).  It would make sense for a computer to drop the rpm as noted for physical deloading, both for the significant aggregate fuel saving and reduction of wear and tear. 

I suggest that the immediate path to a practical answer involves a BatLight call to Randy Stahl...

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Posted by timz on Tuesday, August 25, 2020 10:37 AM

That reminds me of another question --

When a current GE is in Run 8, the engine isn't always at maximum RPM? At low locomotive speed, prime mover RPMs might drop while the locomotive continues to produce maximum TE in Run 8?

Did/do FDL16-powered units do that?

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

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

The daily commute is part of everyday life but I get two rides a day out of it. Paul
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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 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 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 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 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 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 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 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 12:16 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 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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