RT: What do the throttle positions relate to?

The different throttle positions equate to an attempt at providing equivlant/equal power level increases for the Engineer. Since the prime mover diesel engine simply drives a main generator/alternator, the specific engine RPM for each throttle position is mainly based around avoiding critical vibration points. Thus, one will see some pretty strange RPM governor settings, back in the days prior to computer controlled electronic fuel injection. 

Thanks Hot Water!

Kelly Anderson posted:

I (dimly) recall reading in an operator's manual for GP35's, that engineers were advised to avoid using Run 5 as much as possible.

My guess it had to do with fuel consumption....

I can't remember ever seeing such an instruction.  On expedited trains in non-grade territory, the throttle positions I used most were 1, 3, 5, and 8.  This, of course, was when stretch braking was permitted.  Longer, heavier, trains required the use of all throttle positions.

Perhaps one railroad in particular had that instruction. (?)

Kelly Anderson posted:

I (dimly) recall reading in an operator's manual for GP35's, that engineers were advised to avoid using Run 5 as much as possible.  Is that correct, and if so, why?

I never ran any EMD unit that caused any problem in 5th notch. I never cared for the 35 series locos. Not that they were problematic, it was just that they did not have enough power. Some EMD units didn't like the 2nd notch and SOME of those 10 cylinder models shook themselves to death just idling!!!

Big Jim posted:

Kelly Anderson posted:

I (dimly) recall reading in an operator's manual for GP35's, that engineers were advised to avoid using Run 5 as much as possible.  Is that correct, and if so, why?

I never ran any EMD unit that caused any problem in 5th notch. I never cared for the 35 series locos. Not that they were problematic, it was just that they did not have enough power. Some EMD units didn't like the 2nd notch and SOME of those 10 cylinder models shook themselves to death just idling!!!

Must admit that I've heard about any avoidance instructions concerning throttle #5, with ANY EMD units.

What company offered "10 cylinder models"? 

Might have been 12, but the way they vibrated they could have been 3, 5,7, 9...pick a number! Whatever those POS were, they were the worst EMD locos ever made, and at the time I didn't think EMD could make a bad loco! My hatred for the things was so great that I didn't care to know anything about those rattle-traps! Woe be onto you if you had to sit on one for any length of time waiting to make a move!
They used to put them on work trains. You could be on another train and pass one in the clear and watch them shaking themselves to death!

Big Jim posted:

Might have been 12, but, whatever those POS were they were the worst EMD locos ever made, and at the time I didn't think EMD could make a bad loco! W#oe be onto you if you had to sit on one for any length of time waiting to make a move!

Oh, right,,,,,,,the darned 12 cylinder. Yes, even the old 12-567 engines vibrated in certain throttle positions, but then the 12-645, especially the turbocharged versions were REALLY bad. In fact, the Australians complained so loudly that EMD was forced to re-design the crankshaft & corresponding firming order, under a warranty policy adjustment, for those Australian units with 12-645E3 engines.

Did you ever take a piece of sheet metal and shake it to where it made that wooga-wooga sound? That's what the handrails looked like on those units as they were idling!

Since we are on the subject of the EMD 5th Notch, I'll relate this. When coming up out of a dip and going from DB to power, you couldn't skin 'em back past the 5th notch or you would trip the governor. You had to wait for the transition to catch up before going to the higher notches.

Nerve wracking, eh! 

Hot Water posted:

Big Jim posted:

Might have been 12, but, whatever those POS were they were the worst EMD locos ever made, and at the time I didn't think EMD could make a bad loco! W#oe be onto you if you had to sit on one for any length of time waiting to make a move!

Oh, right,,,,,,,the darned 12 cylinder. Yes, even the old 12-567 engines vibrated in certain throttle positions, but then the 12-645, especially the turbocharged versions were REALLY bad. 

Aha!  Thankfully, it wasn't just me.  I never knew that it was a real problem, but the vibration on SD39 and GP39 units annoyed me.  Fortunately, we had few of those units on the Coast Lines.  Those poor Santa Fe Engineers in the midwest and New Mexico had to deal with SD39's and GP39's on a daily basis.

Plus, they only ran fast downhill.  Oh, well, as I have said, "You get what you get and you don't pitch a fit."  The paychecks I earned aboard those 12-645 powered engines cashed just fine at the bank.

Hot Water posted:

Big Jim posted:

Might have been 12, but, whatever those POS were they were the worst EMD locos ever made, and at the time I didn't think EMD could make a bad loco! W#oe be onto you if you had to sit on one for any length of time waiting to make a move!

Oh, right,,,,,,,the darned 12 cylinder. Yes, even the old 12-567 engines vibrated in certain throttle positions, but then the 12-645, especially the turbocharged versions were REALLY bad. In fact, the Australians complained so loudly that EMD was forced to re-design the crankshaft & corresponding firming order, under a warranty policy adjustment, for those Australian units with 12-645E3 engines.

Was the 12-645 non-turbo the prime mover for the GP38 and -2?  I though the 38's ran like Tmex watches?

Number 90 posted:

Hot Water posted:

Big Jim posted:

Might have been 12, but, whatever those POS were they were the worst EMD locos ever made, and at the time I didn't think EMD could make a bad loco! W#oe be onto you if you had to sit on one for any length of time waiting to make a move!

Oh, right,,,,,,,the darned 12 cylinder. Yes, even the old 12-567 engines vibrated in certain throttle positions, but then the 12-645, especially the turbocharged versions were REALLY bad. 

Aha!  Thankfully, it wasn't just me.  I never knew that it was a real problem, but the vibration on SD39 and GP39 units annoyed me.  Fortunately, we had few of those units on the Coast Lines.  Those poor Santa Fe Engineers in the midwest and New Mexico had to deal with SD39's and GP39's on a daily basis.

Plus, they only ran fast downhill.  Oh, well, as I have said, "You get what you get and you don't pitch a fit."  The paychecks I earned aboard those 12-645 powered engines cashed just fine at the bank.

ATSF seemed to "like" the GP39 and -2.

Is stretch brakin allowed anymore?

Dominic Mazoch posted:

Hot Water posted:

Big Jim posted:

Might have been 12, but, whatever those POS were they were the worst EMD locos ever made, and at the time I didn't think EMD could make a bad loco! W#oe be onto you if you had to sit on one for any length of time waiting to make a move!

Oh, right,,,,,,,the darned 12 cylinder. Yes, even the old 12-567 engines vibrated in certain throttle positions, but then the 12-645, especially the turbocharged versions were REALLY bad. In fact, the Australians complained so loudly that EMD was forced to re-design the crankshaft & corresponding firming order, under a warranty policy adjustment, for those Australian units with 12-645E3 engines.

Was the 12-645 non-turbo the prime mover for the GP38 and -2?

No. The 38 series, both GP and SD had roots blown 16-645E prime movers. The 38 series and 38 "Dash 2" series were NOT turbocharged and all had 16-645E prime movers.

 I though the 38's ran like Tmex watches?

They did, because they were NOT 12 cylinder!

Dominic Mazoch posted

ATSF seemed to "like" the GP39 and -2.

Is stretch brakin allowed anymore?

Yes, they had 20 SD39's, all Locotrol equipped and mostly used on coal or potash unit trains; and they had several dozen GP39-2's, heavily used in Texas and Kansas.

Stretch braking is no longer condoned by BNSF.  On the rare occasions when a local would be powered by rebuilt GP7's and GP9's that no longer had dynamic braking, what else could one do?  But, almost all road trains are powered by big GE and EMD power that has the capability to record so many events that the chart won't fit on regular size paper.  Those locomotives download their event recorders at fuel stops, into a huge database that is accessed by an exceptions program.  That software program rubs the events together, can identify stretch braking and several other forbidden practices, and produces a report, rating Engineers on their compliance with train handling instructions.

So, stretch braking?  No, no, no.  

Tom:

I worked for Duval Corporation and successor Western AG-Minerals and can remember those locotrol units on our export potash trains coming out of the Carlsbad basin.  I also recollect that John McCracken, the Santa Fe trainmaster in Carlsbad didn’t care much for them.

Curt

Machines have a condition called resonance where a natural frequency can be struck, and trouble ensue.  "If rotating machinery is operated at or near the natural frequency for free vibrations of the system, abnormally large vibrations may result." (Dynamics by J.L. Meriam).  That's why lathes, for example, have designated speed steps or you could run them at speeds where they will thrash about, unbolt themselves from the floor, and start dancing.  You can put a device off from the machine to serve as an outlet for some of that energy, but better to avoid the condition if at all possible.  My mother's four-door Ford sedan had a solid metal cylinder in free space welded to the end of a piece of steel bar stock welded to the chassis.  That was there to vibrate instead of the car when it hit specific speeds.  Sounds like maybe some of your handrails played that role as well.  

I have read early GE locomotives had 16 positions.  The "extra" spots were half way between the curent 8 postion.  True or myth?