Paul,
I know from your posting and our past conversations that you have a very active curiosity, so taking the time to explain things was more of a fun project than a burden. Besides you know a lot more about the civil engineering side of railroading than I do.
Getting back to the thread topic...
There was some discussion about the relative prices of GP-7's versus the Joe's - I've read some of DPM's early Motive Power Surveys and the price of diesel locomotives ca 1950 ranged from $90 to $105 per hp. This implies that a 1500 hp GP-7 would likely cost somewhere in the range of $135,000 to $157,000. With the tractive effort of a Joe equivalent to 1.5 GP-7's and the power equivalent to 4 GP-7's, each Joe was equivalent to something like $200,000 to $500,000 worth of GP-7's. With the price per Joe of $83,000, they were quite a bargain. In 1950, the Milwaukee was only running about 17% of its freight behind diesels, so the savings from buying the Joe's would have been helpful.
- Erik
erikem Paul, My recollection was that the motors typically had 4 poles and thus would have 4 sets of brushes. I don't recall how many segments in the commutator for the GG1 motors, but I would be extremely surprised if there less than 30 segments in the commutator. The torque pulsations in AC series motors have almost nothing to do with the commutator, it has to do with the AC current supplied to the whole motor going through zero twice per cycle of the AC line - zero current means zero torque. AC cannot be Alternating Current without the current going through zero in the process of alternating back and forth between a positive and negative maximum. [snip] - Erik
My recollection was that the motors typically had 4 poles and thus would have 4 sets of brushes. I don't recall how many segments in the commutator for the GG1 motors, but I would be extremely surprised if there less than 30 segments in the commutator. The torque pulsations in AC series motors have almost nothing to do with the commutator, it has to do with the AC current supplied to the whole motor going through zero twice per cycle of the AC line - zero current means zero torque. AC cannot be Alternating Current without the current going through zero in the process of alternating back and forth between a positive and negative maximum. [snip]
Erik -
Yes, that all makes more sense now. Thanks for your patience in explaining what may seem to be even simpler than 'Electric Motors 101' principles. So without the quill drive to 'buffer' the torque pulsations, the whole locomotive would have surged or 'boogied' down the track at 25 cycles x 2 = 50 times per second, between max. power and 0 power ? And in Europe, it would have been at 33 RPM - er, 33 pulses per second (16-2/3 cycles x 2). I recall that a modern - and very sensitive - dynamometer car run behind either the 610 or 614 steam locomotive as written up in Trains by Bill WIthuhn in the mid-1980's or so was able to pick up the individual pulses from the locomotive's cylinder strokes ! i suppose the same could have happened if we took one of these electrics - without the intermediate quill drive - and hooked it to such a dynamometer car.
That's kind reminiscent of what the 1960's-1970's model railroaders - i was one - did for better speed control and overcoming dirt on the rails, etc. The full-wave plus-and-minus 16+/- volt AC after being rectified would be 2 half-waves of plus-only 12+/- volt DC. By cutting one of the wires on the rectifier, only half the pulses came through, which would slow the locomotive but still provide a higher voltage to get throught the crud and overcome the higher resistance of the rails, etc., so it really helped with low-speed switching operations. It was called 'pulse control' or 'pulse power' back then - as I recall, the more advanced circuits diminished that effect at higher voltages because it wasn't needed then and to avoid motor damage from overheating, etc. No one knew or cared about the mechanical effects at that small scale . . .
Those old guys were pretty smart to figure out a decent mechanical way to cope with that inherent electrical disadvantage, which also yielded benefits with reducing the unsprung weight, etc. But then again, back then the railroads were the equivalent of today's aerospace industry or Silicon Valley enterprises and attracted the best and the brightest talent, although in this instance that talent seems to have been more at the supplier - Westinghouse - than on the railroads themselves . . . .
Thanks again. Wouldn't have been aware of that nuance or that the main purpose of the quill was to cope with it without your comment - and I consider myself to be pretty well-read on the GG1's at the 'fan' (non-EE / non ME) level.
- Paul North.
My recollection was that the motors typically had 4 poles and thus would have 4 sets of brushes. I don't recall how many segments in the commutator for the GG1 motors, but I would be extremely surprised if there less than 30 segments in the commutator. The torque pulsations in AC series motors have almost nothing to do with the commutator, it has to do with the AC current supplied to the whole motor going through zero twice per cycle of the AC line - zero current means zero torque. AC cannot be Alternating Current without the current going through zero in the process of alternating back and forth between a positive and negative maximum.. The zero crossing of the current may not coincide exactly with the zero crossing of the applied voltage, but the relative phase shift between current and voltage will be the same for all the motors on the locomotive, although that phase shift can vary with operating conditions (but will vary the same way for all the motors).
Remember torque is proportional to applied B field time the armature current, the applied B field is proportional to field current (which is the same as armature current in series motors - assuming no field shunting) up to the point where the motor frame and pole pieces saturate, at which point the B field increases at a much slower rate with increasing current. Keep in mind that the magnetic circuit is unsaturated at the zero crossing of the current.
The Westinghouse article on the development of single phase Electrifications did admit that the AC series motor was a poor cousin to the DC series motor. What they did claim was that these disadvantages were outweighed by the higher power available per train and longer spacings between cheaper/simpler substations possible with single phase AC for heavy electrifications such as the NYNH&H and PRR.
How many 'segments' would the commutator on the armature of such a motor - single phase, AC series - have ? I believe it has to be 2 at minimum - 1 for current in or onto it, and another for current out or off of it, and each covering roughly 180 degrees of the circumference of the armature - and that if there are more segments, they have to be in multiples of 2 for the same reason.
The latter would be if there are multiple coils on the rotor to attempt to smooth out the torque pulsations - but wait a minute, if there are only 2 brushes, they could contact only the commutator for 2 such coils at a time, andthe others would be 'dead' . . . I need to find a diagram of one of these. Back a little later on.
I'm not sure if it would be practical to have a mechanical means to change the timing of the torque pulsations. One problem is that a mechanical solution would likely be speed specific. An electrical solution would be to put a capacitor in series with one of the motors - which would which serve pretty much the same purpose as the capacitor in a single phase induction motor.
Rectifier locomotives would have similar problems with torque pulsation, but almost all use a smoothing reactor to filter out the ripple in the rectified DC.
erikem Paul_D_North_Jr: The twin motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as I'm recalling those kinds of things. Paul, The motors are operating in-phase, as they are driven from the same voltage source, so there would be no quartering effect as in a steam locomotive. Using twin motors as opposed to a single larger motor allows for a lower profile and the combined weight of two motors is likely less than the weight of a single motor with twice the power. [snip] - Erik
Paul_D_North_Jr: The twin motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as I'm recalling those kinds of things.
The motors are operating in-phase, as they are driven from the same voltage source, so there would be no quartering effect as in a steam locomotive. Using twin motors as opposed to a single larger motor allows for a lower profile and the combined weight of two motors is likely less than the weight of a single motor with twice the power. [snip]
Erik, I didn't think that question all the way through, and worded it poorly. Let me try again: Can the arrangement and spacing of the commutator, brushes, and coils be set-up so that the twin motors are mechanically 1/4 cycle out of sync with each other ? What I have in mind is something like whenever the twin motors were assembled or re-assembled, that someone would have to check to make sure that the one armature wasn't quite in the same relative position with regard to the same-phase electrical cycle as the other armature when engaging the pinion teeth onto the quill's drive gear . . . if that makes any sense.
Thanks again for the more-thoughtful response to my last question, and in advance for this one.
My understanding is that the AC motors used in both electrics and diesels are NOT truly squirel-cage synchronouse motors, with conducting bars straight across but are what are termed "hysterises non-synchronous motors" with slanted bars. But other than that, the description, with variable frequency excitation, is correct. With a true squirel-cage, at constant frequency excitation, the motor will run at the rpm corresponding to that frequency unless loaded to a specific maximum torque requirement, and then the motor will fail above that torque requirement. With the hysterises nopn-synchronous, loading increases slippage and the motor will run slower even though the frequency remains the same. If anyone has photos of the actual rotors, this question can be resolved.
Erik: Thanks for clarifying that for us posters. Did not have timme or vocabulary to put it that well.
blue streak 1 A follow on may indicate why present day 3 phase AC diesel and electric traction motors work when the older ACs did not work as well. Makes one wonder how much more efficient todays motive power is compared to the NHs and PRRs electrics? Also the ability to regenerate or run dynamic braking?
Keep in mind that the single phase series motors and three phase induction motors are very different beasts - something along the lines as the difference between a reciprocating steam engine and a steam turbine. The three phase induction motor is simpler, more rugged and more efficient than a single phase series motor. Another advantage is uniform torque. Use of three phase induction motors in locomotives is not new - the original GN Cascade tunnel locomotives were so equipped, along with the N&W and original VGN electrics. These were wound rotor motors, necessitated by being operated from a fixed frequency supply.
Modern AC drives make use of a variable voltage variable frequency (VVVF) drive which allow for the use of squirrel cage motors, which are simpler and cheaper than wound rotor induction motors (to say nothing about being simpler than commutator (brush) motors).
blue streak 1 Paul_D_North_Jr: motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as i'm recalling those kinds of things. - Paul North. PDN: You bring up a very good point. I am now wondering as well. A follow on may indicate why present day 3 phase AC diesel and electric traction motors work when the older ACs did not work as well. Makes one wonder how much more efficient todays motive power is compared to the NHs and PRRs electrics? Also the ability to regenerate or run dynamic braking?
Paul_D_North_Jr: motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as i'm recalling those kinds of things. - Paul North.
motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as i'm recalling those kinds of things.
PDN: You bring up a very good point. I am now wondering as well. A follow on may indicate why present day 3 phase AC diesel and electric traction motors work when the older ACs did not work as well. Makes one wonder how much more efficient todays motive power is compared to the NHs and PRRs electrics? Also the ability to regenerate or run dynamic braking?
Would the effciency of the modern solid state inverter have something to do with it? There's also the modern AC "Squirrel cage" traction motor...
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Paul_D_North_JrThe twin motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as i'm recalling those kinds of things. This kind of explanation is what's sadly lacking from almost all of the 'stuffed and mounted' displays of locomotives. When I was too young to fully appreciate it, i was on a tour of the PRR's Electric Locomotive Shop in Wilmington as part of an NMRA Mid-Eastern Region convention. There were many parts spread out over the floor and well-labeled, and people to answer questions . . . Something like that should be done with the displays of the 'guts' from the electric locomotives. None of the GG1's would be less for having one of their axles with the twin motors and quill drive pulled out from underneath and set in front with signs and labels. [end rant] - Paul North.
This kind of explanation is what's sadly lacking from almost all of the 'stuffed and mounted' displays of locomotives. When I was too young to fully appreciate it, i was on a tour of the PRR's Electric Locomotive Shop in Wilmington as part of an NMRA Mid-Eastern Region convention. There were many parts spread out over the floor and well-labeled, and people to answer questions . . . Something like that should be done with the displays of the 'guts' from the electric locomotives. None of the GG1's would be less for having one of their axles with the twin motors and quill drive pulled out from underneath and set in front with signs and labels. [end rant]
The motors are operating in-phase, as they are driven from the same voltage source, so there would be no quartering effect as in a steam locomotive. Using twin motors as opposed to a single larger motor allows for a lower profile and the combined weight of two motors is likely less than the weight of a single motor with twice the power.
The issue with torque pulsation from a single phase commutator motor is something I picked up from an electrical machinery class.
I've been doing a bit more reading on quill drives - turns out that the original B&O electric locomotives used gearless quill drives to provide shock protection for the motors.
beaulieu With these being contemporary with the GG1 I am sure that dynamic braking ability could have been installed at that time.
With these being contemporary with the GG1 I am sure that dynamic braking ability could have been installed at that time.
My guess is that the PRR didn't see the need for dynamic braking, figuring that it was only helpful for mountain railroading. IIRC, it took many US railroads a couple of decades or so to realize that dynamic brakes are a good thing even on low grade lines.
The obvious way of implementing dynamic braking with AC series motors is to treat them as DC series motors - i.e. provide DC excitation to the field coils. I wasn't aware of the Swiss using dynamic braking, but it does make sense that they would want to do it.
The European railway companies had hundreds of single phase AC commutator motored electrics with dynamic braking. A batch of the Swiss Ae 4/7 electric locomotives built between 1930 - 1932 by SLM with electrical equipment by Machinenfabrik Oerlikon had dynamic brakes for service on the Gotthardbahn. With these being contemporary with the GG1 I am sure that dynamic braking ability could have been installed at that time.
Paul_D_North_Jr motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as i'm recalling those kinds of things. - Paul North.
erikem A good start would be to get a copy of CERA's Bulletin 118 . . . the long article on the NYNH&H electrification - the design of the Pennsy's locomotives owe much to the design of the New Haven's fleet, including the twin-motored geared quill drive. The motors for the New Haven electrification were larger versions of the motors designed for AC interurbans. 25 Hz was chosen as that gave better commutation than 60 Hz and was a standard frequency used for systems with large rotary converter loads. Some of the disadvantages of the AC series motors used by the New Haven and Pennsy are: The motors are larger, heavier and less efficient than DC series motors of the same HP rating. The motors were probably more expensive and fragile than an equivalent DC motor sue to the laminated frames and poles. The motors may not have had more problems with sustained overloads than equivalent DC motors. Regenerative braking would have been extremely difficult to implement. AC series motors have a pulsating torque due to current going between maximum and zero twice per cycle. One way of reducing torque pulsations is to put a spring between the motor and driven wheel axle, if the resonant frequency of the rotational inertia of the motor (and gearing) and the spring is substantially less than the twice the line frequency, then the combination will act as a low pass filter and smooth the torque. One way to put springs into the system is to use a quill drive, which has the advantage of lowering unsprung weight. [snip] . - Erik
Some of the disadvantages of the AC series motors used by the New Haven and Pennsy are: The motors are larger, heavier and less efficient than DC series motors of the same HP rating. The motors were probably more expensive and fragile than an equivalent DC motor sue to the laminated frames and poles. The motors may not have had more problems with sustained overloads than equivalent DC motors. Regenerative braking would have been extremely difficult to implement. AC series motors have a pulsating torque due to current going between maximum and zero twice per cycle. One way of reducing torque pulsations is to put a spring between the motor and driven wheel axle, if the resonant frequency of the rotational inertia of the motor (and gearing) and the spring is substantially less than the twice the line frequency, then the combination will act as a low pass filter and smooth the torque. One way to put springs into the system is to use a quill drive, which has the advantage of lowering unsprung weight. [snip] .
The twin motors in the geared quill drive: Would they have been 1/4 cycle out of sync with each other - kind of like the quartering of steam locomotive drivers for timing the cylinder strokes - to prevent both motors from being at zero torque at the same instant ? With that (presumably) sinusoidal variation of torque on each motor being offset by the 1/4 cycle, the sum of the torque from both motors at any instant would always be in a higher and narrower range, around 0.7 of the max. torque of any 1 motor as i'm recalling those kinds of things.
While regenerative braking was impossible with AC commutator motors, dynamic braking is possible and was done in Europe.
Erik, thanks much for that insightful comment. I believe you've just doubled what little I knew about motor characteristics. And that's the best - actually only - explanation for the quill drive that I've ever read. The next time Middleton's book When the Steam Railroads Electrified is reprinted, they should get you to either edit or supplement the appendix about the "Technology of Electrification" (or whatever it's called).
If I'm understanding you correctly: The PRR and NH didn't go for the added weight and expense of Motor-Generator locomotives - which could have had regenerative braking capability - but instead used and stuck with AC series motors, which couldn't do that. My comment to that is: Probably because without major grades on most of their electrified routes - they were both essentially flat 'coastal plain' lines, all the way from New Haven to Washington, D.C. (except for some short portions of the PRR's original "Main Line" route west of Philadelphia to Lancaster, which did have helper service from time to time) there wasn't much opportunity for those roads to use regenerative braking on their regular freight operations, or the high-speed passenger trains. So that was a capability that they wouldn't have gotten as much return on as the N&W, VGN, or MILW.
I'll have to try and get those books/ issues, or copies of them. Thanks again for thsoe references and comments.
Paul_D_North_Jr From 1915 -so it would not cover the 1920's - 1930's developments of the motors that led to the PRR's fleet of electric locomotives.
From 1915 -so it would not cover the 1920's - 1930's developments of the motors that led to the PRR's fleet of electric locomotives.
A good start would be to get a copy of CERA's Bulletin 118, for which a library may be the best bet as the book has been out of print for a while. The two sections of particular interest are on the development of the single phase system (which includes honest comments on the advantages and disadvantages of single phase) and the long article on the NYNH&H electrification - the design of the Pennsy's locomotives owe much to the design of the New Haven's fleet, including the twin-motored geared quill drive. The motors for the New Haven electrification were larger versions of the motors designed for AC interurbans. 25 Hz was chosen as that gave better commutation than 60 Hz and was a standard frequency used for systems with large rotary converter loads.
Some of the disadvantages of the AC series motors used by the New Haven and Pennsy are: The motors are larger, heavier and less efficient than DC series motors of the same HP rating. The motors were probably more expensive and fragile than an equivalent DC motor sue to the laminated frames and poles. The motors may not have had more problems with sustained overloads than equivalent DC motors. Regenerative braking would have been extremely difficult to implement. AC series motors have a pulsating torque due to current going between maximum and zero twice per cycle. One way of reducing torque pulsations is to put a spring between the motor and driven wheel axle, if the resonant frequency of the rotational inertia of the motor (and gearing) and the spring is substantially less than the twice the line frequency, then the combination will act as a low pass filter and smooth the torque. One way to put springs into the system is to use a quill drive, which has the advantage of lowering unsprung weight.
The advantages of single phase include: much higher practical lines voltages, allowing for more power to trains and longer spacing between substations; Cheaper substations as they are basically a transformer and circuit breaker; Less problems with electrolytic corrosion; A much larger range of running speeds.
The lack of regenerative braking with AC series motors was probably the reason why Westinghouse had proposed phase splitter locomotives (N&W and VGN) for the Milwaukee. The M-G locomotives would have worked very nicely on the Milwaukee, but those didn't come into the picture until decade after the Milwaukee picked GE's proposal. For a given power, the M-G locomotives were probably heavier and more expensive than either an AC series motor locomotive or a 3kVDC locomotive. The extra weight and cost are probably the main reasons the Pennsy or New Haven never bothered with MG equipped locomotives, with the exception of the second hand GN's for the Pennsy.
Paul_D_North_Jr From 1915 -so it would not cover the 1920's - 1930's developments of the motors that led to the PRR's fleet of electric locomotives. About $27 from Amazon as a reprint from a scan, to around $45 for a used copy. Although the cover and subtitle appear to refer to mainly trolleys and interurbans, it also appears to cover "electric freight locomotives": http://www.amazon.com/Electric-Railway-Engineering-Francis-Doane/dp/1935327992
From 1915 -so it would not cover the 1920's - 1930's developments of the motors that led to the PRR's fleet of electric locomotives. About $27 from Amazon as a reprint from a scan, to around $45 for a used copy. Although the cover and subtitle appear to refer to mainly trolleys and interurbans, it also appears to cover "electric freight locomotives":
http://www.amazon.com/Electric-Railway-Engineering-Francis-Doane/dp/1935327992
I got my copy of the reprint from Karen's Books, not quite as low price as Amazon, but being local, the delivery is prompt. The Association of Railway Museums did a re-print of the 1924 edition of McGraw-Hill's Electric Railway Handbook about 20 years ago, which covers a bit more on heavy electric RR technology. Another good source for technology used by the PRR is CERA bulletin 118, Westinghouse Electric Railway Transportation.
RWM
That is the most interesting hypothesis about the Pacific Extension I have ever seen. If the Rockerfeller crowd was as smart as you hypothesize I am surprised that they did not see the impact of the Hepburn Act of 1906, which as you know, froze rates at 1906 levels during the inflationary run up to WW I and into the first couple of years. They could have saved hundreds of millions of dollars, when gold was $16 an oz. if they had been that smart and let the Government bleed the carriers for them.
True at the time Hill controlled both the GN and NP which served Butte, so he could have had both work together to raise their rates. The problem with that scenario is that Butte was also served by the UP, which would have tended to moderate any tendenct for Hill to price gouge. Hill, by the way, had the well deserved reputation as a rate cutter.
Finally, if the real objective was Butte, why go on to Tacoma? The copper market in the east was much bigger than in the west, since virtually all of American manufacturing was in Official Territory.
It would be interesting to research. First question would be what were actual published rates via GN, NP, UP and MILW in period 1900-1915? Second question is the degree of shareholder and director overlap as between Anaconda Copper and MILW? Third, was that overlap sufficient to carry the MILW board, either as a block or with help from expansion minded directors looking for an outlet on the Pacific?
Thought provoking.
Merry Christmas
Mac McCulloch
The ideas of big money movers & shakers on how to manipulate markets....oil, gold, silver, copper, coal, transportation etc. are far beyond what those of us who are basic wage slaves can really comprehend.
Never too old to have a happy childhood!
RWM: Interesting!! Perhaps some economic historian should do the lengthy research to confirm that intriguing hypothesis, which on the face of it looks fairly plausible.
C&NW, CA&E, MILW, CGW and IC fan
I do not have the inclination to research the financial records to buttress this hypothesis ... it's just inference drawn from the business press of the era.
The hypothesis is that the Milwaukee Road's promoters in the early 1900s had a substantial investment in Montana copper production and felt that James J. Hill's control of the rail lines in Montana skimmed off more of the profits than they preferred. To reduce that "excess tax" they needed a competing railroad that would force Hill to lower rates. Even more clever, they anticipated regulation of railroads would, once that competing railroad was constructed, would either (a) lock in a lower rate structure than Hill would otherwise have offered, or (b) lock in such a high rate structure that the copper consortium could extract its due profit from the Milwaukee Road's transportation service rather than just FOB refinery. Either way, they win. Even better, given the very foolish belief of most investors of the era thinking that railroads were a magic ticket to riches, they could use other people's money to build the railroad. Again, a winning outcome -- if the railroad was a financial success, it would compete for their copper business and increase their profits. If the railroad was not, well, it wasn't their money, and it could be someone else's problem. As it turned out the ICC locked in long-term noncompensatory rates and their copper profits were protected. But had they not built the Milwaukee Road, the regulated rate might have been higher.
I don't think that Rockefeller, H.H. Rogers and the rest of that crowd put their time into building the Milwaukee Road because they thought it was going to be a money maker on its own merits. I don't think they had delusions that the Northwest needed the capacity of yet another transcon, or that sterile regions would magically blossom when kissed by the steel rail, or that the Milwaukee Road would have superior operating performance, or to serve the sketchy quantity of transcontinental traffic that was offered or likely. I think they were too smart for that. They built it as a useful tool in their much bigger competition against Morgan and Hill.
Anyway, just a hypothesis.
Thanks for that reference, Erik.
VerMontananNoel Holley's book "The Milwaukee Electrics" has Milwaukee Road tonnage charts for various grades and various locomotives. Westbound, the tonnage rating for two Little Joes and one GP9 is close to the 3,600 tons indicated above, or 3,760 tons (page 288 in the book). Interestingly, the book indicates that a similar consist eastbound would handle only 3,965 tons, not the 5,800 tons indicated above. This is because the grade from Avery to St. Paul Pass, though only 1.7 percent compared to the westbound steepest grade of 2.0 percent on Pipestone Pass, was exceptionally curvy.
I took a look through the tonnage rating tables in Holley's and also noted that the Joe's had the same rating for EB St Paul Pass as for WB on Pipestone Pass. The other locomotives listed had a slightly higher rating for St Paul Pass, so the curves make a difference. Most likely culprit was the 20' rigid wheelbase on the Joe's. Both passes could be ascended within about an hour with the Joe's, and they would be able to make use of the hourly rating.
In 1969, GE proposed building C-C's with model 750 motors. These would have had continuous tractive effort ratings equal to the 1 hour ratings of the Joe's and at the same speed - presumably the use of Kapton insulation led to the much higher continuous current rating. The C-C arrangement would have been a much better match to the St Paul Pass approaches. The asking price was $500,000 each, which most likely would not have been a good investment. Would have been interesting to see those in action.
Paul_D_North_Jr I understand that the MILW bought a lot of land and water rights that were intended to be used for hydo-power generation, as there was no good coal on-line and it was expensive to haul in. Also, a lot of the route was in National Forests, and oil was required to be used to prevent forest fires, and that was expensive, too. So the hydropower - "white coal" - looked like it could have saved the MILW some fuel money. But when the electrification was constructed, there were a lot of transactions with a guy named Ryan, who ran Anaconda Copper and also the Montana power company, so I'm not sure what and how all that happened . . .
I understand that the MILW bought a lot of land and water rights that were intended to be used for hydo-power generation, as there was no good coal on-line and it was expensive to haul in. Also, a lot of the route was in National Forests, and oil was required to be used to prevent forest fires, and that was expensive, too. So the hydropower - "white coal" - looked like it could have saved the MILW some fuel money. But when the electrification was constructed, there were a lot of transactions with a guy named Ryan, who ran Anaconda Copper and also the Montana power company, so I'm not sure what and how all that happened . . .
The Milwaukee did have a large source of fairly decent coal at Roundup, from what I understand is of better quality than what the NP mined from Colstrip (prior to ca 1923, the NP was getting its coal from Red Lodge). This is the pretty much the same coal being carried by the recently built branch connecting to the GN's Laurel - Great Falls line, had those mines been developed in the mid-70's, the Milwaukee line between Roundup and Terry would probably still be in service, it is a much better route than the line through Laurel.
Johnston, in his book on the Puget Sound/Pacific Coast extension of the Milwaukee stated that one reason that the extension was built was to provide competing rail service to Butte and Anaconda. Many of the Milwaukee directors were also directors of Anaconda Copper Mining...
narig01: Also on the decision to scrap. By the 1970;s was not 3kv dc obsolete for the long distances? Oh, yeah - since at least 1920-1930, when several northeastern US railroads settled on 11KV 25 Hz for their electrifications - PRR, NYNH&H, and RDG. And then again by 1974, when the BM&LP opened with a 50 KV 60 Hz system, and in those years many studies of other long-distance Class I RR main-line electrifications were undertaken. By then the Muskingum Electric coal mine line was also running a 25 KV 60 Hz demonstration, and a few years later the same was used by BCR's Tumbler Ridge coal branch electrification. So no real research or design would have been needed to upgrade the MILW's system - just a lot of $ to basically replace it all.
narig01: Also on the decision to scrap. By the 1970;s was not 3kv dc obsolete for the long distances?
Oh, yeah - since at least 1920-1930, when several northeastern US railroads settled on 11KV 25 Hz for their electrifications - PRR, NYNH&H, and RDG. And then again by 1974, when the BM&LP opened with a 50 KV 60 Hz system, and in those years many studies of other long-distance Class I RR main-line electrifications were undertaken. By then the Muskingum Electric coal mine line was also running a 25 KV 60 Hz demonstration, and a few years later the same was used by BCR's Tumbler Ridge coal branch electrification. So no real research or design would have been needed to upgrade the MILW's system - just a lot of $ to basically replace it all.
It probably would have been more economical for the Milwaukee to extend the electrification with 3kV than to try to upgrade it to 25kV/60Hz (Michael Sol said that GE quoted $66,000 per mile for filling "the gap" in 1969). Using DC eliminates the problem of phase balancing. The downside is that trains would be limited to about 12MW (~16,000hp). The high voltage DC electric locomotives would probably have been slightly more expensive than an equivalent AC locomotive. One other advantage of 3kV is that clearances are less of an issue at 3kV than 25kV (not to mention 50kV).
(added note) A couple of other issues of AC vs DC are inductive reactance and skin effect. For 25 Hz, the impedance of the overhead is roughly 1.5 times the DC case, and the impedance of the rails is about 6.6 times the DC case (both figures from Chap 20 pages 22-23 of Electric Railway Engineering by Francis H. Doane. Assuming that the impedance increase for the overhead is dominated by inductance and the rails by skin effect, I'd guess at 60 Hz, the overhead impedance would be about 2.2 times DC resistance and rail impedance would be 10 times DC resistance. This means that an AC line needs substantially higher voltages than a DC line.
The first AC electrification that matched the flexibility in speed and regenerative braking found in the Milwaukee's electrification was the GN's Cascade electrification of 1927-29. GN's original three phase Cascade electrification as well as the N&W's and VGN's phase converter locomotives had regerative braking, but operated at fixed speeds. The AC locomotives operated by the PRR and NYNH&H were not capable of regenerative braking.
Paul_D_North_Jr narig01: I don't know, but see the book The Nation Pays Again by Thomas H. Ploss, who was a MILW staff lawyer at the time - it's pretty scathing from what I understand, and may address that topic. narig01: - Paul North.
narig01: I don't know, but see the book The Nation Pays Again by Thomas H. Ploss, who was a MILW staff lawyer at the time - it's pretty scathing from what I understand, and may address that topic.
I don't know, but see the book The Nation Pays Again by Thomas H. Ploss, who was a MILW staff lawyer at the time - it's pretty scathing from what I understand, and may address that topic.
narig01: - Paul North.
I knew Tom Ploss. Tom had a real chip on his shoulder over business decisions being made by the Milwaukee around the time of its bankruptcy, and also with the bankruptcy trustee's decision to settle litigation against BN related to BN merger conditions. He got himself into deep doo-doo with MILW management and his own legal superiors over this issue, apparently forgetting that business decisions are made by the business people, not the lawyers. I reviewed an advance copy of his book when Tom was trying to get an organization I was associated with to publish it. I recommended against publication,because the book seemed to be very nearly slanderous. Given Tom's rather strong biases, I don't think the book can be taken as authoritative. It is useful, however, as the viewpoint of an internal dissenter.
Thanks for further explaning. I don't have a good sense of train tonnage. How heavy would a train be, say, in 1970? 1980?
- Rails West
Rails West Your study looks at just two aspects of the Little Joes: (1) horsepower, and (2) the route they were restricted to. Your conclusion is that because a Little Joe was not as powerful as a Saturn rocket, that it was nothing special. And you conclude that because a Little Joe could not run the entire distance, Chicago to Tacoma, that it didn't make economic sense. It's interesting stuff to consider, but we need to do the cost study and compare it to other alternatives.If I was a consultant given the job of answering Murphy's question, "were the Little Joes a good investment," I would go through each alternative, and for each case would consider every aspect I could think of. It would start with a brain-storming exercise to think of what the alternatives and costs are. As I brain-storm costs and alternatives right now, some things that pop into mind include: cost of labor in places like Harlowton, Avery, Deer Lodge; cost of bulk diesel delivery to places like Deer Lodge; cost of electric power; useful life of electric equipment and diesel equipment; what combination of diesels and Little Joes was cheapest (0,1, 2, or 3 Little Joes); will more diesel exhaust create new problems in tunnels, etc; scrapping the whole system; etc.
Your study looks at just two aspects of the Little Joes: (1) horsepower, and (2) the route they were restricted to. Your conclusion is that because a Little Joe was not as powerful as a Saturn rocket, that it was nothing special. And you conclude that because a Little Joe could not run the entire distance, Chicago to Tacoma, that it didn't make economic sense. It's interesting stuff to consider, but we need to do the cost study and compare it to other alternatives.If I was a consultant given the job of answering Murphy's question, "were the Little Joes a good investment," I would go through each alternative, and for each case would consider every aspect I could think of. It would start with a brain-storming exercise to think of what the alternatives and costs are. As I brain-storm costs and alternatives right now, some things that pop into mind include:
cost of labor in places like Harlowton, Avery, Deer Lodge; cost of bulk diesel delivery to places like Deer Lodge; cost of electric power; useful life of electric equipment and diesel equipment; what combination of diesels and Little Joes was cheapest (0,1, 2, or 3 Little Joes); will more diesel exhaust create new problems in tunnels, etc; scrapping the whole system; etc.
No, I did not look at just two aspects of the Little Joes. My post on December 20 stated:
"There is tremendous cost in modifying locomotives en route, and such would have been the case with the Milwaukee’s segments of electrification. The main costs are locomotive dwell – the amount of time the power is just sitting around waiting for its next assignment – or delay for power, caused by an inbound train being delayed. Another expense would be paying hostlers to position the power at terminals or arbitraries paid to road crews to perform the locomotive work, which were commonplace on most railroads. In the days of the steam engine, locomotive changes en route were frequent. But with the implementation of a diesel-powered railroad, the greatest saving could be realized by utilizing the power from origin to destination, or with as few en route modifications as possible. "
You have also inaccurately stated my conclusion, which had nothing to do with how powerful the locomotives were. My point is simply that the Milwaukee or any railroad could have said that about any new power. For instance, when the SD40s were received, they could have said that three of them could move a 3,600-ton train from Chicago to Tacoma without power modification whatsoever, which would have sounded better than using twice as many GP9s or adding or subtracting power, electric or diesel or a comination, along the way. In other words, their statement about the Little Joes was just advertising, but could be spun about any newer or different locomotives. I also didn't state that horsepower had anything to do with the claim about the Little Joes; I simply am making the observation that if you assign enough power for the train to be pulled over the steepest point, you can make the claim that said power can handle the train from point A to point B without power modification. But that could be said about any kind of power. It is interesting to note, however, that the consist mentioned was two Little Joes and a GP9. Really does make one wonder why the GP9 was included; in other words, if you're trying to tout Little Joes, why not just 2 of them (period) and 3,200 tons? The obvious conclusion was that 3,200 tons isn't much of a train (although it was more of one in 1961), and does highlight the hefty amount of locomotive power needed to move trains on the Milwaukee Road.
I also earlier stated that I thought the Little Joes were a good investment for the Milwaukee Road given that the electrification was in place. The inefficiencies are due to the limits of electrification, given that electrification is the exception and not the rule.
Without doubt in today's railroading, the most cost-effective train operates from origin to destination without power modification, be it 100 miles or across the country on multiple railroads, which is today commonplace. An example of this is Amtrak's Northeast Corridor between New York and Boston. Amtrak was never really competitive with air travel until the segement from New Haven to Boston was electrified, eliminating the cumberson engine change in New Haven. Not only was there the actual delay for changing power, but there was the occasional waiting on locomotive power - either diesel or electric, depending on the direction of the train - when trains were running late. Never a problem when you don't have to worry about changing power en route.
I suspect that by the early 1970s as diesel power was becoming more powerful, more reliable, and runthrough trains with other railroads more commonplace, the Milwaukee looked at their isolated electric operations and their aging assets with limited geographic range and decided that the restrictions were too costly and did away with them.Note to all: The software weirds out sometimes and makes things hard to read. When I opened this up, it was written in teeny-tiny font with no breaks. I enlarged the font and put in some artificial paragraph breaks to make it easier to read on a computer screen.-Norris user/moderator
Mark Meyer
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