MidlandMike bogie_engineer You're correct that E's used 36" wheels - Why would passenger diesels use smaller wheels that freight locos? I wold have guessed the opposite.
bogie_engineer You're correct that E's used 36" wheels -
Why would passenger diesels use smaller wheels that freight locos? I wold have guessed the opposite.
I would imagine it has to do with getting 3 wheel sets within acceptable dimensions on the A1A truck. The bigger the diameter of the wheels the longer the wheelbase of the truck, plus having to 'stuff' traction motors in on two of the axles.
Never too old to have a happy childhood!
EMC began exclusively using its own electrical gear with the advent of the 567 engine in 1938. This includes EMC Demonstrators E3A #822 and SW1 #755 and all the Seaboard E4s.
Ed in Kentucky
bogie_engineerYou're correct that E's used 36" wheels -
daveklepper Apparently, I was in error on the very last DC motors. What about AC motors today? Are there varieties or just one for EMD-Progress Rail? Should be possible to do the job with just one type.
Apparently, I was in error on the very last DC motors. What about AC motors today? Are there varieties or just one for EMD-Progress Rail? Should be possible to do the job with just one type.
EMD has used 3 different motor diameters and several core lengths. The first is the Siemens 1TB2630 which was used in the SD70MAC, designed to take up the space between a gearcase and the opposite wheel in a standard gauge application. Variations of this same diameter were the 1TB2626 as used in the F69PH-AC and the 1TB2624 used in the LIRR DE/DM30AC's. This diameter was also used in the locos for India but I can't recall the length. The first two digits denote the diameter and the second two the core length but it's not any particular units like inches. These motors are designed for 42" minimum new wheels with 1.5" radial wear material (fully worn at 39").
The second size is a bigger diameter as used in the SD80 and 90MAC's, that was also a Siemens designed motor designated 1TB2830 roughly 3" larger in diameter IIRC. This is the only application of this motor size, which requires at least 44" dia new wheels. The bigger motor motor was needed to meet the design requirement of 200Klbs. tractive effort.
With the split from Siemens to using Mitsubishi inverters starting with the SD70ACe, EMD designed in house a new series of AC motors with diameter between the two Siemens motors to have capacity for 200Klbs. TE with 6 motors. This family of motors is designated A29XX and requires 42" new wheels. It's now used on all EMD/Progress Rail locos in widths to fit from meter to standard gauge, wider than standard uses standard gauge or smaller motors depending on axle load. All traction motors are now made in a facility in Mexico.
Dave
This was written about the F3 by a fellow Kentuckian back in the late 1940s.
THE AGE OF THE F-3
“Motive Power historians may well look back at our times, terming them “The Age of the F-3.” The pacemaking performance of Electro-Motive’s fabulous 1500-horsepower road diesel unit last year only accented the unparalleled sales success that the F-3 has been enjoying ever since its birth in October of 1946. Since then EMD has mass-produced it to a staggering 2.3 million horsepower represented by over 1500 cab and booster units, now hauling freight and holding down passenger schedules in three countries: the United States, Canada and Mexico. In all of locomotive history there is not even a close runner-up to that batting average; no other basic unit of motive power has gone so far and done so much in so short a time. Last year the F-3 introduced road after road to dieselized freight service, including potato carrying Bangor & Aroostook and orange hauling Florida East Coast; this year it will carry the banner to such new customer as the Clinchfield Atlanta & West Point, Texas & Pacific and Georgia.”
Overmod Erik_Mag I remember a discussion from a few years back where someone pointed out that the sum of pinion and bull gear teeth always ended up the same - which implied a constant tooth pitch. The reason both for the weird-looking ratios and some of the limitations here is that the pinion-to-axle centerline is fixed, the tooth profile, crowning, etc. is likewise concerned, and the mutual pitch circles for pinion and bull gear have to work out to contain an integral number of teeth.
Erik_Mag I remember a discussion from a few years back where someone pointed out that the sum of pinion and bull gear teeth always ended up the same - which implied a constant tooth pitch.
The reason both for the weird-looking ratios and some of the limitations here is that the pinion-to-axle centerline is fixed, the tooth profile, crowning, etc. is likewise concerned, and the mutual pitch circles for pinion and bull gear have to work out to contain an integral number of teeth.
Since the sum of the meshing radius of the pinion gear and bull gear is constant, the sum of the circumferences of the two gears will be constant. With a standard tooth pitch, this implies that the sum of the teeth will be the same. It does make sense that you need integer number of teeth on each gear.
My understanding is that it is a good idea for the number of teeth on the pinion to be relatively prime (i.e. greatest common divisor is 1) with the number of teeth on the bull gear.
My experience with Kapton was as a teen in the early 1970s when Railway Age included a free sample.
Dad worked at GATX, and railfan son pleaded to read Railway Age after the office circulation list had been completely checked off at Dad's work.
Railway Age was mostly a bunch of ads for center-plate grease cakes and diesel-locomotive lube oil suitable for what the CEO of Rio Grande described as "our turbocharged units", and a person knew that an oil suitable for turbocharged diesel locomotives on the Rio Grande had to be pretty good. The magazine, however, had the slimmest amount of news or rail industry innovations. But there was that sheet of Kapton.
What I remember about it is that it has the most static cling of any substance known to man. The selling point was its resistance to chafing and high temperatures in a traction motor, but it must be a really good insulator, too.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Overmod If you could adjust the nose suspension point, using larger wheels would allow a larger bull gear while keeping enough teeth on the pinion to keep it strong and limit pinion-tooth wear at 'freight' gear ratio, although I don't know if the work Leo Ames mentioned involved that.
If you could adjust the nose suspension point, using larger wheels would allow a larger bull gear while keeping enough teeth on the pinion to keep it strong and limit pinion-tooth wear at 'freight' gear ratio, although I don't know if the work Leo Ames mentioned involved that.
The development of the D90 traction motor for the SD70 was exactly that. Electrically the D90 is the same as the D87 - by increasing the axle to armature spacing allowed for a bigger bull gear while the pinion stayed the same - it's minimun size was dictated by hoop stress from the tapered bore where it mated to the armature shaft. The increased gear ratio more than made up for the effect of the bigger wheel so that's how the SD70 got a higher TE rating than the SD60. Because the HTCR truck was designed for the Siemens traction motor, which is physically bigger than the D87 requiring a greater spacing between the axle and motor nose support on the truck frame, the D90 also fit.
Leo_Ames Is that why the Bangor and Aroostook went to I think 40" wheels when they worked with EMD to retrofit their two E7's for freight service?
Is that why the Bangor and Aroostook went to I think 40" wheels when they worked with EMD to retrofit their two E7's for freight service?
I'm surprised they fit, brake rigging for sure had to be changed. But that truck was out of production before I started so I have no direct knowledge what had to change. We did adapt the GP truck to fit 42" wheels at the start of -2 production; the bigger wheels would hit the end transoms so the pattern was altered to allow them. I suspect something similar might have affected the E truck. To fit 42" wheels to trade-in GP trucks, we had a mod to cut away part of the end transom and weld in a chunk of heavy angle to restore the structure.
Erik_MagI remember a discussion from a few years back where someone pointed out that the sum of pinion and bull gear teeth always ended up the same - which implied a constant tooth pitch.
My understanding was that no part of the nose-suspended arrangement interfered laterally with using at least slightly taller wheels. The effect of 40" wheels would be like one reason for Golsdorf's use of taller drivers on his 2-6-4s in producing easier slip recovery, and perhaps somewhat lower back EMF for a given road speed. If you could adjust the nose suspension point, using larger wheels would allow a larger bull gear while keeping enough teeth on the pinion to keep it strong and limit pinion-tooth wear at 'freight' gear ratio, although I don't know if the work Leo Ames mentioned involved that.
A first pass on the limit on bull gear size would imply that an E could never have the same CTE rating as an F with the same traction motor, though the smaller wheel diameter would partially compensate. I remember a discussion from a few years back where someone pointed out that the sum of pinion and bull gear teeth always ended up the same - which implied a constant tooth pitch.
I'm guessing that kapton was introduced in the early part of the 1960's as the late 1960's Trains article on locomotive production at EMD stated that Kapton was used on the armature windings while the field windings were insulated with silicone. One example of the difference in using kapton was that the GE-750 motor used on the Little Joe's were good for ~375A continuous, whereas a 1969 proposal for the Milwaukee showed the GE-750 rated for 480A continuous.
Erik_MagAny idea when EMD started using Kapton insulation on thsir motors?
If I recall correctly 'Kapton' was the tape or film polyimide; the wire insulation was 'Pyre-ML'.
It would have been commercially introduced by du Pont after the last E units were built. Ghosh's book on the polyimides has the tape marketed in 1965, and the wire slightly later.
Incidentally, for fans of the history of technology, many of the issues in providing high-quality polyimide wire insulation deposition were similar to those in fiber production, and were solved with input from those people in the du Pont organization...
Erik_Mag Dave and Dave, I stand corrected... My understanding had been that the trucks on the E's had 36" wheels versus the 40" wheels on the F's, GP's and SD's and thus needed a smalller traction motor. Now something like a GE-750 traction motor... Any idea when EMD started using Kapton insulation on theor motors?
Dave and Dave,
I stand corrected... My understanding had been that the trucks on the E's had 36" wheels versus the 40" wheels on the F's, GP's and SD's and thus needed a smalller traction motor. Now something like a GE-750 traction motor...
Any idea when EMD started using Kapton insulation on theor motors?
You're correct that E's used 36" wheels - the wheel size dictates the bull gear size so using the same armature to axle distance, the E's were limited in the max numerical gear ratio since the pinion grows as the bull gear shrinks.
As far as Kapton, it was in use when I started in 1968 but I remember it being touted at the time as an advancement so probably wasn't too much earlier. The person I would have asked pass away a couple of weeks ago unfortunately.
daveklepper Before the FT and E-5 and E-6. I believe EMC-EMD used GE and Westinghouse motors. Also, I believe the latest DC EMD motor couild be used as a direct replacement for the first DC EMD motor.
Before the FT and E-5 and E-6. I believe EMC-EMD used GE and Westinghouse motors. Also, I believe the latest DC EMD motor couild be used as a direct replacement for the first DC EMD motor.
The D87BTR (D87B with tapered roller support bearings) as used on the SD60's used the same "box size" and would fit any E or F or switcher. The last NA traction motors, the D90 and D100 are the same box size but have a spread axle to armature distance to get a greater numerical gear ratio and use 42" wheels so would not fit in any truck prior to the HTCR or HTSC2 as used in the 70-series.
The same motor for all power reduced development, manufacturing, inventory, and railroad maintenanc costs, and was an EMD rademark from the E6-FT-era on. The motor was designed with the current capacity for drag-freight service, assuming low-medium-speed gearing, and the insulation for voltages in all operations, again with the right gearing chosen for the application. The same basic design was improved over the years with better insulation, more advanced metalurgy steels for pole pieces, better carbon compound fpr brushes, etc. The basic motor design lasted right up to AC motors.
Possibly, the same is true of their AC motors, today. (No brushes, of course)
bogie_engineer daveklepper My memory is that Es used the same traction motor as Fs and GPs. Ordered with dfifferent gear ratio That's correct.
daveklepper My memory is that Es used the same traction motor as Fs and GPs. Ordered with dfifferent gear ratio
My memory is that Es used the same traction motor as Fs and GPs.
Ordered with dfifferent gear ratio
That's correct.
MidlandMike bogie_engineer daveklepper My memory is that Es used the same traction motor as Fs and GPs. Ordered with dfifferent gear ratio That's correct. The E units had about 50% more HP than the F units, but they still had the same number of motors/powered axles (4). Why did both types use the same motors?
daveklepper My memory is that Es used the same traction motor as Fs and GPs. Ordered with dfifferent gear ratio That's correct.
The E units had about 50% more HP than the F units, but they still had the same number of motors/powered axles (4). Why did both types use the same motors?
I suspect it was a matter of standardization.
Overmod, thanks. IU now remember ther news od the derailment, and the loss hf lives.
For you, like me, it was like a personal tragedy.
for u
daveklepper But PRR's mistake was putting 100mph E8s into freight service without regearing.
But PRR's mistake was putting 100mph E8s into freight service without regearing.
Considering that the the motors on the E's were physically smaller than the motors on the F's, not regearing was a double whammy. Regearing would have improved matters, but still wouldn't have made it the equivalent of an F.
daveklepperInteresting. Can you provide more detail from what you know?
Read the report here:
https://books.google.com/books?id=CGdPAAAAMAAJ&pg=RA12-PP5(This should be accessible without the DOT library rigmarole)
EMD BLOCKAGE
Just as every EMD unit has an order number and a serial number, each diesel engine block installed in a unit has a number. These block numbers are recorded in the EMD Product Data, presumably for maintenance purposes.
EMD began manufacturing 16-567B blocks in 1945. The F2 demonstrators were completed in May of that year and released for test on July 31, 1945. There would have been a 16-567B installed in each of the four #291 demonstrators, plus another block or two for test purposes. Continued 16-567B production may have occurred later in 1945 up to the point where a strike shut down EMD in November. There is a bit of information that backs this up.
At the very end of FT production there were orders completed for 12 Great Northern and 12 Rock Island units. No other F units, that we know of, were produced until July 1946.
Now about those pesky block numbers. When EMD started F2 production, presumably in July 1946, there were nine maybe ten block numbers that point to a 1945 manufacture date. Three are within the number range of the Rock Island 16-567A blocks installed in FTs and six are just after. One block of a July 1946 produced F2A is not known at this time because a mid-1948 production 16-567B was installed at a later date. There were 43 F2As built with a July 1946 production date. In numerical sequence from oldest 16-567B block installed in nine F2As is: Rock Island 39, Rock Island 49, Burlington 152A, New York Central 1604, Alabama Great Southern (Southern) 6700, Burlington 150A, Atlantic & East Coast 401, Rock Island 38, and Rock Island 46. The July 1946 F2A with the unknown block installed is Atlantic & East Coast 400 which shows as a block built in the Summer of 1948, which would obviously be a transplant. The remaining F2A production for July 1946 have 16-567Bs that fall within numbers that mirror other 1946 engine production. You can draw your own conclusions if these block numbers mean anything.
Interesting. Can you provide more detail from what you know?
Problems with transition caused the SOU RR's overspeed wreck of the Southern Crescent.
After thinking some more and exploring my memory, I find additional comments are in order.
1. 18 mph is just one figure, obviously dependent on type of motor and the gear ratio. EMD power gear ratios were optional, with top rated speed up to and including 100mph for E7s and I would guess also E8s.
2. Two ways to implement automatic trqnsition, read off the speed recorder, with downward transition just lightly under the speed of upward transition, to avoid hunting. This requres separate circuits for upward and downward transition. I think this is what used and what was in general use at EMD 1952. I cannot be sure, because this was two-months shy of 68 years ago. The other is by measuring the ratio of the voltage acrosss the armature brushes as compared with across the in-series field coil, the latter a reasnably accurate measure of he current through the motor, and effect transition uward or downward depending on throttle setting, motor characteristics, etc. for most economical and efficient performance. I don't think EMD had arrived at that point in 1952, but they may have before switching to AC motors. With current measuremene, downward transition would not be a separable circuit from upward transition.
3. My assuming PRR's maintenance and overhaul people were stupid enough to remove downward transition was probably a mistake. Granted, EMD would not have sold a locomotive without downward transition. But PRR's mistake was putting 100mph E8s into freight service without regearing. Recall that 90mph GG1s saw both freight and passenger service, but 100mph saw only passenger service except for very rare and controlled circumstances. The downward transition point for the E8 was probably not suitable for extended low-speed operation, with motor-heating from maximum current for extended periods. So it seemed like there was no automatic backward transition, because it did not occur soon enough as speeds fell with maximum power entering a grade.
4. So the only way the locomotive could peform without problems was to insure the practice of manuel backward transmission. Shut off to idle, wait a few seconds, and then reapply power a notch at a time.
5. They should have regeared them. Or contacted EMD about simple circuit adjustments.
I might be proved wrong, because this is all from an 88-yeaar-old's memory of events 68 years ago.
th
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