EMD F2 Built After F3 Production Began

9450 views
84 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    September 2003
  • 12,021 posts
Posted by Overmod on Wednesday, July 1, 2020 9:40 AM

daveklepper
Interesting.  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)

  • Member since
    January 2019
  • 575 posts
Posted by Erik_Mag on Wednesday, July 1, 2020 2:56 PM

daveklepper

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.

  • Member since
    June 2002
  • 16,592 posts
Posted by daveklepper on Wednesday, July 1, 2020 3:35 PM

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

  • Member since
    June 2002
  • 16,592 posts
Posted by daveklepper on Wednesday, July 1, 2020 9:02 PM

My memory is that Es used the same traction motor as Fs and GPs.

Ordered with dfifferent gear ratio

  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Wednesday, July 1, 2020 9:40 PM

daveklepper

My memory is that Es used the same traction motor as Fs and GPs.

Ordered with dfifferent gear ratio

 

That's correct.

  • Member since
    September 2011
  • 4,772 posts
Posted by MidlandMike on Wednesday, July 1, 2020 9:52 PM

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?

  • Member since
    May 2003
  • From: US
  • 18,882 posts
Posted by BaltACD on Wednesday, July 1, 2020 10:56 PM

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?

I suspect it was a matter of standardization.

  • Member since
    January 2019
  • 575 posts
Posted by Erik_Mag on Wednesday, July 1, 2020 11:29 PM

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.

 

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?

  • Member since
    June 2002
  • 16,592 posts
Posted by daveklepper on Thursday, July 2, 2020 5:57 AM

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)

  • Member since
    June 2002
  • 16,592 posts
Posted by daveklepper on Thursday, July 2, 2020 6:42 AM

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.

  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Thursday, July 2, 2020 12:37 PM

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.

 

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.

Dave

  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Thursday, July 2, 2020 12:46 PM

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?

 

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.

Dave

  • Member since
    September 2003
  • 12,021 posts
Posted by Overmod on Thursday, July 2, 2020 2:56 PM

Erik_Mag
Any 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...

 

  • Member since
    November 2008
  • 1,482 posts
Posted by Leo_Ames on Thursday, July 2, 2020 2:56 PM

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?

  • Member since
    January 2019
  • 575 posts
Posted by Erik_Mag on Thursday, July 2, 2020 3:07 PM

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.

  • Member since
    September 2003
  • 12,021 posts
Posted by Overmod on Thursday, July 2, 2020 3:25 PM

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.

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.

  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Thursday, July 2, 2020 5:56 PM

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?

 

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.

Dave

  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Thursday, July 2, 2020 6:06 PM

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.

 

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.

Dave

  • Member since
    July 2004
  • 2,385 posts
Posted by Paul Milenkovic on Thursday, July 2, 2020 8:01 PM

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?
  • Member since
    January 2019
  • 575 posts
Posted by Erik_Mag on Friday, July 3, 2020 12:42 AM

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.

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.

  • Member since
    June 2002
  • 16,592 posts
Posted by daveklepper on Friday, July 3, 2020 1:51 AM

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.

  • Member since
    July 2001
  • From: Shelbyville, Kentucky
  • 1,845 posts
Posted by SSW9389 on Friday, July 3, 2020 12:10 PM

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.”

Ed in Kentucky

COTTON BELT: Runs like a Blue Streak!
  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Friday, July 3, 2020 2:48 PM

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.

 

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

  • Member since
    September 2011
  • 4,772 posts
Posted by MidlandMike on Friday, July 3, 2020 8:37 PM

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.

  • Member since
    July 2001
  • From: Shelbyville, Kentucky
  • 1,845 posts
Posted by SSW9389 on Saturday, July 4, 2020 3:52 AM

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

COTTON BELT: Runs like a Blue Streak!
  • Member since
    May 2003
  • From: US
  • 18,882 posts
Posted by BaltACD on Saturday, July 4, 2020 7:35 AM

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.

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.

  • Member since
    September 2003
  • 12,021 posts
Posted by Overmod on Saturday, July 4, 2020 9:22 AM

BaltACD
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.

How do you figure this?  The wheelbase of the truck is fixed by the axle spacing, which changes not a whit when the wheel diameter is changed.  This is why the Niagara wheelbase did not change when the conversion from 75" to 79" was made ... the "increase" in wheel width was pre-accommodated by making the cast engine bed and side rods with appropriate length to allow the wheels to fit longitudinally, meaning the rigid wheelbase was 'longer than it needed to be' for an engine with 75" drivers' in the first place.

Likewise if the motor system fits between the inside faces of the wheels, increasing the wheel radius by 2" may be of little importance.  It will depend on whether any part of the TM or its nose suspension is wider (and cannot be milled down, etc. to allow the larger wheels).

As Mr. Goding indicated, the brake rigging would require adjustment, which might be substantial, but that's another issue.

  • Member since
    April 2007
  • From: Palos Park, IL
  • 85 posts
Posted by bogie_engineer on Saturday, July 4, 2020 11:43 AM

MidlandMike

 

Why would passenger diesels use smaller wheels that freight locos?  I wold have guessed the opposite.

 

I have a book published in 1945 with a section entitled "Diesel Locomotive Trucks and Draft Rigging" written by Martin Blomberg that has detailed descriptions of the "Six Wheel Passenger-Locomotive Truck, Freight-Locomotive Truck, and Switcher Truck" as he titles them. He fully describes all the elements of the truck and some of the design rationale but makes no mention of why the E truck was designed around 36" wheels. The drawings and photos in the book make it seem to me to be possible to apply 40" wheels with only brake rigging modifications. However, I believe the idlers would have to stay at 36" (not a problem, we had an A-1-A export truck with 33" idlers and 40" driven axles).

Given the E pre-dates the F units, it may be that the 36" wheels were the starting point and when they designed the FT, they realized the benefit of larger wheels allowing a higher gear ratio for a net increase in tractive effort, or more likely that all could have been mapped out when the traction motor was designed.

He does mention that the 36" wheels have only 1" of radial wear material as opposed to the the 40" wheels on the GP truck and others with 1.5"radial wear. I have to think the choice of 36" wheels was driven by desire to keep the E locomotive height low. He does mentions the truck is designed for 117 mph operation but I haven't found any mention of actual service at that speed, perhaps someone here can give me a reference. 

Dave

  • Member since
    July 2010
  • From: Louisiana
  • 2,032 posts
Posted by Paul of Covington on Saturday, July 4, 2020 12:33 PM

   Just a thought from someone who doesn't know:  I was thinking about unsprung weight.  The smaller wheels being lighter might give a better ride at higher speeds in passenger service.

_____________

My mind's made up.  Don't confuse me with the facts.

  • Member since
    May 2003
  • From: US
  • 18,882 posts
Posted by BaltACD on Saturday, July 4, 2020 4:20 PM

Overmod
 
BaltACD
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. 

How do you figure this?  The wheelbase of the truck is fixed by the axle spacing, which changes not a whit when the wheel diameter is changed.  This is why the Niagara wheelbase did not change when the conversion from 75" to 79" was made ... the "increase" in wheel width was pre-accommodated by making the cast engine bed and side rods with appropriate length to allow the wheels to fit longitudinally, meaning the rigid wheelbase was 'longer than it needed to be' for an engine with 75" drivers' in the first place.

 

Likewise if the motor system fits between the inside faces of the wheels, increasing the wheel radius by 2" may be of little importance.  It will depend on whether any part of the TM or its nose suspension is wider (and cannot be milled down, etc. to allow the larger wheels).

As Mr. Goding indicated, the brake rigging would require adjustment, which might be substantial, but that's another issue.

How much space are you allocating between axles - 40" wheels occupy 4 more inches than 36" wheels.  If there were 2 inches of clearance between each of the 36" wheels - the 40" wheels won't fit the same axle spacing.

I don't know the actual spacing of the EMD A1A trucks and what clearance is necessary for the traction motors of the day.  I suspect the traction motors are configured to occupy the space between the powered and unpowerd axles on the truck.

Things can get tricky when you start relating to things like gear ratios and the required pitch of the various gears that are necessary to mesh properly with each other.

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

Newsletter Sign-Up

By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy