Discussion in 'E8A' started by FRISCO4503, Sep 12, 2012.
Why did the Frisco not have any of the E8B units?
I think they would have looked neat.
I do not recall seeing any passenger train with over two E units, so my guess is that they did not need them.
The Frisco did have an E8B ..... on the cover of their public timetables!
Don is correct, the Frisco passenger trains and passenger runs were amply served with two E units.
Thus, the flexibility of an A-A power set is obvious. You do not ever need to turn them as you would if it were an A-B set. If extra power was ever needed for some reason, probably only because one of the E units was sick, they stuck a passenger equipped FP7A, GP7, F3B, F7B or F9B in between the two A-unit E units.
But, the Frisco should have had real B-unit E units because, as F-4503 noted, they would look neat. That is why I am making a Frisco E8B If I would ever get off my a_s and finish it! I am hung up now on the correct shade of red to paint it such that it matches my P2K Racehorse units.
In the same light, they should have had a few Alco PA Racehorse units, even if they would certainly have been operational and maintenance nightmares.
I would say that is right.
I do not know about the E8As but in later years, I ask several General Managers the same question. I always got the same answer. They really did not like cabless units, they were of no value.
If the lead engine lost the heater, a headlight or anything, a cabless unit was of no value. When I was about six or seven, we went down to the Springfield Diesel Shop when it rained to pickup Grandpa Jackson. He worked for Frisco as a boilermaker. Everyone in the shop knew him, and also they knew me. I used to walk in like I owned the place.
The shop in about 1959 or 1960 was almost always full of covered wagons or that is what they called them. At the time, of course I would not know the difference. Still might not. I remember the site though. Lots of the black and yellow units. Quite a site.
We did that for several years, most likely until I was ten or twelve. That is just a guess, a kid does not pay much attention to how old he is. The shop smelled of oil and diesel. it was kinda dark. I used to walk down the platforms with the pits in the center.
After I hired on, they used to pass out paychecks at the shop. It was a neat place. Kinda like a part of my past.
FP7As were also sometimes lashed up with the E units.
Also, there are photographs of F7Bs sandwiched between E units.
In the book Frisco Southwest, there is a picture of two Frisco E8As with a Katy F7B in between on the Texas Special at Dallas, TX.
As discussed below, a pair of E-units was sufficient to handled the typical Frisco passenger consist.
An A-A set made easy the task of going back in the other the direction.
An E8B would have been overkill, and an A-B set would complicate operations.
When passenger train consists became swollen with additional cars due to troop movements, holiday mail, or other special circumstances, the Frisco did not hesitate to add additional power.
The lack of a nose multiple unit (MU) receptacle on its E units precluded the use of a third E-unit in any locomotive consist, but as noted, the Frisco had SG-equipped GP7s and steam line-equipped, covered wagon B units to handle the task.
In the photograph listed at this link, post #4, a swollen southbound train No 101 passes Rosedale with a pair of E units framing a GP7.
During the summer of 1966 some 30,000 machinists struck TWA, Eastern, United, National, and Northwest airlines. Between July 8 and August 19, 60% of the US air capacity disappeared. Passengers, mail and parcel express returned to the rails in numbers not seen in over a decade.
The Frisco even aired commercials for the Southland on a couple of Kansas City area radio stations. It was a good time.
Dumb question - I can understand not needed an MU connection on the nose-end.
But in the above photo the last E unit is coupled to the express cars.
So they did not always need a steam generator equipped unit for this type of consist as the cars had their own heating equipment?
Those booster units, be it a GP7 or a F7B/F9B, would have constrained the "legs" of the E units.
No speed record to be set on those runs.
The booster would help in the effort to pull out of a station stop quickly, in climbing a tough grade or running around a tough curve.
However, they would run out of gas about the time the E units got their legs.
But, they certainly helped handle a heavy train.
The issue with the Gp7 or F-units would be the gear ratio.
Theoretically, the maximum speed of a diesel-electric locomotive is infinite. I do not have any Frisco documentation handy, but generally speaking, the maximum speed on these freight units would be 65 mph.
They would go faster if you kept the overspeed device from kicking in. I have been there and done that. The problem comes in with the speed that the traction motors are turning.
When you exceed the maximum speed for a given gear ratio, you risk destroying the traction motor.
What usually happens is the windings spin apart and the inside of the traction motor looks like a bird's nest.
Yep, "birds nest". not pretty.
Call the machinist, remove the gear case and cut the bull gear with a torch, an especially miserable job.
I was train watching at the depot in Springfield around Christmas 1962 when train No 106 arrived late.
The train had with 22 cars, including 11 express refrigerator cars of Christmas mail on the head end!
It was pulled by two E-units and a freight B-unit spliced in between.
Visiting with the station master, he told me that the B unit did not help with speed, but was there to help start the heavy train from stops.
Yep, the Frisco was not a particular high-speed passenger railroad, so the use of primarily freight GP7 or booster F3B, F7B, F9B did help when needed. Only one of the F3Bs, SLSF 5117, also had steam pipes.
Some of the Frisco GP7s had steam boilers, the F3B and some of the F7Bs, F9Bs were equipped with through steam pipes.
What about the use of one of the Frisco FP7As mated with an E-unit, for whatever reason?
How common was that?
I do seem to recall seeing a picture of this combination, I think at Ft Smith, AR.
Perhaps it is one of Mike Condren's pictures?
The same speed limitations due to gearing would exist with the FP7A with their 62 to 15 ratio.
If speed was truly an issue, the units we have been discussing could have had the gear ratio changed to match the E8As.
Granted, this would have reduced the tractive effort available in freight service.
But, they would not have slowed things down when used on passenger trains.
I have seen former Amtrak F40PHs used in freight service with no modifications.
Not the greatest, but they did work.
The Frisco passenger trains never made the TRAINS magazine’s speed surveys.
But on the St. Louis-Oklahoma City and Kansas City-Birmingham, and I think on the Tulsa-Denison lines, the maximum speed limit for passenger trains was 70 mph. The Frisco E‘s were geared for 85 mph, and in places, the 70 mph limit was exceeded.
As noted the Frisco’s “passenger” GP7s and covered wagons were geared for 65 mph, and one might be inclined to think that this added significantly to the time required to get from Kansas City to Birmingham for example.
I have attached a graph that shows seconds per mile for a given speed. The curve is asymptotic, which means that as the curve moves away from the origin, it will approach, but never touch or cross the x or y axis.
In short, this means that at higher speeds a very large increase in speed is required to achieve a significant time savings. So, when we reduce our passenger train speed from 70 mph to 65 mph, we are only losing about 4 seconds per mile. It will take 15 miles to lose a minute off our schedule.
Conversely, at lower speeds an increase of that same 5 mph will generate a very large savings in time over a given distance.
This has several interesting applications. For example, if you were a roadmaster, who wanted to improve the travel time over his subdivision, one would get more bang for your tie budget if you eliminated the low end speed restrictions.
Getting all of those 10 mph restrictions bumped up to a 20 or a 30 mph restriction would improve times more cost effectively than raising a 45 mph restriction back up to a 55 mph speed limit, all other things being equal.
I think that we can draw some similar inferences from the chart with regard to our speed-constrained passenger train consist of an E8A/F7B/E8A verses an E8A/E8A consist. As noted, placing that freight unit in our consist will reduce our top speed, and we will lose at least 4 seconds a mile wherever the speed limit is above 65 mph.
On the other hand, the third unit will improve the acceleration, so that the train will get back to its maximum speed more quickly after station stops and speed restrictions. The 3-unit passenger train will spend more time running at its maximum speed, even though slower than a 2-unit train.
Consequently, I believe that the 3-unit train will have faster average “acceleration speed” on the low end of the spectrum. Depending on the number of station stops and the number and nature of the speed restrictions encountered, this improvement on the “low side” could offset the lost time at the high end of the speed axis.
I had no doubt that Frisco management made their decision to use freight units based on an analysis that was probably very similar to yours.
Without a sustained long-distance run, the difference in speed between 65 and 70 is minimal.
Thanks for providing the graph and explanation that helps put everything in perspective.
Nice chart and explanation.
Ain't math great!
I love it when you speak math asymptoticly or geology, stratigraphic succession, crypto-crystalline quartz.
I do not know how you do that, I was thinking almost the same thing.
Well, maybe not exactly!
That was cool...
Sent from my Galaxy Siii
Who would have thought that Coach Mo's Advanced Algebra and Trigonometry Class or Dr. Kurtz's Geology of Missouri Class would have paid dividends for my interest in railroads.
I should have been a more diligent student.
What is it that they say about "great minds"? ;-)
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