What's so special about Big Boys?

[Anonymous]

QUOTE: Originally posted by feltonhill

trainjunky29,

Thanks for the title. I'd forgot about the reference.

For those who don't have the book, it's an impressive looking thing, with various chapters written by well-known railroad history authors. The chapter you cited, Hard Times, was written by H. Roger Grant, author of several railroad history books outside Rails Across America. Currently Professor of History at Clemson, too. However, he makes one step into technical material and stubs his toe. Probably believed something he read along the way somewhere and didn't stop to check it out. I'm surprised that it got past the consulting editor, Bill Withuhn.

In a larger sense, how does one combat this sort of misinformation? Book looks good, prestigious writers, what chance do any of us lesser mortals have against that? Why, you can easily imagine people looking down their noses and saying, "How do you know more than he does? You're not an author!" Yep, he who publishes first wins.

Just one more example of how hype keeps going, and going, and going......

The other thing is that steam locomotives could in reality do some incredible things--a class A hauling 160 cars on the level, an FEF-3 cruising at 100 just 10 miles out of a station stop, etc. It's hard to know where the capabilities end and the misinformation begins. When you see a book like Rails Across America, with the aforementioned prestigous and authoratative looks, you tend not to question it. Equations help, but they are not perfect, nor are the measurements of a locomotive's tractive effort, horsepower, etc. And just to make matters worse, there are so many numbers floating around for horsepower on big locomotives that agreeing on what is larger in one area is itself difficult.

Sincerely,
Daniel Parks

[feltonhill]

timz,

Good observation. The location wasn't specific either, so why not a downgrade?.

The author said:

"......Then the greatest steam beasts of all debuted in September 1941. Again, Union Pacific took the lead. Between 1941 and 1944 that company added 25 of the behemoth 4-8-8-4's called 'Big Boys,' to its fleet of locomotives. The only engines of their type, they weighed 600 tons and their 7,000 horsepower could pull a loaded 5 1/2 mile long train at speeds of 66 mph [not a typo] on level track."

Above quoted from Rails Across America, page 145, chapter titled Hard Times, by H. Roger Grant.

That's it. No relevant footnote or endnote that lists possible source that I can find.

[timz]

What did he say, exactly?

After all, if you assemble it at Archer a 5 1/2 mile train will easily reach 65+ mph coasting downgrade eastward, if it holds together.

[feltonhill]

trainjunky29,

Thanks for the title. I'd forgot about the reference.

For those who don't have the book, it's an impressive looking thing, with various chapters written by well-known railroad history authors. The chapter you cited, Hard Times, was written by H. Roger Grant, author of several railroad history books outside Rails Across America. Currently Professor of History at Clemson, too. However, he makes one step into technical material and stubs his toe. Probably believed something he read along the way somewhere and didn't stop to check it out. I'm surprised that it got past the consulting editor, Bill Withuhn.

In a larger sense, how does one combat this sort of misinformation? Book looks good, prestigious writers, what chance do any of us lesser mortals have against that? Why, you can easily imagine people looking down their noses and saying, "How do you know more than he does? You're not an author!" Yep, he who publishes first wins.

Just one more example of how hype keeps going, and going, and going......

[Anonymous]

The name of the book that states that a Big Boy could haul a 5.5 mile train at 65 mph is Rails Across America. Though I concede that a Big Boy could not haul it at 65, I am confident that, with an experienced engineer, it could start it.

Dear GP40-2,
Please stop with the personal attacks.

Sincerely,
Daniel Parks

[feltonhill]

GP40-2,

Misinterpreted your direction, my bad.

[Anonymous]

Thanks for the info Old Timer.

[Anonymous]

Sayeth andysmith9670:

"There is a Y-6a (2156?) in a museum in Missouri but I don't know if there is much difference between the 2 sub classes."

There is no difference in the performance of the 4 2100-2200-series N&W 2-8-8-2s - the Y-5s, Y6s, Y6as and Y6bs. The Y6bs were the most famous because they were the newest, but as new improvements were developed the older 2100s were retrofitted with all of them.

Old Timer

[GP40-2]

QUOTE: Originally posted by feltonhill

Trainjunky29,

Your estimate of 75,000 lbs seems to be in the ballpark. I got 94,000 lbs train resistance at 1 mph for the 785-car train and about 71,000 lbs resistance for the 548-car train.

Actually, according to the info I have, a figure of 20 lbs/ton for starting inertia of friction bearings is at the low end of available estimates. Some sources go as high as 30-40 lbs/ton. The biggest problem is "bumping" each car into motion using slack. With a 100-150 car train, this isn't too bad; with 785 cars it's beyond careful. I was trying to illustrate that one BB could theoretically start and move such a train, and that it really wasn't such an over-the-top accomplishment. The downside was the practical matter of getting the whole assemblage moving without breaking in two.

GP40-2,

Yes, I've heard of cutoff. How else would the drawbar pull curves have been developed? Running a loco in full gear at speeds greater than 20-25 mph will exceed the boiler's capability to produce steam. From about 15 mph on, the loco is being hooked up. What are you driving at?

Feltonhill,

What are you talking about????

I never mentioned you in that post. I was making a comment about the B.S. posts Electro-whatever and the Fantasy-junky29 made up.



Oldtimer,

No use arguing with the Trainjunky. He obviously know a lot more about steam locomotive than you will ever know[(-D] Besides, everybody just knows that the Big Boys were the greatest,most powerful, efficient,heaviest,longest,tallest,widest,highest tractive effort AND horsepower,best looking,best riding,best engineered,longest lasting (oh, wait a minute isn't that from a Chevy truck commercial??) locomotive.

[selector]

QUOTE: Originally posted by trainjunky29

One thing to bear in mind is that resistance from friction bearings decreases as speed increases. At low speed, you have brass (or bronze) on steel, but at higher speeds, a film of oil develops.

Sincerely,
Daniel Parks

You seem to support my assertion earlier, thanks. I hope someone will address my question...?

-Crandell

[Anonymous]

One thing to bear in mind is that resistance from friction bearings decreases as speed increases. At low speed, you have brass (or bronze) on steel, but at higher speeds, a film of oil develops.

Sincerely,
Daniel Parks

[Anonymous]

Did a Big boy ever ride togethwe with a Big blow turbine?

I've seen a picture of it running with a "standard" turbine, but never with a big blow.

Accoarding to their years, it was possible, but doesn't mean they did it

[Modelcar]

Up829....An interesting bit of run down on what really took place.

[Anonymous]

The Wyoming Division of the UP was and is a choke point for the railroad. Lines split off to the east and west but virtually everything goes through Wyoming. UP was a bridge route and traffic of all types went over the division in both directions. Sherman Hill on the east and the Wahsatch on the west are the major grades, but the saddle in the middle is roughly 350 miles with a 1% eastbound grade between Laramie and Sherman summit. Big Boys also worked the line down to Denver.

The Big Boys can be thought of as Challengers on steroids, their drivers were only 1 inch smaller. Like the Allegheny and the A, they were designed to start heavy trains AND to get them over the road at reasonable speeds without tying up this criitical bottleneck. They along with the Challengers pulled general freight, refer trains, livestock trains, and even troop trains. Coal drags were generally handled by older rebuilt 2-8-8-0's and during the war by a group of 30 2-8-8-2's purchased from the C&O and 5 2-8-8-2's from N&W. The N&W compounds tied up the Sherman hill so bad, they were re-assigned to the coal mine branch lines around Rock Springs, where they worked succesfully doing what they were designed to do for many years, outlasting the C&O locos.

Unlike the Allegheny's, Big Boys actually worked in the service they were designed for for many years and were doing so at the close of the steam era when Cheyene became almost a meca for steam fans. By then double headed Big Boys or occasionally a Big Boy double headed with a Gas Turbine thundering by was a memorable experience.

The name Big Boy came from a worker at Alco. The trade press caught on, and railroad PR departments of that time were always looking for something to hype as the biggest, greatest, fastest, etc, plus I suspect a lot of these claims are a little like fish stories. It's interesting to sepculate how many cars a Big Boy could drag out of a yard or what a NP Yellowstone would do burning eastern coal, but neither was really designed or optimized for that service. One reason steam loco's lasted as long as they did on certain roads, was because the railroads owned the coal mines.

[feltonhill]

Trainjunky29,

Your estimate of 75,000 lbs seems to be in the ballpark. I got 94,000 lbs train resistance at 1 mph for the 785-car train and about 71,000 lbs resistance for the 548-car train.

Actually, according to the info I have, a figure of 20 lbs/ton for starting inertia of friction bearings is at the low end of available estimates. Some sources go as high as 30-40 lbs/ton. The biggest problem is "bumping" each car into motion using slack. With a 100-150 car train, this isn't too bad; with 785 cars it's beyond careful. I was trying to illustrate that one BB could theoretically start and move such a train, and that it really wasn't such an over-the-top accomplishment. The downside was the practical matter of getting the whole assemblage moving without breaking in two.

GP40-2,

Yes, I've heard of cutoff. How else would the drawbar pull curves have been developed? Running a loco in full gear at speeds greater than 20-25 mph will exceed the boiler's capability to produce steam. From about 15 mph on, the loco is being hooked up. What are you driving at?

[amtrakjackson]

Nothing. Real engines have extended range dynamic brakes.

[Anonymous]

I know that 8 Bigboys and I think 3 H8s survive, but as far as I know all the Y-6bs were scrapped. There were apparently 2 rusting in a scrap yard in Roanoke up until the seventies but I think that there gone now. (Can anybody shed any light on this)

There is a Y-6a (2156?) in a museum in Missouri but I don't know if there is much difference between the 2 sub classes.

[Anonymous]

QUOTE: Originally posted by trainjunky29

QUOTE: Originally posted by piouslion

QUOTE: Originally posted by cuddlyjools

The only answer now would be an H8, Y6b and a Big Boy head to Head over the same conditions and see who was top dog. It's a shame that non are in a operating condtition but if anyone ever came up with a scheme where this was going to be done and needed contributions, i'd put $100 in.

http://julian-sprott.fotopic.net

That's the easy part, finding a qualified shop with available space, qualified operators,track time and space, and a very understanding benevelant railroad officer with a since of humor. Then mabe something like what you're talking about might happen. Good luck.

Yeah, but money can fix all of that [:)]!

Get volunteers to do at least some of the job.

Sincerely,
Daniel Parks

[Anonymous]

QUOTE: Originally posted by Old Timer

Steve Lee of the UP steam program said on a videotape that Big Boy was capable of starting a 5 1/2 mile long freight train. He didn't say it ever had started one. In other words, its starting tractive effort of 135,375 pounds was enough to start a 5 1/2 mile train.

I think that in this instance, we sort of have to defer to Mr. Lee.

[Anonymous]

QUOTE: Originally posted by GP40-2

QUOTE: Originally posted by electro-ortcele

Ok, lets supose you have a train of 5.5 miles long.
That's 8.8km , or 8800 meters.
Let's say you have bigger cars that are 20m long, that's 440 cars.
Let's say each car has 60 tons loaded. That's 26400 tons.

The rolling resistance on horisontal terrain is about 5 lbs per ton.
So you'd have to apply a force of 132000 lbs to keep that train at your desired speed.

If you used diesels, then the amount of HP required would be: (force in lbs)x(speed)/375 and that's about diesel 22880 hp on the drawbar

When it comes to steamers, they act differently. The are able to sustain their starting tractive effort for a long range of speeds.
Big boy already had a starting tractive effort greater than 132000lbs that is required for this, but I don't think it could keep it up to 65mph

If Big boy could keep its starting tractive effort up to 65mph (which I doubt, but I don't know for sure), then it could indeed pull a train 5.5 miles long at 65mph.

But even if it couldn't, it could do the same at lower speeds.
Steamers have constant force as oposed to electrical transmision locomotives that have contant hp but changing( falling) force.


In other words, as incredible as it may sound at first, a steamer could pull much more load for the same hp because it could keep its starting tractive effort for a long range of speeds, and didn't have a minimum continuous tractive effort.

The reason why a single diesel can't pull 5.5. miles long trains, is not because it is too weak, but because the required trative effort could only be reached at lowers speeds which are forbiden for a DC traction locomotive because the motors would burn up.

Blah,Blah,Blah...A steam locomotive is not a constant force machine. I guess you and the Trainjunky never heard of steam cutoff.

Trainjunky; you are like an pesky little fly that buzzes around a picnic table. You post made up crap and lies all over this site, and when others tell you your little fantasy can't happen, you buzz off for a while, olny to return to bother us WITH THE SAME CRAP AND LIES.

No go and fly off and eat some dog poop.

Dear GP40-2,
Firstly, I will gladly argue with you about steam locomotives until the cows come home. But please, don't go into personal attacks. We've had plenty of forum fires recently.

Firstly, cutoff does not effect maximum tractive effort, only average tractive effort throughout the stroke, and the horsepower consequently. Wether in full gear or hooked up, the valve gear will still admit full pressure to the cylinder, so in all cases the locomotive has full tractive effort at some portion of the piston's stroke (except of course when the reverser is very close to center and no steam is admitted). The Big Boy's engines' exact characteristics would of course vary depending on the time since last overhaul etc. In short, if you put the reverser full forward and open the throttle wide, you'll have full force throughout just about all of your motion (1.2 million pounds of inertia helps too).

I have to agree with the post above that the grade of coal also affected the Big Boy's horsepower.

And please, let's not get in a fight over a bunch of statistics where we're not even sure which numbers are right and which are wrong.

Sincerely,
Daniel Parks

[Anonymous]

Quoth WMohrCHS:

"Also, I agree the N&W etc. (on the East coast ) engines were more powerful, but not correctly employed (I hope that word is okay) like the Big Boys had been. - "

Beg to differ, sir. N&W designed its locomotives to produce their maximum drawbar horsepower at the speeds they'd spend most of their time running. The Y-5-6 series developed its maximum drawbar horsepower at 25 MPH, ideal for N&W's tonnage, grades and curves. The class A 2-6-6-4 developed its maximum drawbar horsepower between 40 and 45 MPH, exactly at the point where it could be used to greatest advantage in the services in which it was used.

Big Boy developed his maximum drawbar horsepower at 41 MPH. Working westbound up Sherman Hill he never got that fast if he had his full tonnage. Working eastbound up the Wahsatch he had one short area where he'd get up that fast if he had his full tonnage. The rest of the time he was working below his maximum horsepower speed. In the "saddle" between the Sherman summit and Wahsatch summit, he could run that fast, but there were no big grades to deal with. Figured on the basis of time spent working at or above the maximum drawbar horsepower speed, the N&W engines were far better utilized than the Big Boy.

Welcome to the Forum, BTW.

Old Timer

[GP40-2]

QUOTE: Originally posted by electro-ortcele

Ok, lets supose you have a train of 5.5 miles long.
That's 8.8km , or 8800 meters.
Let's say you have bigger cars that are 20m long, that's 440 cars.
Let's say each car has 60 tons loaded. That's 26400 tons.

The rolling resistance on horisontal terrain is about 5 lbs per ton.
So you'd have to apply a force of 132000 lbs to keep that train at your desired speed.

If you used diesels, then the amount of HP required would be: (force in lbs)x(speed)/375 and that's about diesel 22880 hp on the drawbar

When it comes to steamers, they act differently. The are able to sustain their starting tractive effort for a long range of speeds.
Big boy already had a starting tractive effort greater than 132000lbs that is required for this, but I don't think it could keep it up to 65mph

If Big boy could keep its starting tractive effort up to 65mph (which I doubt, but I don't know for sure), then it could indeed pull a train 5.5 miles long at 65mph.

But even if it couldn't, it could do the same at lower speeds.
Steamers have constant force as oposed to electrical transmision locomotives that have contant hp but changing( falling) force.


In other words, as incredible as it may sound at first, a steamer could pull much more load for the same hp because it could keep its starting tractive effort for a long range of speeds, and didn't have a minimum continuous tractive effort.

The reason why a single diesel can't pull 5.5. miles long trains, is not because it is too weak, but because the required trative effort could only be reached at lowers speeds which are forbiden for a DC traction locomotive because the motors would burn up.

Blah,Blah,Blah...A steam locomotive is not a constant force machine. I guess you and the Trainjunky never heard of steam cutoff.

Trainjunky; you are like an pesky little fly that buzzes around a picnic table. You post made up crap and lies all over this site, and when others tell you your little fantasy can't happen, you buzz off for a while, olny to return to bother us WITH THE SAME CRAP AND LIES.

No go and fly off and eat some dog poop.

[Anonymous]

5.5 mile long trains - I don't think so. At the time 50 ft. cars were were common place which let's say measured 53 ft. overall between coupler knuckles. This would make a train of 548 cars. While a bigboy might have a theoretical TE sufficient to start a consist of 548 empty cars on level track as a practical matter it could not be done. There would be over 200 feet (2/3 the length of a football field) of bunched slack in a train of that length. As the slack ran out a drawbar would be pulled out probably somewhere short of mid-train. If by some miracle all drawbars held up, the conductor and rear shack better be strapped into space capsule like seats. The G force when the slack runs out at the caboose would be enough to pull the fillings out of their teeth. LOL

Mark

[selector]

My understanding has always been that a steam loco produces it maximum torque at the main rod pintle, or TE along the rail, at stall. This is the same as start-up from standstill. As feltonhill's table demonstrates, this is the case. As the train gains momentum, the coefficient of drag displaces the friction resistance at start-up, but only as speed is developed. I don't know the actual figures... not an engineer, nor have I studied this, but I would love if if someone would educate me of the true parameters if I am mistaken.

All that said, I can only guess that the real limiting factor would be one of them pesky couplers. Could the train be spread so that no one coupler would ever have to withstand the shock of starting more than, say, 10 cars?

[Anonymous]

Dear feltonhill,
While I concede that one Big Boy probably could not have pulled a 5.5 mile train at 65 mph, I'm pretty sure it could have started it. To be perfectly honest, your starting friction bearing requirements seem a little high to me. It would not be impossible to start a train by using slack--just requires skill. Using 5 lbs. of force per ton, I got about 75,000 lbs. of tractive effort once moving.

Sincerely,
Daniel Parks

[feltonhill]

Let’s have some fun with numbers regarding this 5.5-mile-long train that a Big Boy is said to be capable of starting.

We have a pretty good idea what a Big Boy could actually pull from William Kratville’s book on the subject, pages 20-22. Lots of test data there, no guesswork necessary except for tractive effort, which is my estimate. The actual DB pull and DBHP are from graphs in Kratville’s book, and they’re the figures that count anyway.

The following table, which will not stay in column format, I’m sure, lists the following items in order:

Speed - Calc TE (lbs) - Actual DB Pull (lbs) - Actual DBHP

0 - 135,300 - 131,000 - 0
10 - 132,500 - 124,000 - 3,307
20 - 109,000 - 98,000 - 5,227
30 - 83,000 - 75,000 - 6,000
40 - 67,000 - 57,000 - 6,080
50 - 56,100 - 43,000 - 5,733
60 - 48,700 - 32,000 - 5,120

Now comes the fun part. Keep in mind that the only specification that’s been given here is train length, not the weight or number of cars, nor the type of car. I believe the idea was to use a large reference unit that everyone would be impressed with, then let the collective imaginations of the public take over with further superlatives. So, why do as we’re told?? Let look at this problem another way so we won’t be misled. How about empty cars instead of loaded cars? Try to get minimum weight per linear foot.

Since BB was built first in 1941, let’s use empty 50-ton hopper cars which were commonplace at the time. They weighed about 38,700 lbs, and were about 37 ft long. So, a 5.5-mile-long train would consist of about 785 cars and weigh 15,190 tons. However, starting inertia with friction bearings would be about 397,000 lbs, far more than one Big Boy could start if the train were stretched. In order to get the train moving, considerable slack would have to be taken (no pushers allowed), then stretched out carefully without breaking a drawbar. The real railroaders here can comment on the probability of that happening. However, if the train could be coaxed into motion in one piece, a Big Boy could probably move the train at about 14 mph on tangent level track. It would also take about nine BB to roll this train at 60 mph (43,700 DBHP).

Based on current standards, let’s use empty 100-ton gondolas. They weigh about 61,600 lbs and are about 53 ft long. This time a 5.5-mile-long train would consist of about 548 cars and weigh about 16,880 tons. Today, all cars have roller bearings, so starting inertia is not nearly the problem it was with friction bearings. In this case, one BB could start the train and possibly move it along at 25 mph. Even with newer cars, roller bearings, larger wheels, and welded rail, it would still take about seven BB to make 60 mph (32,350 DBHP).

See, Old Timer wasn’t exaggerating at all!!

The above estimates were made using two versions of the Davis resistance equations (See Railroad Engineering, Second Edition, by W. W. Hay, pgs 76-80). This approach was in widespread use by the railroad industry for many years. I crunched a lot of numbers faster than I should have, so I hope others on this forum will take note and correct any errors.

[Anonymous]

Yo APG45,
the press runs the country! For example the same story goes for the Wright Bros. Please believe me, I do not want to take away their extremely well organized and hard earned success, but almost 3 months earlier a simple taxman flew (without a catapult like the Wrights) in Hannover, Germany: a Mr. Karl Jatho. Check Smithsonian.
Also, I agree the N&W etc. (on the East coast ) engines were more powerful, but not correctly employed (I hope that word is okay) like the Big Boys had been. - Many years ago I was one of the first to buy a Rivarossi model of the UP # 4013, and this engine is still one of my favorites besides the N&W "J" class # 611.

[Anonymous]

QUOTE: Originally posted by txhighballer

Big Boys were not the most powerful locomotives ,nor were they the biggest....but they operated on the biggest stage and had the best press.The Alleghenies,which had more horsepower,and some 2-8-8-2's which had starting tractive efforts of better than 160,000 pounds,would have outpulled her,but they could not have outrun her.
If Big Boys were fed a diet of good Pocahontas coal on those huge grates,she most likely would have been up higher in the horsepower category.

Said like a true gentleman on the question of the biggest and best no matter what or where it was. Well said ! ! !

[txhighballer]

Big Boys were not the most powerful locomotives ,nor were they the biggest....but they operated on the biggest stage and had the best press.The Alleghenies,which had more horsepower,and some 2-8-8-2's which had starting tractive efforts of better than 160,000 pounds,would have outpulled her,but they could not have outrun her.
If Big Boys were fed a diet of good Pocahontas coal on those huge grates,she most likely would have been up higher in the horsepower category.

[Modelcar]

....The sight of them seems to inhance their being....They really did {do}, look like the mightest....!