What's so special about Big Boys?

[Anonymous]

Can you tell me a bit more about this longest train ever?
When and where was it, and where did you hear that?

[espeefoamer]

One could debate all day long about whether the Big Boy or Alleghenney was larger,had more horsepower or tractive effort,but the Big Boy was the only 4-8-8-4 [8D].

[Anonymous]

QUOTE: Originally posted by espeefoamer

One could debate all day long about whether the Big Boy or Alleghenney was larger,had more horsepower or tractive effort,but the Big Boy was the only 4-8-8-4 [8D].

Your reputation as the voice of high iron reason and tractive peacemaking remains secure - - - -My Compliments - PL

[bobwilcox]

Daniel-They also pulled more green fruit blocks through Sherman than an Allegahney ever did.

[GP40-2]

Trainjunky29, man where do you come up with all that crap? Honestly, I don't think I could make up that much stuff if I was smoking weed and tripping on LSD at the same time.

"Routinely pulled 5 1/2 mile long trains at 65 MPH" yea, right--would love to see that.

How old are you; 10 maybe 11 ???

"No locomotive had greater tractive effort and horsepower" I guess you meanstarting tractive effort, because the Allegheny did have greater tractive effort at speed than the Big Boy. However, even if you did mean starting tractive effort you still are not right because the DM&IR 2-8-8-4 M4's had both greater starting tractive effort and greater horsepower than the Big Boys.

[Anonymous]

Daniel: Have you been visiting the West slope of Rabun Gap to many times or did you hollar to much from Coleman Mountian and not get an answer? Espeefoamer gave you good support on this one as far as he could and as a fellow native of the GA/NC hills to another, I will say this about this thread and topic. - - - Let it alone. - - - PL

[Anonymous]

Ahh, GP40-2, my old nemesis about Big Boys [:)].

You probably remember this from awhile ago. To be perfectly honest, the stuff about the 5-1/2 mile train is from a book whose title I will get tommorrow.

You might be right about that post-starting tractive effort, but you couldn't take the H-8 at the speeds a Big Boy went without either severely damaging thet track or derailing.

The 7-mile train bit I believe I got off of www.steamlocomotive.com, though I'm not sure.

By the way, there are a number of different figures floating around for drawbar horsepower on a Yellowstone and Big Boy. Guess what? The most reliable figures I could find for BOTH was 6000 HP!

Cordially yours,
Daniel Parks

[Anonymous]

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.

As far as pulling it 65 MPH - - - well, my friend, go figure out how many cars would be in a 5 1/2 mile train, and figure the tonnage of such a train. Then get your horsepower formulas out and see how much drawbar pull it would take to haul such tonnage 65 MPH on level track. I don't have the material in front of me right now - I've got it in my library - but I'm betting that it would take probably 4 Big Boys quadruple-headed to get 5 1/2 miles of train up to 65 MPH and hold it there.

And Daniel, what makes you think that the Allegheny wouldn't run as fast as Big Boy without damaging itself or the track? There was only one inch difference in the driving wheel diameter, and in spite of what you might hear the four-wheel lead truck wasn't of any extra benefit until speeds of, oh, say, 80 MPH were reached, which were beyond the requirements of either locomotive.

And traintownofcowee, what makes you think that our American butts would have been whooped without the "bigboy" (sic)? Do you have any factual evidence upon which to base such a statement?

If the Santa Fe hadn't had EMD FTs, we'd have been in more trouble than we would have with UP without Big Boys, but we'd still have won in the end.

Old Timer

[jchnhtfd]

The UP 4-8-8-4's had two advantages over most of the oppostion, although the debate about 'biggest', 'best' or what have you will rage forever...

First, and possibly most important, the had excellent PR. Union Pacific, then as now, was aware of the possibilities of PR, and used it. So the Big Boy had a nice high profile.

Second, from the engineering standpoint, they did have an advantage: the front engine hinging and equalization was definetly superior to other articulateds, with the exception of the Challengers, which had much the same system. This meant they were a lot more stable at higher speeds -- not that they were necessarily able to go faster, but that they were considerably more likely to go faster on the track...

[Anonymous]

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.

[Modelcar]

....WWII effort was a combined effort from all directions and not having {one}, of the contributors probably would not have been a deciding factor of winning or losing. We're just glad we had them all....and the people, the way everyone rallied to do what was needed to be done....I remember as a young boy {Scout}...even getting out of school to help collect in Paper and metal collection drives to the point we made large piles of it in the center of our little town at the collection point, etc.....So, we're glad we had Big Boy, but it was just one of the massive efforts....

As stated several times above....The discussion of biggest, most powerful, and all the rest is too far in back of us and will be never be settled. We're glad we had them all....

[jeaton]

I have come to the conclusion that the argument over which of the big power was "best" will end only on the day that one of each will be brought to some good location and tested under a variety of conditions. That would be a good time to put each model on a long track scale to find wich was heaviest and take accurate measurements of the size. At the same time, a committee of engineers and firemen could rate the cabs for best seats, best forward vision and best ergonomics.

Then we could get to the real controversy-Was big steam the way for railroads to go?

Meanwhile-Argue On!!

[Anonymous]

The largest train ever pulled was not behind a Big Boy- it was behind diesel power.

The train was in Australia, and TRAINS had a picture of part of it. Not sure why the Australians put it all together, but I'm sure there was a reason for it.

Erik

[AztecEagle]

Well,They Were Some Big Honkin'Steamers,That's Fer Sure.

[Anonymous]

QUOTE: Originally posted by erikthered

The largest train ever pulled was not behind a Big Boy- it was behind diesel power.

The train was in Australia, and TRAINS had a picture of part of it. Not sure why the Australians put it all together, but I'm sure there was a reason for it.

Erik

Heaviest, but not longest [:)].

[Anonymous]

Expanding on what Jamie said, the Big Boys were SUPERBLY counterbalanced machines. I don't know about the Alleghenies.

[Bob-Fryml]

During Thanksgiving weekend I spent a couple of hours at the RailsWest Museum in Council Bluffs, Iowa. It's located in the old Rock Island / Milwaukee Road joint passenger station, a short ways south of downtown, and also includes a rather nicely done HO club layout.

During Saturday's operating session the club ran a freight train pulled by a Union Pacific Challenger (4-6-6-4) and a U.P. "mail train" (2-R.P.O.s + 3-mail storage cars + 2-coaches) pulled by a Big Boy (4-8-8-4). The Challenger looked pretty impressive with its consist, just like U.P. 3985 does in real life; but, there was something about that extra set of drivers on the Big Boy model that made it really stand out. Whether it's 3.5mm-to-the-foot or 12-inches-to-the-foot scale, a moving Big Boy is a PRETTY IMPRESSIVE MACHINE!

[Modelcar]

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

[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.

[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 ! ! !

[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.

[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]

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

[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]

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

[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]

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

[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]

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 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