Longest train pulled by a steam engine

[Valleyline]

N&W class A 2-6-6-4's regularly hauled 175 car coal trains between Crewe and Norfolk, VA during the 1950's. These were not unusual moves. Practically every coal train on this flat route was of this size and was pulled by one class A at track speeds of 50+ mph. I was there and witnessed it whenever I could find the time.

[Anonymous]

Although UP's 4-8-8-4's didn't have the pulling power of an Allengy, their tractive effort
was greater, allowing them to pull 2.5mile trains up grades as steep as 2.1%.

Kyoshi

[gabe]

QUOTE: Originally posted by mac 4884

Although UP's 4-8-8-4's didn't have the pulling power of an Allengy, their tractive effort
was greater, allowing them to pull 2.5mile trains up grades as steep as 2.1%.

Kyoshi

OK, I will admit my inexperience, how does tractive effort, pulling power, and drawbar power differ from one another. I would have thought tractive effort would necessarily translate to drawbar power?

Gabe

[Anonymous]

Garyaiki, no offense but I dont even think a T1 shay could get up a railway that steep, let alone a big boy. A rack railway could, but you probbally know that.

[Anonymous]

You are right on that Gabe.

[feltonhill]

Gabe -

You asked a good question, but the answer's not quite so easy. Tractive effort is measured in the cylinders and is an indication of how much pull a locomotive can develop. Usually the figure you would see quoted is the TE at starting, zero mph. TE falls off from this value as speed increases. Drawbar pull (not drawbar power) is the amount of tractive effort that gets through locomotive and tender resistance, flange resistance, wind resistance, etc, and ends up at the rear of the tender. This is the amount of pull available to move the train. This also falls off as speed increases. The speed at which drawbar pull equals train resistance is the maximum speed a locomotive can move its train. I'll leave it at that for starters.

[espeefoamer]

I noticed a few posts mentioning long trains pulled by diesels.I once saw one UP SD40-2 pulling an SP train north out of Bakersfield with 105 cars.

[Anonymous]

Mac 4884 -- plenty of adhesion railroads incorporated grades in excess of 8.1%. And a lot of them used ordinary rod engines, too! Look in the history books.

OS

[Anonymous]

Back to the original question, Which locomotive would hold the triple crown in the three catagories of longest, heaviest, and highest horsepower. Averaging is permitted.

[Anonymous]

After doing some research I found out a (simple rod) line on the WP's route that has
a 5.6% but no 8.1% grades. Be glad I didn't say there was a grade like the one in the
polar express.

[Anonymous]

QUOTE: Originally posted by mac 4884

Although UP's 4-8-8-4's didn't have the pulling power of an Allengy, their tractive effort
was greater, allowing them to pull 2.5mile trains up grades as steep as 2.1%.

Kyoshi

The Alley had horsepower. And the ability to get up and run. The Big Boy was designed for long lonely runs of rail in the middle of no where with constant grades for tens of miles. No engine is capable of stamina over hundreds of miles with the trains that were assigned to the Big Boys.

The alley could probably do the same job but sadly I have no understanding of which engine would come off first in a western setting. However, if you brought the big boy east to Saluda or Sand Patch I think the sharper curves and greater vertical changes would prevent this engine from performing as designed.

[Anonymous]

The steepest adhesion grade on a US common carrier railroad was (is) the 5.89% Madison Hill grade on the former Pennsylvania Railroad branch from Columbus to Madison, Indiana. This excludes, cog, inclined plane, logging and tourist railways. The grade descends for a distance of maybe 3/4 mile down into the Ohio River Valley town of Madison. Today it is operated by a shortline, the Madison Railroad. The Madison Hill grade was originally an inclined plane but under PRR ownership it became an adhesion line over which the PRR operated steam locomotives designed specifically for this grade. The locomotives that operated over the years on the Madison Hill were unique one-of-a kind, not to be found elswhere on the PRR roster.

[Anonymous]

QUOTE: Originally posted by mac 4884

Garyaiki, no offense but I dont even think a T1 shay could get up a railway that steep, let alone a big boy. A rack railway could, but you probbally know that.

I pasted a whole paragraph from a website I found because it claimed a BigBoy "kept moving" a 10km long train. A claim no one in this thread has confirmed or denied. The rest of the paragraph was full of errors and it was a mistake to paste them.

[Anonymous]

is that for one thing, so few were tested in any kind of standardised way; and also, that performance varied depending on how well the locomotive was being fired (in other words, crew skill).

Tractive effort is a practical measurement in theory but, for a steam locomotive, a theoretical one in practice! It is calculated as the amount of effort the locomotive's cylinders can produce, given boiler pressure, cylinder size, and an approximated pressure drop-off. It's a static measurement. It measures what train a locomotive can start, but not how well it can pull at speed.

Power is effort over time, or useful work. It was impossible with the technology of the time to estimate a locomotive's power output with numbers, so it had to be tested. Two ways: on a stationary locomotive test plant, which is what the PRR and some others did; or with a dynamometer car, that measures drawbar pull from the locomotive, distance travelled, speed etc.

It's hard to compare the two results.

The PRR Q2 was the most powerful locomotive tested on a test plant. The C&O's Allegheny was the most powerful tested by dynamometer car. It's probable the Allegheny was more powerful.

Both locomotives developed their maximum power at fairly high speed, and were not nearly as powerful at drag freight speeds.

[GP40-2]

At 140 feet long, the Pennsylvania RR S-1 6-4-4-6 locomotive was nearly 8 feet longer than the Big Boy. At 7200 DBHP, it was also far more powerful.

My orginal statement stands: The Big Boy was neither the longest, heaviest, or most powerful steam locomotive.

[GP40-2]

Drawbar HP is nothing more than drawbar pull (tractive effort) at a certain speed.

The basic formula is:

(Tractive Effort X Speed)/375

For Steam Locomotives, YOU CAN NOT use the listed Tractive Effort, because that is the Starting tractive effort at 0 mph. You need to find the tractive effort graph for the locomotive at speed. As fentonhill stated, the tractive effort will fall off as locomotive speed increases.

So while the Big Boy has greater pull starting than the Allegheny, the Allegheny has more pull at speed, thus more HP.

[Anonymous]

Mr. Foster, you're absolutely certain Madison Hill was or is the steepest adhesion grade on a U.S. common-carrier railroad? Now, or at any time in the past? How are you specifying the minimum distance over which the grade must be measured to qualify as steepest? And must it be in a main track or can it be in a spur, etc.?

OS

[Anonymous]

Garyaki, there's no harm in reasearch.

[daveklepper]

Regarding the long diesel powered N&W train, as far as I can recall, the first road switchers the N&W bought were GP-9's not GP-7's. I may be mistaken.

The GP-9's were bought to do just about everything. Including the Powattan Arrow and Pokahuntis (excuse spelling please).

I think all things considered, the N&W Y's could probably move the longest and heaviest train. It might take a study of drawbar pull vs speed curves to confirm or deny the point, but I think they would do better than either the Alleghany or Big Boy.

I don't count the Pennsy duplexes. Whatever any of them were in theory, they were all slippery in practice and the tractive effort was thus not converted into drawbar pull. None were really successful locmotives, including maintenance as well as operation. And the old K-4's and H-10's and 2-10-0's (I-5's?) served for many years after the last duplex was scrapped. If I remember, the J's, the 2-10-4's modern as they were, had no real pulling power over the I's. Of course the C&O versions had had booster trailer trucks, and I believe this feature was ommitted on the PRR copies.

The Swiss may have something better in their history, but for electrics it is the New Haven EF-3, in my view the best electric ever built and a further improvement on the GG-1 which had been based on the EP-3. It was equal to four GP-7's and two E-33/EF-4's in pulling power.

[feltonhill]

Replying to a bunch of subjects above -

PRR's S1 did not develop 7,200 DBHP as far as any account that I've found so far. The source of this number would have to be extremely suspect. They were usually credited with low to mid -5,000s over the road. The only known thorough history of this locomotive was written by the late Charlie Meyer, and published about 15 years ago in Friends of the Railroad Museum of PA magazine Milepost. Most of what was learned was negative. However, Big Boy engine length was greater than the S1.

BB 85.8' + 47.0' + 132.8' total e+t
S1 80.5' + 59.7' = 140.6' total e+t

See, it just depends on the standard of evaluation, like how high is up?

The PRR T1s had their problems to be sure, but they were not as bad as we've been led to believe. Check PRRT&HS magazine The Keystone for the past 2-3 years. The 50 production units were not as troublesome as the two prototypes. They were also tested on C&O and N&W and , contrary to popular opinion, worked well within their design capabilities. There's more coming on this subject. Watch "the literature".

The old guys were better than we think. I suggest at least two books for anyone seriously interested in locomotive and train performance:

1 - The Steam Locomotive by Ralph Johnson. This is available in used book sites, but the price is usually way too high. Check libraries.

2 - Railroad Engineering, Volume 1 by William W. Hay. Also available from used book sites, sometimes at reasonable prices.

If you're a glutton for punishment, I also recommend a third:

Mastering Momentum by L. K. Sillcox. This has reasonable prices as low as $20.00

These books give methods for estimating train performance using tools available in the 1940s and 50s. Very labor intensive, but they could get pretty close to generally expected performance over a division using locomotive diagram specifications, road data from track charts, and train resistance equations. It's a lot easier to put the various formulas/equations into a spreadsheet and work from there.

[GP40-2]

That 7200 HP figure came from steamlocomotive.com. Probably is a bit too high, just like the Allegheny's 7500 HP figure.

However, with 300psi, 132sq.ft. grate area, 5661sq.ft. evaporative heating surface, and 2085sq.ft. of superheater, I would suspect the S1 was over the 6000 HP range.

[feltonhill]

Well, the 7,500 figure for the Allegheny is actually a peak dynamometer reading at about 47 mph. The full scatterplot is in Huddleston & Dixon's book, The Allegheny Lima's Finest, pg204. If you have access to this graph, you can see that the dyno readings become erratic as speed increases, and at around 45 mph they range from 6200 to 7500. Although I understand the test report has survived at C&OHS archives, I haven't checked the underlying conditions that produced this peak reading. The train could have been coming out of a sag, or something like that. C&O did not correct for acceleration, and not doing this would produce artificially high readings under those conditions. The sustainable DBHP at 47 mph is closer to 6,600 based on my read of the scatterplot data, still a very good figure.

I always thought the S1 should have done better, but I've never found the figures to support much above 5,000-5,500 dbhp. Strange.

Fun with numbers......

[Anonymous]

I lived in the Mississippi - Yazoo Delta where the town was split by the tracks, and train length was an issue because we only had one firehouse. I remember losing count on one train at a hundred and fifty cars. Got no idea what was pulling it, except I can pretty much guarantee it was steam, maybe a double header. Long freight trains were pretty common because the land was absolutely flat.

[Anonymous]

Ok OS, what is the steepest grade that a straight rod job ever faced in revenue service?

(I dont know the answer but that Saluda would be my next guess if Madision wasnt it.)

[Anonymous]

HighIron: How short a distance do you want to consider? If you're willing to entertain a very short distance as the "steepest," there are plenty of grades in the region of 20% -- on short spurs. Think of the grades running up to the old elevated coal trestles!

Some notable steep grades of greater than one mile in length operated with rod-type adhesion engines include:

1. D&RG's Calumet Mine Branch, in central Colorado, with 2,700 foot rise in seven miles, an 8% grade, was said by A.M. Wellington (the dean of locating engineers) to be "undoubtedly the heaviest grade on any regularly operated railroad in the world."

2. B&O successfully operated 10% grades for two months over the top of Kingwood Tunnel by Benjamin F. Latrobe in 1852 (for an account by Latrobe see Railroad Gazette, Dec. 5, 1874).

3. Uintah Railway successfully operated a five-mile 7.5% ascent on Baxter Pass in northwestern Colorado until 1938, with 66-degree curves.

Madison Incline was for a time the steepest main-track sustained gradient in the U.S. on a standard-gauge steam railroad (what a mess of caveats!) Because it's now a short line, one would have to go survey the short lines and see if there's one steeper. I would not be willing to award the purse to Madison until I'd canvassed the short line community.

OS

[timz]

"If you're willing to entertain a very short distance as the "steepest," there are plenty of grades in the region of 20% -- on short spurs."

Are? Where?

[Anonymous]

Short as in less than a carlength!

Do you have a definition for the minimum length over which an average is taken to qualify as "steepest grade"? Because if no minimum is set, I'll go look for a really bad rail joint stepping up in the direction of travel.

OS

[timz]

Okay-- how about a carlength?

[Anonymous]

Being originally from West Virginia the couple of references to the Cass Scenic Railroad brought back pleasant memories. My wife's roommate in college was the daughter of the last manager for West Virginia Pulp and Paper in Cass before the mill and railroad were shut down. Having visited Cass during its operating days was a great experience. The railroad ascends the mountain on a series of switchbacks with a grade of 11% (yes-eleven percent). From the tourist car it does look steep and is. Shays were the motive power of choice for the line.

As a kid growing up in the northern panhandle of WVa I observed a lot of mighty power on the Pennsylvania. I remember counting one coal drag (loaded) with 125 cars. Unfortunately I do not remember the motive power being used, however, it was steam.

I remember hearing a steam train starting upt with the slow frequency of "chuffs" which often would rapidly momentary go into fast chuffs. Wheel slip. I also remember the steam engine backing up to remove slack before starting forward. You would hear a repeated series of bangs as the slack was removed from each car. The crew in the caboose had quite a ride as the caboose would go from stopped to 8-10 mph in less than a second. I have heard of desks and pot bellied stoves being torn from their mountings when the slack was pulled out in such a manner. The crew had to really hold on or they would have been launched. This might be a good location for a back surgeon to practice.

[Anonymous]

Kalmbach published a really great book entitled "Faces of Railroading" not long ago. One of the lead stories in the book was by an AMTRAK engineer talking about his grandfather, who suffered a broken neck when slack ran out of his coal train. (Yeah, I know. I was supposed to be looking at the pictures, not reading the stories.)

As a kid I had a book (entitled "Trains") which had a picture of a "mile and a half long" coal train- it might have been a C&O train. The implication of the photo was that this was a routine run by C&O.

Erik