WorldRailFans

Daniel Hoins responded:


> 2-10-10+10-10-2 DOUBLE Meyers in Norway


This is the first time I've ever heard of such engines. Perhaps this was a proposal, never built, for an engine for the Narvik ore line. I'd like to see some photos, as the biggest Norwegian steam locomotive I've seen cited is something called the "Dovre Giant", which was a 2-8-4. See http://www.njk.no/~njk/articles/dovregubben_e.html for more information.



> I had found out about some 4-8-4+4-8-4 Garrets in
New South Wales and Africa that had a weight of 375 tons!!!!


I'd check Dusty Durrant about the weight of those. It seems a bit steep.


> The Virginian RR not only had 2-10-10-2s, but also had
2-8-8-8-4s that could reach 199,560lbs.of TE!!


The Virginian (and Eire) triplexes had a slight problem. They might have had that much starting tractive effort, but they didn't have the grate to supply steam for all those big cylinders (especially since the tender engine exhausted in such a way as to not help to induce draft), and they couldn't move a train very fast.


> the fastest Articulateds were a batch of 2-8-2+2-8-2s
that could move at 140 to 150 mph!!!


Garratts faster than "Mallard"? I'm very surprised that Beyer Peacock didn't advertise their capabilities. Could you possibly cite a reference for these engines? What engines were these, and where were these speeds recorded?

I think that our friend Daniel, being 10, isn't up on the meaning of "apocrypha". That http://home.att.net/~Berliner-Ultrasoni ... html#ac100. is a joke. It isn't reality, but it is pretty funny.


I'm not putting you down, Daniel. If I saw that page when I was 10, I would probably have found it credible. Probably most of us would. If you don't already know a fair bit about a subject (any subject) a well written article presented as fact, but in reality intended as a joke, might come off as real.


I could only imagine some poor kid blundering into a thread on alt.history.what-if when doing research on, say, the Napoleonic Wars, and presenting a report in which Moscow is captured and France winds up having a European and Asian empire that only falls apart in the early 20th century after a major war with a Chinese-American alliance. It sounds plausible...if you don't know the actual history of the past two centuries (or the meaning of the music quoted in the "1812 Overture").


Don't believe everything you read on the Internet!

I just came across this interesting question on the "largest" steam engine and have not had a chance to read all of the replies over the past couple of years. As far as U.S. steam locomotives are concerned, the C&O H-8 Alleghenies had more horsepower (about 7,500) than the UP Big Boy (around 6,500) and were slightly heavier. In the December 1998 issue of Trains Magazine there is a very interesting article that suggests the first 10 H-8s delivered in December 1941 to January 1942 weighed actually weighed in the area of 775,330 lbs in "working order". This was just the engine weight including water in the boiler, 12,000 lbs of sand in the domes an a two man engine crew. This is interesting because the specifications for the order between the C&O and LIMA called for a weight of 726,000 lbs. Apparently it became known by some senior managers at the C&O that the engines were considerably overweight. They did not start to raise questions as there was a cover-up attempt by C&O and LIMA, until the neighboring Virginian Rail Road ordered their own Alleghenies. The president of the Virginian, one Frank Beale, was a former high level person in the C&O and knew what the H-8 was supposed to weigh. When he got the specifications from LIMA for the Virginian's engines, he could not understand why they weighed considerably more and one thing led to another.The Virginian had a lot of trouble getting their 8 Alleghenies delivered as the surrounding rail roads did not want that much weight on their rails.

The same article gives the engine-only weight for the first order of Big Boys at 762,000 lbs, and the second order at 772,000 lbs. One engineer at LIMA gave the H-8's weight as high as 778,200 lbs. For the engine and tender combined weight I have seen several references in other sources around 1,200,000 lbs.

As for power, in 1943 a C&O dynamometer test reportedly gave the highest drawbar horsepower (where it really counts) of any locomotive made. They had the highest weight on drivers of any steam locomotive, and must have really pounded the rails. With 67 or 69 inch drivers (I can't remember which off hand) they would esaily have been capable of 60 mile an hour or faster speeds and I have seen some photos of them hauling express box cars trains. I have also read that some of them were used during WW II to haul fast troop trains for the military.


I believe the Big Boy was the longest of any US Steam Locomotives, if not in the rest of the world. For weight and power, it was definitley eclipsed by the Alleghenies as well as other engines that have been previously reported. One thing for sure, they were all magnificent pieces of engineering. Modern diesels with all of their high-tech wonders may have higher tractive effort, but the most powerful diesel ever in the US, the UP DD-40X only had 6,600 horsepower under its hood.The EMD SD-90 MAC only has 6,000 horsepower albeit from one huge motor versus two smaller ones inthe DD-40X


Now for the fun...Has any one checked on the Pennsylvania Rail Road's duplex drive 4-4-6-4 Q-2 engine? I have read that that produced up to 8,000 horsepower (but don't know if that was at the cylinders or drawbar)with a total engine and tender weight well over 1,000,000 lbs.They were peculiar to the Pennsy, but I have also read that they were considered the most powerful steamer ever.

Who knows for sure anymore but is is fun to speculate!


For lots of information on US Steamers, check our www.steamlocomotive.com. It will knock your socks off with available information and great photos.

Bob Quehl

I've also come across the various stories about the "overweightness" of the C&O Alleghenies. Whilst I have no reason to challenge the deductions made about the likely weight of the first batch, a strong inference from the whole issue is that builder's nominal weights are just that - very nominal. If the Allegheny weight issue was a scam, then just maybe it wasn't the only one concerning US (and for that matter global) locomotives. What's a really interesting consequence is that in the Allegheny/Big Boy comparisons, the deduced weight of the former is compared with the nominal weight of (the second batch) of the latter. But I've not seen any evidence provided to support the fact that the nominal weight of Big Boy is the best available estimate of its actual weight. Who knows? Maybe there's no prime facia evidence to suggest that Big Boy's nominal weight is much different to its actual weight, but if you take pains to deduce an actual weight for the first Alleghenies, and provide detailed support for your deductions, then similarly the number used for any "competing" loco should be just as carefully checked, and more importantly, just as well supported.


That said, my guess, and it's only a guess, is that Big Boy's actual weight is not too far from its nominal weight. My impression is that UP cared quite a bit about such things, and wanted (and mostly got) a machine that was a good business solution to its requirement to haul full trains up the Wasatch and then run them fast to Green River. On the other, C&O may have been more concerned simply with getting a bigger machine than rival N&W, that at the same time was less track pounding than its 2-10-4. (Given the eventual weight of the Allegheny, it may have simply traded extreme hammer blow for crushing axle loading!)

Hi,

Well, there are 2 Allegheny's and many Big Boys left alive, measure them, and take the average of the Allengheny's, first and second batch Big Boys.

Sure, there will be no tenders, or at least loaded ones, but tenders are not actually on the loco.

Brad

Several locomotives exceeded the big boy in size and power, mainly the C&O's 2-6-6-6 class H-8 Alleghenies, but they couldn't produce the power that a big boy did at 60 miles an hour! All of the other U.S. Locomotives never were that powerful or that fast, except mainly the 4-6-6-4 challenger, but it still couldn't produce the power of a bigboy. All of the other locomotives that are very large are garratts, and they rarely superceeded the power of a U.S. articulated. I'm pretty sure a more powerful locomotive could be built, and it doesn't have to be huge. Just use the geared locomotive concept to crank out the most possible horse power.

I am IN compliance that the ALLEGHENY 2-6-6-6 was a more powerful locomotive,BUT I think even at 60 MPH it was a more powerful locomotive. I am in FURTHER agreeance, that the most POWERFUL NON ARTICULATED locomotive was the U P 4-12-2?? OR was it 2-12-4?... REGARDLESS. I Am without a doubt, that, THE most POWERFUL NON-ARTICULATED LOCO was the Santa Fe 4-8-4 2900 series!!

A quick check of data on hand shows the ATSF "big" 4-8-4s at around 5500 ihp/4500 dbhp, as compared with the NYC Niagaras at around 6600 ihp/5100 dbhp. The Pennsy Q-2 4-4-6-4 non-articulated was close to 8000 ihp, which implies above 6000 dbhp. The UP 4-12-2 non-articulated was quoted at 4900 ihp, and the ATSF 2-10-4 at above 5500 dbhp. (Note that some of these numbers are dbhp, some ihp. I'd prefer a consistent set, but we have to play with the hand as dealt, so as to speak.)


Allowing that steam locomotive power output measurements need to be viewed as situational rather than definitive, and may not correlate all that well with perceived daily performance capability, I think that the above numbers don't seem to indicate that the ATSF 4-8-4 was a clear leader in either the ihp or dbhp stakes. In fact, it appears to be beaten by its 2-10-4 stablemate. Maybe there's some more data lurking somewhere that changes the order of things? Although, 5500 ihp is in line with comparable other 4-8-4s of its era. An unanswered question of mine is whether the over-cylindered/limited cut-off configuration of the ATSF design was an asset or a liability as compared with the more conventional proportions of say the UP FEF-2 & 3? Surely at least the extra inertia of the 28" pistons as compared with 25" could not have been a good thing.

In reply to Steve Palmano's 2/6/2000 message on the Allegheny V. Big Boy weight issue,the data in the www.steamlocomotive.com web site gives the total weight of the Allegheny as 1,207,040 lbs. The article I quoted from Trains Magazine unfortunately doesn't give the loaded tender weight, but states the"official" engine in working order weight as 775,330. This is exactly the same as in the web site's data. I do not know what the Allegheny's empty tender weighed, but considering in coal and water when loaded it was carrying at least 250,000 lbs the 1,207,040 total weight doesn't look out of place to me.


The same website gives gives the Big Boy's weight as 1,208,750, or 1,710 lbs more than the Allegheny.

In "The Encyclopedia of Trains & Locomotives", C.J. Riley, 1995 by Michael Friedman Publishing Group, Inc. shows the Big Boy's total weight as 1,120,000.


I think it will always be a matter of comparing apples to oranges in determining these engines'weight as the necessary records may long ago have been lost. They were both big and both powerful though without a doubt.


On the subject of power, I have routinely seen the Big Boy shown as having the greater tractive effort (but neither of these engines had the highest TE compared to other articulateds such as the DM&IR Yellowstones, or the N&W Y6s) but I have yet to see any source show the Big Boy near to the Allegheny's drawbar horsepower.


The website shows the Allegheny at 7500 dhp at 40 mph. It shows the Big Boy at 6200 at undisclosed speed. The Encyclopedia of Trains gives 7000 hp (ihp or dhp?) at an unstated speed. Any way you look at it, the Big Boy would get a train started easier, but once the Allegheny was rolling look out!


The Trains article had one more interesting observation on the Allegheny. As first designed by Lima, they called for a booster engine on the rear truck, but C&O decided against it. The original specifications also called for 23 1/2 inch cylinders, but a sleeve was put into the cylinders to narrow it to 22 1/2 inches for some reason. As others have said before, the true potential of the Allegheny was never realized.

Bob Quehl

Hi,

That booster engine, what was its specs?

Thanks

Brad

William W. Kratville in "Big Boy" prints a facsimile of a typewritten test report (The use in the report of the letters "I" and "l" for the numeral "1", which was usual for typewriters and which I have reproduced here, and the handwritten symbol for "degree" attest to its being genuine.) on 4016 on April 3, 1943, in which at mile post 958 between Ogden and Evanston at a speed of 4I.I mph and a grade of .57 percent, the "Actual Drawbar Pull" is recorded at 5I000 (pounds, presumably). Then there are given a "corrected drawbar pull" of 57400 and a "Drawbar Horsepower Corrected" of 6290, which are "explained" by a footnote as "Corrected to level tangent track and includes grade and acceleration." What these corrections comprise, I don't know; it seems to me that the actual pull and speed are what is important. I suspect that this table is the source of the number "6200" cited above.

Also from Kratville's book, here is some weight information. A drawing, apparently by the UP, dated "2/15/44" gives several measurements or estimates of weights at each axle, subtotals, and totals. I will quote the "total on drivers" and the "total loco":


Dead w[eigh]t 4000 cl[ass] 121,200 148,700

Dead w[eigh]t 4020 cl[ass] 119,400 148,200

Alco. official rail w[eigh]ts. 4000-19 class from Alco sheet 8/23/41 rec[eive]d air. mail 8/27/41. 540,000 762,000

U.P. theor[etical]. rail w[eigh]ts. L[ocomotive].4000 U.P. theoretical rail w[eigh]ts. p[age?]. 4346 4000-19. 4000-19 cl[ass]. based on weighing L[ocomotive]. 4000 540,000 762,000

U.P. theor[etical]. rail w[eight]ts. L[ocomotive].4013 U.P. theoretical rail w[eigh]ts. 4000-19. 4000-19 class based on act[ual]. w[eigh]ts.(2). loco 4013. p[age?]. 4346 543,400 757,360

Alco. est[imated]. rail w[eigh]ts. 4020 cl[ass] Alco. est[imated]. rail w[eigh]ts 4020-24 class based on w[eigh]t. of loco 4013 (2) modified. Front eq pin moved 1/8" [arrow pointing left toward rear of locomotive] tr.tk. eq pin moved 1/16 [arrow pointing left toward rear of locomotive] 540,000 764,000

U.P. theor[etical]. est[imated]. rail w[eigh]ts 4020 cl[ass]. U.P. theo[retical]. rail w[eigh]ts with [the same] modifications. 540,060 764,000


Could the dead weights be swapped? I thought the 4020 class was heavier because the preferred metals were not available because of the war.

Bob N., I also dug out the Kratville book for another look. Since the numbers you quote (from p.15) don't totally agree with the roster diagram numbers on p.64, I'm left with the impression that the usually quoted Big Boy numbers aren't totally safe for unqualified use in any comparisons. Kratville doesn't address this; his book seems to be in the nature of an appreciation coupled with a documentary record, with no obvious axe-grinding.


The Huddleston & Dixon book on the Allegheny takes a somewhat different tack, though. That the originally published weight of the initial batch (724 500 lb) was understated seems to have been adequately demonstrated; indeed the C&O roster diagram for #1600-1644, shown on p.192, quotes 771 300 lb. H&D make a case that there were differences amongst the individual batches in this group.


Incidentally, numbers like 771 300 lb for the Allegheny, and 772 250 lb for the second series Big Boys imply mind-boggling levels of precision! They must have had really good scales in those days! Although to be fair, many numbers and statistics get bandied around without apparent regard for implied precision - rigorous inclusion of the precision and bias aspects in test methodologies seems to be a relatively recent development. I wonder too, how good was the casting and machining; did the weights within a batch of nominally identical locos vary much? Let's guess a quarter of a percent. Hmmm, at 777 000 lb, that's close to a ton!


But as Bob Q. has outpointed, the "real" numbers are likely by now inaccessible.


My own take is:


There's some evidence that the heaviest Allegheny might have been a bit heavier than the heaviest Big Boy, but the difference was probably small.


The evidence suggests that an optimized Allegheny (i.e. without the excess weight) is probably a bit lighter than an optimized Big Boy.


But both statements must be qualified by the fact that quoted Big Boy weights don't appear to have been as closely scrutinized as the Allegheny case, perhaps because there's no prime facia case to suspect foul play.

- Really, too close to call with any precision on weight.


On power output, the limited measured data available, roundly 7500 dbhp for the Allegheny and 6300 dbhp for the Big Boy don't seem to be wildly inconsistent with the relative proportions of each. I'd expect the BB to have more machinery friction, and so a bigger gap between ihp and dbhp.


So, one might expect the Allegheny to have the edge in (drawbar) power, and the available data don't contradict this.

- Allegheny is the probable winner on power.


On the 7000 hp number for BB raised by Bob Q., I suspect that this comes from the Alco advertising of the 1940s, which did use this number. Ihp or dbhp - who knows, probably bshp, aka hype.


On the Allegheny cylinder sleeving, consider that the designers might have been working to the original (mythical) weights, which had 471 000 lb on the drivers, giving a 4.27 factor of adhesion (FA). Now as far as I can determine, 6-coupled engine units need a higher FA than 8-coupled engine units for similar slip resistance. And early x-6-6-y articulateds had a reputation for being slippery on the front engine. Another inch of cylinder diameter, all else unchanged, would have taken the FA down to around 3.9, a bit on the low side. Or, the weight on drivers would have to be increased to around 513 000 lb to maintain the same FA. So maybe the designers were playing safe.


Turning away from statistical comparisons, here's something I'd like to see from someone qualified knowledgable enough to address it. I'll state it in the form of an "essay question".


"In the context of the immediate post-WWII period, compare and contrast, in a semi-quantitative way, the relative utilities of the following articulated steam locomotives (list below). On what kind of operations - loadings, topograhies, speeds - would each be optimally and adequately deployed. What kind of operations is each definitely unsuited for? For these purposes consider actual US rail routes, and take into account interaction of locomotive and track. What special requirements in respect of facilities, operating procedures and/or maintenance procedures might be needed for specific locomotives? For the purposes of this exercise, assume that main lines generally will accommodate axle loads up to 70 000 lb, with higher values requiring special construction. Also consider what circumstances might indicate the use of a non-articulated locomotive (suggested list below) rather than say an x-6-6-y articulated. Incremental or evolutionary changes to any of the locos may be proposed provided the reasons for and expected benefits from these are supported. Highlight any individual locos that lack any distinct, or have a very narrow utility benefit as compared with all of the others."


The list of articulated locomotives is: BB, Allegheny, N&W A, DM&IR 2-8-8-4, N&W Y6, UP "big" Challenger, late "small" Challenger (D&H or Clinchfield variant). The suggested non-articulateds for consideration are: ATSF 2-10-4, C&O 2-10-4, and KCS 2-10-4. (Apologies to anyone if your favorite is not there!)


OK, so that's a "tall order", likely a pipedream, but if it could be done by some steam locomotive enthusiast/genius out there, I think that it would tell us a lot more about these locos than statistical analysis!


)

Here's a possible explanation for the excessive number of "significant" digits in the locomotive weights: The drawing in Kratville's book suggests that the weight on the axles (or maybe even the wheels) were measured individually, then added up to get the total weight. This has an obvious practical advantage over weighing the entire thing at once; but the several smaller leading and trailing wheels in particular are likely to introduce some quite small digits into the sums which might not be rounded out.

There are other records including:Tallest, Widest, Bulkest,

Tallest drivers, Biggest firebox, Biggest tender, Biggest boiler,

Biggest smokebox,Bulkest tender and highest superheat.

Tallest and widest are the 11'8" high and also 11'8" wide

2-8-8-4s of Russia. Tallest drivers are the 9' drivers of a

English and German railway 4-2-4T locos. Biggest firebox

is of the Z-5 2-8-8-4 locos(Grate area is 182 sq ').

Biggest and Bulkest tender is from the S-1(62'3" long).

Highest superheat is that of the Z-5 also(I think).

It is 13,500 sq ". All others I do not know the answer.

Well, see'ya later. D.H.

Hi,

I all think we are missing the point here, who gives a toss about weight, the only weight that isn't important is adhesive weight, total loco weight should be as low as possible, while adhesive weight should be as high as possible, and very close to the max axle loading the track allows.

Now t.e., hp adhesive weight, and wheel size are the most important aspects, once a loco has a sufficient boiler, grate etc.

This list is only my top 5 locos, if anyone drills me for not including the triplexs I am going to shoot you

T.E.


AE 2-10-10-2 147000lbs 177000lbs

Y6c 2-8-8-2 166000lbs

BB 4-8-8-4 135000lbs

H-8 2-6-6-6 110000lbs

Q2 4-4-6-4 100000lbs 115000lbs with booster


well, AE wins here, BB and H8 42000lbs and 67000lbs down on it, big differance, note Q2 more than H8 with booster


HP


Q2 8000ihp @ 60mph

H8 7500ihp @ 40mph

AE 6300ihp @ 30mph

Y6c 6200ihp @ 25mph

BB 6000ihp @ 40mph


Adhesive weight

AE 275t

Y6c 240t

BB 247t

H8 214t

Q2 164t


Driver Size

Q2 69in

BB 68in

H8 67in

Y6c 63in

AE 56in


So, draw your own conclusions, take an AE or Y6c for drag service, BB and H8 for general service, Q2 for fast freight.


AE is better for drag service, with greater te, and adhesive weight

BB is better for off the line, and all out speed, but the H8 is better once moving at mid speeds with an incredible HP figure.

Q2, one example reached 80mph with 3000t, need I say more?




Thanks for reading this, and I hope you realise that one loco can't do all heavy freight jobs.


Brad

Brad, in a practical sense you're right, of course, but in any field of endeavor, biggest, heaviest, fastest and so on seem always attract a lot of attention regardless of their actual merits. Hence the Guinness book of records. I prefer the holistic approach - e.g. my "essay question", but it's also a lot of fun to join the fray in questioning the basis of claims that A is bigger than B, and so on.


By the way, I think that the Pennsy Q2 was a bit too slippery to be a serious candidate for general application.


To add to your list, how about a triplet (note - not triplex) of SD70Ms for drag, general and fast freight service!


))))))

Hi,

The Q2 wasn't slippery, people made it out to be much worse than it actually was, it was never going to be as good as a BB or H8, but if sand was used, there was no problems.


Grrr, how dare you mention diesels. Yuck.


Anyway, my 4-10-2 + 2-10-4 would do a better job.


I have done a listing of specs for it, but I am using someone elses computer right now, so I can't tell you them, but it has 65" drivers, 5 cylinders per set of wheels. 2HP 2MP and 1LP, the 2HP (21 x 26) are internal, and drive the second axle, being mounted over the bogie. The 2MP (24 x 26)are mounted outside, in the normal position, driving the third set, the LP (28 x 34)is mounted on top of the third axle, driving the last set of wheels, so in total 4HP, 4MP and 2LP. I can't remember the te, but working compound, it is 280000lbs or something like that. Simple it is 3something. So the FOA is 2.9 or something like that, now although that is very slippery, keep in mind that the LP cylinder can have HP steam feed to it only, with no other cylinders working, once off the line, extra cylinders can be bought into play, until all 5 are working, and it is the drivers choice how the compounding goes, to reach as much power as possible, I reckon 10000hp will be possible.

I have forgotton the other specs of this engine, however, later on today, when I can use my own copmuter, I can tell you.


Brad

Brad, what's wrong with diesels? They're a good business solution to railroad operating requirements! Don't you just enjoy watching those DX, DFT and DC classes down there in Auckland? Actually, I must admit that one of my early 1960s recollections is a Wab 4-6-4T starting an evening subbie (I think it was the then 17:24 ex Auckland, last steam-hauled on the Waitakere line except the 15:30 for Helensville) after the stop at Sturgess Road, with some of the train still on the 1 in 45 up from Henderson. It always slipped a bunch, there was a heap of black smoke, a lingering odor of SO2, every now and again a brush fire, but once it gripped, it really got away smartly with a healthy, sharo-edged exhaust. (Had a cab ride in a Wab once, too!) On a scale of 0 - 100, where 100 was watching an EE Df diesel restart the old Saturday morning mixed, the Wab on the subbie rated at least 20. )))


Re the Pennsy Q2, I must admit to not having researched this one too well. I simply based my statement on what I've read in Brian Reed's "Pennsylvania Duplexii", and various comments in the E.S. Cox books. Reed says that the duplexii failed to pass "elementary tests of engineering judgement". Even Staufer ("Pennsy Power") doesn't cast the duplexii as successes, and records that the Q-2s were set aside long before the 2-10-4s and other older freight power. It seems to be almost a universal truth that simplicity is a virtue in steam locomotive design; excursions into complexities have mostly been met with limited success or outright failure.


Anyway, good luck with your 4-10-2+2-10-4!!

Hi,

Well, to me, we have Co-Co's and DMU's, I wouldn't have a clue about what classes they are. The DMU's break down constantly. going to school, once a week is the norm. The train is scheduled for 7:53am, it arrives at 8:05 to 8:12 everday. It is so bad that if it runs on time, everyone misses the train. It takes 10min in a car, 26min in a train, if it doesn't break down.


The Co-Co's, now these are curious beasts, we have a couple of 4-8-4's and 4-8-2's preserved, they can pull twice that of the diesels, and still run on time.

Another time, I was being pulled by a 4-8-4. and we were going to go into a very long tunnel, the steam engine would have suffocated all the passengers, so they stopped the train, put 2 deisels in front, and we went through, the entire way was level, before we were sitting on 60 - 70mph, with the 2 diesels, we were doing 40mph, still on the flat and as I was in the first carriage, I could tell you they were working very hard. Then just at the other side of the tunnel, the front one stopped working, and because they were in NZ's mu system, both stopped.

So the 4-8-4 had to puch the train until the next set of points, then pull the diesels away, then continue on.


This is my exerience with deisels, so as you can see, I have no reason to like them.

Brad