C&O 2-6-6-6

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C&O 2-6-6-6
Posted by IA and eastern on Monday, July 01, 2019 6:04 AM

I have been told that C&O would have been better off with a 2-8-8-2 than the 2-6-6-6s. Would a updated D&RGW L-131 with 140.000 lb TE and a speed of 50 MPH pulling at least 200 coal cars and with 2-10-4s as pushers. Or would something else been better. Gary

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Posted by CSSHEGEWISCH on Monday, July 01, 2019 7:19 AM

There is no doubt that the Alleghenys were first-rate steam locomotives.  The common wisdom is that Lima built a fast freight locomotive akin to a large Challenger that C&O and VGN primarily used in drag freight service.  It would be interesting to speculate on what UP might have done with such a design.

The irony is that C&O's last new steam locomotives were compound 2-6-6-2's designed and built for mine run service.

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Posted by BaltACD on Monday, July 01, 2019 7:51 AM

CSSHEGEWISCH
There is no doubt that the Alleghenys were first-rate steam locomotives.  The common wisdom is that Lima built a fast freight locomotive akin to a large Challenger that C&O and VGN primarily used in drag freight service.  It would be interesting to speculate on what UP might have done with such a design.

The irony is that C&O's last new steam locomotives were compound 2-6-6-2's designed and built for mine run service.

Of which the 1309 which the Western Maryland Senic Railroad is restoring to operation is an example.

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Posted by Overmod on Monday, July 01, 2019 8:03 AM

IA and eastern
I have been told that C&O would have been better off with a 2-8-8-2 than the 2-6-6-6s. Would a updated D&RGW L-131 with 140.000 lb TE and a speed of 50 MPH pulling at least 200 coal cars and with 2-10-4s as pushers. Or would something else been better.

The chief 'problem' with the Alleghenies on C&O is that much of their expensive (and ultimately heavy) construction was to facilitate making high horsepower at speed -- something that was wasted when the engines were used predominantly for drag service.  The 'usual' argument for 2-8-8-2s  (rather than, please note, 2-8-8-4s or even 2-8-8-6s which are the more 'logical' alternative) usually ignores the point you make about the T-1 class 2-10-4s in service, which is that they could (and did) run at higher speed when required ... one "answer" being to see whether a 2-8-8-x design of suitable efficiency could be made to run at comparable speed to one of the 2-10-4s with 'beauty treatment' balancing when desired (e.g. for what C&O considered fast or merchandise traffic'

As an additional consideration we remember that a 2-8-8-4 or 2-8-8-6 has the advantages of a deep firebox, while a 2-8-8-2 'perches' its boiler and firebox over the driver wheelbase with the same effect on restricting permissible water-leg length that a Challenger has.  This determines to a degree the maximum effective steam-generation rate for high horsepower ... but this also affects the effective water rate, which in turn limits the practical real-world horsepower by restricting range between water stops and hence vitiating much of the effect of added speed.  Meanwhile the 2-8-8-2 can be dramatically shorter and somewhat lighter, and has much more of its weight on drivers.  (I do some handwaving over fitting an efficient steam circuit on a 2-8-8-2, but the job was effectively done by the time the Alleghenies were designed.)

I would argue that the 'right' engine for C&O would have been comparable to a N&W-size 2-8-8-2, perhaps as large as a Y7, reverting to compound but equipped with Chapelon's full modulated IP injection instead of the N&W-style 'booster valve' which was primarily for reheat rather than balancing LP to HP performance at speed.  This would have produced efficient operation at drag speeds, but the ability to run 50+mph in regular service whenever needed.  You'd want the deep-pocket outside-frame engine trucks with careful attention to equalization, again as reasonably perfected on the N&W A class, to run that fast, and some of the care with lateral motion on the driver pairs adjacent to the trucks, but these are not particularly difficult design details once you know they're needed. 

One 'catch' is balancing the engines for acceptable augment at the higher speed.  By the time of the ACE6000 it was nominally possible to accommodate angled weight of the necessary amounts in a cast 58" wheel ... but the augment overbalance there was supposed to be inherently handled by the Withuhn conjugation, and the leading engine of a 2-8-8-2 might not be amenable to the stiffer compliance needed for near-zero overbalance there.  Some of the putative savings from locating the boiler over the coupled wheelbase will be lost if you have to go to lightweight close-in rod design ... but, strange as it may seem, there might be advantages to using even Timken-style rods if the engine is to be operated flexibly between slow-speed and high-speed service.

My guess is that these would produce comparable DBHP at practical C&O speeds to an Allegheny while being enough lighter as to keep the union bill down, and perhaps efficient enough to make better time net of water stops.  I also think they would beat the pants off any D&RGW design, variable-lead valve gear and all, but at least part of that is natural prejudice and I entertain arguments to the contrary. 

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Posted by timz on Monday, July 01, 2019 2:50 PM

IA and eastern
I have been told that C&O would have been better off with a 2-8-8-2 than the 2-6-6-6s.

Lots of railfans like to think that. They figure the 2-8-8-2 could have pulled longer trains, which is true, and apparently they figure C&O didn't know that. But C&O did know that, of course.

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Posted by IA and eastern on Tuesday, July 02, 2019 6:27 AM

unless the C&O borrows a N&W Y-6 2-8-8-2 and borrows a D&RGW 2-8-8-2 along with that railroad engineers the when the C&O would have some real data, If the C&O does not the the C&O would not go near a compound. The C&O 2-6-6-2 would world simple going uphill. I wonder what N&W engineers would thing of that.Gary

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Posted by CSSHEGEWISCH on Tuesday, July 02, 2019 7:19 AM

Considering the length of some of the grades, I can't imagine an H-6 running simple for very long on uphill portions before running out of steam.

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Posted by Overmod on Tuesday, July 02, 2019 11:22 AM

IA and eastern
... [if] the C&O borrows a N&W Y-6 2-8-8-2 and borrows a D&RGW 2-8-8-2 along with that railroad engineers ... would have some real data[;] if the C&O does not the C&O would not go near a compound.

Now of course the L-13x classes were simple articulateds, some of the earliest batches, so we can leave the compounding arguments aside for that part of the discussion.

I'd argue that the L-132 was a better class to use as a 'starting point' for the demonstration (look at the differences in boiler construction, reflecting evolution in steam-generation thinking at that time).  How would you propose to get around what was by most accounts a tremendous gas and unburnt fuel problem with these engines?  Have you actually calculated the corresponding water rate and checked to see if an uneconomical number of water stops would result?

Locobase points out that the number in these class designations is the 'official' starting TE, rounded conservatively down; they speculate that this reflects a use of .80 rather than the more usual .85 in the formula.  Would C&O have tested them expecting a full 140K, or perhaps uprate the test pressure even further (with the assumption that 'native' 2-8-8-2s built to the test results would use welded boilers or otherwise benefit from higher pressure)?

These engines had a 63" wheel, which should be adequate with lightweight rods and better balancing (mainstream from the late 1930s on, in plenty of time for the advent of the Alleghenies) to get that 50mph speed referred to.  Problem then becomes, in fairly short order, that the chassis is incompetent at that speed -- it would need to be redesigned along the lines of the N&W A and Y7 or the Challengers, constraining the vertical component of 'freedom' of the forward engine.  Not, perhaps, a radical change in terms of cost, but necessary if you expect to actually run the engines at higher speed when the service allows.

Now, the point of a Chapelon-optimized compound (which is what would be 'sold' to C&O in the first place to get them to consider compounds; they certainly wouldn't otherwise!) would be to produce better operation both dynamically and thermodynamically out of a given investment in larger articulated power -- specifically, a logical improvement from the T-1s (which very successfully and very famously supplanted the H-8 articulateds, a cautionary tale for the simple 2-8-8-2 proponents).  If that can be done with a lighter coal-burning engine, far less smoky,  The Y-6, 'ancient' as much of its design was (at the time the Alleghenies were being drafted up as a solution in search of an adequate problem) is a perfectly good starting place for a reasonably stable design with maximum adhesion weight.  The whole of a Chapelon system is unlikely to add more than a ton or so of weight to a Y-6 with the homegrown booster valve, and it allows balanced compound working at most any speed, or more importantly, automatically adjusted for load, speed, and grade without the kind of fiddling that, say, a de Glehn compound expects.  That will likely translate into better water rate, which becomes leveraged in importance as you go to full 'scientific' water treatment for feedwater.  We can of course expect concomitant saving of fuel with the lower combined steam mass flow, while preserving the 'gains' from Snyder preheaters or a good Cunningham circulation system in the firebox water legs.  I believe C&O tried Snyders (on a 2-8-4 Kanawha?) and observed a nominal saving over 10% (don't ask me to remember exactly 10% of what offhand, though!) and the benefit would likely translate to a simple 2-8-8-2 also, but on an engine demonstrating a new operating principle I'd expect simple 'mod cons' to be installed.

The C&O 2-6-6-2 would [work] simple going uphill. I wonder what N&W engineers would think of that.

Big Jim will probably have a comment, and mine would be only slightly less profane.  

N&W had its own comparable engines (the first class of which was significantly derived from a C&O engine, and which did not 'take' to being rebuilt as simple articulateds - see #1399).  By the time of the Alleghenies neither the C&O nor the N&W engines would have been used (except in emergency) on the significant grades; they were excellent mine-run engines at correspondingly low speed.  The thought of flogging one up Sand Patch with the intercepting valve fully open to "make more TE" is ... disturbing.

Now, cracking the intercepting valve to reduce condensation losses in the LP engine is a different thing entirely.  Just don't go calling it 'working simple' because it isn't.

The additional augment alone, out there at the end of the double hinged joint, on the LP engine operated at the full percentage of effective pressure set in the intercepting valve is likely something that would constrain speed pretty dramatically.  Let alone an engine capable of expressing peak thrust in the LP cylinders comparable to boiler pressure.  Let alone an engine that size with adequate boiler reserve to work the four cylinders simple (or approximated so) for the length of these meaningful grades...

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Posted by Paul Milenkovic on Tuesday, July 02, 2019 2:51 PM

On the subject of misapplication of steam locomotives, I still can't get out of my head Wardale's accounts of the C&O 614 tests by ACE written in the Red Devil.

I guess a coal-fired anything is anathema these days, but the idea in the early 1980s Oil Crisis was that if you could get a steam locomotive thermal efficiency into the range of making synthetic fuel from coal and then running a Diesel, you were ahead of the game.  Or at least that is what Wardale and Porta were pinning their hopes on.

 

Wardale tries to "correct the record" claiming good performance from 614 by explaining that the tests were a disaster.  The BTUs per ton mile (or MJ per metric ton-kilometer -- Wardales insistence on metric units in that book) was anywhere from a factor 12 to 16 worse than a contemporary C&O coal drag using a pair of 6-axle EMD diesels.  The test runs, by the way, were where C&O used to run Alleghenies.

Wardale tries to explain in part the poor showing of 614 to three factors -- a leaking firebox that increases the water rate substantially along with the coal needed to evaporate that water, a poor exhaust system and removal of the feedwater heater.  I think Wardale is only partly correct about the feedwater heater because I read the J3a "Greenbrier" was said to have an exhaust-steam injector, not a feedwater heater as on the J3 class.

I think Wardale is missing the forest from the trees in applying a Northern (OK, Greenbrier) to a coal drag.  OK again, the compromises in its shallow firebox and its "booster" valve, but in a fantasy universe, a Y6b may have been a much better comparison to the Diesels in this application.  If you can deal with the condensation problem in the LP cylinders, a coal drag is a good application for compound expansion where you need to generate near maximum tractive effort for hours on end.  A compound can get some semblance of expansive steam working under those conditions.

The simple-expansion Northern was just the worst choice to show that a steam locomotive is a good fit to coal service.  The 12:1 thermal efficiency gap seemed too big to bridge by the ACE 3000's long list of exotic features.

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
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Posted by nhrand on Wednesday, July 03, 2019 1:44 PM

I think the criticism that the C&O built a fast freght locomotive and used it in drag freight service is a bit overdone.  I think the C&O needed a high capacity freight locomotive that could keep coal trains moving fast -- not at passenger speeds, just fast enough to keep the road fluid. I think it got a super locomotive.  Of course there were alternative designs that could have done the work but I think the C&O knew what it wanted and obtained what it needed.  

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Posted by BaltACD on Wednesday, July 03, 2019 2:11 PM

nhrand
I think the criticism that the C&O built a fast freght locomotive and used it in drag freight service is a bit overdone.  I think the C&O needed a high capacity freight locomotive that could keep coal trains moving fast -- not at passenger speeds, just fast enough to keep the road fluid. I think it got a super locomotive.  Of course there were alternative designs that could have done the work but I think the C&O knew what it wanted and obtained what it needed. 

With diesel-electrics and how current affects traction motors being operated at slow speeds - there is a 'minimum continuous speed' to prevent overheating the traction motors account being required to handle excessive currents at slower speeds which then generate more heat.

I never had the opportunity to work in the vicinity of steam engines being used in revenue freight service so I am not totally familiar with their operating characteristics when loaded to maximum tonnage other than to know that a maximum tonnage they will move slower than if they were not loaded so heavily.

I don't know what kinds of speeds steam locomotives handled their maximum tonnage trains over a territory when compared to a diesel-electric locomotive handling its maximum tonnage train.  The minimum continuous speeds for diesel-electric were on the order of 11 - 12 MPH.  I have no first hand knowledge of the speeds of steam under similar circumstance, however, I suspect steam engines designed for 'drag' freight speeds were operating in the 5 - 6 MPH range when loaded to maximum tonnage on the ruling grades.  The C&O mine run engines 1300 series with the 'small' 56 inch drivers would personify a 'drag' engine.  

To correlate that to the C&O 1600's with 67 inch drivers - my guess is they handled their max tonnage trains at speeds comparable to the diesel-electrics that would replace them.

 

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Posted by Overmod on Wednesday, July 03, 2019 2:16 PM

nhrand
I think the C&O needed a high capacity freight locomotive that could keep coal trains moving fast -- not at passenger speeds, just fast enough to keep the road fluid. I think it got a super locomotive. Of course there were alternative designs that could have done the work but I think the C&O knew what it wanted and obtained what it needed.

The issue isn't what C&O could have done with the Alleghenies; it's that -- repeatedly and systematically -- they used them for services well below the horsepower range for which they were designed, rather than 'as intended'.  That would not have been as severe a 'waste' had the engines been eight-coupled.

I have always thought that the Alleghenies represented a kind of Procrustean design, a complex and ultimately heavy design for 'one and a half' fast Berkshires that Lima flogged around looking for customers.  They clearly found a willing one in C&O, but I have to wonder whether the rhetoric used by Lima's salesmen accurately matched what the locomotives could deliver if 'abused'... much the same as Baldwin repeatedly touted the design that became the N&W TE-1 as being able to run 65mph when it was woefully unable to do so with even an approximation of a useful number of trailing tons actually being pulled.

All he was saying is that there were clear designs of locomotive that could have fulfilled the mission C&O actually required of their engines most of the time, while still being capable of running 'fast enough' to make time when used in practical fast freight (or M&E) service, again as C&O would have required.  

It is not my particular opinion that C&O actually had enough fast-freight traffic to justify large and ultimately heavy locomotives for the range of trains too large for one Kanawha but too small for two.  Except in the same artificial wartime conditions that led to the success of the PRR Q2s, where 'snapping' delivery was more significant than in peacetime.

We certainly know C&O conducted some comparative tests in the late Forties, notably of the duplex designs.  We also know they bought more Alleghenies ... and proceeded to 'abuse' them all ... but those were a costed-down design by then, and it might be relevant to note that fairly rapid dieselization was the 'answer' even by the late Forties (when C&O famously flogged a large number of nearly-new switchers to N&W, who then built still more copies than they could get, and ordered modernized 2-6-6-2s rather than large road power at the end) so any follow-on "better" steam design for C&O coal traffic wasn't going to be looked into.

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Posted by timz on Wednesday, July 03, 2019 2:35 PM

nhrand
I think the C&O needed a high capacity freight locomotive that could keep coal trains moving fast -- not at passenger speeds, just fast enough to keep the road fluid.

Probably C&O wanted coal trains to be doing 15 mph or less on the 0.57% to Allegheny, so a 2-8-8-2 or 2-8-8-4 would have done just as well, far as us fans know. But C&O got 2-6-6-6s, which us fans can't explain -- as usual, we don't know why RRs did what they did, since we don't know the costs for the alternatives.

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Posted by Overmod on Wednesday, July 03, 2019 2:40 PM

timz
But C&O got 2-6-6-6s, which us fans can't explain

We fans can explain it damn well: there was this thing called the AMC that worked out at least part of the idea. 

It might be interesting to see if there was a kind of 'institutional memory' that remembered what an advantage even the original T-1s were over the slightly earlier 'first-generation' simple-articulated 2-8-8-2s, and had a prejudice against relatively low-drivered simple-articulated power from that earlier epoch without realizing fully how the technical world had advanced, notably in terms of rebalancing, in the intervening years.

The real question is what transpired when Lima started fleshing out the idea, and it got heavier as it got more complex; I think somewhere there came to be a disconnect between what a heavy modern six-coupled articulated could do and what was expected of the corresponding capital investment in motive power.

I have not yet seen a full discussion of the sordid aspects of the 'overweight' cover-up; it has always seemed to me (outside the loops) that there was conscious intent to cheat on the crew arrangements.  It was interesting to see how C&O implemented the Virginian's "savings" on the late-Forties batch...

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Posted by timz on Wednesday, July 03, 2019 6:12 PM

Part of what idea?

Found the Poultney article on the tests of 1608. With 141 cars, 11623 tons, two H-8s ran Hinton to Alleghany in 2 hr 09 min; with 144 cars, 11606 tons, an H-8 and an H-7 took 1-59. (Just under 50 miles.)

With 70 cars, 5826 tons (and no pusher I assume) time was 1-43; with 70 cars, 5760 tons, time 1-48. Don't have the whole article -- dunno if he explained why the single (?) trains did better.

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Posted by Overmod on Wednesday, July 03, 2019 6:25 PM

timz
Part of what idea?

The idea of a truly fast Super-Power articulated.  (With the implicit understanding that six-coupled engines gave the peak horsepower any high-speed reciprocating steam locomotive in fast service could use).

It was my strong opinion that some of the folks at Lima got a bit of target fixation over beating the N&W at its own game; I think it was Hirsimaki who reported on the general glee and gloating when the early high dynamometer results were observed...

Some part of this involved C&O's permissible axle load, which was substantially high (at what I recall to be 42T per axle at the time).

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Posted by timz on Wednesday, July 03, 2019 7:10 PM

That's what us fans can't explain -- why C&O chose "a truly fast Super-Power articulated" to haul coal to Alleghany. Some fans like to think C&O knew it was a bad choice, but ordered it anyway (and re-ordered it a few times).

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Posted by BaltACD on Wednesday, July 03, 2019 9:11 PM

timz
 
nhrand
I think the C&O needed a high capacity freight locomotive that could keep coal trains moving fast -- not at passenger speeds, just fast enough to keep the road fluid. 

Probably C&O wanted coal trains to be doing 15 mph or less on the 0.57% to Allegheny, so a 2-8-8-2 or 2-8-8-4 would have done just as well, far as us fans know. But C&O got 2-6-6-6s, which us fans can't explain -- as usual, we don't know why RRs did what they did, since we don't know the costs for the alternatives.

0.57% in the world of real railroading is not much of a ruling grade.  Yes any grade required more power to move tonnage up it than to move the tonnage on level ground.  That being said, the eye has a hard time visualizing about 7 inches per 100 feet of change in elevation as being a grade.

B&O and N&W on moving their coal trains to Tidewate terminals had grades of over 1% and into the 2% range as their ruling grades - grades requiring seriously more power than the C&O did over the 0.57% grade of moving their coal.  Not all the territory is grades, and the 2-6-6-6's could probably maintain close to track speed in the 'non-grade' territories.  East of Clifton Forge the C&O operated coal loads over the James River water level grade to Newport News.  The empties returned from Newport News to Clifton Forge over the North Mountain route - a route that had over 1% grades.  Two single track alignments operated as double track for their most important commodity.

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Posted by selector on Wednesday, July 03, 2019 10:32 PM

According to Mr. Krug, each 0.5% increase in grade requires a bit over 3X the horsepower to maintain track speed.  15 mph isn't much of a speed, but even a drag would want to stay pretty close to that speed up a mere 0.5% grade.

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Posted by BaltACD on Wednesday, July 03, 2019 10:41 PM

selector
According to Mr. Krug, each 0.5% increase in grade requires a bit over 3X the horsepower to maintain track speed.  15 mph isn't much of a speed, but even a drag would want to stay pretty close to that speed up a mere 0.5% grade.

You are proving my points - B&O & N&W needed 3 to 6 to 9 times more power to move the equivalent tonnage over their ruling grades.

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Posted by Overmod on Thursday, July 04, 2019 6:33 AM

BaltACD
B&O and N&W on moving their coal trains to Tidewate terminals had grades of over 1% and into the 2% range as their ruling grades - grades requiring seriously more power than the C&O did over the 0.57% grade of moving their coal. Not all the territory is grades, and the 2-6-6-6's could probably maintain close to track speed in the 'non-grade' territories. East of Clifton Forge the C&O operated coal loads over the James River water level grade to Newport News. The empties returned from Newport News to Clifton Forge over the North Mountain route - a route that had over 1% grades. Two single track alignments operated as double track for their most important commodity.

The problem here is that it's dancing around the important issue here: whether east or west of Clifton Forge, C&O apparently chose to routinely load down the Alleghenies to the point they regularly ran 20mph or more below their best-horsepower speed.  Whether or not this represented 'lowest net cost' vs. running lighter trains more quickly is immaterial if considering better, or more economical, locomotives optimized to run at the speeds C&O wanted.

We have still not addressed whether C&O ran a significant mileage per month of non-wartime fast freight with these locomotives, and what both the average and peak speeds of that service were (or had to be).  That determines the 'other half' of the question that was asked: how fast would the alternative 'have' to run to be an effective alternative to the Alleghenies?  This can be answered, but better by someone like Dave Stephenson, who knows the actual details, than by me.

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Posted by BaltACD on Thursday, July 04, 2019 7:27 AM

The locomotives did the job the C&O wanted done at what the C&O considered a reasonable cost.  If they had not done the job or had cost more than what the C&O considered reasonable they would have been replaced post haste.

The utility and economy of diesel-electric locomotives replaced all steam in short order after it became available consistant with manufacturing capacity.

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Posted by BigJim on Thursday, July 04, 2019 7:30 AM

Have any of you heard the old adage..."Don't worry about the mule, just load the wagon"? There is the answer to many of your questions!

I don't personally know of any sound recordings of C&O coal trains on a grade. If they do exist, I seriously doubt that you would be hearing a coal train running anywhere close to 15 mph on the ruling grade! Remember that the real world is very different than what you railfans percieve it to be.

.

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Posted by Shadow the Cats owner on Thursday, July 04, 2019 9:24 AM

There's a saying here also.  As long as the load gets to the final safe the customer doesn't care if the truck is a Pete Freightliner KW or Volvo.  Only the driver and the name on the door matters.  The only person that complains that complains about what brand of truck it is are the driver.  In railroading the beancounters don't care what engine pulls the train as long as it gets it there the only ones that female dog are the RAILFANS and the crews when it comes to the GE EMD wars.  

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Posted by nhrand on Thursday, July 04, 2019 11:42 AM

The original question was whether the C&O should have bought more 2-8-8-2's rather than 2-6-6-6's that allegedly produced more horsepower than the C&O could use on its coal trains.  I suggested in an earlier post that I think the C&O made a reasonably good decision in buying the Allegheney type and will elaborate a bit.  I assume the C&O wanted a dual service locomotive although it seems coal train use predominated.  The criticism of using the H-8 Class mainly in coal service is that its peak horsepower developed at higher speeds and therefore the engines should have been used at speeds at which the horsepower output was at a peak.

       I don't have drawbar horsepower vs speed curves handy for the H-8 but I do have curves for the N&W Class A 2-6-6-4 and the Y6b 2-8-8-2 handy and they give an approximation of what could be expected if the C&O stayed with a 2-8-8-2.  The Class Y6b produced more drawbar horsepower than the Class A until about 32 miles per hour at which point the horsepower of the 2-8-8-2 fell substantially.  The peak drawbar horsepower of the Y6b was about 5,500 at about 25 mph while the 2-6-6-4 peaked at about 5,200 at about 35 mph.   However, due to the high capacity of the boiler, the Class A maintained that same high drawbar horsepower at 60 mph or more.  By the time the Y6b had reached a top speed of about 40 mph, drawbar horsepower had dropped to nearly 4,000. (We seldom talk about the drawbar horsepower of a diesel but that is another story.)

         If the C&O had wanted to restrict the Allegheney type to purely coal trains a 2-8-8-2 would have done the job but flexibility would be lost.  The Allegheney could easily handle coal, merchandise or passenger trains. The power was there when needed.  Whether it was need often enough to justify the cost of such a large engine is hard to say. Was it being wasted when it was used on coal trains  --- I think not.  The high power output of the H-8 was still useful in moving a coal train at a more than "drag" speed and the C&O had enough 2-8-8-2's to know their capabilities.  The C&O also had the nearby N&W as a model for building both 2-8-8-2's and 2-6-6-4's and stayed with the Allegheney type. (If you get the impression I like the Alleheney you are right.)

         Regarding wasted horsepower, why are trains today seemingly overpowered.  Short or long trains today get diesel power amounting to 8, 12, 16 or more thousands of horsepower.  Some of these heavily powered trains move on lines that have low speed limits.  If the Allegheney was more than was needed, I think the same can be said about the way power is managed today.  I doubt the CSX gets more bang for the buck with its high horsepower diesels than the C&O did with its 2-6-6-6's. 

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Posted by timz on Thursday, July 04, 2019 11:54 AM

BigJim
I seriously doubt that you would be hearing a coal train running anywhere close to 15 mph on the ruling grade [to Alleghany]

Apparently the test trains did anywhere close to 15 mph -- they ran Hinton to Alleghany in about two hours.

The Allegheny - Lima's Finest quotes a report on the test with two H-8s -- says they got stopped by a red signal on 0.57% just west of MP 316. After the stop they reached 18 mph in 2-1/2 miles.

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Posted by Miningman on Thursday, July 04, 2019 12:56 PM

nhrand-- That's a great answer/analysis.. a keeper! I'm sure glad and most of us are that they built them, (except for the one that blew up). 

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Posted by kgbw49 on Thursday, July 04, 2019 2:31 PM

I know population and traffic levels north of the border at the time made a high-speed articulated unnecessary, but it would have been something to see what a CN or CP 2-6-6-4, 4-6-6-4 or 2-6-6-6 would have looked like.

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Posted by Miningman on Thursday, July 04, 2019 3:29 PM

Yeah a Challenger on the Prairies between say Winnipeg and Calgary would have been a sight on the Dominion. The CPR had 0-6-6-0's in the mountains for a bit. Some logging roads had articulates but that's a different cookie. 

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Posted by BigJim on Friday, July 05, 2019 8:41 AM

timz
Apparently the test trains did anywhere close to 15 mph


The key word being "test". Show me what they did hauling actual everyday tonnage. 
Before you go reading too much into this and coming to wild fantastic conclusions, remember that tonnage can be adjusted so that the train can make a certain speed upgrade. The less tonnage (read less profit), obviously the greater speed. 

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