"Big Iron"

[chefjavier]

     I know UP was legendary in their pursuit of big, powerfull locomotives, like Big Boys, Turbines, and DD40's.  Were any other railroads into specialized big engines?

I agree with your theory. I really enjoy the DD40's

[Railway Man]

It's been my experience that idiosyncacy exists in just about every industry.

But in railroading idiosyncracy is more remarkable because of the industry's age, technological maturity, and broadly disseminated culture.

I wouldn't be surprised if it was a case of correlation rather than causation. One point, the UP line between Cheyenne and Ogden lent itself to high power locomotives, moderately steep grades, an alignment that permitted relatively high speeds, lots of traffic and an operating department that wanted to keep the traffic flowing. It would have made a good place to demonstrate the technical benefits of electrification.

I agree with your characterization of the Overland Route, but I don't see why the technical benefits would need to be demonstrated once the BA&P had electrified.

The most probable reason that the Overland Route was never electrified was economics. In addition to the usual first costs of catenary, substations and locomotives, the UP would have to have financed an electric power essentially dedicated to the railroad. I suspect that most of the power would have come from burning coal, which would have reduced the cost advantage compared to a railroad that could tap into large amounts of hydroelectric generation (e.g. the Milw).

 

Economics undoubtedly was the reason, along with a Board of Directors not beholden to outside directors with other business interests to advance, e.g., sale of copper wire and electrical power.  The only possible source of electrical power would have been steam generation fueled by coal; of note is that the Union Pacific Coal Company was one of the largest coal producers in the U.S. but the parent company was above seconding the interests of the railroads to the subsidiary in order to obtain self-enrichment or aggrandizement (unlike many boards then and now).

What may have been the most effective application of short term power was when the Joe's were helping a train with SD-40's - the power helped get the train speed high enough to allow the SD-40's to transition. More often the short term power would have allowed for faster acceleration of the train.

I am wondering why achieving transition speed is important?  I can't recall seeing a big step in the T.E. curve at transition speed.

Granted in that the continuous rating of the Little Joe's were roughly equivalent to a pair of GP-40's - the point being that the Joe was a single unit. The relative worth of having power in a single unit compared to a pair of units is another question - and I rather doubt if there is much benefit of a "single unit".

 

If the tractive effort of a higher-horsepower unit can be regularly exerted in the predominate rail conditions and train-speed conditions, and if the higher-horsepower unit does not have substantially worse availability than the low-horsepower unit, then the higher-horsepower unit is always a benefit as much of the maintenance cost of a locomotive is fixed on a per-unit basis, e.g., FRA 93-day inspections, wheel truing, etc.

The marginal solutions are often more fun to analyze

Unit reduction in the diesel era has largely been accomplished by increasing power of the prime mover, with an assist from improved traction control. It looks like hybrids wil be the next step in design. In addition to a small savings in fuel from regenerative braking, other advantages could be improvement in "throttle" response (production of rail horsepower can exceed prime mover output) and reduction in emissions as the prime mover can ramp up or ramp down power more slowly (especially useful with turbocharged engines). 

A hybrid commuter locomotive would make a lot of sense, especially if the battery/capacitor/flywheel was designed with high peak power - it would reduce both fuel consumption and schedule times. 

There's an interesting parallel in the airliner world, for almost 4 decades the largest airliner was the 747, but the most common is the 737.  I rather doubt that there will be enough of a market for the Airbus-380 to pay for the development.

I follow airliner manufacturing strategy as a hobby  and I agree with your observations but I am not sure it really parallels to railways too closely.

RWM 

[erikem]

After 30 years in the trade, including time in the mechanical department, I can't ascribe the attraction for turbines and double-diesels, as opposed to a big string of F7s or GP9s, to anything but idiosyncracy.  (It indeed exists in this 150-year-old railroad industry!)

It's been my experience that idiosyncacy exists in just about every industry.

 

Since the double-diesel and turbine, disregarding the one-offs, did not follow behind electrification on a road-for-road basis I don't see how one was informing the other, or that electrification was setting up a culture that to an unusual degree valued high single-unit horsepower.  I see your logic but I think it's mere correlation not causation.

I wouldn't be surprised if it was a case of correlation rather than causation. One point, the UP line between Cheyenne and Ogden lent itself to high power locomotives, moderately steep grades, an alignment that permitted relatively high speeds, lots of traffic and an operating department that wanted to keep the traffic flowing. It would have made a good place to demonstrate the technical benefits of electrification.

The most probable reason that the Overland Route was never electrified was economics. In addition to the usual first costs of catenary, substations and locomotives, the UP would have to have financed an electric power essentially dedicated to the railroad. I suspect that most of the power would have come from burning coal, which would have reduced the cost advantage compared to a railroad that could tap into large amounts of hydroelectric generation (e.g. the Milw).

 

And speaking of the short-time horsepower, did that performance value really matter?  Traction motor heating is traction motor heating whether it's fed from catenary or a diesel-driven main generator. 

The Little Joe had a continuous rating of 5,500 hp distributed to 8 motors, or 687.5 hp per motor.  In round numbers it's the same on the rail as a pair of GP40s.  There's an point to be made that it achieved this 20 years ahead of the diesel-electric.

What may have been the most effective application of short term power was when the Joe's were helping a train with SD-40's - the power helped get the train speed high enough to allow the SD-40's to transition. More often the short term power would have allowed for faster acceleration of the train.

Granted in that the continuous rating of the Little Joe's were roughly equivalent to a pair of GP-40's - the point being that the Joe was a single unit. The relative worth of having power in a single unit compared to a pair of units is another question - and I rather doubt if there is much benefit of a "single unit".

 

There's a 100-year-old dialectic in railroading between achieving the inherent economies of unit reduction (or increasing ton-miles per train-mile, the same thing) and overreaching technologically on the locomotive.  It would have been less aesthetically pleasing if everyone solved the problem with the fat-boilered, hand-fired 56" driver 2-8-0 in 1903, the simple 2-8-8-2 in 1930, the F-unit in 1949, the SD45 in 1966, the SD0-2 in 1975, and the AC4400CW in 1995, but speaking as a grumpy railroader I think there's more money to be made analyzing the central solutions than the marginal solutions.

The marginal solutions are often more fun to analyze

Unit reduction in the diesel era has largely been accomplished by increasing power of the prime mover, with an assist from improved traction control. It looks like hybrids wil be the next step in design. In addition to a small savings in fuel from regenerative braking, other advantages could be improvement in "throttle" response (production of rail horsepower can exceed prime mover output) and reduction in emissions as the prime mover can ramp up or ramp down power more slowly (especially useful with turbocharged engines). 

A hybrid commuter locomotive would make a lot of sense, especially if the battery/capacitor/flywheel was designed with high peak power - it would reduce both fuel consumption and schedule times. 

There's an interesting parallel in the airliner world, for almost 4 decades the largest airliner was the 747, but the most common is the 737.  I rather doubt that there will be enough of a market for the Airbus-380 to pay for the development.

[Railway Man]

I wrote "dabbling" with tongue firmly planted in cheek - note that I wrote "seriously dabbling in" - certainly a bit more serious than the Espee's work with diesel hydraulics.

To expand on this thread a bit more, the GN, VGN and Milw (+CSS&SB) all bought electrics in the late 1940's that have yet to be equalled by any single unit diesel locomotive (at least in short term rail horsepower) - one could go on to say that the gas turbine locomotives were an attempt to bring electric performance to a non-electrified line. 

 The Espee did have its own form of "big-iron" power in that they were the largest buyer of SD-45's.

After 30 years in the trade, including time in the mechanical department, I can't ascribe the attraction for turbines and double-diesels, as opposed to a big string of F7s or GP9s, to anything but idiosyncracy.  (It indeed exists in this 150-year-old railroad industry!)

Since the double-diesel and turbine, disregarding the one-offs, did not follow behind electrification on a road-for-road basis I don't see how one was informing the other, or that electrification was setting up a culture that to an unusual degree valued high single-unit horsepower.  I see your logic but I think it's mere correlation not causation.

And speaking of the short-time horsepower, did that performance value really matter?  Traction motor heating is traction motor heating whether it's fed from catenary or a diesel-driven main generator. 

The Little Joe had a continuous rating of 5,500 hp distributed to 8 motors, or 687.5 hp per motor.  In round numbers it's the same on the rail as a pair of GP40s.  There's an point to be made that it achieved this 20 years ahead of the diesel-electric.

There's a 100-year-old dialectic in railroading between achieving the inherent economies of unit reduction (or increasing ton-miles per train-mile, the same thing) and overreaching technologically on the locomotive.  It would have been less aesthetically pleasing if everyone solved the problem with the fat-boilered, hand-fired 56" driver 2-8-0 in 1903, the simple 2-8-8-2 in 1930, the F-unit in 1949, the SD45 in 1966, the SD0-2 in 1975, and the AC4400CW in 1995, but speaking as a grumpy railroader I think there's more money to be made analyzing the central solutions than the marginal solutions.

RWM

[erikem]

Are you sure you would categorize under "dabbling" 25 4,500-hp gas turbines and 30 8,500-hp gas turbines?  You're referring to the single coal turbine perhaps?

I wrote "dabbling" with tongue firmly planted in cheek - note that I wrote "seriously dabbling in" - certainly a bit more serious than the Espee's work with diesel hydraulics.

To expand on this thread a bit more, the GN, VGN and Milw (+CSS&SB) all bought electrics in the late 1940's that have yet to be equalled by any single unit diesel locomotive (at least in short term rail horsepower) - one could go on to say that the gas turbine locomotives were an attempt to bring electric performance to a non-electrified line. 

 The Espee did have its own form of "big-iron" power in that they were the largest buyer of SD-45's.

[Railway Man]

The diesel era is however quite different -- UP did indeed want something bigger than what the manufacturers thought was practical, and was quite different than its peers.  The exceptions were the Centipede (PRR and SAL), U50s and DD35s (SP), and N&W and C&O gas turbines.  But all of those were short-lived or one-offs not followed up on, whereas UP liked the big engine and made it a foundation of its mechanical and operating philosophy until 1972. 

I presume you meant to say "N&W and C&O steam turbines".

Before the big diesels (DD's, U50's and C855's), the UP was seriously dabbling in gas turbines - and some have commented was that the UP wanted diesels that could replace the turbines one for one.

One reason for the demise of the turbines was the (ahem) impressive fuel consumption - the 4500HP turbines consumed as much idling as the current 4400HP diesels do at full throttle. 

I did!

Are you sure you would categorize under "dabbling" 25 4,500-hp gas turbines and 30 8,500-hp gas turbines?  You're referring to the single coal turbine perhaps?

RWM 

[erikem]

The diesel era is however quite different -- UP did indeed want something bigger than what the manufacturers thought was practical, and was quite different than its peers.  The exceptions were the Centipede (PRR and SAL), U50s and DD35s (SP), and N&W and C&O gas turbines.  But all of those were short-lived or one-offs not followed up on, whereas UP liked the big engine and made it a foundation of its mechanical and operating philosophy until 1972. 

I presume you meant to say "N&W and C&O steam turbines".

Before the big diesels (DD's, U50's and C855's), the UP was seriously dabbling in gas turbines - and some have commented was that the UP wanted diesels that could replace the turbines one for one.

One reason for the demise of the turbines was the (ahem) impressive fuel consumption - the 4500HP turbines consumed as much idling as the current 4400HP diesels do at full throttle. 

[Railway Man]

     I know UP was legendary in their pursuit of big, powerfull locomotives, like Big Boys, Turbines, and DD40's.  Were any other railroads into specialized big engines?

By mixing steam and diesel the assertion becomes untrue.  In the steam era, UP was not unusual; almost everyone with big grades and big trains ran big locomotives.  SP, D&RGW, WP, GN, NP, UP, DM&IR, B&O, C&O, VGN, and N&W all rostered "big" steam locomotives circa 1945.  Size differences between them are not very significant, and I see no justification for stating that UP in that era was doing anything much differently than its peers.

The diesel era is however quite different -- UP did indeed want something bigger than what the manufacturers thought was practical, and was quite different than its peers.  The exceptions were the Centipede (PRR and SAL), U50s and DD35s (SP), and N&W and C&O gas turbines.  But all of those were short-lived or one-offs not followed up on, whereas UP liked the big engine and made it a foundation of its mechanical and operating philosophy until 1972. 

In a marginal sense (and the margins is where these discussions occur) railroads have idiosyncracies that manifest themselves in ways that matter only to railfans and to us rails over beers after the day's AREMA or ARS convention.  And in that sense it's fun to speculate and critique.  Otherwise the discussion is arcane; the overwhelming majority of owners and users of railroads don't know and wouldn't know.  I think we'd be very hard pressed to say that if UP had foresworn the double diesel if its net would have changed by more than 0.000001% per share.

RWM 

[Virginian]

I do not think it is biased to state facts.  I am rather partial to the VGN, but the 2-6-6-6 was a fish out of water on the C&O and the VGN.  It's capabilities were never close to fully utilized.  On the UP it would have been an interesting contest with the Big Boys, which is precisely why UP did not need them.  The Class A was a better engine all the way around, and it was designed to be fully utilized on the railroad that built it, and was.

VGN's Triplex was a 2-8-8-8-4, not a 2-6-6-6-4, and it was a dog.  They never accepted that thing, but gladly bought used third hand N&W Y's.  Surely that tells the tale.  The old VGN 2-10-10-2's had the tractive effort bulge on everything but the turbines if memory serves, and they were very successful for years before the Triplez concept reared it's ugly head.

The turbines failed because the technology at that time could not stand up to the pounding of running over the rails.  The fire controls were the bugaboo on the Jawn Henry, and everything went wrong with the C&Os if I heard right, but I am not authority on C&O (other than to say that their later Greenbriers were Outstanding locomotives).

ATSF's, NYC's, UP's, and SP's Northerns would all have not done well on the N&W's profile.  Too up and down and too twisty for engines designed to be relatively flatland flyers.  And none matched the J's tractive effort, and only the NYC mathced her horsepower.

The N&W mallets were the penultimate commodity drag freight locomotive.  They did their job as efficiently as a four unit GM diesel yet, and made major bucks for the N&W while doing it.  They were the primary freight loco on the Shennandoah line because of their axle loadings and size, and yet they had more tractive effort than a C&O 2-6-6-6 or a Big Boy.

[switch7frg]

  feltonhill; Thank you very muchfor the info on my favorite engine.2179 was like the tracks it ran on ( always there) , some time in the lead or second . One of my favorite sights was when the fireman sanded the flue ~~~ ,impressive to say the least.  Respectfully, Cannonball another Jim

[dldance]

The ability of the boiler to produce steam is one part of the equation.  Without so many lbs of steam per hour, not much is going to happen.  However, if the machinery is not up to the task of converting the available steam to mechanical energy, not much is going to happen either.  You need steam (grate area and heating surface) and well proportioned machinery (cylinders and drivers) to get it all together.  That's power.

there is a 3rd part of the equation and that is the ability to transfer the mechanical energy to the rails.  That is why traction control for modern diesels is so important.  Historically there have been a lot of slippery engines - they had the mechanical energy but were inefficient at  getting it to the track.  A good engineer could and had to finess this problem.

dd

[VAPEURCHAPELON]

My candidate for "Big Iron" is the 6-4-4-6  Pennsy S-1

YES! I second that! That engine in my eyes is by far the most spectacular thing ever being on rails! Anywhere!

[samfp1943]

My candidate for "Big Iron" is the 6-4-4-6  Pennsy S-1 that handled the Chicago east to Bellvue,Oh part of some of the railroads hot passenger runs:

Here is a link to a photo of it.

http://prrsteam.pennsyrr.com/images/prr6100.jpg

The streamlining was designed by Raymond Loewy for the Railroad; he also did a design for the Pensy K-4's that pulled the Broadway Ltd. and others. 

 

[Anonymous]

The Y6b was a wonderful engine. But too slow to keep up with Western Schedules. One must wonder if the Alleys were sent west to get up and go instead of being wasted in Y6b country. But when something just has to be moved there were plenty of different options. I consider the B&O 2-10-2's known as the Big 6 a favorite because it helped passenger schedules over the hill in it's time. Not too many engines can do that.

[wjstix]

Well the DM&IR ran 2-8-8-4's on iron ore trains until June 1960, into the mid/late fifties they ran 2-8-8-2's, 2-10-2's and ex-B&LE 2-10-4's. They also used huge 0-10-0 and 0-10-2 engines for switching and transfer work.

[feltonhill]

According to data in Richard Prince's book, Norfolk & Western, Pocahontas Coal Carrier, 2179 was scrapped Feb 1959 (pg 152).  Unfortunately it was one of the earlier Y6b's to go.  Sorry to be the bearer of bad news.

[feltonhill]

The ability of the boiler to produce steam is one part of the equation.  Without so many lbs of steam per hour, not much is going to happen.  However, if the machinery is not up to the task of converting the available steam to mechanical energy, not much is going to happen either.  You need steam (grate area and heating surface) and well proportioned machinery (cylinders and drivers) to get it all together.  That's power.

[bakupolo]

I just read a book about Lima's superpower locos. Seems power had nothing to do with starting effort or size of cylinders or number of drivers - it was all about the ability to make a lot of steam quickly. The Allegheny and Berkshires had enormous fireboxes and lots of heating area and could pull a heavy load at high speed. That's power.

[switch7frg]

 J.Edgar  and Feltonhill;  ~~~ Thank you very much for the info on poppet valves . Through the years from time to time search for that info was next to nil . It seemed that they just faded away . My next quest is for the demise of my favorite Y6b. 2179. I wonder if N&W kept records of scrapping. That engine was seen many times by me coming up from Portsmouth to Circleville Ohio. The big horse sure had an easy stride .  Respectfully, Cannonball ( another Jim)

[feltonhill]

The final versions of N&W's Y5 through Y6b classes could develop 5,500 DBHP operating compound at 25-30 mph, not simple.  Simple operation was sustainable up to about 8-10 mph.  The so-called booster valve, a device controlled by the engineer that would allow a small amount of higher pressure steam to be admitted into the receiver pipe, was used below about 15 mph while the loco was still in compound operation.  This feature was generally used on sustained grades to keep speed from falling too low, but without resorting to more uneconomical simple operation.

 Comparing the H8's peak reading of 7,489 DBHP with the A's 5,300 average operating DBHP of the A is apples and oranges.  The H8's sustainable maximum DBHP is closer to 6,700-6,800, still the highest of any steam loco.  See Huddleston's book, The Allegheny Lima's Finest, p204 for DBpull and DBHP scatterplot and curves.  The A had the edge in being able to produce its DBHP using less coal and water per unit of output than the H8, because of its lighter weight. Too much "iron" has its disadvantages.

The Virginian's 2-8-8-8-4 could start a tremendous train but couldn't move it very far before running out of steam, if lore is correct.  It did not have enough boiler to support its machinery.  VGN never accepted ownership of the thing.  It was sent back and rebuilt into a 2-8-8-0 and a 2-8-2, both of which did much, much better.  

Regarding C&O and N&W steam turbines, the book has been written about Jawn Henry (Tale of a Turbine, Rails Remembered Vol.4, by Louis Newton) and is available through the N&W Historcal Society.  I understand that a history of the C&O's M1's is currently in process and may debunk some of the myths surrounding these three locos.   

As stated above, there was one PRR T1 with Walschaerts, 5547, reclassified as T1a after a rebuild ca 1947.  Another T1, 5500, was rebuilt with rotary cam poppet valve gear around the same time, maybe 1948.  The outside drive was a major improvement in accessibility over the original oscillating cam gear, as well as performance, based on interviews with the operating crews.

Steamlocomotive.com is a great resource, provided you examine the figures carefully.  They're only as good as the source that sends them to the site, much like Wikipedia.  Wes can't edit everything.  Some of the performance figures should be viewed and used with considerable caution.  Comparing steam locomotive performance is a very difficult process and requires much more complete info than this site can provide.

For serious comparisons, better check with the various RR historical societies.  I know that N&W, C&O, PRR and NYC groups have a lot of documented test data in their archives and some of it has been published in their respective magazines.

[CSSHEGEWISCH]

As a whole, poppet valves were a major improvement in efficiency over piston valves.  The downside was that they were non-standard (usually one or two locomotives in a piston valve equipped roster) and suffered from the problems that go with being oddballs.

[J. Edgar]

 J. Edgar kind sir;  I wonder if you could go back in wisdom and tell me about the PRR 4-4-4 engine with the new poppet valve . Did it work? if not , why?  They were supposed to be better than conventional valves. Big Iron is my favorate type of engine .Uh Oh , I forgot one set of axles.  Make that a 1942? T1 4-4-4-4. maybe 500.000 lbs.at 100ft. length. Respectfully , Cannonball

 not sure what your asking but heres some simple numbers.....the T1 had #65,000 of tractive effort and 5000 HP at the drawbar...all T1's had poppet valves when new....i think 1 was refitted with walshaerts as an experiment...poppet valves were used to increase efficiency...meaning less fuel and water used

[switch7frg]

 J. Edgar kind sir;  I wonder if you could go back in wisdom and tell me about the PRR 4-4-4 engine with the new poppet valve . Did it work? if not , why?  They were supposed to be better than conventional valves. Big Iron is my favorate type of engine .Uh Oh , I forgot one set of axles.  Make that a 1942? T1 4-4-4-4. maybe 500.000 lbs.at 100ft. length. Respectfully , Cannonball

[J. Edgar]

The ultimate was the Norfolk and Western, which, at the end of steam, basically used three classes of locomotives for over-the-road traffic.

1. Passenger - Class J 4-8-4, had the highest tractive effort of any 4-8-4 anywhere, and routinely rolled along at 90mph on 70 inch drivers (low, by passenger standards.)
2. Fast freight - Class A 2-6-6-4, could generate in excess of 6000 hp, move manifests at 60mph and run up to 70 when pressed into passenger service (thanks to the 70 inch drivers it shared with the J.)
3. Everything else - Class Y(various) Mallet compound 2-8-8-2.  Slow, thanks to dynamic augment, but could move a mountain if somebody could secure a coupler to it.  By "everything," try slower mainline freight, mine runs, pusher service, even yard switching!  The Y6b was the ultimate, but there were still Y3s in abundance on the property right up to the end.

The N&W had other locos, notably USRA 0-8-0s, but they just filled in around the edges and handled the few jobs too light for the Big 3.

Chuck 

lol......some bias there... but for what its worth.....ATSF's UP's and NYC northerns would and could do 100+ with any train given to them....the C&O's Allegheny 2-6-6-6 had over 115,000# TE and could produce over 7500 hp @48 mph..the A only made 5300 hp@ 43 mph..plus it was heavier and hadda bigger firebox then the A class...as far as the y class.....they reached 5400 hp @ 25 mph in SIMPLE expansion with BOOSTERS cut in.........what about the Virginian 2-6-6-6-4 triplex compound.....if started in simple which it could this engine could get 199,000# TE.....as far as big bigger and biggest lest us not over look the 2 steam turbines built for/by C&O and NW....the Jawn Henry for the NW and the M-1 for the C&0 ....but even then the M-1 made more HP.....numbers come from steamlocomotive dot com

[CSSHEGEWISCH]

In the diesel era, UP was pretty much by itself with jumbo locomotives.  SP dabbled a bit with 3 U50's and 3 DD35B's.

Similarly, the SP/D&RGW experiment with diesel-hydraulics was aimed at getting higher horsepower and better adhesion than was available from the domestic builders in 1961.

[tomikawaTT]

The ultimate was the Norfolk and Western, which, at the end of steam, basically used three classes of locomotives for over-the-road traffic.

1. Passenger - Class J 4-8-4, had the highest tractive effort of any 4-8-4 anywhere, and routinely rolled along at 90mph on 70 inch drivers (low, by passenger standards.)
2. Fast freight - Class A 2-6-6-4, could generate in excess of 6000 hp, move manifests at 60mph and run up to 70 when pressed into passenger service (thanks to the 70 inch drivers it shared with the J.)
3. Everything else - Class Y(various) Mallet compound 2-8-8-2.  Slow, thanks to dynamic augment, but could move a mountain if somebody could secure a coupler to it.  By "everything," try slower mainline freight, mine runs, pusher service, even yard switching!  The Y6b was the ultimate, but there were still Y3s in abundance on the property right up to the end.

The N&W had other locos, notably USRA 0-8-0s, but they just filled in around the edges and handled the few jobs too light for the Big 3.

Chuck 

[Murphy Siding]

     I know UP was legendary in their pursuit of big, powerfull locomotives, like Big Boys, Turbines, and DD40's.  Were any other railroads into specialized big engines?