Could steam make a comeback?

[Norman Saxon]

For what it's worth, here's some numbers projected by the EIA concerning coal through 2030:

http://www.eia.doe.gov/oiaf/aeo/trends.html

Boy, they sure missed the boat in projecting future oil prices!

http://www.eia.doe.gov/oiaf/aeo/prices.html.html

The thing about oil vs coal futures is that oil is highly vunerable to speculation, while coal just seems to bore those futures traders - probably because there are viable alternatives to using coal for electricity generation, but few viable alternatives for using oil for liquid transportation fuels (except of course for CTL!)

The EIA shows a greater increase in coal use for electricity, while nuclear, natural gas, and renewables used for generation are essentially flat.

figure data

My guess is that we'll see less coal and more nuke used for electric generation, and coal prices will remain relatively flat.  That would put coal at the top of the most stably priced fuel sources for locomotives, and as such using ROM coal in reciprocating steam will be the lowest operating cost option.

(Sorry for the mess with the graphs, haven't quite figured out how to link them properly.)

[wsherrick]

I live in PA where good Anthracite coal is readily available.  I just ordered my coal for the winter.  The price has remained stable over the past few years, but demand for coal for home heating has gone up quite a bit.  My coal dealer already has a 50% increase in new orders over last year and the companies that make coal heaters and stoves are back logged with new orders. It costs me about 1/8 th to heat my house with coal over the equivalent amount of oil required to do the same job.

Apparently a lot of smart people are figuring this out on their own. It's time for the Railroad Industry to wake up. 

[MichaelSol]

The thing about oil vs coal futures is that oil is highly vunerable to speculation, while coal just seems to bore those futures traders -

The railroad industry is a key industry. It has tied its future to a fuel source in which 90% of the proven reserves of the Devil's Excrement are nationalized, owned by nations which have no incentive themselves to subject oil to market prices, and every incentive to encourage speculation -- when they are not using their resource for political purposes.

It is a catastophe waiting to happen when the spigot is turned off for some reason, and the rail industry can't move essential freight, or as it happens, just keeps sending US dollars to tinhorn dictators, and continuing to depreciate the dollar, while strengthening each day, the economic hands of enemies of Democracy.

The obvious alternative, coal, is safe from speculation and safe from political upheaval, unless Wyoming starts to act up ...

The discussion, ostensibly framed in terms of the economic efficiency of Steam/coal in today's changed world, is more important when framed in the ability of railroads to insulate themselves and by extension the US economy from making both the railroads and the economy hostage to speculation and political manipulation.

 

[MichaelSol]

An interesting comment from another forum:

>
> . . .Freight trains with empty cars are restricted to 55 mph or
> less to reduce hunting.
>
> ___________________________________________

Only since roller bearings - friction bearings allowed a certain
amount of sideplay in the wheelsets that allowed them to compensate
for minor track irregularities without transmitting that motion to the
entire car.

I remember watching this from the front door of a caboose. Friction
bearings allowed the wheelsets to move back and forth in the bearings.
With friction bearings, everything, including 1915-era tank cars, ran
70MPH on Santa Fe

I also remember watching the scary harmonic rocking action of roller
bearings until someone in higher places finally "discovered" that this
rocking action could rock an empty car right off the rails, especially
with a little sand or other "grit" to give flanges a "bite" as they
climbed the railhead.

Rigid Roller bearings, especially on locomotives, are death to a
right-of-way. Even at that, steam locomotives were easier on track
structure because they had a certain amount of flexibility built in to
accomodate minor track irregularities, plus, a steam locomotive driver
set actually weighs less than a diesel locomotive wheel/traction motor
assembly, resulting in less rail pounding at joints, etc.

 

[Anonymous]

In the middle ages they argued how many fairies could dance on the head of a pin.

Here the arguments are about fuels, electrification, and tractive effort curves.

Let's see about actually pulling trains. 

What is less debatable than peak oil is peak capital. Anyone want to argue the current federal and trade deficits are sustainable? You do not have to be a right-wing sore tooth to see that much higher interest rates are on the way.

Ergo, electrification, whether mobile or centralized, in a non-starter. Both require huge outlays of capital that simply will not be there. The July TRAINS says the average age of the US locomotive fleet is 22 years. There will have to be a major outlay of capital that is available.

One traditional advantage of steam is its much lower capital cost. That will mean a lot more, given the higher interest rates on the way, as opposed to artificially low mid-century rates.

Furthermore, the railroads are having severe capacity problems on the one hand and have had to reduce freight train speeds in recent years because of fuel costs on the other.

Even in mid-century the NYC Niagara was more powerful than a three unit E7 at 60 mph but cost less to operate. 

How about some pudding to prove something in?

Which is why I propose a test of Class A 1218 and three current diesel units on a 7500 ton train.

There have been scattered if not specific reports of the Class A hauling 7500 trains over 60 mph. Thre has been corroboration of that feat in this thead.

That is the equivalent of 4 1/2 SD45s, considering that three SD45s can haul a 5000 ton train at 62 mph. Apparently this was commonly done in regular service.

Let's see which can do what and at what cost. This is no toy department exercise.

What does 1218 need? A flue job? How much will it cost to be restored to running condition?

UP Challenger 3985 might be similarly tested, but it would be nowhere as instructive. It burns oil and has been fitted with a Lempor exhaust.

Nothing wrong with the latter, but it does diminish the controlled experiment. 1218 is still pristine 1930s technology. Let's see what we have been missing all these years.

Then let's figure what 1218 could do with a Porta/Wardale firebox, Lempor exhaust, poppet valves, etc. 

Again, this is no toy department exercise.  There is a lot at stake.

[rrnut282]

???

Why do we need tests, you conceded in your post that the 1950s Niagra was already more powerful than its contemporary diesel. 

How is (3) 2000 vintage diesels  vs. (1) 1930s steam locomotive a fair comparison?  Are you hoping to prove a 3:1 advantage for steam?

[Anonymous]

Tonight on CBS Evening News I heard that the future of coal is doomed unless a method is perfected to sequester the CO2, and the federal government should fund the research.  I would think that the reward for developing a practical method of CO2 sequestration would be immense.  Is not this reward sufficient to attract enough private capital to fund the research?    

By the way, I too am thinking about converting to coal for the house heat.  I heard that natural gas is expected to spike upward next winter somehow in resoponse to the gasoline/diesel price crisis.  They said mabye 40% higher than last winter.  Great. 

[Railway Man]

Tonight on CBS Evening News I heard that the future of coal is doomed unless a method is perfected to sequester the CO2, and the federal government should fund the research.  I would think that the reward for developing a practical method of CO2 sequestration would be immense.  Is not this reward sufficient to attract enough private capital to fund the research?    

There's no issue with pumping CO2 into the ground; oil producers have been doing it for years.  The issue is who takes the liability if it leaks back out, and when, and at what rate, and causing what damage.  As yet there's no law to quantify that liability and no one is quite sure how to write it, either, since the science and engineering of long-term sequestration has no experience yet.  I write a lot of contract language and public documents that the lawyers review, but ultimately they're relying on me to be the technical expert that tells them what's feasible and what's not.

RWM

[fredswain]

Wouldn't it just be cheaper to buy the Chinese steam engines such as the QJ's as they go out of service and use them here? There are already a few here. How much would it cost to buy one of them, and then go in and update some things to "clean them up"? That would seem cheaper than trying to develop new ones. We still get into the issue of the infrastructure for steam engine service being gone. 60 years ago we had it. Today we don't.

[Anonymous]

Tonight on CBS Evening News I heard that the future of coal is doomed unless a method is perfected to sequester the CO2, and the federal government should fund the research.  I would think that the reward for developing a practical method of CO2 sequestration would be immense.  Is not this reward sufficient to attract enough private capital to fund the research?    

There's no issue with pumping CO2 into the ground; oil producers have been doing it for years.  The issue is who takes the liability if it leaks back out, and when, and at what rate, and causing what damage.  As yet there's no law to quantify that liability and no one is quite sure how to write it, either, since the science and engineering of long-term sequestration has no experience yet.  I write a lot of contract language and public documents that the lawyers review, but ultimately they're relying on me to be the technical expert that tells them what's feasible and what's not.

RWM

Aside from the issue of pumping it into the ground, and the liability in case it leaks back out, where are we at in terms of capturing it from the combustion process of a mobile vehicle?  I would think it would need to be captured and temporarily stored onboard the vehicle until it can be transferred to the permanent storage underground.  What impact does this have on the economics of a locomotive pulling a train?

[Railway Man]

I'm somewhat familiar with the Selexol process to remove CO2 from stack gas as several shippers I work with are looking at it for new plants, but the process doesn't appear to me to be amenable to scaling down to a size suitable for a vehicle application, not even a locomotive-size vehicle.  If there's other technology on the horizon suitable for that purpose I don't know about it.  Once the CO2 is captured, it has to be compressed or liquified to store it or inject it, which is energy-intensive.  My inkling is that it if it's important enough to capture the CO2 from a locomotive to spend the money on a locomotive-sized system, it will be much much cheaper to erect catenary and capture the CO2 at the fossil-fueled electricity source.

RWM

[Norman Saxon]

I'm somewhat familiar with the Selexol process to remove CO2 from stack gas as several shippers I work with are looking at it for new plants, but the process doesn't appear to me to be amenable to scaling down to a size suitable for a vehicle application, not even a locomotive-size vehicle.  If there's other technology on the horizon suitable for that purpose I don't know about it.  Once the CO2 is captured, it has to be compressed or liquified to store it or inject it, which is energy-intensive.  My inkling is that it if it's important enough to capture the CO2 from a locomotive to spend the money on a locomotive-sized system, it will be much much cheaper to erect catenary and capture the CO2 at the fossil-fueled electricity source.

RWM

This nonsense about "needing" to capture CO2 - as if CO2 is some kind of toxic gas like CO or SOX - will run it's course and end up on some future history text as an example of how backward those Y2K Americans were.

However, it appears that the AGW brown shirts will need to be placated by some federal response despite the reality that facts say otherwise.  That being said, our nation can reduce total CO2 output by simply converting coal-fired generation into nuclear, and subsequently adding value to coal by refocussing it's usage on CTL, gasification/methanization, and of course external combustion of locomotives/ships/tugs.

I am hesitant to support either Presidential candidate at this point, given their dip****ted agreement on AGW, but at least McCain has come out in favor of building 50 or so new nuclear generating plants, and encouraging the construction of clean coal technologies.

The bottom line is that the railroads should not fear a return to reciprocating steam because of the slight increase in CO2 per unit of work.  There are more significant ways to reduce CO2 emissions than from a few thousand steam locomotives scattered across the nation.

Remember, regulation of CO2 is focussed on it's supposed global impacts, not on local and regional impacts like SOX and NOX et al.  It makes sense environmentally to encourage reductions of those emissions for localized environmental improvements (reduce smog, etc) but regulating CO2 under the same parameters is nothing short of pointless.

Note to moderators - this is about science, not politics (errrrr, except for the McCain reference!)

[Anonymous]

 

This nonsense about "needing" to capture CO2 - as if CO2 is some kind of toxic gas like CO or SOX - will run it's course and end up on some future history text as an example of how backward those Y2K Americans were.

I hope so.

[tomikawaTT]

 

This nonsense about "needing" to capture CO2 - as if CO2 is some kind of toxic gas like CO or SOX - will run it's course and end up on some future history text as an example of how backward those Y2K Americans were.

I hope so.

If the "problem" is to sequester carbon monoxide, why not do it by genetic engineering some form of plant that can be readily fermented to provide all the ethanol the green weenies think is so wonderful?  Seems to me that makes a lot more sense than pumping it into the ground.  After all, plants (the green, growing kind) do a pretty good job of sequestering CO2 from the atmosphere now.

With sufficient ethanol, maybe we could reserve petroleum for lubricant and plastic production...

Chuck

[MichaelSol]

This nonsense about "needing" to capture CO2 - as if CO2 is some kind of toxic gas like CO or SOX - will run it's course and end up on some future history text as an example of how backward those Y2K Americans were.

I hope so.

If the "problem" is to sequester carbon monoxide, why not do it by genetic engineering some form of plant that can be readily fermented to provide all the ethanol the green weenies think is so wonderful? 

As temperature increases, carbon fixation by increasingly stimulated plant life increases. It's called "buffering." It is one of the reasons, rarely discussed because it has no political utility, that most of the major predicted effects of "global warming" cannot occur.

 

[erikem]

Rigid Roller bearings, especially on locomotives, are death to a
right-of-way. Even at that, steam locomotives were easier on track
structure because they had a certain amount of flexibility built in to
accomodate minor track irregularities, plus, a steam locomotive driver
set actually weighs less than a diesel locomotive wheel/traction motor
assembly, resulting in less rail pounding at joints, etc. 

If I'm understanding you correctly, you're saying that a typical steam locomotive has a lower unsprung weight than a diesel or electric with a nose mounted traction motor (I'm inclined to believe that). I suspect that the larger diameter driving wheels were also a bit easier on the track. One, because they would be less affected by minor track irregularities and two, the would exert less peak pressure on the rail for a given axle weight (e.g. C&O class H-8).

[erikem]

My inkling is that it if it's important enough to capture the CO2 from a locomotive to spend the money on a locomotive-sized system, it will be much much cheaper to erect catenary and capture the CO2 at the fossil-fueled electricity source.

I'm pretty much of the same opinion in the relative costs of mobile CO2 capture vs electrification. Electrification is something unique to railroads, no other form of transport has an easy a way of getting power from an external source of electricity. 

[wsherrick]

This nonsense about "needing" to capture CO2 - as if CO2 is some kind of toxic gas like CO or SOX - will run it's course and end up on some future history text as an example of how backward those Y2K Americans were.

I hope so.

If the "problem" is to sequester carbon monoxide, why not do it by genetic engineering some form of plant that can be readily fermented to provide all the ethanol the green weenies think is so wonderful? 

As temperature increases, carbon fixation by increasingly stimulated plant life increases. It's called "buffering." It is one of the reasons, rarely discussed because it has no political utility, that most of the major predicted effects of "global warming" cannot occur.

 

Back years ago when reason more or less was thought to be one of Man's best attributes; there was this concept called, "The Balance Of Nature," in other words, Nature had a mechanism whereby it took care of itself and there was not much Human Kind could do about it. 

[wsherrick]

Rigid Roller bearings, especially on locomotives, are death to a
right-of-way. Even at that, steam locomotives were easier on track
structure because they had a certain amount of flexibility built in to
accomodate minor track irregularities, plus, a steam locomotive driver
set actually weighs less than a diesel locomotive wheel/traction motor
assembly, resulting in less rail pounding at joints, etc. 

If I'm understanding you correctly, you're saying that a typical steam locomotive has a lower unsprung weight than a diesel or electric with a nose mounted traction motor (I'm inclined to believe that). I suspect that the larger diameter driving wheels were also a bit easier on the track. One, because they would be less affected by minor track irregularities and two, the would exert less peak pressure on the rail for a given axle weight (e.g. C&O class H-8).

Mr. Sol is indeed correct in his statement.  Steam locomotives can transmit their weight through the spring system which is designed to flex over uneven surfaces. 

I have been on a C&O Berkshire at 70 MPH on jointed track and it was quite smooth.  I have been over the same track with SD-40's at 40 MPH and you had to hang on for dear life.  The diesels pitching back and forth made me sea sick.

[Modelcar]

....Doesn't the diesel electric have all the flexibility needed to "soak" up a bit of the irregularities as well......?  Trucks have "loose fitting" parts and of course the springs that carry the loco's weight as well...

Am I correct...part of the traction motors are supported directly to the truck frame structure of the loco with some kind of moveable joint....?

Drivers and {part of the rods}, would be unsprung weight on a steamer.  Some of those driving wheels had massive counter weights that sure makes it difficult to imagine they would be "lighter" than the diesel's driving mechanism.

I'm certainly no authority on the subject but I sure am curious on it.

[eltraino2]

NO---- Mainatnce of the Steam Locomotives was a big issue and it was very labor intensive...

When the railroads went diesal they were able to lay off thousands of pipefitters and boilermakers..and close big shops in Cleveland and Altoona

[MichaelSol]

NO---- Mainatnce of the Steam Locomotives was a big issue and it was very labor intensive...

When the railroads went diesal they were able to lay off thousands of pipefitters and boilermakers..and close big shops in Cleveland and Altoona

It is intuitive to me that the maintenance requirements for a near 30 year old average aged steam fleet would be higher than a five year or so fleet average of the new Diesel-electric fleet. I would expect significant reductions in shop forces, but does that really say anything about the relative needs of steam engines vs diesel-electric engines per se?

Interestingly, there is some evidence that the drop in shop forces wasn't as significant as might have been expected from the simple shift in the age of the machines themselves.

With one exception, "machinists, boilermakers, electricians, etc." showed the smallest productivity gains of any class of railroad employment, 1946-1972 according to Kent Healy in Performance of US Railroads Since World War II. p. 185. Indeed, aside from the dramatic shift in the age of the fleets being maintained, the drop in this class of employment was comparable to the drop in ton-miles of freight being handled post-war, during the period of dieselization.

Ton-miles dropped by 43% post-War. Of course there were large reductions in shop forces. The drop in employment in that class would have happened anyway. Statistically, it appears to have almost nothing to do with dieselization.

The fact that the drop in employment is roughly comparable to the drop in ton-miles and the drop in units being maintained, on a percentage basis, leaves a lingering question of what happened to the additional drop in numbers that should have resulted from the dramatic difference in fleet ages?

Had the fleet remained all-steam, but largely newer as old steam was retired due to fleet size reductions, there would have been a significant drop in costs associated with maintenance, simply because of the age adjustment. Given the drop in tonnage, and fleet age adjustment, I would have expected a drop in boilermakers, etc. of about 75%.

But, with dieselization, the expected effect can't be found in the statistical record. The drop in employment is much less than would be expected. The savings aren't there. It didn't happen.

By 1960, when a good statistical record had been developed, the inflation-adjusted cost of maintenance curves, per hp, showed that it cost substantially more to maintain an equivalent age diesel-electric than a steam engine.

And that included labor.

 

[tomikawaTT]

eltraino,

Yeah, the railroads laid off pipefitters and boilermakers - and replaced them with diesel mechanics and electricians.  And, since they were competing for those skills with non-rail industry, probably had to come up with more $ per hour to attract and keep them.

When a railroad bothered to look at efficiency (most didn't) the cost versus availability of maintaining a steam fleet could be dramatically reduced.  Case in point - the N&W lubritoriums, which reduced turnaround time after a run by a couple of hours while dramatically increasing the productivity of the people using the neatly spotted oil fill hoses and grease guns.  Two less hours in the terminal getting prepared was two more hours on the road, making money.

Then, too, there have been 70 years plus of advances in mechanical design technology since the last steam loco came off the drawing board.  I suspect that a present day steamer, possibly using an updated version of the Withuhn machinery layout under a boiler and firebox with all the Chapelon/Porta/Wardale improvements, would be a lot easier to maintain than a machine whose design was frozen in 1942.  It could certainly be made easier on the track - and far more fuel and water efficient.

Chuck

[wsherrick]

....Doesn't the diesel electric have all the flexibility needed to "soak" up a bit of the irregularities as well......?  Trucks have "loose fitting" parts and of course the springs that carry the loco's weight as well...

Am I correct...part of the traction motors are supported directly to the truck frame structure of the loco with some kind of moveable joint....?

Drivers and {part of the rods}, would be unsprung weight on a steamer.  Some of those driving wheels had massive counter weights that sure makes it difficult to imagine they would be "lighter" than the diesel's driving mechanism.

I'm certainly no authority on the subject but I sure am curious on it.

The entire weight of a steam locomotive rests on a system of springs and moveable levers, which allows the weight to be distributed across the entire wheel set.  If one wheel rises or falls relative to the others, then the movement is transmitted through the spring and lever system to equalize the weight on all of the wheels at the same time.  Steam locomotive spring systems act like a three legged stool. Each leg will bear the weight of the stool on an uneven surface so that the whole is steady.

 

[Modelcar]

....wsherrick:

I'm aware of the suspension springs....{muliti-leaf}, but not the "lever" system you mention on steam engines.

[erikem]

The entire weight of a steam locomotive rests on a system of springs and moveable levers, which allows the weight to be distributed across the entire wheel set.  If one wheel rises or falls relative to the others, then the movement is transmitted through the spring and lever system to equalize the weight on all of the wheels at the same time.  Steam locomotive spring systems act like a three legged stool. Each leg will bear the weight of the stool on an uneven surface so that the whole is steady.

The lever and spring arrangement is common;y referred to as an equalizer, which are also found on many diesel locomotive trucks - especially visible in the old AAR type A trucks and the trucks used on the Alco PA's. One difference that both you and Michael were hinting at is the steamer will probably have a lower fraction of unsprung weight than a diesel or electric with a nose suspended traction motor - but probably does not have that advantage over an electric with a quill drive (e.g. Pennsy GG-1's, Milwaukee EP-3's and some of the NH locomotives).

Westinghouse made several types of electric locomotives with side rods, notably the Pennsy DD1's, the N&W electrics and the first generation VGN electrics. The Pennsy DD1 was an especially interesting case as testing showed it to exert less lateral force on the rail at speed than electrics with more conventionally mounted traction motors.

Where large steam was at an undeniable disadvantage to diesels was in bridge loading. Where a pair of early SD's may put 800,000 llbm in 120', the Big Boy would put 1,200,000 lbm in 128'. The early 4 axle power had even less weight per foot. 

[tpatrick]

Erikem wrote:

Where large steam was at an undeniable disadvantage to diesels was in bridge loading. Where a pair of early SD's may put 800,000 llbm in 120', the Big Boy would put 1,200,000 lbm in 128'. The early 4 axle power had even less weight per foot.

Entirely true, but Big Boys were the biggest, not really typical. Compare N&W's A (951,600lbs) or Y6 (961,500 lbs) and the gap closes significantly. On the diesel side a pair of C44s would outweigh the SDs, although maybe not by much. Still, they make a fairer comparison, I think. So your point is correct, but not as dramatic as you have suggested.  

 

 

[Modelcar]

....Any suggestions as to where {on here}, one might seek to find an illustration of the "equalizer suspension system".....?

[ONEHAGGIS]

HI, FIRST TIMER HERE. I HAVE BEEN READING WITH GREAT INTEREST THE MANY PAGES ON THIS SUBJECT - STEAM VS. DIESEL VS. ELECTRICITY.

SO HERE IS MY 3 CENTS WORTH.

ONE THING I DON'T THINK THAT HAS TALKED ABOUT IS NOISE ISSUES. 

AS I LIVE WITHIN A 1/4 MILE OF NORFOLK SOUTHERNS MAIN LINE IN VIRGINIA WITH A FEW GRADE CROSSING WHERE IT GETS REAL QUIET AT NIGHT, WHAT WOULD YOU RATHER HEAR GOING PAST YOU MANY TIMES DURING THE DAY OR NIGHT, THE ROAR OF A DIESEL, THE HUM OF AN ELECTRIC MOTOR, OR THE CHUG OF A STEAM LOCOMOTIVE?

ELECTRICS - I DON'T TRUST THEM, PERIOD. 

AND DON'T GET ME STARTED ON THE STENCH OF THE DIESEL ENGINE AS THEY IDLE NEARBY AND THE NOISE THEY MAKE IN THE MIDDLE OF THE NIGHT WITH THEIR ENGINES AND HORNS. YES, THEY MIGHT BE MORE EFFICENT AND FASTER, BUT AT WHAT EXPENSE?

IF WE PUT STEAM BACK ON THE RAILS, WE WON'T BE SO DEPENDENT ON "OPEC". WE ALREADY HAVE THE COAL FIELDS HERE, SO IF WE STOP EXPORTING COAL TO FORIGN NATIONS AND KEEP IT FOR OURSELVES, WE WILL HAVE A UNLIMMITED SUPPLY OF FUEL.

AS FOR THE STEAM LOCOMOTIVE INFRASTRUCTURE, DON'T YOU THINK THAT IT WILL CREATE THOUSANDS OF NEW JOBS FOR THOSE WHO NEED WORK?

AS FOR THE NEED FOR SPEED. INSTEAD OF 100+MPH TRAINS, A SLOWER JOURNEY BEHIND A STEAM LOCOMOTIVE WILL GIVE US TIME TO CATCH OUR BREATH FROM THE RAT-RACE AND GIVE US TIME TO GET TO KNOW ONE ANOTHER BETTER.

AS FOR THE LOCOMOTIVE OF THE FUTURE - WHAT ABOUT NUCLEAR POWERED?

THIS IS JUST MY OPINION.

THANX FOR LISTENING.

MARK.

[Anonymous]

....Any suggestions as to where {on here}, one might seek to find an illustration of the "equalizer suspension system".....?

Quentin, I can't find much reference on the web, but here is a drawing that shows equalization between two drivers of a 4-4-0: 

http://cprr.org/Museum/Science_of_Railways_1899/Steam_Locomotive.html

Scroll down to the bottom of the page where the image is blown up, and you can clearly see the leaf springs under the driver axles.  The springs load as the axles rise.  The end of each spring that faces out or away from the driver set is basically fixed to a bracket on the frame.  However the ends of each spring that are near each other are connected to a short link, and those short links are in turn connected to a rocking lever, which looks like an inverted teeter-totter.  That is the equalizer lever (Item #43, Driver Spring Equalizer). 

If one driver runs over a high spot on the track, it raises the inner end of its spring, which raises that end of the equalizer lever.  That lowers the opposite end of the equalizer lever, which lowers the inner end of the spring of the other driver.  So the equalization system keeps the weight born by each driver exactly the same, even though there are high spots on the track.  It also keeps the drivers in contact with the rail so the flanges remain engaged.

Typically, in larger locomotives with six, eight, or more drivers, the leaf springs are inverted from what is shown here, and placed above the axles, but the equalizer levers are basically arranged the same way.  The arrangement of springs and levers is also carried through to the lead and trailing trucks.  The levers that connect the system to these trucks do not pivot at their center like the levers between the drivers.  The off-center pivot modifies the leverage so that less weight is transferred to the lead and trailing trucks than is transferred between drivers.  The system also transfers weight from one side of the engine to the other by means of a transverse equalizer lever. 

So the system of levers controls equalization, and the springs absorb shocks as a system of suspension.  They are two independent systems, with each performing its own function.