Sorry if this has been brought up before, I haven’t seen the topic before in the last month.
I wanted to get some expert opinions going on the advantages/disadvantages
of steam & diesels & see where the debate goes.
I’m no expert, however the biggest difference/advantage I can think of is that diesels are more versatile in the the way they can be utilised. Secondly the amount of manpower required for the care and feeding of a steam locomotive is greater.
For all its romance (I love 'em, too!) the steam engine is far too limited in its versatility and requires far too many resources to maintain. Entire facilities disappeared along with the steamers.
While there were some “general purpose” types, steam locomotives were mostly purpose built. That’s why there were 0-4-0Ts and Big Boys. On the other hand, I can la***ogether as many (or as few) diesels as I need to do the job.
$$$$$$ - Pure and simple.
Like tree68, I loved steam too, but with the advent of diesels steam was on a hiding to nothing. The one of the major drawbacks with steam were the small numbers of many classes that were built, so apart from the maintenance costs the cost of spares was disproportionately high.
The ready acceptance of many railroad managements of standardised, mass-produced diesels, is to my mind an implicit criticism of many managements and their “ego trips” with small classes unique to particular railways. Looking at the UK’s steam rosters post-WWII, there were some really prize examples.
My take:
Steam locomotives have boilers. Boilers are always a pain. The boiler is by far the most maintenance intensive part of a steamer (usually, though, just because of inspections).
As I recall, the NYC found a 4-8-4 to be slightly cheaper than a four unit diesel set. However, if you only needed a three unit set, the Niagara was just a waste of money. This is one aspect not often touched on that I feel needs more attention: Because, before computers, there was no practical way to MU steam locomotives, you needed a crew on each one. As a consequence, it was cheaper to overpower the train with one big steamer, and have only one crew. On a diesel, because of the MU, you could get the number of diesels you needed, and only one crew. Just one of many facets to the picture, but an interesting one. It’s sort of abstract, I’m sorry if I lost anybody.
A diesel has a higher starting tractive effort, but it drops off with speed much more quickly than a steamer’s. So, while one ACWHATEVER might be able to start that two mile drag, it won’t get all that much speed up.
I’ve seen pictures of steamers doing some pretty incredible things, such as one 2-10-2 with 80-so cars going up Cajon Pass, and one 4-6-6-4 taking one hundred cars up Archer hill at a respectable pace. How many diesels do these trains get today? Read the Union Pacific section of The Last of Steam by Joe G. Colias for some incredible feats.
In the end though, the diesel was more versatile. However, don’t underestimate the fact that the FT was shiny, with a bright paint scheme. In a neck and neck passenger market, this is what made the difference. In my opinion, if the railroads had not cared about the shine factor, the progress of the diesel would have taken into the 1960’s.
Sincerely,
Daniel Parks
Pay no attention to Mr. Parks. A 6000 HP “ACWhatever” will get that train up to
Actually, were it not Christmas, you would have just started one.
Didnt steam loco’s use only 10% of their horse power?
Docster:
I buy books about steam locomotives out of sentiment, but if I ran a RR, the choice of motive power would be a no-brainer, the best diesels I could buy. Even if it were the late '40s.
The reasons are so numerous and varied that we could hardly do justice to the topic here. I suggest that you get the special issue of Classic Trains, Diesel Victory. I’m sure you can order it through this Web site.
Steam is noisy, hot, and fun, but in order to get that pleasure (or work) you need to produce 20 or 30 times as much carbon dioxide per ton moved as you do with a diesel…not exactly an environmentally friendly machine. As stated before, you also need a crew in each steamer you use, and you still need all the trackside infrastructure to keep the steamers’ logistical requirements handy, plus the people to build, maintain, and stock those items (coaling, water). I’m thinking near 3/1 in operating costs against the steamers.
The truth is that with steam, horsepower increases as speed increases, until 45+ mph on a 4-8-4. On diesels the horsepower curve remains flat throughout the speed range. With diesels the tractive effort curve descends with acceleration more dramatically than in the case of steam.
None of this compensates for steam’s disadvantages of course. But between fuel stops, passenger steam would out-perform passenger diesel every time.
“But between fuel stops, passenger steam would out-perform passenger diesel every time.”
You don’t happen to have Farrington’s book, The Santa Fe’s Big Three? He reproduces the horsepower curves for their 4-8-2s and 4-8-4s. The early 4-8-4s were about out of gas at 70 mph. (I’ve never learned whether the curve shown is pre- or post-rebuild.)
Oh boy.
4000 hp steam is waaaay poorer loco then 4000hp diesel (if both are rated at the same speed - say 70 mph)
For starters - 4000hp steam reaches its power about 40 mph. Diesel has this power avalible at about 15 mph. This means that the diesel will have much better acceleration. Steam locos lose power when the speed goes above certain value (pistons moving too fast to effectively use all power stroke) diesels do not.
On any course 4000 hp diesel will rape 4000 hp steam. Period.
Actually - SD70MAC will outpull and outspeed a BigBoy - esp on a hilly route.
Got to love when people rely on myths and only look at Horsepower. there are other factors involved, engine wieght, torgue and gearing are all involved, which when taken into account make steam engine better than Deisels. but the fact is, Deisels won out in the cost department, it took less manhours to work a deisel than it did a steamer, 2 man crews as opposed to 3 man crews, not to mention all the water/fuel stop crews that were no longer needed, the multitude of roundhouse mechanics no longer needed, ect.
Then, as mentioned above was the sheer “shiny” factor, after WW2, people were looking at brand new shiny things, with the now aboundance of metal available, all things stainless steel became envogue, so when those streamlined shiny deisels arrived for passenger service, it doomed the steamers to backwork, then finally to no work.
Profit was the biggest motivator for switching to Deisels, it was cheaper in manhours and that’s it. if companies were more worried about pulling power and abilities, then steam would still be the rulling choice, but alas it’s 75-80% cheaper to operate a deisel in manhours than it is a Steamer, and that equates to more money for the company, which then equates to more money for the execs.
We seem to have forgotten the real woe of the steamers (aside from what has already been mentioned). Tractive effort! See while steam locomotives may have more horsepower it can’t get it all down to the rails at lower speeds, or the wheels will slip. Like Coborn noticed steam locomotives, generally, didn’t get to use their full horsepower. On the other hand, if memory serves me right, a FT diesel, I think, will be able to put its full horsepower down at about thirty mph. This makes one question the reasoning the diesels took over the fast trains, and left the steamer to drag freights and other slow work; most likely the diesels were put on the passenger trains because it made the railroad look “modern” and advanced.
To original thought of Post: Versatility and economics. Steam vs. Diesel motive power. Of course diesel on the must have side.
JP Lamb’s book “Perfecting the American Steam Locomotive” ends with a
section “Why Steam Power Vanished” with pretty much the same points
made by art and tree. He’s an academic (mechanical) engineer and he
says it this way:
“It’s inevitable that steam locomotives […] would be supplanted…”
“… the working fluid for a steam engine is water.” “If we could
discard the carrying of water and instead use a free and abundant
working fluid, (air) we would be able to dispense with a large amount
of ‘parasitic power’ needed to pull the tender, along with [all the
support stuff …]”
“… We could discard the large mechanical transmission system
[…] and replace it with an easily modulated electric motor …”
“… The primary duty of a steam locomotive is fixed during its
manufacture. For example, an 0-8-0 cannot be used to pull a passenger
train at 60 mph, while a 4-6-4 does very poorly as a yard engine. In
contrast, an early diesel unit of the 1950s could be used indivisually
to switch cars in a yard. Within a short time […] it could be
connected […] to provide a propulsion systme with greater power than
a U.P. Big Boy.”
“Railroads could replace/repair engines, generators, and traction
motors in relatively short time as compared with the major repairs of
a steam locomotive.”
John
<who doesn’t really know this stuff, but can read and report>
So, as several of us have said, in one way or another, the diesel made economic sense to corporations that had a duty to supply returns on investment to shareholders. That’s it. The bottom line. If the Company was going broke, and diesels were the clear saviours, what was so hard to figure out? Steam had served its purpose, just as had the hot-air balloons and Zeppelins, and just as steam engines had served in the engine rooms of trans-oceanic freighters. Time to move on and relegate the steamers to wistful fans of nostalgia.
Tempus edax rarum. “Time is voracious.”
Oh youth that doesnt listen to elders. two SD-70 macs to drag a coal train up albia hill at a crawl.a 2-10-4 dragging a 10,000 ton train up the same hil at about 30. I can hear you guys now ,thats 8,000 tons less,ahh touche but they had fricton bearing’s. Not the nice roller bearings that todays power house junkers get to pull. Took 4 count em 4 to get the same train pulled by one steam loco.So before you all say steam was horrible l suggest you re read your history. Had WWII not forced railroads to run power that was beat up and out of repair the diesel might have had to wait till the 70’s.
Funny we all talk about how great diesels are and versatile but can a 70 mac do locals? a Trash 9? I dont think so folks! Diesels were versatile one day long ago,not now.
The way I heard it WWII kept steam going because you couldn’t get diesels, of course I don’t know for sure. What do you guys think, would steam have lived longer, or died quicker?