Here's an interesting academic paper that I came across:The authors used a good source of data:

The paper was published on February 22, 2023 by the Royal Society Open Science journal: The end of the line: competitive exclusion and the extinction of historical entities

I was just reading about that. What a cool use!

Holy cow, this touches so many aspects of my nerdiness (I have a PhD in ecology) it's incredible. I'd love to meet the authors!

-Philip Marshall

In my opinion, some of us might send comments to the journal regarding the paper's methodology and assumptions.

There are a number of cofactors that (clearly to us) affected the replacement of steam motive power, including corporate readiness to develop alternatives with the correct characteristics (for example, GM post- Winton/EMC), cost-effectiveness of suitable fuel or electrical infrastructure, suitable personnel at acceptable cost, and development of functional alternatives that change cost-effectiveness. Against the electrification in Europe, the very pointed counterexample of traction interurbans in North America is an interesting topic to consider -- including the precise types of motorized vehicle, and the state of 'good roads' development, that can be synergistically observed.

An interesting point is that, in the United States, there was a very sharp distinction between 1946 and 1947 regarding the workability of modern large steam power. I don't think this was a consequence of 'sharp' marketing by diesel builders, but the special conditions known to railroad historians might expand on some of the authors' discussion and perhaps conclusions regarding the course toward extinction in what may be a much more complex and interdependent model.

An interesting point is that, in the United States, there was a very sharp distinction between 1946 and 1947 regarding the workability of modern large steam power

Overmod, I'm interested in your expanding on this. There was certainly a lot of worn-out and obsolete steam power on railroad rosters in 1946 (and 47), and most of it was replaced by diesel power.

Howard P.

I had to read through this three times to convince myself that this wasn't yet another "practical joke" paper that demonstrated (as others have) that one can throw together meaningless or completely non-interrelated scientific jargon to get a nonsensical paper published by some scientific journal or another. And, to be honest, I'm still not 100% convinced it's not.

A note about the publication, from Wikipedia:
"After an article is accepted, authors must pay an article processing charge to see the article published. The fee, as of January 2021, is GBP 1200, or USD 1680, or EUR 1440.[11] The journal offers a number of article processing charge waivers."
It's not like the Royal Society is some fake for-profit publisher, but much of academia has drifted somewhat astray in recent years with politically-driven agendas and missives.

It might have been useful for the authors to have examined other texts, most notably Albert Churella's From Steam to Diesel. or David Wardale's (unobtainable) The Red Devil and Other Tales of Steam. The overall question of steam's demise is very multi-faceted, and attempting to distill such a hypothesis down to a somewhat simplistic parallel to extinction events is fraught with potential bad leads and missteps.

I think the authors are having a bit of fun with this paper, but it's not intended as a joke or spoof. It's real. Yes there's a lot of jargon, but they're using it correctly.

(In contrast to the infamous Sokal hoax which involved physicists submitting fake papers to humanities journals to poke fun at their fashionable nonsense, this is clearly real evolutionary biologists writing for other evolutionary biologists, albeit slightly tongue-in-cheek.)

Whether their somewhat simplified and incomplete engineering history can provide a useful model for biological speciation and extinction is a different question. Evolutionary biology is known for a certain amount of handwaving and adaptive just-so stories (to borrow a term from Kipling), because as a historical science rather than an experimental one it tends to rely on reasoning from induction and analogy more than deduction and hypothesis testing. That's really a problem with the discipline as a whole rather than this one paper in particular. But I have to say I really enjoyed reading it!

-Philip Marshall

We should remember that the paper isn't about railroads; it's about technology extinction. The simplifications of the model and the discussion are intended to emphasize this.

In my opinion it enhances, rather than subtracts from, that concern to point out that "electrification" of what would formerly be steam-powered railroads has a long and checkered career, at many points demonstrating a very different type of technological extinction driver by different combinations of factors. Were I interested in the 'vanity press' thing, I'd be tempted to put together a paper that more fully explained this.

The 1946-1947 boundary applies to large modern steam, and is independent of the trend toward replacing antiquated or no-longer-'cheap' handed-down power with internal-combustion machinery (which can, for example, be seen markedly in switcher adoption in the 1930s, and in the evolution of road switchers in the period from the late 1930s through the early '50s). It is separate (in my opinion) from the financial access to expensive lines of capital available to the railroads after the 'flush years' of WWII, but it is relatable to, for example, the Korean war.

One very remarkable way to look at this is to read through the discussions of increasing cost and decreasing availability of the 'grunt' workers necessary to sustain steam as American railroads practiced it, and then look at the history of the PRR steam turbine 6200, as recorded by the documents at the Hagley. We see glowing defense of the concept, even past the first staybolt fiestas; we see Westinghouse promoting the 4-8-4 version into 1948; we see the patent for the two-speed planetary transmission that fixed the most significant design faults. And then -- the defending stops.

Not to fuel a pet conspiracy theory of mine, this is at the time that the expensively financed PRR T1 production, which had already had to have streamlining and boiler-steel 'modifications', was slated to have its comprehensive 'lessons-learned' set of fixes applied... which was abruptly cancelled, the locomotives shifted to services where their advantages disappeared, and great effort seemed to be made to brand them unfixable dogs and ridiculous errors in motive power design. (Not coincidentally when it was time to make the case for getting out of the equipment-trust obligations...)

What really struck me was in figure #1. Right after WWII the average tractive effort fell off a cliff. That means the first steam locomotives to succumb to the diesel were the larger engines, 10-coupled and articulated. Of course, that is what the diesel did best, being able to be MU'd. The big thing, besides the labor savings of the diesel, is that about 95 percent of the steam locomotives by 1946 were over 15 years old and worn out from WWII. Fifteen years is their economic life, and in need of expensive overhauls to reduce maintenance and increase reliability. If not outright updating, as the B&O did when they rebuilt their 2-8-2's into faster 4-8-2's. Most railroads opted for spending the money on diesels and their infrastructure.

A lot... a LOT... of the preferential gains for diesels were for services where all the 'older' locomotives that had been replaced by new power were serving. The switch engines with their smoke-opacity problems and continued need for firing whether actively running or not, the antiquated road power on commuter services, the branch-line ramblers -- all those things had 100% of the cost of roundhouses, and water towers, and the need for enginehouses and hostling and expensive regular repairs and boiler work. They went upside down as fast as the big road power, which wasn't, I think, characteristic of the British experience all the way to the '60s.

A number of authors have mentioned the serious access to credit that came with the end of profitable wartime operation. Railroads often used this for the 'magic' new diesels that supposedly ran well on deferred-maintenance track, while the arguments for the Government to subsidize the wartime traffic damage were still going on. By the time things like lateral from traction-motor mass were fully realized... steam "and all the baggage that went with it" was extensively gone.

A point that parallels, although it does not strictly mirror biological extinction is that very, very seldom did a railroad, once it had dieselized, go back to working steam. Which implied that, as each holdout railroad encountered its own combination of circumstances that made steam power go 'upside down' as commodity motive power, more locomotives were thrown out and the market for specialty equipment droped even more.

Several comments…

This has a British perspective that might not be as true for the US… particularly the belief that passenger service was still a traffic driver. Likely also locomotive size which they saw as diminishing, while in the US switchers were the first locomotives generally adopted, and very large steam the last built.

Of course acknowledging the different pressures in different regions (continents) would mirror nature...

The use tractive effort as a gauge without addressing the differences in tractive effort curves for steam locomotives and diesels… Steam could maintain tractive effort as speed increased which earlier diesels could not.

The call out that steam locomotives need solid fuel (coal) which was increasingly not true particularly in the western us.

They miss the point that in the eastern US there was a perception that railroads should burn coal because that was a significant traffic source… noting that in Britain, both coal and railways were being nationalized, so the relationship with coal producers was likely not as big an issue. On the other hand you might discuss the relationship between coal production and coal as locomotive fuel in the same terms you discuss co-dependent biological communities.

They might have looked at the very long term effort of railway management to reduce the size of the workforce, both before and after the elimination of steam, much as one might look at certain ecological pressures on a species..

Finally I suggest that if interested in their thesis, you should read any of George Hilton’s books, on cable cars, on narrow gauge, and with Due on Interurbans… in all three cases he notes that if the promoters had known what was coming in as little as 10 years, for Cables it was electric street railways, for narrow gauge, free interchange of cars, and for interurbans automobiles and trucks, they would never have adopted the technology.