Tue Dec 20th, 2005 at 10:28:36 AM EST
back from the front page
Homo sapiens, we call ourselves, and see all the products of our technological development as signs of our ingenuity. Yet, in truth, most of that development came by trial and error1 – where we view the (successful) trials as ingenuity, while (if we are shown them at all) we laugh at the errors: this looks ridiculous, what a stupid idea!
Whereas back then, when people had no benefit of hindsight, the errors too had a rationale. For example: if the steam engine could be made into a locomotive, why not put a coal-fired power plant on the rails?
Norfolk & Western class TE-1 #2300 "Jawn Henry", a steam-turbine–electric locomotive (click image for larger version at Gunter's Locomotive Pages)
Go below the fold for more on this one, plus another US and a Stalin-era Soviet failed design.
- Or, to prod the Dawkins-allergic in our rounds: it came by memetic evolution.↑
This post is the middle part of an exotic steam locomotives mini-series, whose three parts are connected, indeed not clearly separated – and indeed the "Jawn Henry" is another Bigger Than Big Boy: it was the longest steam locomotive ever built both with (161'1" / 49.10 m) and without tender (111'7" / 34.01 m), and also the second strongest and second heaviest. The heaviest (and second longest...) was a similar type the N&W TE-1 was inspired by: the Chesapeake & Ohio class M-1 (1,233,970 lbs / 559.7 metric tons with tender, 856,000 lbs / 388.3 t without).
Chesapeake & Ohio class M-1 "Sacred Cow" #500, another steam turbine – electric locomotive (photo from Gunter's Locomotive Pages)
While the three C&O M-1's built were total failures, the sole "Jawn Henry" prototype ultimately came out of its teething problems – but economic it was not. The obvious problem: just its sheer size. It was maintenance-heavy for several reasons – including turbine fans that didn't like acceleration/braking, coal dust clogging up parts, and the complexity of it all. And starting up and power regulation was nowhere near as flexible as Diesels or [catenary-supplied] electrics.
Most of the 'normal' biggest steam locomotives (and all in my Bigger Than Big Boy post) were articulated: two pairs of cylinders drove two groups of coupled wheels. But, why not put a third driving unit under the tender?
The Virginian class XA #700 (photo from Douglas Self's page on Triplexes)
Built during WWI, the Virginian XA was another sole prototype modelled on another railroad's similar class (the Erie class P-1, again 3 built). It was the strongest steam locomotive ever (tractive effort of 199,560 lbs / 887.7 kN) – but that was too strong for the couplers of the time, so the XA broke a few. Also, as a Triplex needed enormous amounts of steam, it could barely accelerate above walking speed. And as the tender got lighter (when water and coal was used up), the wheels under it began to slip.
As befitting for a megalomaniac, Stalin had his go for largest locomotive ever, too. What he got instead was perhaps the single most expensive mistake in railway history. It was no articulated – it was the only steam locomotive with seven coupled axles:
The Soviet Railways class AA-20 01 "A. Andreyev" (photo from Gunter's Locomotive Pages)
Now the AA-20 was already straddling the limit to the finishing part in this mini-series, on truly crazy designs: for, more coupled axles mean more stress on rails in curves, and more instable running that throws the locomotive body right and left. On the other hand, there was no obvious limit – and a number of six-coupled loco types ran successfully. Begun in a German factory, finished by a Soviet one, the AA-20 made one single trip in service – and ruined tracks on the entire stretch it travelled.
It expanded curves, ruined switches, derailed repeatedly, and on top of this couldn't accelerate to higher speeds. So after the propaganda run, to not embarrass Stalin, the loco wasn't scrapped – just kept in the engine shops permanently...
Previous Monday Train Bloggings:
- (Premiere/ modern Austrian trains & locos)
- Fast Steam
- Heavy Haul
- Forgotten Colorado
- The Hardest Job
- Highest Speed
- New England Autumn
- Bigger Than Big Boy