Since I always interested in massive, powerful and fast steam locomotives from different countries, this monster caught my attention since the first time I saw it on my stamp collection when I was a child. But I didn’t know any detail of her background story until her wiki page was established. This monster was built in Essen, Germany by Krupp, following a Soviet design in 1935, another example of a massive, impractical machine from the USSR.
Note that she was built not long before the 1939 World Fair, I suspect that this 4-14-4 was one of the reasons why PRR S1 was built unnecessary long and heavy for the sake of national prestige. This is a very rare footage that you could only find it by using the Russian language in the search engine. I hope you guys would enjoy it.
(PLEASE TURN OFF THE VOLUME OF YOUR COMPUTER FIRST, THANK YOU!)
Slow down the video speed to 0.5 or 0.65 (if you have the plug-in) will show you the normal speed.
The AA20-1 locomotive was built at Lugansk in 1934.
A design was prepared in Germany, possibly as the result of a commericial enquiry (a number of locomotives were purchased by the Soviet Union in the 1930s, including a Beyer Garratt, Baldwin 2-10-2s and Alco 2-10-4s)
The locomotive can’t be said to have been a good idea, but there were good reasons for its design. The “20” in the number indicates the axle load in metric tonnes, so it is around 60% of the axle load of a similar US locomotive. To get a locomotive with the desired power, more axles are needed. A 2-6-6-2 simple articulated would have been more practical, and one was built in the late 1940s (type P34) but in the end, the solution of smaller locomotives (2-10-2s) was adopted. there have been a number of reasonably successful twelve coupled locomotives in Europe but these were much smaller than AA20-1. the 4-14-4 was the result of trying to get a locomotive as powerful as the Alco 2-10-4 type Ta which could run on the lighter track that made up much of the Russian system.
Although there had been publicity at the time, I don’t think AA20-1 was well enough known to influence PRR 6100, nearly six years later.
You are welcome, Firelock76. Ironically, I can find a video of a steam locomotive which was built behind the Iron Curtain but can’t find a decent video of PRR S1 and S2 after they were put into service, but I won’t give up.
I have always wondered what became of M. Andreev in the subsequent years. That was not a happy time to be an engineer in Russia… ‘wrecker’ trials less than half a decade earlier.
There is nothing particularly obscene about this design; the reported difficulty as I recall was poor performance traversing s’witches, which need not be a problem for main-line traffic on lines with traffic density suitable for a locomotive this size. Yes, thought was given to proper lateral, and yes, it was not impossible to fire something this ‘size’ – this design uses the result of intelligent study of American locomotives as well as details of the 2-10-4 design from Alco that has been mentioned.
Not surprising, though, that 10-coupleds were a better approach.
M636C-- if you’re still around ( asked by me from another thread )…what the heck is a sheep trek and kangaroo bushes? Kangaroos live in thick brush? Head to imagine with all that fast hopping.
Yeah you wouldn’t want to be responsible for anything Railway or anything else either during the Stalin regime.
Can you give me some context for the quotes about sheep and kangaroos?
Sheep tend to walk in single file in open country following established paths through the fields. If scared they will move as a group, but normally they move in a line.
Indeed kangaroos like open country but they sleep in groups under trees and bushes. You often see then hopping through the carpark to my office which is located next to a nature reserve. The main thing to do is to avoid hitting them with a car. They graze on the front lawn of my house at night. On hot days they lie in the shade.
This is one I’m familiar with, because the main line between Melbourne and Sydney runs through it. The railway has a horseshoe curve adjacent to the location marker, assuming you see the same view as I do.
I’ve been visiting this spot for nearly 30 years. You can get a great range of photos from spots around the “Cullerin Road” bridge. The road, until 1994 was the main highway between Sydney and Melbourne which seems unbelievable now although I used it myself.
However, the point I’m trying to make is that there are effectively no trees, as can be seen in the aerial photo. You don’t run sheep in a thick forest.
The photo of the two cars looks remarkably like a “set up” to me, on an unsealed road onto which a couple of branches and large rocks have been placed which look like they have been posed for the photo. The cars do have right hand drive, and the scene is definitely in Australia. But while Kangaroos might live in the surrounding “bush” sheep would not find it convenient.
Note that the term used in Australia is “bush” for rural and remote areas. The use of “bushes” suggests a misunderstanding
I assume this was to allow greater lateral movement of the driven axle. Even though the wheels lack flanges, the tapered tread will cause them to move laterally, possibly to an extent that would exceed the allowable limits of the valve gear.
This might be a feature carried over from the German proposal. The Prussian P10 / DRG 39 2-8-2 was driven on the second coupled axle with the valve gear eccentrics on the third coupled axle.
I’d think, first, that the likeliest reason for moving the valve gear would be to reduce the augment on the main, which would be insufferable if the main bore both the heavy big-end and center-of-percussion mass of the main rod AND the outboard rotating mass of the eccentric crank and rod… this is I think a major reason for the prominently gun-drilled axles visible, and the absence of knuckles on the main and following driver pairs (although a very long one is present behind them)
I’d then move promptly to the nasty characteristics of having to carry the entire structure of the eccentric fully outboard of the main, on what is already certainly a heavily-loaded main pin. And in the process putting the components of the valve gear far out toward the clearance limit, involving some (undesirable) offset in the valve gear to get things in line with the cylinders. As built, only the eccentric rod itself has to clear the big end (which it appears to do very closely!)
It is fun to assume that this design is one of those wacky Soviet dialectical-materialist assertions of political will over mechanical possibility (or ‘capitalist’ wrecker definitions of engineering) but it has never really seemed to me that the AA20 wasn’t a product of the same people who detail-designed the IS-class 2-8-4s. Perhaps with the same manipulation and inherent threat as that suffered by Bartini, and with the product having the same amusing Japanese-radio-circuitry ‘relation’ to American prototype details as the “Tu-4” did to the B-29, or the Canadian C40-8s to something like a GMD/EMD cowl unit…
