Anorak Break

Meet the largest tank ever built - "The Tsar Tank".
It was so-called because the Kaiser's cousin, Nicky was so excited by the clockwork-driven model he'd seen demonstrated that he funded the whole thing.
It would have been nice to be able to say that it "Ruled the battlefield" and sent the Germans running away screaming.
In reality, you're looking at the remains of the only Tsar tank ever constructed.
The photo was taken sometime before 1922, when the relic was broken up.
In August of 1915, she'd been assembled on-site and fired-up.
She traversed some hard ground admirably, knocking over a tree in the process. The tree seems to have been important. Every account mentions it.
Then, the beast went off into some soft ground where the smaller rear wheels sank down toward the center of the earth and stopped.

The tank was scrapped where she sat at the end of this, rather brief test.
That's how stuck she was.
Of course, as long as we're Monday-morning-quarterbacking, we could say that the weight's distributed incorrectly. It seems balanced front-to-back but I suspect therein lay the problem. Perhaps someone should have anticipated the differing footprints offered by the various wheels
The load of the two , front, driving wheels - each nearly 30' in diameter - vs that of the triple, rear wheels, each maybe eight-feet across.
Each set carrying their fair share of the 40-ton total.
They should have known better, I guess.

Nowadays, people flip a lot of shit at the Tsar tank - in the more rarefied corners of the Anorak Internet (AI) where folks would care about such. It's scorned, called naive and fairly. Its big failing, the weight distribution thing, should have been pretty obvious.
Still it predated the Brit crawlers. The Mk I was introduced a year after the big fella's abortive maiden voyage.
The Mk I, when it first showed up on the Somme, hardly carried the day. They broke down and got stuck as well (most having covered more a hundred yards - one would hope). Also, when so-stuck, became sitting ducks for the field artillery. So there.
The scary bit was that the Mk I achieved SD status without being thirty-feet tall with huge, fragile bicycle-wheels that simply screamed "Shoot me".
The Tsar wouldn't have lasted long.
But I think, its propulsion system was pretty ingenious. Instead of being torqued by the axle, those giant wheels were each driven by a separate engine - depending on what you read either a 250 hp Sunbeam or 240 hp Maybach - at the rim.

The position of these engines, as pictured above occupied the wedge shaped structure just ahead of the sponson (hint - if you spit out the viewing slit, you stood a fair chance of hitting the rather self-possessed, virtual fellow in the foreground).
Inside the power was transferred from the engine (the identical thing happening across the way in the other sponson) by means of two, counter-rotating, automobile wheels.
"A large, railway-coupling spring" - whatever that was - held the two wheels in contact with the inner rim of the big wheel (covered with a layer of wood) in effect pinching the wheel.
It's brilliant. Everything depended on two separate engines, well out of harms way with what seems a foolproof clutch system.
They predicted that this thing could travel at 17kph which would have been a good clip for 40-tons. The British Whippet, at 14-tons, could only hit 13kph. Of course, the Whippets were successful tanks - ie lots of them actually operated at those speeds.
With the big guy here, I can imagine either the tires slipped on the wooden, inner rim or maybe the big wheels on the ground (I almost wrote "mud" but - August). Either way, not enough traction to pull that 20ton dead-weight, formerly known as the "tail", out of the hole. And not a very deep hole. Where it was photographed is where it got stuck and stayed for the next several years.
The amount it is "buried" in the pic is apparently how deep it went.
Pathetic.
Anorak update: More info for my old Anorak pastime (linked above).



Ah, the late Missoula roundhouse.
The period pic was taken from a point close to the NE corner of the Googlemap, frame.
The hip-roofed structure in the center is the NP depot, lower left on Google - the orange, tile roof.
Facinatin' innit?