They say that necessity is the mother of invention.

At times it& #39;s closer to the Bride of Frankenstein...
It& #39;s worth unpicking how we got here, "here" being the Carcassone-Quillan railway line in 1943 Vichy France.

First up, the Germans had requisitioned all the fuel. This meant pivoting to burning wood gas - the fuel of choice for low-flying blimps since 1901.
The Carcassone-Quillan line had been using Michelines - pneumatic tyred, diesel-powered railcars.
Michelines, incidentally, had been used experimentally in Britain. The first one was... not a looker.
At some point it dawned on someone that basic aesthetics were a thing. The excitingly-named Coventry Pneumatic Railcar Company built a couple under licence for trials in the UK:
Michelines needed diesel and weren& #39;t easily converted to other fuels. With 65,000 wood gas powered vehicles in France, the Vichy government demanded that the railway switch to the obvious solution: run a bus service instead.

Augustin Talon saw a loophole...
Humping the buses up onto bogies turned them into pseudo-Michelines whilst still very obviously being buses. As a bonus, a carriage could be attached and about 150 people carried per trip - more than previously. Traffic soared.

The three month & #39;experiment& #39; lasted until 1946.
Proving that no idea is too stupid to avoid trying twice, German engineers later had a go.

The result was every bit as ridiculous as you might hope.
In fact, with ruthless German efficiency this thing combined TWO stupid ideas. Not only was it a bus that ran on rails, it was also a ro-railer...

Here it is on the road. It looks fine until you notice the back wheels.
The ro-railer bus as a concept is one of those stupid ideas that cannot stop resurfacing. Here& #39;s the LMS Karrier stinking up the line circa 1931:
Two years of experimental development failed to alert the LMS to the idea that the ro-railer was a daft idea. It briefly made holidays in Stratford Upon Avon even more depressing for a few weeks, broke an axle, and was quietly disposed of.
Combining two bad ideas together makes absolute mathematical sense, albeit purely because multiplying two negatives makes a positive.

The Schi-Stra-Bus is why you should never trust an engineer who says it& #39;ll work fine according to their calculations.
Only 15 were ever used on the rails, which a quick calculation reveals was 15 too many. German Wikipedia claims the 140km between Passau and Cham took five and a half hours to cover at the stately average of 16 miles per hour.
The ultimate problem wasn& #39;t speed though. They topped out at 120kmh on rails. Transitioning between road and rail was slow - ten minutes was timetabled - but not a showstopper.

What stopped them was winter. Or - more precisely - didn& #39;t.
It turns out that a lightweight pseudo-locomotive running partially on pneumatic tyres on snow-covered rails has all the braking force of jelly on a waterslide. Getting the thing moving in the first place can hardly have been a laugh either.
Somehow these things remained in service until 1967 on the Koblenz-Betzdorf line, German wikipedia again unreliably suggesting that they were regularly overloaded with passengers.
If nothing else the saga of the Schi-Stra-Bus finally proves that the Germans definitely have a sense of humour. And that when they do produce a joke, they take it very seriously...
Want footage? The switching in of the wheels is, erm, not what I was expecting. https://www.youtube.com/watch?v=9ldN0KlxHM0">https://www.youtube.com/watch...
Finally, to prove that you REALLY can& #39;t keep a bad idea down, here& #39;s a Japanese attempt from 2007.

Given what natural selection inevitably does to these things, tagging it with "Darwin" seems to be unusually optimistic...
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