Paper models, photos and musings of a Paper Kosmonaut

19 December 2016

Zil 4906: a little history

Imagine for a moment you’re a cosmonaut. Returning to earth after becoming the first crew to perform a space walk, you you make an unexpected emergency landing somewhere far away on the Siberian taiga,in the middle of the woods, in the snow, with no roads or villages in sight for miles and miles.

Belyayev (L) and Leonov (R) are entertained by their good friend and colleague Vladimir Komarov on their way to the launch pad. Note the special sun visors the cosmonauts have inside their helmets.
That was what happened to Alexei Leonov and Pavel Belyayev. Instead of returning to the wide open steppes of Kazakhstan, they had a bit of trouble* during re-entry and more or less crash landed in the inaccessible woods of the remote Perm region. When they finally were localized, a helicopter dropped some warm clothes but they yet had to wait until the rescuers reached the Voskhod capsule (called a sharik). They had to wait in the sharik for a whole day while knowing they could also be attacked by aggressive packs of wolves (it was their mating season). Finally was an expedition arrived on skis to get them out. After getting there was yet another problem: the sharik could not just be lifted out of the woods so they had to stay there another day. The cosmonauts and the rescuers built a small cabin of chopped wood and made a fire to stay warm.


Rescue crew meeting up with the stranded cosmonauts. (recognisable by their white caps) Photo: Unknown. I presume these pictures from the soviet era are made by 'the state' but if anyone claims this picture, let me know.)

The dense woods required the rescue team to land their helicopters many miles away, and they had to continue their journey to rescue the cosmonauts on skis.
After arriving, the cosmonauts too had to don skis and together they returned to the helicopters. So, all in all it took two days to get them back.
This has come to be known as “the Perm Incident” and, of course, the Russians didn’t want that to happen again. Chief designer of the Soviet manned space Program, Sergei Korolyov, asked the design bureau of Vitaly Andreyevich Grachev, specialised in designing rugged all-terrain vehicles, to come up with a vehicle to get to such remote locations more easily and practically. it had to be very rugged.

PEU-1 carrying a boilerplate Soyuz, presumably for training purposes.
In 1966 Grachev came with a design of a very big 6x6 transporter with a fiberglass bottom construction. It caried a crane on its back for the capsule. This vehicle rapidly evolved into a usable machine for getting stranded cosmonauts out of woods or other locations unsuitable for helicopters. Grachev took his design to the Zil factory to build this vehicle. Enter the PEU-1 and not long thereafter, the PEU-2. 
PEU-2. Even bigger, but also having an extra crew cabin.
But they were far too large and heavy for any transport aircraft of that time. So it would be hard to take them to remote locations. The preferred vehicles had to be smaller and light enough to be airlifted.

ZIL 4904-2. Smaller yet more versatile.
In 1972 Grachev came with the ZIL 4904-2, the prototype of the “Blue Bird”. It was a lot lighter, propelled by water jets and fitted into modern cargo planes. However, it had to be refined a little, and finally in 1975, the first ZIL 4906 vehicles were built. they were smaller, could reach 80 KM/h on roads and 9 km/h when in the water.

a ZIL 4906 assisting in salvaging a Vostok Sharik. These capsules were used long after the ending of the Vostok / Voskhod program as spy sats (Yantar) or biological research vessels (called Bion). They could return to earth with lots of equipment and were relatively small, so that is why they were in use long after.
They were assisted by another Zil vehicle, 2906-1, which was driven by two screw-like tubes under its fuselage. It could race through bogs, swamps and the most inaccessible sorts of terrain thinkable at speeds of 25 km/h. It could be carried on the back of the 4906 with the crane. The other one, called the “salon” had an aft cabin in which the cosmonauts could recuperate, be checked upon and be nursed if necessary. Here's a nice little video on how it all worked:

From that moment on, the “Blue Birds”, as the big amphibians were christened, became a regular sight at Soyuz landing sites.

*Trouble during re-entry: A bit hard to explain in two or three sentences but here goes: The bulky, partially inflated space suits Leonov and Belyayev wore made them unable to easily reach the instrument panel from their seats and they had to unbuckle to get there and flip the retro fire switches. The capsule had a specific centre of gravity, which was necessary for re-entering the right way and landing at the right spot. Therefore they had to be in their seats. But they were too late. When they finally were back in their seats, which also was troublesome due to their suits, the re-entry already had begun and they overshot their target by many many miles.

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