Jaw-dropping stuff. Must-see for atomic junkies.

That build is like something out of the Jodie Foster movie, Contact.

incredible engineering feat that nearly came a cropper due to some barbed wire

glad to see it was a success but will it contain the radiation??? thats the big question

Yes, the steel structure will block most of it although its main role is to stop radioactive debris escaping in the event that the existing sarcophagus collapses, and also to allow for the dismantling and clean-up of the reactor.

Interesting and vital project, makes me wish I'd been good at maths, structural engineering is one of the jobs of the era. Projects now are being done on such a scale.

Fascinating prog.

Very high tech stuff, apart from using bog standard mild steel for the roof with the resultant corrosion problems, I thought they might have used special alloys, carbon fibre or aluminium, although it is a huge structure so maybe only steel will do.

Spotted this by accident and missed a chunk of it, really good bit of TV.
When my downloader program unbuggers itself I'll download the program.

As a very dull person, I could watch 3 or 4 hours about that project, the whole design and build process, strand jacking, skidding etc.

Classic BBC4 fodder. Informative and fascinating. Love it!

I'm sure I heard them say it was stainless steel.

The main structure was made of mild steel but they were using dehumidification to slow the corrosion enough for it to last 100 years. I did wonder why they could not have used a better paint scheme such as a Glass-flake Epoxy which has been used on the Forth Bridge. I suppose they have worked it all out. It's the cladding that's stainless steel..

Heavy structural steel will probably be mild, cladding stainless.

For those passing by who won't have a clue what this is about:
Documentary which follows the construction of a trailblazing 36,000-tonne steel structure to entomb the ruins of the nuclear power plant destroyed in the 1986 Chernobyl disaster. It films close up with the team of international engineers as they race to build the new structure before Chernobyl's original concrete sarcophagus - the hastily built structure that covers the reactor - collapses.

Built to last just thirty years, the temporary sarcophagus is now crumbling, putting the world at risk of another release of radioactive dust. Radiation levels make it impossible for workers to build the new shelter directly over the old reactor, so engineers are erecting the new megastructure - taller than the tower of Big Ben and three times heavier than the Eiffel Tower - to one side and will then face the challenge of sliding the largest object ever moved on land into place over the old reactor.

50mm clearance was the bit that blew my mind! Heroic stuff all round. They must've been on quadruple bubble for that gig.

Wish it'd been longer. Reminded me a lot of that show from a few years back that I loved - Monster Moves.

I missed the explanation for using sliding pads and hydraulic rams [ and lots of aerosols of Pledge it seemed ] to move the arch rather than good old fashioned round things called wheels that have served us rather well for millennia.

Or were they just being French, with lashings of flamboyant Gallic contrariness ?

Axles wouldn't take the weight.

I missed the explanation of what they were planning to do with the reactor core.

Just watched it on iPlayer, fantastic documentary. The entire team that committed to build a structure designed to secure the health of both nature and human deserve all the recognition in the world. Truly fascinating stuff.

I thought it was 50cm.

I think you're right......

That's not quite as impressive tolerance - wise , Christ, that's 19 inches, that's a fair old gap to seal if you're trying for air-tightness

Interesting stuff, especially the explanation for why they are installing air conditioning to preserve the steel structure for as long as possible as it will be too radioactive inside the dome to repaint once in position. Although it doesn't explain how they make repairs to the cranes and other equipment as I doubt they will last 100 years.

Didn't recognise the narrator as Helen Baxendale.

Fascinating. Thanks just caught it on catch up.

I spotted this last night in enough time to stick on record but thought what an obscure weird time to schedule it. I've not viewed yet but judging by the posts i'm not going to be disappointed.

I've long wanted to go and visit and looked at lots of YT clips on it. Some are really well made and filmed.

Preparing and repainting all that steel would take many weeks with the attendant exposure to radiation. One might hope that the repair of the cranes could be done much more quickly so that radiation exposure could be kept within limits. Much more likely to swap units rather than attempt an in-situ repair.

As I understand it the choice of mild steel was not dictated by cost so much as strength vs. weight. Greater corrosion allowances or the use of stainless steel would have added to the weight which could quickly have become self-defeating and nigh on impossible to move at seven times the weight of the crawlers used at Cape Canaveral.

Skidding is a regular tool used in the heavy lifting and shifting game has been probably since the industrial revolution, I'd guess, nothing Gallic about it, see Mammoet's, VSL's or ALE's websites.
Don't know how many axles it would take to move that on SPMT's but it would be in the hundreds I guess.
Just worked it out, using Mammoet's current kit 44 tonne per axle, 818 axles, then you've got to get it on/off the SMPT's.

ALE's youtube channel, if you're really bored, a company from over here doing rather well everywhere, to paraphrase Hanson's old advert.

Lead surely, wasn't that what most of the nuclear bunkers were made of back in the day?

The various bits of the aircraft carriers being assembled in Rosyth were skidded into place, albeit over shorter distances, in dry dock.