Perfect controlled demolition of twin chimneys - video

[Ralphxyz]

yeah right get inside to work those timber will keep it standing.

Ralph

[Frank S]

it only takes 1 brick to keep it standing or 1 brick to make it fall the key is knowing how many other bricks are needed to keep that 1 brick in place until you want to remove it.

[Toolmaker51]

This has got to be fake Jon - he's not in flip-flops

No flip flops is one clue; but again, notice carefully selected and fully engineered shoring beams. There is an operator INSIDE hammering away, obviously those pilings offer sufficient confidence.
In lieu of mythical skyhooks...

[wizard69]

Further proof that explosives are often the right answer. Actually artillery might be even better as you can keep your distance.

[owen moore]

That guy's cornbread ain't done in the middle!

[basil3w]

He must think he's going to survive, after all, he's wearing a dust mask!

[Jon]

Admittedly, that demolition-from-inside is probably at or near maximum craziness. I don't think we'll be able to beat it. However, maybe we can top it:

[PJs]

Yep, that tops it!

[Frank S]

While I don't have any pictures of it in operation in the early 90's I made what I called the arms of destruction for a customer to use in demolishing a reinforced concrete chimney that was inside of a 41 story hotel. The top 30 feet that stuck above the building was brick. That was the easy part just erect a scaffold around it and use electric hammers to break the bricks loose let them fall to the bottom and hauls them away with a skid steer. But from roof level on down it was concrete with a 2 ring re bar reinforcement spaced every 10 inches with vertical bars on 6 inch spacing's.
Prior to his getting the contract 2 other companies had tried the demo of it. they had taken a few months just to remove the brick work down to the roof.
When he got the contract His initial plan was to just cut the concrete into small blocks and remove it that way. but after only 2 days he decided there had to be another way. So he and I sat down and came up with a design for breaking the concrete from inside. this is what we came up with





I made the arms out of 2 inch thick t1 steel . I made the turnbuckle out of 3" hydraulic cylinder rod the nut for the turnbuckle was just a piece of 5" hex I found at the scrap yard the pins were made out of cylinder rods as well.
we powered it with a 16 Hp Honda with a 4 to 1 2 s stage pump. We had to carry it to the roof in pieces since the arms alone weighed 150 Lbs. used a chain hoist to lower it into the chimney. then once adjusted it was simply a matter of open and close then rotate and do it again the foot thick concrete broke up in chunks we used a torch to cut the re bars as the concrete was broken away. in 18 days we had the chimney removed. At times so much concrete was falling out the slanded steel ramp we had made at the bottom that 2 skid steers couldn't keep up with the removal.

[PJs]

Nice design, Very cool Frank. Curious how you fed and released the cylinder...must have been a double acting cylinder and switch/valving? And keeping the lines (400ft) & fittings from harm must have been a bit of a challenge.