I am convinced between us we know everything
 

....so how do they get the cranes off the roof of a high-rise when construction is finished?

Driving to work this morning and this question had me baffled.

Dismantle and bring in 'nother crane to haul down the pieces.

Who turns on the light in my refrigerator when I open the door?

Push it over the side of the building...of course...

Yes - but in the case of the building next door (~90 floors) HOW IN THE HELL DO THEY GET THE SECOND CRANE DOWN??

Those gigantic Helicopters I would imagine.

The celery. And when they are out, the carrots take over.

Maybe - but then why have I never seen this happen? Has anyone else?

There must be someone in the construcion industry here.

The main tower crane that is planted in the ground next to the building "builds" and dismantles itself. If you look real close, the top section is on a platform with hydraulic rams under it, connecting it to another platform with the center hollowed out. The top section raises itself, picks up another section, places it in the gap, and the crew secures it. The lower platform is then retracted back to the top of the new section and secured once again. When it's time for the next section, the rams are deployed, lifting the upper platform again, etc. etc. As this crane gets taller, it is eventually fastened to the building it's building. Reverse the process to take it down. I believe the smaller cranes that are fastened to the upper floor of the building are constructed using one of these tower cranes.

They follow up the side of the structure - they never are part of it. Vash does this work, has some pics.

Mr Scott beems them to the next job site, or in the case of Mike Mulligan they become boilers for heat

Stolen from How Stuff Works - Jeff is right on, the darn things build themselves...

http://forums.pelicanparts.com/uploa...1132266600.jpg
http://forums.pelicanparts.com/uploa...1132266614.jpg
http://forums.pelicanparts.com/uploa...1132266625.jpg
http://forums.pelicanparts.com/uploa...1132266638.jpg
http://forums.pelicanparts.com/uploa...1132266651.jpg

And once again, the blind faith that "Somebody on Pelican will know" is proven true. This is getting kind of scary.

Helicoptors would have been much cooler:)

Look closely next time. You'll see Yoda in a hardhat at the site, waving the crane down with the Force. Easy to spot, he's the one that's green.

And here I thought that the main structure became the elevator shaft. Heck, not a bad idea.........perhaps that's why I'm a cpa and not an engineer......

The real impressive cranes are the 'Hammer Heads" that load and unload containers. If your ever in Long Beach or the Philly Coast check'm out. The Evergreens - the gearboxes and wire ropes our all lubed with our stuff. They say the operators make $150/hr - union of course. I've been up on a few and talked with them - all great guys but it would have been poor form to actually ask if the rate was true.

Collective brain trust - Wayne is slowly assembling his team for world domination!

you guys never watch transformers, do ya?

A guy I know wanted very badly to run one of the center tower cranes on the Tacoma Narrows Bridge project. I told him he was nuts. Those two middle cranes sit in the middle of windy Puget Sound (have you guys seen the video of Galloping Gertie?), and they are FIVE HUNDRED FEET HIGH!

He got his wish.