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**Dwencejed** · 10-24-2005, 08:00 AM

Until someone with experience visits the forum basement and responds to this post, I'll try my best.

The crane body breaks apart into sections. I've seen them being delivered to construction sites on several flatbed trailers. I suppose with multiple cranes as is the case with 7 WTC, one crane would lower the others, then a more portable derrick crane would be rigged to lower the last tower crane.

As for the shaftway left behind with interior tower cranes: each building situation is different. It would be logical to place the crane in an elevator or some other service shaftway.

If you look closely at the south side of 7 WTC, they took a different approach. The tower extends down about 10 storeys from the crane. Below that, the floorplates are completed. There are also temporary diagonal braces on the "box" where the tower rises, which are removed after concrete is poured.

The cranes are raised using jack sections. They are usually directly under the crane, as is the case in the outer crane at 7 WTC, but the interior crane has the jack section on the bottom because the entire assembly has to be lifted.

10-24-2005, 08:00 AM	#1
Dwencejed Join Date Oct 2005 Posts 474 Senior Member	Until someone with experience visits the forum basement and responds to this post, I'll try my best. The crane body breaks apart into sections. I've seen them being delivered to construction sites on several flatbed trailers. I suppose with multiple cranes as is the case with 7 WTC, one crane would lower the others, then a more portable derrick crane would be rigged to lower the last tower crane. As for the shaftway left behind with interior tower cranes: each building situation is different. It would be logical to place the crane in an elevator or some other service shaftway. If you look closely at the south side of 7 WTC, they took a different approach. The tower extends down about 10 storeys from the crane. Below that, the floorplates are completed. There are also temporary diagonal braces on the "box" where the tower rises, which are removed after concrete is poured. The cranes are raised using jack sections. They are usually directly under the crane, as is the case in the outer crane at 7 WTC, but the interior crane has the jack section on the bottom because the entire assembly has to be lifted.
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