Crane erections!!

[bigbankhank]

When putting up a crane, I assume a crane needs a bigger crane to put it's self up, and that crane in turn needs a bigger crane to erect the one erecting the first and so on and so on. So how does the biggest crane in the world get put up??

[Toureman]

It puts itself up !

The large tower cranes are built by a small crane then as they get higher the tower has a cradle around it which can jack the crane up then the same crane adds another section into the space that has been jacked up.

Here is a picture of the cradle

http://frank.itlab.us/bridge/large/apr_08_jack .jpg

[what..the?]

I saw this on tv the other day it showed how a crane is erected.

Basically they build a mini crane with just two components the legs and the very top part of the crane where cab is - where the crane controller sits.

Then basically with a smail to medium sized crane they slide more and more building blocks/units in between these two components which makes the crane taller and taller so with each building block/unit added the top part of the crane and the legs get further and further apart.

To slide the units in they use the jack toureman describes this separates the tower/cuts it in half and opens it up to allow a new unit to be slid in.

New crane technology has seen the development and production of the first mega cranes which are self erecting - it is a lorry and crane in one basically a lorry with a huge folded arm on the back it takes just minutes to park the lorry up and fully erect the crane ....amazing.

[bazwillrun]

i was working in the Canary Wharf Tower, Docklands when the HSBC building was put up .I used to work on the 24th floor and watched in amazement when the crane being used was made higher, by jacking the jib and cab section up and itself hauling a new section into place, and when it was in place 2 men just tightened up some bolts and then waited for it to jack up again and another section was inserted.
Up to then i had always wondered how it was done, simple when you know how !