How Tower Cranes Build Themselves

A tower crane does not get lifted onto a building. About once a month it unbolts itself from its own tower, and for half a morning the whole top of it stands on a single hydraulic ram.

This is how a crane that weighs more than the floor it sits on gets to the top of a skyscraper — and why the thing keeping it level while it grows is a weight hanging on its own hook. Two answers, both the opposite of what you would guess, and the second one only makes sense after everybody has gone home.

CHAPTERS
0:00 A crane with a gap in its mast
0:49 What everyone gets wrong about how it got up there
1:17 A plank, a log and two children
1:44 The chart in every crane cab
2:16 Why a crane on the ground cannot reach
2:34 The crane arrives before the building
3:05 Why it has to lean on the thing it is building
3:40 Six inches of lean on a 230 foot tower
4:09 The counterweight it is not allowed to move
4:28 The crane weighs itself
4:52 The climbing cage, the ram and twenty bolts
5:28 The gap opens
5:45 Why the crane must not turn
6:36 Battersea, 2006
7:23 Six hundred and thirty two people
7:56 What a crane does at the end of the shift
8:31 A long flat steel sail
9:17 Back on the sidewalk

#machine #Equipment #HeavyMachinery #crane