I alsways see projects where there are these massive cranes sitting on top of huge buildings...how they hell do they get them up there?
The big tower cranes you see on high rise structures actually....lift themselves. Their bases sit inside square lattice support structures and can climb them. When they get to the top of the structure they raise two more half squares that are bolted together around the base of the crane and the crane can then climb into the higher structure. The process is repeated until they get to the height limit of the crane. It's pretty amazing. Sometimes the crane base remains at the bottom, but sometimes, they close the floor below and remove the base that is no longer used, and just march the whole crane up the floors. Smaller cranes can be lifted by mobile cranes that go elsewhere, but the big ones use the method above.
With more massive cranes. Sometimes, they will put them up in pieces - and assemble them on top of the building.
probably with the use of another crane
