When they build tall skyscrapers, how do they get those cranes on top to keep going up?

Question

I have always wondered how they get those cranes they put on top of tall buildings to keep going up as they build the building taller? I mean it's not like they can just lift the crane up higher with another crane or anything. So how do they get those cranes to go up and up and up?

Answer 1

they use a helicopter to bring those stuff up..its as simple as that.satisfied?