How do they erect those tall tower cranes at construction sites? The answer, it turns out, is really simple.

The crane consists of different sections, each delivered by truck to the construction site. The engineers start by building the foundation for the crane, and anchoring the bottom vertical section of the crane to it.

The engineers then add a section known as the top climber, or climber frame to the crane. This is essentially a vertical section of the crane that can lift the horizontal part of the crane using hydraulics.

There are two ways to add the horizontal section. It either gets assembled piece by piece to the top of the climber frame using smaller truck mounted cranes, or the entire horizontal section gets assembled on the ground, & then lifted onto the climber frame.

To “grow”, engineers detach the horizontal section from the vertical section, and raises it with the climber frame. The crane then lifts another vertical section/frame and places it inside the climber frame, where workers bolt it in place. The climber frame can then be detached from the vertical frames and raised one unit, before the entire process starts again.

To break the crane down, the process gets reversed.