tårnkran

A tårnkran, or tower crane, is a modern climbing crane that uses a mast to support a horizontal jib. These cranes are commonly found on large construction projects, such as the erection of tall buildings. The mast provides the height, while the jib, often a counter-jib as well, allows for lifting and moving heavy materials.

The basic components of a tower crane include the foundation, the mast, the slewing unit, the operator's cab, the jib, and the trolley. The foundation is crucial for stability, anchoring the entire structure to the ground or the building itself. The mast is typically a lattice structure that provides the vertical height. The slewing unit allows the crane to rotate 360 degrees, giving it a wide reach. The operator's cab is where the crane operator controls all movements. The jib is the long horizontal arm that extends out over the construction site. A trolley moves along the jib to position the hook precisely where it's needed.

Tower cranes can be assembled on-site using smaller cranes, or they can "climb" as the building they are constructing gets taller. This climbing is facilitated by adding more mast sections and using hydraulic jacks. They are essential for efficiently lifting and placing heavy construction materials at significant heights, playing a vital role in modern construction.