1949: Tower Cranes
Innovation: Fast assembly tower crane development
By: Hans Liebherr
Until 1949, cranes used in construction could lift vertically but had no horizontal movement, and materials were manually carried after being dropped. With Hans Liebherr’s innovation, the tower crane could not only swing materials horizontally, but also be transported in parts and fully assemble itself at the construction site. His design, the TK-10, was a machine that had the slewing unit on the bottom, allowing the entire crane to rotate, with a horizontal jib on top. It was presented at the Frankfurt Trade Fair in 1949, but new designs came to the market almost immediately after its unveiling.
The development of these new tower cranes came in time for the construction boom of the 1950s, when buildings were needed quickly and therefore cranes and other equipment were in high demand. This need was facilitated by increasing crane efficiency. The jib was modified to luffing jibs, which kept the material relatively level to the base while lifting. Self-climbing mechanisms allowed cranes to grow along with the building. In addition, the job radius of the jib increased. Altogether, the ease in transportation and assembly, as well as the increasing efficiency, contributed to the development of taller building structures .
Watch a video here of a tower crane building itself. `