I have this assignment to find out how a climbing crane is able to move up the building as construction continues.
They add extra stages from the bottom. A tower crane is erected from a boom assembly, first and second tower sections of different cross section, and a base in a sequence of steps in which the boom assembly is mounted on a hollow climbing section dimensioned to be received in each of the larger second tower sections and defining a cavity dimensioned to receive each of the first tower sections. One of the latter is secured on a base in upright position, and the upright section is received in the cavity of the climbing section which is then raised relative to the first section and enveloped by one of the second sections. The enveloping section is secured to the base and the raised climbing section for supporting the climbing section whereupon the first tower section may be released from the base, raised, and secured to the second tower section. The climbing section may then be raised relative to the first tower section to permit the installation of another second section, and the procedure repeated, until all second or larger tower sections are superimposed on each other, the one first section being ultimately attached to the topmost second section. When the climbing section is raised relative to the attached first section, another first section may be superimposed on the one first section and the procedure repeated until the slimmer portion of the tower is assembled from superimposed first sections. Ultimately, the boom assembly is attached to the topmost first tower section, and the climbing section may be removed or stored for further use on the wider, lower tower portion.
