There are several commercial and industrial buildings which now surpass 60 stories or more. These buildings all require tall cranes to help move the materials to the higher floors. There are cranes which have their own vehicle connected or other types that are operated from the rear of trucks. Tower cranes are the biggest kinds offered on the market.
Tower cranes are stand-alone structures seen as part of a major city's downtown skyline on high-rise building projects. When new construction like for example apartment buildings and skyscrapers and commercial facilities like for example shopping center are being constructed, chances are a crane would be on site.
Types
The two key kinds of cranes could be differentiated by the way in which their jib or boom raises supplies. The jib is the metal frame that extends from the main section. On a flat tower crane, the jib remains horizontal when it carries things. On a luffing type of tower crane, the jib can ratchet to downward or upward angles. The lifting capacity for both types could vary from 30 pounds to 10,000 pounds
Body
The body of the crane is composed of a mast. This is a vertical steel frame that is a combination of individual parts. In order to increase the overall height of the machine, parts are added. The mast extends upward to wherever the desired height is, to the control module, that is a small room which has glass windows on all four sides or to the tower as it is also called. The crane driver works from inside of the tower.
Lift
The crane utilizes a braided metal cord to be able to lift supplies. This cord extends out from a motor located near the control module to the end of the jib or boom. There is a pulley system situated at the end of the jib, through which the cord is positioned and lowered down. The jib which holds the cord becomes balanced by a counter jib situated on the tower's opposite side. The counter jib holds weights. These weights help to prevent the crane from toppling over when heavy materials are carried.