There are several commercial and industrial buildings which now surpass 60 stories or more. These buildings all need tall cranes to be able to help transport the materials to the upper floors. There are cranes that have their own vehicle attached or other kinds which are operated from the back of trucks. Tower cranes are the biggest types available on the market.
Tower cranes are the stand-alone structures which are normally seen on high-rise building projects. Usually, they are part of a major city's downtown skyline. Wherever new construction such as apartment buildings and skyscrapers and commercial facilities like for example shopping center are being built, odds are a crane would be on site.
Kinds
There are two different kinds of cranes: boom crane or the jib crane. The jib is a metal frame that extends from the main section. On a flat tower crane, the jib remains horizontal when it carries things. On a luffing kind of tower crane, the jib could ratchet to downward or upward angles. The lifting capacity for both types could vary from 30 pounds to 10,000 lbs.
Body
The crane's body is composed of a vertical steel mast which is composed of individual sections. The parts are added to be able increase the overall height of the machine. The mast extends upward to wherever the desired height is, to the control module, which is a small room that has glass windows on all four sides or to the tower as it is also referred to. The operator of the crane works from inside of the tower.
Lift
The crane uses a braided metal cord to raise supplies. This cord extends out from a motor situated near the control module to the end of the boom or jib. There is a pulley system situated at the end of the jib, through which the cord is positioned and lowered down. The jib that holds the cord becomes balanced by a counter jib located on the opposite side of the tower. The counter jib holds weights. These weights help to prevent the crane from toppling over when heavy materials are lifted.