Several commercial and industrial buildings are capable of reaching heights of over 60 stories. Apparently, when these buildings are being constructed, they need equally tall cranes to be able to move the materials to the upper floors. There are cranes that have their own vehicle connected or other kinds which are operated from the back of trucks. Tower cranes are the largest ones available on the market.
Tower cranes are stand-alone structures seen as part of a major city's downtown skyline on high-rise building projects. Wherever new construction like for instance skyscrapers or apartment buildings and commercial facilities like for example shopping center are being constructed, 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 which extends from the main section. On a flat tower crane, the jib remains horizontal as it lifts things. On a luffing kind of tower crane, the jib could ratchet to upward or downward angles. The lifting capacity for both types can range from 30 pounds to 10,000 pounds
Body
The body of the crane is composed of a vertical steel mast which is composed of separate [parts. The parts are added to be able increase the overall height of the equipment. The mast extends upward to where the desired height is, to the control module, that is a small room that has glass windows on all four sides or to the tower as it is also called. The driver of the crane works from inside of the tower.
Lift
In order to raise supplies, the crane uses a braided metal cord. The cord extends all the way to the end of the boom or jib from a motor situated near the control module. 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 situated on the opposite side of the tower. The counter jib holds weights. These weights help to prevent the crane from tipping over when heavy materials are lifted.