Some commercial and industrial buildings could reach heights of over 60 stories. Apparently, while these buildings are being constructed, they require equally tall cranes to be able to move the supplies to the higher floors. There are cranes which have their own vehicle connected or other types that are operated from the back of trucks. Tower cranes are the largest types on the market.
Tower cranes are the stand-alone structures which are usually seen on high-rise building projects. Often, they are part of a major city's downtown skyline. When new construction like for instance skyscrapers or apartment buildings and commercial facilities like for instance shopping center are being built, chances are a crane will be on site.
Kinds
There are two different kinds of cranes: jib crane of the boom crane. The jib is a metal frame that 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 could range from 30 pounds to 10,000 lbs.
Body
The body of the crane 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 equipment. The mast extends upward to where the desired height is, to the control module, which is a small room which has glass windows on all four sides or to the tower as it is also called. The crane operator works from inside of the tower.
Lift
The crane utilizes a braided metal cord to lift materials. 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 located 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 supplies are carried.