Several industrial and commercial buildings can reach heights of over 60 stories. Obviously, when these buildings are being built, they require equally tall cranes 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 found as part of a major city's downtown skyline on high-rise building projects. When new construction like for instance apartment buildings and skyscrapers and commercial facilities like for example shopping center are being built, chances are a crane will be on site.
Kinds
The two key types of cranes can be distinguished by the manner in which their jib or boom lifts materials. The jib is the metal frame that extends from the main section. On a flat tower crane, the jib remains horizontal when it carries items. On a luffing type of tower crane, the jib can ratchet to downward or upward angles. The lifting capacity for both kinds could range from 30 pounds to 10,000 pounds
Body
The crane's body is composed of a vertical steel mast that is composed of individual [parts. The parts are added to increase the overall height of the machinery. 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
To lift materials, the crane uses a braided metal cord. The cord extends all the way to the end of the jib or boom 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 has weights. These weights help to prevent the crane from toppling over when heavy materials are lifted.