Some industrial and commercial buildings could reach heights of more than 60 stories. Apparently, when these buildings are being built, 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 types which are operated from the back 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 apartment buildings and skyscrapers and commercial facilities like shopping center are being built, chances are a crane will be on site.
Types
There are two different types 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 items. On a luffing kind of tower crane, the jib can ratchet to downward or upward 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 mast. This is a vertical steel frame that is a combination of separate sections. In order to increase the overall height of the equipment, sections are added. 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 referred to. The crane operator works from inside of the tower.
Lift
The crane uses a braided metal cord to lift materials. This cord extends out from a motor located next to 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 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.