Several commercial and industrial buildings can reach heights of over 60 stories. Apparently, when these buildings are being constructed, they require equally tall cranes to be able to transport the supplies to the higher floors. There are cranes which have their own vehicle attached or other kinds which are operated from the rear of trucks. Tower cranes are the biggest kinds 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 like apartment buildings and skyscrapers and commercial facilities like for example shopping center are being built, odds are a crane would be on site.
Types
The two major types of cranes could be differentiated by the manner in which their boom or jib raises supplies. The jib is the metal frame which extends from the main section. On a flat tower crane, the jib remains horizontal as it lifts things. On a luffing type of tower crane, the jib can ratchet to downward or upward angles. The lifting capacity for both kinds could vary from 30 pounds to 10,000 lbs.
Body
The body of the crane is composed of a vertical steel mast that is composed of separate [parts. The parts are added to be able increase the overall height of the equipment. The mast extends upward to wherever the desired height is, to the control module, that is a small room which has glass windows on all four sides or to the tower as it is also referred to. The driver of the crane works from inside of the tower.
Lift
In order to raise supplies, the crane utilizes a braided metal cord. The cord extends all the way to the end of the boom or jib from a motor located 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 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 tipping over when lifting heavy materials.