Used Self Erect Cranes Norwalk - The base of the tower crane is typically bolted to a huge concrete pad that provides very necessary support. The base is attached to a tower or a mast and stabilizes the crane that is connected to the inside of the building's structure. Usually, this attachment point is to a concrete lift or to an elevator shaft.
Typically, the mast is a triangulated lattice structure measuring 0.9m2 or 10 feet square. The slewing unit is connected to the very top of the mast. The slewing unit consists of a gear and a motor that enable the crane to rotate.
Tower cranes may have a max unsupported height of 80m or two hundred sixty five feet, while the tower crane's maximum lifting capacity is 16,642 kilograms or thirty nine thousand six hundred ninety pounds with counter weights of 20 tons. Moreover, two limit switches are utilized to be able to ensure the driver does not overload the crane. There is also another safety feature called a load moment switch to ensure that the driver does not surpass the ton meter load rating. Lastly, the maximum reach of a tower crane is seventy meters or 230 feet.
There is certainly a science involved with erecting a tower crane, especially because of their extreme heights. First, the stationary structure needs to be brought to the construction location by utilizing a large tractor-trailer rig setup. After that, a mobile crane is used so as to assemble the machine portion of the crane and the jib. Afterwards, these sections are connected to the mast. Next, the mobile crane adds counterweights. Forklifts and crawler cranes can be some of the other industrial machines that is used to erect a crane.
When the building is erected, mast extensions are added to the crane. This is how the crane's height can match the building's height. The crane crew utilizes what is called a climbing frame or a top climber which fits between the top of the mast and the slewing unit. A weight is hung on the jib by the work crew in order to balance the counterweight. When complete, the slewing unit is able to detach from the top of the mast. In the top climber, hydraulic rams are used to adjust the slewing unit up an additional twenty feet or 6.1m. After that, the crane operator uses the crane to insert and bolt into position one more mast section piece.
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