Used Self Erect Cranes Texas - The base of the tower crane is generally bolted to a huge concrete pad that provides very crucial support. The base is attached to a tower or a mast and stabilizes the crane which is connected to the inside of the structure of the building. 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 attached to the very top of the mast. The slewing unit consists of a gear and a motor which enable the crane to rotate.
Tower cranes may have a max unsupported height of 80m or 265 feet, while the minimum lifting capacity of a tower crane is 16,642 kg or 39,690 pounds with counter weights of 20 tons. Furthermore, two limit switches are used to be able to ensure the driver does not overload the crane. There is also one more safety feature called a load moment switch to make certain that the driver does not exceed the ton meter load rating. Finally, the tower crane has a maximum reach of 70 meters or two hundred thirty feet.
There is certainly a science involved with erecting a tower crane, particularly because of their extreme heights. First, the stationary structure has to be transported to the construction site by using a large tractor-trailer rig setup. After that, a mobile crane is used so as to assemble the equipment part of the jib and the crane. These parts are then attached to the mast. The mobile crane then adds counterweights. Forklifts and crawler cranes may be a few of the other industrial machinery that is typically used to erect a crane.
Mast extensions are added to the crane as the building is erected. This is how the height of the crane could match the building's height. The crane crew uses what is referred to as a climbing frame or a top climber that fits between the slewing unit and the top of the mast. A weight is hung on the jib by the work crew in order to balance the counterweight. When complete, the slewing unit can detach from the top of the mast. In the top climber, hydraulic rams are used to adjust the slewing unit up an extra 6.1m or 20 feet. Next, the driver of the crane uses the crane to insert and bolt into position one more mast part piece.
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