Used Self Erect Cranes Chula Vista - Typically the base that is bolted into a large concrete pad provides the necessary support for a tower crane. The base is connected to a tower or a mast and stabilizes the crane that is affixed to the inside of the structure of the building. Often, this attachment point is to an elevator shaft or to a concrete lift.
Usually, 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 is made of a gear and a motor that allows the crane to rotate.
Tower cranes may have a max unsupported height of 80m or 265 feet, while the tower crane's maximum lifting capacity is 16,642 kilograms or 39,690 lbs. with counter weights of 20 tons. Moreover, two limit switches are used to be able to make certain that the operator does not overload the crane. There is even one more safety feature known as a load moment switch to ensure that the operator does not exceed the ton meter load rating. Lastly, 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, specially because of their extreme heights. First, the stationary structure has to be brought to the construction site by utilizing a huge tractor-trailer rig setup. After that, a mobile crane is utilized in order to assemble the machine part of the crane and the jib. Then, these sections are connected to the mast. The mobile crane then adds counterweights. Crawler cranes and forklifts may be a few of the other industrial equipment which is used to erect a crane.
Mast extensions are added to the crane when the building is erected. This is how the height of the crane can match the building's height. The crane crew uses what is called a top climber or a climbing frame 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. Once complete, the slewing unit can detach from the top of the mast. In the top climber, hydraulic rams are utilized to adjust the slewing unit up an extra twenty feet or 6.1m. Then, the driver of the crane uses the crane to insert and bolt into place one more mast part piece.
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