Used Self Erect Cranes Santa Clarita - The tower crane's base is generally bolted to a big concrete pad that provides very necessary support. The base is attached to a tower or a mast and stabilizes the crane which is attached to the inside of the structure of the building. Usually, this attachment point is to an elevator shaft or to a concrete lift.
Typically, the mast is a triangulated lattice structure measuring 10 feet square or 0.9m2. The slewing unit is connected to the very top of the mast. The slewing unit is made of a motor and a gear 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 kg or thirty nine thousand six hundred ninety lbs. with counter weights of twenty tons. In addition, two limit switches are utilized to be able to make sure that the driver does not overload the crane. There is also one more safety feature called a load moment switch to make sure that the driver does not surpass the ton meter load rating. Last of all, the tower crane has a maximum reach of seventy meters or two hundred thirty feet.
Due to their extreme heights, there is a science involved to erecting a crane. The stationary structure will at first need to be transported to the construction site by using a huge tractor-trailer rig setup. After that, a mobile crane is utilized so as to assemble the machinery portion of the crane and the jib. These parts are then attached to the mast. Next, the mobile crane adds counterweights. Forklifts and crawler cranes could be some of the other industrial machinery that is commonly 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 is able to match the building's height. The crane crew uses what is called a top climber or a climbing frame that fits between the top of the mast and the slewing unit. A weight is hung on the jib by the work crew so as to balance the counterweight. When complete, the slewing unit could detach from the top of the mast. In the top climber, hydraulic rams are used to adjust the slewing unit up an extra 20 feet or 6.1m. Next, the crane driver uses the crane to insert and bolt into place another mast section piece.
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