Used Self Erect Cranes Elk Grove - Usually the base that is bolted into a big concrete pad provides the crucial support for a tower crane. 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. Normally, this attachment point is to an elevator shaft or to a concrete lift.
The crane's mast is normally a triangulated lattice structure that measures 10 feet square or 0.9m2. Connected to the very top of the mast is the slewing unit. The slewing unit is made of a motor and a gear 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 kilograms or thirty nine thousand six hundred ninety lbs. with counter weights of twenty tons. Additionally, two limit switches are used to be able to ensure the operator does not overload the crane. There is even another safety feature referred to as a load moment switch to ensure that the operator does not exceed the ton meter load rating. Finally, the maximum reach of a tower crane is seventy meters or 230 feet.
Because of their extreme heights, there is a science involved to erecting a crane. The stationary structure would at first have to be transported to the construction site by using a big tractor-trailer rig setup. After that, a mobile crane is used so as to assemble the machine portion of the jib and the crane. These sections are then attached to the mast. Then, the mobile crane adds counterweights. Crawler cranes and forklifts can be some of the other industrial machinery which is commonly utilized to erect a crane.
Mast extensions are added to the crane as the building is erected. This is how the height of the crane can match the building's height. The crane crew utilizes what is referred to as 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 can 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. Next, the crane driver uses the crane to insert and bolt into position one more mast part piece.
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