Used Self Erect Cranes Oklahoma - The base of the tower crane is generally bolted to a big concrete pad that provides very crucial support. The base is attached to a mast or a tower and stabilizes the crane that is attached to the inside of the building's structure. Usually, this attachment point is to a concrete lift or to an elevator shaft.
The crane's mast is often a triangulated lattice structure that measures 0.9m2 or 10 feet square. Attached to the very top of the mast is the slewing unit. The slewing unit is made 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 sixteen thousand six hundred forty two kilograms or 39,690 lbs. with counter weights of 20 tons. In addition, two limit switches are utilized to be able to ensure the driver does not overload the crane. There is also one more safety feature referred to 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 two hundred thirty feet or seventy meters.
There is definitely a science involved with erecting a tower crane, specially due to their extreme heights. First, the stationary structure needs to be transported to the construction site by using a big tractor-trailer rig setup. Next, a mobile crane is used in order to assemble the equipment part of the jib and the crane. Afterwards, these parts are attached to the mast. The mobile crane then adds counterweights. Forklifts and crawler cranes could be a few of the other industrial equipment that 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 could match the building's height. The crane crew uses what is known as 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 so as 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 extra 20 feet or 6.1m. After that, the driver of the crane uses the crane to insert and bolt into place another mast part piece.
Self Erect Cranes PDF
