Used Self Erect Cranes Bakersfield - The base of the tower crane is generally bolted to a big concrete pad that provides really crucial support. The base is connected to a mast or a tower and stabilizes the crane that is affixed to the inside of the building's structure. Often, this attachment point is to a concrete lift or to an elevator shaft.
The crane's mast is normally a triangulated lattice structure that measures 0.9m2 or 10 feet square. Connected 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 twenty tons. In addition, two limit switches are utilized in order to make certain that the driver does not overload the crane. There is also one more safety feature referred to as a load moment switch to make sure that the operator does not exceed the ton meter load rating. Finally, the tower crane has a maximum reach of two hundred thirty feet or seventy meters.
There is certainly a science involved with erecting a tower crane, specially because of their extreme heights. First, the stationary structure has to be transported to the construction site by using a huge tractor-trailer rig setup. Next, a mobile crane is utilized in order to assemble the machine portion of the jib and the crane. These sections are then connected to the mast. Afterward, the mobile crane adds counterweights. Forklifts and crawler cranes can be some of the other industrial equipment that is 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 known as a climbing frame or a top climber which 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 utilized to adjust the slewing unit up an additional 6.1m or 20 feet. After that, the crane operator uses the crane to insert and bolt into position one more mast section piece.
Self Erect Cranes PDF
