Used Self Erect Cranes Long Beach - Usually the base which is bolted into a big concrete pad provides the essential support for a tower crane. The base is attached to a mast or a tower and stabilizes the crane that is attached to the inside of the structure of the building. Often, this attachment point is to a concrete lift or to an elevator shaft.
The crane's mast is normally a triangulated lattice structure which 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 gear and a motor that enable the crane to rotate.
Tower cranes may have a max unsupported height of eighty meters or two hundred sixty five feet, while the minimum lifting capacity of a tower crane is 16,642 kg or 39,690 pounds with counter weights of twenty tons. Additionally, 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. Finally, the maximum reach of a tower crane is seventy meters or two hundred thirty feet.
There is definitely a science involved with erecting a tower crane, particularly due to their extreme heights. At first, the stationary structure has to be brought to the construction location by using a huge tractor-trailer rig setup. Then, a mobile crane is utilized in order to assemble the equipment part of the crane and the jib. Then, these parts are attached to the mast. The mobile crane next adds counterweights. Forklifts and crawler cranes can be a few of the other industrial machines that is utilized to erect a crane.
When the building is erected, mast extensions are added to the crane. This is how the crane's height is able to match the building's height. The crane crew uses what is known as a top climber or a climbing frame which fits between the slewing unit and the top of the mast. 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 6.1m or 20 feet. After that, the crane driver utilizes the crane to insert and bolt into place one more mast part piece.
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