Used Self Erect Cranes Orange - Typically the base which is bolted into a huge concrete pad provides the necessary support for a tower crane. The base is attached to a mast or a tower and stabilizes the crane that is affixed to the inside of the structure of the building. Often, this attachment point is to a concrete lift or to an elevator shaft.
Generally, the mast is a triangulated lattice structure measuring 0.9m2 or 10 feet square. The slewing unit is attached to the very top of the mast. The slewing unit is made of a gear and a motor which allows the crane to rotate.
Tower cranes are able to have a maximum unsupported height of 80m or two hundred sixty five feet. The maximum lifting capacity of a tower crane is sixteen thousand six hundred forty two kg or 39,690 pounds with counter weights of 20 tons. Furthermore, two limit switches are used to be able to ensure the operator does not overload the crane. There is even one more safety feature called a load moment switch to ensure that the driver does not exceed the ton meter load rating. Lastly, the maximum reach of a tower crane is 230 feet or seventy meters.
There is definitely a science involved with erecting a tower crane, particularly because of their extreme heights. First, the stationary structure has to be transported to the construction location by utilizing a huge tractor-trailer rig setup. After that, a mobile crane is utilized in order to assemble the equipment part of the jib and the crane. These sections are then attached to the mast. The mobile crane then adds counterweights. Forklifts and crawler cranes can be a few of the other industrial equipment which is used to erect a crane.
As 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 utilizes what is known 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 operator utilizes the crane to insert and bolt into position one more mast section piece.
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