Used Self Erect Cranes Northwest Territories - The base of the tower crane is generally bolted to a huge concrete pad which provides really crucial support. The base is connected to a tower or a mast and stabilizes the crane which 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 mast of the crane is usually 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 gear and a motor that enable the crane to rotate.
Tower cranes are able to have a maximum unsupported height of 80m or two hundred sixty five feet. The tower crane's maximum lifting capacity is 16,642 kg or thirty nine thousand six hundred ninety pounds with counter weights of twenty tons. In addition, two limit switches are used to be able to ensure the operator does not overload the crane. There is even one more safety feature known as a load moment switch to make sure that the driver does not exceed the ton meter load rating. Last of all, the maximum reach of a tower crane is 230 feet or seventy meters.
Because of their extreme heights, there is a science involved to erecting a crane. The stationary structure will first need to be transported to the construction location by using a huge tractor-trailer rig setup. After that, a mobile crane is utilized in order to assemble the machine portion of the jib and the crane. Then, these parts are connected to the mast. Next, the mobile crane adds counterweights. Crawler cranes and forklifts could be some of the other industrial machinery which is commonly utilized to erect a crane.
When the building is erected, mast extensions are added to the crane. This is how the crane's height can match the building's height. The crane crew utilizes what is referred to 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 can detach from the top of the mast. In the top climber, hydraulic rams are utilized to adjust the slewing unit up an extra 6.1m or 20 feet. After that, the crane driver uses the crane to insert and bolt into position another mast part piece.
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