Used Self Erect Cranes Saskatchewan - Typically the base which is bolted into a large concrete pad provides the crucial support for a tower crane. The base is attached to a tower or a mast and stabilizes the crane which is connected to the inside of the building's structure. Usually, this attachment point is to a concrete lift or to an elevator shaft.
Typically, the mast is a triangulated lattice structure measuring 10 feet square or 0.9m2. The slewing unit is attached to the very top of the mast. The slewing unit is made of a motor and a gear which allows the crane to rotate.
Tower cranes may have a max unsupported height of 80m or two hundred sixty five feet, while the tower crane's maximum lifting capacity is sixteen thousand six hundred forty two kilograms or 39,690 pounds with counter weights of 20 tons. Moreover, two limit switches are used in order to ensure the operator does not overload the crane. There is even another safety feature called 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 230 feet or 70 meters.
There is definitely a science involved with erecting a tower crane, especially because of their extreme heights. First, the stationary structure has to be brought to the construction site by using a big tractor-trailer rig setup. Then, a mobile crane is utilized so as to assemble the equipment portion of the crane and the jib. These sections are then attached to the mast. After that, the mobile crane adds counterweights. Forklifts and crawler cranes may be a few of the other industrial equipment that is commonly used to erect a crane.
Mast extensions are added to the crane as the building is erected. This is how the height of the crane is able to match the building's height. The crane crew uses what is known as a climbing frame or a top climber which fits between the top of the mast and the slewing unit. A weight is hung on the jib by the work crew in order 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 6.1m or 20 feet. Then, the crane operator uses the crane to insert and bolt into position one more mast section piece.
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