Used Self Erect Cranes Vancouver - The base of the tower crane is usually bolted to a big concrete pad which provides very necessary support. The base is connected to a tower or a mast and stabilizes the crane that is connected to the inside of the structure of the building. Usually, this attachment point is to a concrete lift or to an elevator shaft.
Usually, 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 gear and a motor which allows the crane to rotate.
Tower cranes may have a max unsupported height of eighty meters or 265 feet, while the minimum lifting capacity of a tower crane is 16,642 kg or 39,690 lbs. with counter weights of 20 tons. Furthermore, two limit switches are utilized in order to make certain that the operator does not overload the crane. There is even one more safety feature referred to as a load moment switch to make certain that the driver does not exceed the ton meter load rating. Finally, the tower crane has a maximum reach of 230 feet or seventy meters.
Due to their extreme heights, there is a science involved to erecting a crane. The stationary structure would at first have to be transported to the construction site by utilizing a big tractor-trailer rig setup. Then, a mobile crane is used in order to assemble the machine portion of the crane and the jib. These sections are then connected to the mast. After that, the mobile crane adds counterweights. Forklifts and crawler cranes may be some of the other industrial equipment that is used 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 referred to 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. Once 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 twenty feet. Next, the driver of the crane uses the crane to insert and bolt into place one more mast part piece.
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