Used Self Erect Cranes New York - The tower crane's base is generally bolted to a big concrete pad which provides very necessary support. The base is connected to a mast or a tower and stabilizes the crane which is affixed to the inside of the building's structure. Normally, this attachment point is to an elevator shaft or to a concrete lift.
The mast of the crane is usually a triangulated lattice structure that measures 0.9m2 or 10 feet square. Connected to the very top of the mast is the slewing unit. The slewing unit consists of a motor and a gear 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 tower crane's maximum lifting capacity is sixteen thousand six hundred forty two kilograms or thirty nine thousand six hundred ninety pounds with counter weights of twenty tons. In addition, two limit switches are utilized in order to ensure the operator does not overload the crane. There is also another safety feature referred to as a load moment switch to make certain that the operator does not surpass the ton meter load rating. Finally, the tower crane has a maximum reach of 230 feet or seventy meters.
Because of their extreme heights, there is a science involved to erecting a crane. The stationary structure will at first have to be transported to the construction location by using a large tractor-trailer rig setup. Next, a mobile crane is used in order to assemble the machine portion of the crane and the jib. Afterwards, these parts are connected to the mast. The mobile crane then adds counterweights. Crawler cranes and forklifts may be some of the other industrial equipment that is commonly used to erect a crane.
Mast extensions are added to the crane when the building is erected. This is how the height of the crane could match the building's height. The crane crew uses what is called a climbing frame or a top climber that 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 20 feet. After that, the crane operator uses the crane to insert and bolt into place another mast section piece.
Self Erect Cranes PDF
