Used Self Erect Cranes Ventura - Typically the base which is bolted into a huge concrete pad provides the crucial support for a tower crane. The base is attached to a mast or a tower and stabilizes the crane that is attached to the inside of the building's structure. Normally, this attachment point is to an elevator shaft or to a concrete lift.
The crane's mast is often a triangulated lattice structure which measures 0.9m2 or 10 feet square. 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 265 feet. The maximum lifting capacity of a tower crane is sixteen thousand six hundred forty two kg or thirty nine thousand six hundred ninety pounds with counter weights of 20 tons. Furthermore, two limit switches are utilized in order to ensure the driver does not overload the crane. There is also one more safety feature called a load moment switch to make certain that the operator 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 due to their extreme heights. First, the stationary structure needs to be transported to the construction location by using a huge tractor-trailer rig setup. Then, a mobile crane is utilized in order to assemble the equipment part of the crane and the jib. These sections are then attached to the mast. The mobile crane then adds counterweights. Crawler cranes and forklifts can be a few of the other industrial equipment that is typically utilized to erect a crane.
When the building is erected, mast extensions are added to the crane. This is how the crane's height could match the building's height. The crane crew uses what is called 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 so as to balance the counterweight. Once complete, the slewing unit could 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. After that, the crane operator utilizes the crane to insert and bolt into position one more mast section piece.
Self Erect Cranes PDF
