Outside of smaller self-erecting tower cranes, the components of a tower crane are hauled to the job site, typically a Mobile All Terrain Crane is used to assemble the mast sections, jib sections, the slewing unit, and the counterweights.Ĭrane Market has a wide selection of Tower Cranes for Sale.How to Read A Crane Load Chart Learn about some insightful guidelines on how to read a mobile crane load chart. The switch monitors the load to ensure it doesn’t exceed the maximum load rating A secondary switch ensures the load, does not extend to an unsafe distance along the jib. Most Tower Cranes come equipped with “load moment indicators (LMI)" which stop the crane from being overloaded. Tower crane jib sections can reach out to around 230', and the maximum allowable tonnage to be lifted at the end of the jib section for most tower cranes is around 19.8 tons or 18 metric tons. This process is repeated to add more mast sections as building rise during construction. When a tower crane is secured to the side of a building, mast sections can be added as the building rises with a jacking system to increase the height of a tower crane. The climber jacks boost the topmast sections leaving enough space for an additional mast section to slide in. Some Heavy lift tower cranes reach up to 265'. Some tower cranes have an elevator lift attached to the mast sections for crane operators to quickly access the operator cabin. The crane operator’s cab is typically accessed by climbing the tower crane mast. The boom section extending from the top of the crane is known as the jib section.Ĭoncrete slabs are typically used as counterweights to balance the crane. The main tower sections extending upward are primarily referred to as the mast sections by the crane industry.Ī slewing bearing ring is located at the crane enabling the crane to rotate 360 degrees
The concrete pad ensures the tower crane's stability.įor the largest of tower cranes, the pad may be up to 30' by 30' and 4' deep with a pad weight up to 400, 000 lb. Then the base of the crane is bolted down with massive bolts and the base of the tower crane is secured to the concrete pad. To erect a hammerhead, flat top, luffing jib tower crane, a heavy concrete pad is laid for the base of the crane. There are key parts to making a tower crane fully operationally. Tower cranes are erected and tower crane operators lift concrete, steel beams, and building materials from the ground to heights sometimes higher than 100 stories. Tower Cranes range from small mobile self-erecting tower cranes up to large fixed-based hammerhead tower cranes that are used for large-scale industrial projects.
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