How To Calculate The Arm Length Of A Jib Crane?
Oct 07, 2025
In fields such as engineering, construction, logistics, and transportation, the jib crane is an important tool that can assist in the lifting and handling of large objects. When purchasing a cantilever crane, many customers are not clear about the specifications they need, especially the length of the cantilever. The specific calculation method for the cantilever jib crane is as follows:
Calculation Method for Arm Length
1. Determination of the Weight of the Lifting Object and the Lifting Radius
Before calculating the length of the cantilever, it is necessary to determine the weight of the lifting object and the lifting radius. The weight of the lifting object can be obtained through measurement or by referring to relevant materials, and the lifting radius generally refers to the horizontal distance from the center axis of the crane to the center of gravity of the lifting object.
2. Consideration of Wind Speed and Working Conditions
When calculating the length of the cantilever, it is also necessary to consider the wind speed and working conditions of the working environment. Excessive wind speed may affect the stability of the crane, so when choosing the length of the cantilever, the rated wind speed of the crane and the relevant working conditions should be referred to.
3. Calculation Formula for Arm Length
The calculation of the arm length usually uses the formula: Cantilever Torque = weight of lifting object multiplied by lifting radius.
Cantilever Jib Cranes
Jib Crane Structure
4. The selection method of the crane arm length
Consider the rated load of the crane: When choosing the cantilever arm length, it is necessary to determine the appropriate length based on the rated load of the crane. The rated load of the crane refers to the maximum allowable weight of the lifted object designed and manufactured for the crane.
5. Matching with actual needs
The selection of cantilever arm length also needs to take into account the actual engineering requirements, such as hoisting height, radius, and site space limitations, etc. An overly long cantilever arm length may lead to poor stability of the crane, while an overly short cantilever arm length may fail to meet the hoisting requirements.
6. Considerations of safety and economy
When choosing the cantilever arm length, the safety and economy of the crane should also be comprehensively considered. An overly long cantilever arm length will increase the torsional moment and overturning risk of the crane, while an overly short cantilever arm length may result in low hoisting efficiency.
Finally Words
The calculation and selection of the arm length of a jib crane are crucial steps to ensure the safe and reliable operation of the crane. When calculating the arm length, the weight of the lifted object and the lifting radius must be determined, and wind speed and working conditions should also be considered. The selection of the arm length requires a comprehensive consideration of the crane's rated load, actual requirements, as well as safety and economic factors. Only by accurately calculating and reasonably choosing can the stability and working efficiency of the crane be guaranteed, ensuring the smooth completion of construction and logistics tasks. If you need to buy a jib crane and do not know how to calculate the arm length, please feel free to contact us!