## Introduction
Designing a jib crane base plate requires a thorough understanding of various factors such as the crane design, placement of the system, crane foundation, and the lifting mechanism. In this comprehensive guide, we will explore the calculations and considerations involved in designing a robust and efficient base plate for a jib crane. Utilizing insights from multiple reference articles, we will provide step-by-step instructions to ensure a successful design.
Crane Design
The first step in designing a jib crane base plate is to determine the most suitable crane design. Two main options are commonly considered: a ceiling-mounted trolley system and a cantilever rotating system. While the former may exceed the project budget, the latter offers a cost-effective and efficient solution. Gorbel, a renowned manufacturer, provides a state-of-the-art jib crane design capable of 360-degree rotation, making it an ideal choice for our project .
Placement of the Crane
The placement of the jib crane plays a crucial role in ensuring optimal functionality. Two key factors to consider are reaching all the required areas and providing sufficient counterbalance to overcome loading moments. After careful evaluation, the final placement should fulfill both these requirements. In our case, a span length of 16 feet was determined to be appropriate, as shown in .
Crane Foundation
Designing a suitable foundation for the jib crane is essential to ensure stability and structural integrity. In our case, the existing isolated slab posed a challenge as it did not meet the foundation requirements specified by Gorbel. To overcome this, two potential solutions were considered: constructing a concrete slab on top of the existing foundation or designing a metal plate foundation.
Due to space constraints, it was decided that a metal plate foundation would be the most viable option. This involved fastening a metal plate to the existing slab using an anchor system. The chosen material for the metal plate was ASTM A36 carbon steel, known for its high tensile strength. The calculations for determining the plate thickness were performed with a safety factor of two, resulting in a minimum thickness of 1.1 inches.
baseplate_mounted_jib_drawing_2
Plate Widths and Anchoring
To ensure the stability and secure attachment of the jib crane to the metal plate foundation, it is crucial to determine the appropriate plate widths and anchoring system. In our case, a Powers Rawl epoxy anchor system was chosen for its high bond strength and ease of installation.
By calculating the total moment at the base of the crane and considering the strengths of the selected anchor system, it was determined that a minimum plate width of 4.63 feet by 4.63 feet, using eight epoxy anchors, would be necessary for adequate support.
Welding Considerations
Welding plays a vital role in the overall structural integrity of the jib crane base plate. It is crucial to select the appropriate welding method and ensure compliance with industry standards. For our project, an A.W.S. E60xx weld was specified, with a weld height of 3/8 inch. This height was determined based on the failure analysis calculations and A.W.S. standards.
Concrete Counter-Balance
Counterbalancing the jib crane is essential to ensure smooth operation and prevent excessive loading moments. The concrete counter-balance method was employed to achieve this. By calculating the total loading moment at the base of the crane, including the periscope can, lifting device, and the mass of the I-beam, the appropriate counter-balance weight can be determined.
Analysis for Plate Thickness
To ensure the structural integrity of the metal plate foundation, it is essential to analyze the plate thickness. By considering shear and bending as potential failure modes, the minimum plate thickness was determined to be 1.1 inches, providing ample strength to withstand the calculated loading moments.
Analysis for Plate Widths
The plate widths play a crucial role in providing stability and distributing the loads effectively. By utilizing a static model and considering the total moment at the crane base, it was determined that minimum plate widths of 4.63 feet by 4.63 feet, using eight epoxy anchors, would be sufficient for our jib crane base plate design.
Conclusion
Designing a robust and efficient base plate for a jib crane requires careful consideration of various factors. By following the calculations and design considerations outlined in this comprehensive guide, you can ensure a successful and safe jib crane installation. Remember to adhere to industry standards, consult with experts when necessary, and perform thorough structural analyses to validate your design. With proper planning and execution, your jib crane base plate will provide the stability and support required for optimal crane operation.
