How to Choose the "Personal Assistant" at Your Workstation?

In factory on-site management, the bottleneck in material handling often lies not with large overhead cranes, but with the "last meter" at each workstation. As a workstation-level lifting device, the jib crane's core value lies in fixed-point, high-frequency, and precise material delivery. However, if selection is based solely on lifting capacity and price, while ignoring spatial constraints, frequency of use, and operating trajectories, the equipment often ends up with issues like "can't reach," "takes up too much space," or "frequent breakdowns." This article, referencing the technical requirements of national standards GB/T 3811-2008 and JB/T 8906-2018, outlines the logic for selecting jib cranes based on workstation environment and operational characteristics.

First, Look at the "Spatial Identity": Pillar-Mounted or Wall-Mounted?

This is the first step in selection, depending on which structure the plant is willing to bear the load.

A pillar-mounted jib crane has an independent foundation, secured to the ground concrete via anchor bolts, forming its own load-bearing system. It is suitable for independent workstations in the middle of a workshop, surrounded by equipment, and supports a full 360° rotation, covering a complete circular area. For renovation projects in older plants where wall load-bearing capacity is uncertain, the pillar-mounted type, which does not rely on the building structure, is a safer option.

A wall-mounted jib crane, on the other hand, is attached to the plant's load-bearing columns or walls, occupying zero floor space, making it suitable for assembly lines arranged along walls or in narrow aisle areas. However, its slewing angle is typically limited to no more than 180°, and it has stringent requirements for wall strength.

Decision logic: If the workstation is in the center of the workshop, requires full-circle coverage, and has a concrete foundation that can be poured → choose pillar-mounted. If the workstation is against a wall, floor space is tight, and the lifting capacity is ≤ 2t → choose wall-mounted.

Next, Look at "Boom Length and Load": Usable Does Not Mean Adequate

There is an inverse rule in jib crane selection: the longer the boom, the smaller the actual allowable lifting capacity. In practice, two values need attention:

Rated lifting capacity: Referencing GB/T 3811-2008, a safety factor of 1.25 should be applied. For example, if the workpiece weighs 200 kg and the spreader weighs 20 kg, the theoretical requirement is 275 kg; it is recommended to directly choose a 0.5 t specification to leave a margin for impact loads.

Slewing radius: This refers to the distance from the column center to the farthest point of the hook. It must satisfy: the farthest point of the workstation + 0.5m operating margin. According to JB/T 8906-2018, the deflection at the boom end must be ≤ 1/250 of the span. For booms exceeding 6m in length, additional diagonal bracing is required.

Then, Examine the "Mounting Type": Choosing Between Straight-Boom and Articulated-Boom

Straight-boom jib cranes have a simple structure, using wire rope hoists for lifting, offering a large working radius and high cost-effectiveness. They are suitable for open workstations without obstructions, such as general machine tool loading/unloading and welding fixturing.

Articulated-boom jib cranes are hydraulically driven and feature multi-joint folding capabilities, allowing them to navigate around obstacles in low-ceiling workshops or dense equipment areas, achieving precise obstacle avoidance. Articulated booms can also be equipped with interchangeable attachments like grabs or clamps for multi-purpose use.

Decision advice: If there are pipelines or columns above the workstation obstructing movement, or if the workpiece needs to be inserted into equipment, the articulated-boom type offers an advantage. For general open workstations, a straight-boom crane is sufficient and has lower maintenance costs.

Consider the Duty Cycle: Can a Mobile Type Replace a Fixed One?

Fixed types offer the best stability and are suitable for long-term, continuous operations. Mobile jib cranes come with casters and adjustable outriggers on their bases, allowing them to be moved to different workstations, making them suitable for equipment maintenance, temporary tasks, or locations without fixed foundations. It is critical to note: the outriggers must be firmly set and brakes locked before any operation. Lifting without proper support is strictly prohibited, as it poses a tipping hazard.

Conclusion

The essence of jib crane selection lies in finding a balance between equipment performance and workstation constraints. It is recommended to conduct on-site measurements of the workstation's farthest point distance and clear height, and to verify the load-bearing capacity of the floor or wall before purchase. If possible, request the manufacturer to provide a boom-length vs. load capacity curve for verification, to avoid the safety risks associated with experience-based selection.