Safe Rigging Methods Every Lifting Crew Should Know
In industries such as construction, manufacturing, and logistics, rigging plays an important role in moving and positioning heavy materials and equipment. When done right, rigging operations ensure that lifting activities are performed efficiently and, more importantly, safely. Among the many aspects of safety on a jobsite, the correct application of rigging techniques is one of the most critical. This emphasis on proper rigging comes at a crucial time. The Multi-Agency Workplace Safety and Health Taskforce (MAST), along with various industry associations, recently urged companies in Singapore’s construction sector to conduct a Safety Time-Out (STO) last year in November 2024 due to the recent uptick in fatal incidents. This initiative serves as a timely reminder of the importance of ensuring safety procedures are not only in place but strictly followed. Below, we explore several proven rigging techniques and outline how they contribute to a safe lifting operation. These methods are approachable and easy to understand, even for those new to the field, yet powerful enough to make a significant difference in daily worksite safety. Whether you're learning the basics or aiming to supervise safe lifting operations, mastering these techniques is essential for preventing accidents and ensuring efficiency. 1. Single-part line The single-part line is one of the most straightforward and commonly used rigging configurations. It involves a single wire rope or sling lifting a load vertically. This method is best suited for light loads where the object is naturally balanced and there are no obstacles in the lift path. Ideal scenarios for single-part lines: - The load falls within the crane’s direct lifting capacity - The item is self-balanced - The lift path is clear and vertical - The job requires quick setup and execution Benefits: - Quick to assemble - Minimal equipment needed - Direct and responsive load control However, the single-part line offers limited mechanical advantage. If the load requires more control or involves complex weight distribution, it's best to upgrade to a more advanced setup. Setting it up: Start by evaluating the load’s weight and checking if it aligns with your equipment’s capabilities. Inspect the load, the crane, and all rigging gear for damage or signs of wear. Choose appropriate lifting slings and hardware, ensuring they are rated for the load. Securely attach the sling to the hook and load, then apply a light strain to verify all connections and safety devices are in working order. For added control during lifting, use a tagline or tether. When greater lifting efficiency is needed, consider mechanical advantage systems like 2:1 or 4:1 configurations. 2. Two-part line A two-part line builds upon the single-part system by doubling the lifting capacity through reeving the wire rope into two segments. This method is especially effective for heavier loads that require precision. Why choose two-part lines: - Provides twice the lifting power of a single-part system - Allows more refined control for delicate or valuable equipment - Suitable for applications that balance power and accuracy Considerations: Although two-part systems lift heavier items, they often operate at slower speeds than single-part systems. However, this trade-off results in greater control and better weight distribution. How to set it up: Begin by thoroughly inspecting all components: the wire rope, pulley blocks, drums, and connection points. Check that identification tags show correct safe working loads. Route the wire rope through the drum and pulleys to form two lines. Use hooks with safety latches and taglines to guide the load. Confirm that the load is within the system’s maximum capacity and that everyone on the team understands their role before initiating the lift. 3. Choker hitch A choker hitch is ideal when you need a tight grip on a load, such as when lifting pipes, logs, or steel beams. This hitch tightens around the object as the lift progresses, providing a secure hold. Performance based on angle: - 100% lifting capacity when the choke angle is between 120° to 180° - Capacity decreases as the angle narrows; below 29°, capacity can reduce by up to 50% Setup process: Loop the sling around the load, making sure that only the body of the sling contacts the choke point. Pass one end (sling eye) through the other and connect it to the lifting hook. Tighten the choke completely and ensure the crane is positioned directly above the load’s centre. For an enhanced grip, you can use a double wrap. If you're handling sensitive items, synthetic slings are ideal; for tougher tasks, wire rope offers durability and strength. Comparison with other hitches: - Wire rope choker hitches: Operate at 75% of vertical lifting capacity - Double wrap chokers: Offer better compression and grip - Synthetic chokers: Maintain up to 80% of their vertical lifting capacity If you're dealing with unbalanced or bundled loads, consider switching to a basket hitch or using doubled chokers for added stability and control. 4. Basket hitch The basket hitch offers a balanced and stable lifting solution for evenly distributed loads. It works by forming a cradle under the load using a sling, distributing weight across two contact points. Best use cases: - Lifting large or symmetrical equipment - Transporting construction materials with a stable centre of gravity - Handling machinery with predictable weight distribution When configured correctly, especially when the sling legs are at a 90° angle and the D/d (diameter ratio) is at least 25:1, a basket hitch can lift up to double the capacity of a single vertical leg. Setup guide: Select strong, flat webbing slings rated for your load. Wrap the sling under the load, ensuring both sides are equal in length and free of twists. Choose the right configuration for your situation: - Standard basket: One sling wrapped once under the load - Double basket: Two slings for greater load control - Double wrap: Twice around the load for improved grip on smooth surfaces Ensure the load is centred and stable. Watch your sling angles, as anything less than 90° can reduce lifting capacity. Use multiple slings for irregular or complex loads to maintain balance and control. 5. Bridle sling The bridle sling is a go-to method for lifting irregular or heavy items with multiple attachment points. It distributes force across several sling legs, which helps stabilise and orient the load. When to use bridle slings: - Handling heavy machinery with built-in lifting lugs - Lifting frames or beams with multiple connection points - Managing awkward or unbalanced equipment Benefits: - Increased lifting capacity - Enhanced control and precision - Even stress distribution - Reduced wear on any one sling leg However, be mindful of the sling angles, as steeper angles can increase the tension on each leg, placing more stress on the rigging hardware. Always refer to rigging angle charts to ensure safe usage. Setup steps: Start with a full pre-lift inspection. Identify the load’s centre of gravity and lifting points. Select the right material for the slings: - Nylon webbing: Good for light, sensitive loads - Wire rope: Best for heavy or abrasive environments - Chain slings: Ideal for hot or extreme conditions Ensure all legs are equal in length and connected on the same horizontal plane. This allows the load to remain balanced as it rises. Communicate clearly with all team members before executing the lift. Conclusion Every lift deserves the same level of care and attention to detail. The techniques outlined above are foundational practices that support safer and smarter operations on every jobsite. As the industry continues to evolve, the commitment to rigging safety must remain firm because the lives and well-being of workers depend on it. Safety in lifting operations starts with proper training and strong leadership. At Wong Fong Academy, our Safe Lifting courses empower you with the knowledge and skills needed to oversee crane operations effectively and responsibly. Whether you’re a supervisor or part of the lifting team, investing in our training means investing in everyone’s safety on site. Register now and lead with confidence!
