Qingdao Haosail Machinery Co., Ltd.

In warehousing and logistics, construction, and machinery manufacturing, rigging serves as the "bridge" connecting lifting equipment and heavy objects, and its safety directly impacts personnel and property safety. However, in actual operations, many people's understanding of rigging remains at the level of "as long as it can lift," neglecting details in key aspects such as selection, operation, and maintenance. Today, we'll analyze common misconceptions in rigging use, combining real-world case studies and industry standards, to help you safeguard your safety.

I. "Diagnosis" Before Selection: Mismatch is More Dangerous than Overloading

Many people believe that rigging selection only requires considering "load capacity," but this is not the case. Rigging of different materials and structures is suited to vastly different scenarios, and the risk of choosing the wrong rigging can even exceed that of overloading. Below are the core selection points for three main types of rigging to help you accurately match your needs

1. Wire Rope Slings: Don't Let Corrosion Ruin Strength

Wire rope slings are a staple in heavy industry due to their high strength and impact resistance, but their sensitivity to the environment is far greater than imagined. In humid or corrosive environments such as coastal ports and chemical workshops, ordinary wire ropes without anti-corrosion treatment can have their service life shortened by more than 60%, and are prone to "hidden wire breakage." A shipbuilding company experienced a sling breakage accident after only three months using ordinary wire ropes to lift seawater-soaked steel plates; fortunately, no one was injured.

Recommendation: For humid environments, prioritize galvanized or plastic-coated wire ropes. For chemical environments, custom-made acid and alkali resistant special wire ropes are required, and anti-corrosion maintenance should be performed at least monthly.

2. Synthetic Fiber Slings: Avoid the Two Major Pitfalls of "High Temperature" and "Sharpness"

Synthetic fiber slings (such as those made of polyester and polypropylene) are lightweight and flexible, protecting the surface of workpieces from scratches. They are suitable for lifting electronic equipment, precision instruments, food raw materials, and other similar applications. However, its weaknesses are also quite obvious: poor temperature resistance; it softens above 80℃ and carbonizes and fails directly above 120℃. A worker in an electronics factory once used synthetic fiber slings to lift freshly welded components; the slings instantly melted, causing the equipment to fall and resulting in tens of thousands of yuan in losses.

Recommendation: Confirm the ambient temperature before operation. For heavy objects with sharp edges, corner protectors or sleeves must be used to prevent the slings from being cut.

3. Lifting Chains: The "Preferred Choice" for High-Temperature Operations, But Don't Ignore Wear

Alloy steel lifting chains can withstand temperatures above 200℃ and are wear-resistant and anti-aging, suitable for high-temperature environments such as metallurgy and casting. However, many people overlook the wear problem at the chain connections—when the chain links wear more than 10% of their original size, or when cracks or deformation appear, the load-bearing capacity drops sharply. According to the "Safety Regulations for Lifting Machinery and Rigging," such lifting chains must be scrapped immediately.

II. There are "Red Lines" in Operation; These Behaviors Must Never Be Crossed

More than 80% of rigging accidents are caused by violations of operating procedures. The following four types of high-risk behaviors must be strictly prohibited:

1. Strictly Prohibited:Reusing Scrapped Rigging is Like Planting a Time Bomb

Some companies, in an effort to save costs, re-weld broken wire ropes or grind worn-out chains and continue using them. This is tantamount to "suicidal operation." In 2023, at a construction site, workers used a repaired wire rope to lift steel bars. When the rope reached a height of 5 meters, it suddenly broke, causing the steel bars to fall and damage equipment below. Fortunately, no one was in the work area.

Remember: Rigging is a consumable item. Once it reaches the scrap standard (e.g., excessive broken wires in the wire rope, deformed chains, damaged slings, etc.), it must be replaced immediately. There is no possibility of "repairing and reusing."

2. Refuse "Oblique Pulling and Lifting":Uneven Stress Can Lead to "Tilting Over"

Many workers, for convenience, lift heavy objects directly when they are off-center from the lifting equipment. This "oblique pulling and lifting" causes uneven stress on the rigging, with localized loads momentarily exceeding the rated value. For example, when the lifting angle is 30° to the vertical, the tensile force on the rigging increases by 1.15 times; at a 60° angle, the tensile force skyrockets to twice its original value, easily leading to breakage.

Standard Operating Procedures: Before lifting, adjust the position of the load to ensure the rigging is under vertical load. If angled lifting cannot be avoided, calculate the actual tensile force and replace with rigging with a higher rated load.

3. Don't Remove the "Safety Lock": The Anti-Disengagement Device is Not a "Caution"

The anti-disengagement device on the hook is the last line of defense against falling loads, but some workers find it "in the way" and remove or bend it without authorization. In 2022, at a warehousing and logistics park, a pallet slipped from the hook during lifting because the anti-disengagement device had been removed, injuring a passing employee.

The law clearly states: According to the "Safety Regulations for Lifting Machinery," a hook with a malfunctioning anti-disengagement device is considered a substandard component, and using such a hook will result in administrative penalties.

4. Avoid "Rough Handling": Impact Loads Can "Overdraw" Rigging Lifespan

Sudden acceleration during lifting and a violent slam into the ground during descent can generate impact loads far exceeding the weight of the load itself, causing irreversible damage to the rigging. Tests show that lifting a 1-ton load suddenly at a speed of 0.5 m/s can generate an impact load of up to 3 tons, enough to instantly break a rigging with a rated load of 2 tons.

III. Three Steps for Daily Maintenance to Extend Lifespan and Ensure Safety

The lifespan of rigging depends not only on its quality but also on daily maintenance. Three simple steps can keep your rigging in "healthy condition."

1. Before Each Use: Conduct a "Visual Inspection"

Before lifting, spend one minute checking the condition of the rigging: For wire ropes, check for broken strands, looseness, and rust; for synthetic fiber slings, check for damage, aging, and staining (staining may be a sign of contact with chemical media); for chains, check for deformed links and secure connections. If any abnormalities are found, stop using the rigging immediately.

2. Post-Use: Proper Storage is Key

After use, rigging must be cleaned and dried to avoid contact with oil, acids. Wire ropes should be neatly coiled and hung on a dedicated support to prevent knotting or crushing; synthetic fiber slings should be protected from direct sunlight and stored in a well-ventilated, dry warehouse; lifting chains should be lubricated regularly to reduce wear.

3. Establish an "Identity File": Full Life-cycle Traceability

Assign a serial number to each set of rigging, recording the manufacturing date, specifications, usage scenario, inspection records, and maintenance status. For rigging used in large-scale projects or with high frequency of use, it is recommended to conduct a professional inspection every 3 months to ensure safety performance meets standards.

Emergency Reminder: If the rigging exhibits abnormal noises, sudden elongation, or deformation under stress during use, stop work immediately, lower the load gently, and never attempt to continue lifting.

Rigging safety is never about "after-the-fact remedies," but rather "prevention before the event." Whether you are a business owner or a front-line worker, you should all pay attention to the selection, operation, and maintenance of rigging, and implement safety awareness in every detail. If you encounter any specific problems in the use of rigging, please feel free to contact us. Our technical team will provide you with one-on-one answers.