Soft sling fails during lift

Background

Recently, a 950kg steel beam fell five metres when a round soft sling failed. The beam was being lifted for placement by a mobile crane and struck the boom of an occupied elevating work platform, and landed on the crane’s outrigger.

While nobody was injured, the failure of rigging equipment had the potential to cause serious or fatal injuries. Soft slings can fail if they are used inappropriately or if they have not been maintained in a safe condition.

Control measures

As an employer, you must provide the highest level of protection against risks to health and safety, so far as is reasonably practicable.

Soft slings should not be the default choice for lifting loads as they are more susceptible to damage than other sling types. Common causes of soft sling failure include:

• sharp edges on loads cutting slings
• slings being cut when contacting obstructions while under load
• mechanical damage from exposure to chemicals or UV light, dirt or grit in the fibres, or poor storage or handling practices
• working load limit (WLL) being exceeded.

Soft slings should be used in accordance with recognised rigging practices and the manufacturer’s instructions.

Where the edges of a load are not rounded, protect the sling from the sharp edges with suitable packing material. If any corner has a radius of less than three times the compressed thickness of the soft sling, packing will be required. The packing should be secured to prevent release when tension is taken off the sling.

Lifting operations on construction sites are high risk construction work and require a safe work methods statement (SWMS) to be prepared and followed for the work. When soft slings are used to perform this work, the risk of sling failure should be considered and the measures to control the associated risks detailed in the SWMS.

Sling selection

Sling selection should be based on risk management principles with the safest sling type used for each specific lift. Sling selection must be made by a person with a high risk work licence for dogging or rigging. A range of sling sizes and types should be available to ensure the safest sling is selected.

Protection of surface finish or paintwork of loads should not be factors in sling selection. This can generally be achieved by fitting engineered lifting points during manufacture or having suitable packing materials under the load when using chain or wire rope slings.

Sling inspection

An inspection regime for slings may assist employers to maintain slings so that they are safe and without risk to health. Regular inspections should identify damaged or defective slings and ensure they are removed from service before failure occurs.

Soft slings must be checked by the person using the sling before each use. They must also be inspected by a competent person at least every three months. Where soft slings are exposed to harsh operating or storage conditions, more frequent inspection by a competent person is required. A competent person is trained to inspect the slings to the requirements of the relevant standard, including specific rejection and acceptance criteria (eg an inspection service of a specialist chain and sling supplier).

Information, training and supervision

Employers must ensure workers who use soft slings are instructed and trained in procedures for pre-use inspection and the appropriate control measures to reduce the risk of sling failure. Employers must also supervise workers as is necessary to enable the work to be done safely.

Further information

• AS 4497.2-1997 Round slings - Synthetic fibre - Care and use
• AS 1353.2-1997 Flat synthetic- webbing slings - Care and use