Two incidents involving chain slings have revealed that chains made by an as-yet unnamed Chinese manufacturer may fail well below their safe working limit. Step Change In Safety has issued an alert on the incident.
On two separate occasions chain slings were used to perform lifting operations. The slings, from the same supplier, failed whilst a lift was being performed.
In the first incident an arrangement of four 5.3 tonne collared chain slings were used in a ‘basket’ configuration around the lifting points of a 20 tonne concrete block. After 5 blocks had been moved using this method team members noticed that one of the chain links had parted at its weld point.
The second Incident invoved two 2-legged 11.2 tonne chain slings to create a 4 point sling arrangement was used to relocate 13 tonne concrete blocks, similar to the first incident, after four blocks had been moved the work party noticed that a link in the chain had failed at its weld point.
The lift plan and slinging arrangement techniques were appropriate for the task. All of the slings were new prior to the start of the operations.
The chain slings were sourced from a single supplier.
It was found that the chains received were certified by batch testing only and it transpired that the name and signature on the certification was replicated by computerised signature and not necessarily the person who actually carried out the inspection or testing, giving concerns as to whether there had been any testing.
The company which bought the chains from a UK supplier has initiated a requirement for all chains purchased to be tested to Safe Working Limit.
All chains recieved from this supplier were immediately placed in quarantine and returned to the supplier, which was instructed to perform an investigation as to why the equipment failed and all similar equipment is recalled awaiting the investigation and report.
The UK based sub-supplier does not manufacture the chain but acts as an agent on behalf of manufacturers in China, some of whom do not hold export licences. They have immediately withdrawn all chain from sale supplied by this company, additionally cancelled all orders with this agent and will continue to request the manufacturers details but more importantly the reason for failure.