15.12.2021

Tree company guilty in structural failure incident

An OSHA report looking into the structural failure of a CMC 83HD spider lift in Lake Wales, Florida, in October 2020, has cited the owner of the machine, Medlock Tree Service of Lake Wales, with three violations that may have contributed to the failure.

Medlock Tree Service was ordered to pay an $11,300 penalty and agreed to legally abide with three corrective citations following the serious incident, in which the top boom of the spider lift suffered a severe structural failure, causing the operator to be thrown from the basket at a height of 17 metres, putting him in the intensive care unit of the local hospital. His injuries included a crushed shoulder, cracked sternum, a punctured lung, broken ribs and a head injury.
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The Florida failure

Citations included not having taken the machine out of service following an earlier incident which had caused damage to the boom section that later failed. The report states that there were signs that the tree company had made an attempt to repair the damaged boom by welding it, and then reattaching cables and services to the boom with cable ties. It was also charged with not having carried out any regular or annual inspections of the machine, for not taking a damaged machine out of use, and failing to report an accident that involved hospitalisation, as well as failing to provide proper training or a fall arrest harness and lanyard.

The company has committed to corrective action citations requiring it to carry out regular inspections, remove damaged machines from service, hold regular safety meetings to highlight the importance of safety equipment, and to report any serious incidents within 24 hours. Any failure to comply with these citations will result in a $10,000 charge for each violation.

The manufacturer and its distributor AA Access cooperated fully with the OSHA investigation and subsequent follow up and have not been cited for the incident. The report appears to say that there were no contributing factors from the manufacturer or distributor.

After the details of this incident came out, the manufacturer alerted all 83HD owners to carry out a safety inspection of the area of the boom that had failed in Lake Wales and developed a retrofit reinforcement kit to strengthen this part of the upper boom for machines that showed signs of any cracks. Attention was especially given to machines used by the tree industry where the risk of the boom and basket being struck by falling limbs etc... is high - see: Safety check for CMC 83HD. When a similar failure occurred early this year on a machine in Milwaukee, Wisconsin, which had not been inspected or retrofitted, the manufacturer stepped up its efforts, made the retrofit mandatory, pulled machines out of service and sent retrofit teams all over North America to ensure that the kits were installed.

CMC has confirmed that the majority of machines, most of which were in the USA, have now had the reinforcement kit installed. But it has highlighted the fact that there are 24 'missing' machines, where owners have moved or machines have been sold etc... It is keen to track them down.