Investigators zero in on cause of Daintree zipline tragedy
METAL grips holding a zipline in place between Daintree rainforest trees appear to have slipped, leading to the fatal fall of a South Australian tourist.
Workplace Health and Safety investigators have released new findings from their investigation into the death of Dean Sanderson, who fell to his death from Jungle Surfing Canopy Tours' zipline at Cape Tribulation, on October 22.
The Adelaide father-of-three fell 16m from the recreational cable into rainforest alongside wife Shannon, 48, who survived with spinal and shoulder injuries.
Jungle Surfing Canopy Tours has closed its zipline until the end of March.
In their latest report, WHS officials said their investigation into the incident was still ongoing, but it appeared a wire rope grip at the top of the zip line had failed.
This allowed the zip line to disengage suddenly, causing Mr and Mrs Sanderson to both fall to the ground.
While it does not specify what type of grips were used on Jungle Surfing's zipline, the WHS report notes that wire rope grips - which are in use on some Queensland zip lines - are not intended for the permanent fastening of ropes that are subject to heavy dynamic loads, under Australian Standards.
The report states that this is due to the grips requiring tightening to a specific torque, and some types of wire rope grips deforming parts of the rope.
"With regards to tightening to a specific torque, it is important that the appropriate wire rope grips for the cable are used, installed correctly and that they are not over-tightened or under-tightened," the report's authors wrote.
"If under-tightened, the wire rope can slip through the rope grips, and cause the zip line to pull out.
"If over-tightened, the threads on the rope grips can be stripped so that pressure on the rope is lost and the line pulls out.
"If over-tightened and threads are not stripped, the rope can be damaged so that premature failure of the rope could potentially occur."
There is no suggestion of negligence on the part of Jungle Surfing.
A Jungle Surfing spokeswoman said the company was continuing to assist WHS with its ongoing investigation into the incident.
"Until the investigation has been completed, it's inappropriate for us to make any further comment," she said.
She said subject to approval from the authority, the company was hoping to have its zipline tour back in operation by April 1.