13.12.2008

Cranes drop Dragline

A large dragline boom has been badly damaged after it was dropped while being lowered to the ground for routine maintenance at Wesfarmers Curragh coal mine in central Queensland. The incident also pulled over a five axle All Terrain that appears to have been supporting the dragline's pendants.
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The scene shortly after the incident occurred

A statement from the mine said: "The boom of the dragline was being lowered by four cranes and, as a result of winch failure with one of the cranes, the boom fell around 30 metres."
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A five axle AT was also pulled over

"The incident caused major structural damage to the dragline's boom and a full investigation into the cause of the incident has been initiated by the mine's management and independent assessors, including government work safety authorities.”
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The damaged dragline and crane

The operator of the crane that dropped the load was the only person injured and his injuries were reported to be minor.

The mine operates five draglines - four Marion electric draglines for overburden removal including a Marion 8750 Super, with 114 cubic metre bucket one of the largest in the world. The fifth dragline is a P&H 2355.
The mine has not disclosed which dragline was involved.

The video below captures the moment it occurred



UPDATE
An initial official report cited operator error, suggesting that the operator may have been inexperienced and pulled the wrong control lever which allowed the winch to go into free fall. He reportedly tried to catch it on the drum brake but that overheated, exploded and caught fire, leaving the boom to drop whcih then struck the Lampson.

Vertikal Comment

While the mine says four cranes were lifting the dragline’s booms, it looks as though it was a Lampson 4600 Transilift that was supporting the boom and which appears to have dropped it.

Three telescopic cranes were working around the perimeter while a large crawler crane looks to have either been standing by or called in for the clean up. A five axle All Terrain that was helping support the boom was also pulled over.

The Lampson crane appears to be as badly damaged as the dragline, if not more so. Unofficial reports from the site suggest that the crane's winch may have gone into its free fall mode and attempts by the operator to stop it failed. If anyone has further information we would appreciate hearing from you.