13 metre fall off bosun's chair down mine shaft

Mine type

Metalliferous mine - underground

Incident

A timberman received serious injuries when he fell approximately 13m down a mine shaft. Immediately prior to the accident the timberman was suspended in a Bosun's Chair approximately 13m above the shaft bottom. He was intending to carry out work on guide rope stays. A new Moxham Rescue Master portable rescue system including a Bosun's Chair was suspended in the shaft. It was slung from a beam in the center of the shaft using a 2m long polyester sling.

The timberman had strapped himself into the Bosun's Chair and associated harness and lowered himself into the shaft. After he had descended a short distance he stopped to make some adjustment to the ropes when the Bosun's Chair parted from the rope pulley system. The timberman fell to the bottom of the shaft (13m) and received serious injuries.

Equipment

Bosun's Chair and Moxham Rescue Master System

Hazard

Potential to fall from height

Cause

From the evidence presented at a Wardens' inquiry, it came to the following conclusions:

1. The timberman inadvertently attached the lower carabiner of the Moxham Rescue Master to an identification tag split ring which was located immediately adjacent to the D ring attachment point at the top of the Bosun's Chair.
2. The identification tag ring was not designed to carry weight and failed allowing the timberman to fall to the bottom of the shaft.

Contributing factors

• Neither the timberman nor his supervisor were trained in the use of the equipment.
• Both the timberman and his supervisor had failed to recognise or address the hazards associated with the use of this equipment.
• The identification tag was incorrectly located.

Comments and recommendations

In situations where persons are exposed to hazards or unfamiliar tasks, an appropriately qualified supervisor should be provided to ensure that safety procedures and safe work methods are followed.

People attaching identification or SWL tags must ensure that they are not located adjacent to lift points.

Authorised by Frank Jones - Regional Inspector of Mines (Northern)

Contact: minesafetyandhealth@dnrm.qld.gov.au

Issued by Queensland Department of Mines and Energy