Ruptured pump prompts safety alert

By: Paul Hayes
12 March, 2010

The Queensland Mines Inspectorate has been forced to issue a safety alert after a high pressure emulsion line on a hydraulic longwall pump sled ruptured, causing a longwall coal mine to lose electrical and hydraulic power on the face.

There were no personnel working in the area at the time and consequently no injuries were sustained, but the ruptured line damaged a walkway platform that was above the unit as well as an electrical cubicle and the pump cart itself.

The sudden release of energy and high pressure hydraulic fluid cut power to the longwall machinery as the attached walkway was ejected approximately three metres into the air.

An investigation by the Mines Inspectorate found that the pump cart had suffered significant damage due to the rupture of the high pressure emulsion line.

The Mines Inspectorate said that the emulsion hoses had rubbed together, which then compromised the integrity of the pump sled's outer casing and steel reinforcing braids.

After the investigation it was ultimately determined that inadequate preparation and design were significant factors in contributing to the incident.

"Poor design was a major contributing factor in the incident, including the hose routing, hose retention and hose segregation," the Mines Inspectorate said.

"No inspection regime was in place for the hoses and other components.

"In this instance, a personnel walkway was directly above the site of the hose failure and the section of walkway was ejected.

"Segregation of personnel from high pressure hoses needs to be considered in the design process.

"Fortunately no one was in the area or on the walkway."

The Mines Inspectorate has since recommended that from now on mines ensure hose and pipe layouts are properly designed in order to eliminate contact and rubbing.

High pressure hoses will now also need to be securely mounted and more regularly inspected in order to check for any potentially damaging wear and abrasion.

In order to better ensure worker safety, the Mines Inspectorate has also recommended that personnel access in and around high pressure installations needs to be kept to a minimum and segregated where possible.