The company recently completed a diesel emissions monitoring programme during the driving of a longwall gateroad panel in 2002 at their southern New South Wales Elouera Colliery.

Over a 9 month period, readings were taken on a regular basis, and were openly communicated to the workforce during regular occupational health and safety communications.

Technology and External Relations manager Steve Pratt said the findings of the trial confirmed the validity a number of best practice actions which the company had instituted over a long period of time.

“Briefly, the major factors in play were vehicle exhaust filters, vehicle control procedures, monitoring of ventilation, vehicle maintenance and servicing and the use of low emission fuels. We were able to monitor the use and effectiveness of each component during the trial, “ he said.

“The fresh filters in use in the industry today are there as a result of our research project in the 1990’s.”

Pratt said filters continue to be the most effective method of controlling employee exposures to diesel particulate, but they were the “end-point” in the process.

“We believe that if we can make engines more efficient, we can not only reduce the amount of particulates but increase the service life of filters and ultimately eliminate them,” he said.

“This type of technology already exists for surface-based vehicles with the use of electronic engine management. However, it’s not legal in underground coal mines as yet, so the industry needs to advance this very important factor in improving underground employees’ work environment from a health and safety perspective.”

Pratt said the company has the only device in the country that measures elemental carbon from exhausts – the sooty residue portion of diesel particulate.

An R&P 5100 analyser has been incorporated into a mobile laboratory trailer so that it can be routinely transported to each mine to perform routine raw exhaust gas tests.

“Overseas experience, and limited trials by Illawarra Coal, has demonstrated that good maintenance procedures (eg cleaning dirty flame traps) can significantly influence the level of raw exhaust diesel particulate generation.

“The aim is to monitor the majority of the business’s diesel fleet and identify ‘dirty’ engines and correct them if possible, using substantial data collected during ACARP Report C7014 as a guide,” he said.

Pratt said that as a result of extensive monitoring and corrective actions taken in recent years, the results from the recent Elouera study confirm that readings show approximately half the level of emissions recommended in the NSW Minerals Council guidelines.

For over 15 years BHP Billiton Illawarra Coal has been involved in a pro-active strategy aimed at reducing employees’ exposure to diesel exhaust emissions. Initial work began in 1988 with an international literature search that culminated in a 1990 study into the issue.

In 1993 the study group made recommendations to Illawarra Coal’s senior management team, which were all accepted. To assist with the implementation of the work, research funding was sought and granted.

This was followed by an Australian Coal Association Research project being carried out at the company’s operations in the Illawarra region of New South Wales, with findings finalised in 1995.