Suspicious fire under the microscope

A fire-damaged excavator investigated by Fire Forensics in Mozambique.

Fire Forensics has a reputation as a capable team of fire and explosion investigators in Australia and globally, with a job at a major coal mine in Mozambique opening a can of worms that the company was determined to solve.

For more than 40 years, Fire Forensics has been known for its commitment to dissecting the causes of fires and creating thorough investigations to determine how and why a blaze occurred.

While no investigation is a straightforward task, Fire Forensics managing director and senior investigator Belinda Jane (BJ) Jones was enlisted to examine a fire that had occurred on a Hitachi excavator at a major coal mine in Mozambique, Africa.

Fire Forensics, which is based in Australia, was hired for the job due to the company’s previous track record working with the Australian expats hired by the company operating the mine.

The operator may have enlisted Fire Forensics for a fire that occurred on the excavator, but unlike most mine fires that are caused by machine or human error, Jones discovered that fuel theft had been involved.

“This was a first for us,” Jones says. “It blew my mind that none of the other investigations looked at the refuelling systems.”

Unlike Australia, Southern African mines do not have dedicated internal maintenance personnel, they use many sub-contracted companies which can lead to a conundrum of people trying to diagnose an issue or cover their tracks if responsible.

“In Mozambique, it’s all contracted out. The local maintenance crew could touch everything except the engines, which were maintained by a separate sub-contractor,” Jones says. “We were dealing with 12 different people who can’t touch different parts (of the machine).”

Fire Forensics was hired because a previous investigation could not uncover the cause of an excavator fire.

“They had another investigator hired by the fire suppression system because it was an aftermarket system, as well as an investigator for the company which made the machine,” Jones says. “At the time, they had two reports that said different things and they weren’t happy with that.”

While Fire Forensics was initially hired for a second single excavator fire, Jones was asked to analyse the previous excavator fire and two unrelated fires which had occurred on the site since.

“Within half a day of arriving at the site I knew that someone had been stealing fuel from this second fire in the Hitachi excavator, since the fuel cap was off,” Jones says.

“Because the refuelling systems are in such large tanks, they require high pressure guns to fill the tanks under super high pressure and safety mechanisms are installed in the refuelling system, including high pressure caps.

“In the first instance, they decided to use very large shifters to get these high-pressure caps off the top deck of the fuel tanks, to then remove the breather, which is meant to equalise the pressure.

“Because they broke the refuelling system below the machine, there was also recharge in the fuel lines dumping fuel under the excavator.

“They removed the fuel cap and breather to get to the fuel, broke the fast refuelling system under the machine, which dumped fuel under the excavator. 

“Then, because they’ve had a diesel fuel spill on the top deck after manually pumping into jerry cans from the fuel cap; this has then been pulled through the rear fan of one engine and blown across and been ignited by the hot engine, which then had blown forwards through the machine.”

The previous six-month-old excavator fire was similar, Jones continues. 

“The other two fires on this first trip were unrelated,” she says. “One was caused when a high-pressure sensor on a boom failed and sprayed oil everywhere, with the other one caused by a loader’s front pivot point.”

A second trip to the site involved the third excavator, where the refuelling system was also damaged and fuel theft occurred.

Jones says the excavator caught fire and progressed much faster than usual due to coal dust build up on the machine. 

“There was maintenance and hygiene issues on the machine,” she says. “We’re talking like 10-15 centimetres of build-up. It was so bad it progressed the fire through the machine much faster than it should have.”

Despite solving the puzzle of the fires, a key question remained: why were people stealing fuel?

Jones says the mine was plagued by union issues due to workers being underpaid, and that the operator was in negotiations with unions to reduce the average wage of its workers below $US600 ($777) per month.

“Each excavator carries 8000 litres of fuel and its $US2 per litre of fuel on the black market in Mozambique,” she says.

“The mine is near a trucking route to Zambezi so people can nick fuel and sell it for $US2 per litre, which is far more than the average monthly wage of $US600 per tank.

“Everyone was aware of the black market for fuel the mine workers were involved in except people who needed to understand what was going on.”

According to Jones, each excavator is worth $US15-$US20 million each and takes a year to commission. 

“So, you’ve lost the machine and the capacity to work for about a year in Africa. The actual loss in its output capacity was huge,” Jones says.

Jones reveals that multiple parties were attempting to cover up why the fires on the excavators started. However, she says that sticking to her guns to ensure she delivered an accurate investigation into what occurred was important. 

“Forrest Gump says ‘life is like a box of chocolates, you never know what you’re gonna get’ – this was just that at the extreme,” she says. 

“The bribery out there was a bit crazy. You just have to be flexible in those situations and that’s part of what we do: holding ourselves to high standards and standing our ground to provide a thorough investigation.” 

This story also appears in the July issue of Safe to Work.

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