Safety

Little known hero

Darren Flanagan is employed by Johnson Hi-Tech Explosives in Nowra. He is their Sales Manager for the east-coast of Australia. He received a phone call from Beaconsfield late one Sunday evening while watching TV. He was not to realise that when he picked up the phone and said yes to an appeal from mine management, his life was to change.

Darren was born in Nowra on the NSW South Coast in 1965. His father was a butcher and his family moved to Parkes to set up a business there when he was seven. After finishing his schooling, without any particular objective in mind, Darren tried to find his place in life. An opportunity came when he joined the drilling supply company Sandvik in Parkes. After three years he was promoted to branch manager in Kalgoorlie where he spent the next three-and-a-half years. However Darren said he had itchy feet and wanted to move on. Rather than lose him, the company sent him to Darwin to start a new branch. After a year in Darwin, he was invited to join the relatively new company RockTek Limited, which is a wholly owned subsidiary of Brandrill Limited from WA.

The company had identified a growing niche market for a specialist explosive that could be safely used in situations where conventional explosives would damage adjacent structures. The company had purchased patent rights from the USA and originally traded as Rock Breaking Solutions before changing to RockTek. The product is now sold as RocKracker.

The rock breaking process relies on the rapid generation of a large volume of high-pressure gas to fracture the rock by tension and not compression as with conventional explosives. The propellent used in the cartridge is similar to that in shotgun and rifle cartridges and is contained in a plastic cylinder varying from 27.5mm to 60mm diameter. The charge is varied according to the situation and can be as low as 30 grams or as much as 300 grams. Once the cartridge is in place, specialist stemming packs are inserted. When ignition occurs, the cartridge tries to escape up the hole. The cartridge's wedge shaped tip expands the stemming pack to seal the hole and force the expanding gas down.

Having developed the product to suit Australian conditions, the company then employed Darren as its Sales Manager. The company allowed him to choose from where to operate, and Darren returned to Nowra to be reunited with family and relatives. Darren has spent the past six years travelling across Australia developing and refining the skills necessary to conduct blasting operations in very delicate situations.

In 2006, RockTek Limited appointed Johnson Hi-Tech Explosives as their Australian distributor to the mining and civil construction industries in Australia. Darren moved to Johnson's with the product.

The collapse at Beaconsfield occurred on Wednesday 25 April 2006 and as the days elapsed, it was naturally assumed that the three missing miners had perished, particularly as one body had already been discovered. On the following Sunday Darren was watching television and like most people, could not believe the news that the other two miners, Todd Russell and Brant Webb, were found alive. At 9pm the phone rang and Darren answered thinking it would be a workmate talking about the news. Instead it was Beaconsfield Gold asking if RocKracker was suitable to create a small drive towards the trapped men and how close to the men could it be safely used. He explained the process but stressed in a situation such as this, many site factors could influence the results.

The caller told him to pack a bag immediately and that he would shortly receive a call with flight details. At 10.30pm the call came telling him that a chartered Lear jet was preparing to leave Sydney and would pick him up from the HMAS Albatross Naval Station, which was only 10km from Darren's home, at midnight.

He was at Beaconsfield by 2.30am and taken straight to a room full of officials from the mine and government authorities.

Darren was told to leave his salesmen's hat at the door and make a presentation to the group of facts only. He was advised a stenographer was recording his every word, this was a life and death situation that required the truth and nothing but the truth.

The spokesman said they liked what they heard but wanted him to prove it.

Initially the rescuers were contemplating driving a tunnel 1.8 metres high x 1.2 metres wide straight into the accident site. So Darren and a team of miners from Stawell gold mine were taken down to the 630m level to conduct trials to check vibration readings and also what rate of advancement could be expected with this hard rock.

Two of the team were from Orica and they had the necessary vibration measuring equipment.

“I arrived late on Sunday night and my bag was still sitting in reception on the Tuesday. We worked hard and with little sleep. We evaluated different strength charges and ways of detonation and wrote up reports of what we had discovered.”

Mine management made it clear that because of the dangerously unstable roof over the men, the use of explosives anywhere near the trapped miners would be an absolute last resort.

Nearly a kilometre below the surface, there were two parallel roadways 35m apart. The one where the men were trapped was seven metres higher than the open tunnel. The rescue team had driven 20m towards the upper tunnel with high explosives before it was realised the men were alive. A raise bore machine was then used to push a one metre diameter hole 14.5m to within 1.7m of the cage.

A close pattern of holes were then driven into the face of the rock at the end of the tunnel with the intention of jack hammering the remaining rock away, piece by piece.
The 200mpa rock defied the jackhammers, the rescue team were devastated – they were so close to the boys but their best efforts were in vain. Morale among the rescue team fell to rock bottom.

After a week of test blasting, at 3am on Sunday morning 7 May, Darren received a phone call at his motel. Mine management said: “Darren, we have tried everything to break this rock without success, it's time for you to start blasting.”

He was shown a video which had been taken by the trapped miners giving a 360 degree progressive image of the roof over the cage in which they were trapped.

“To say that at that point I was shocked is an understatement – you wondered just what was holding the roof from falling, it was so shattered and unstable – the rocks were like daggers hanging above the trapped men,” Darren said.

The effectiveness of using RocKracker is dependent on working with precisely placed drill holes in a set pattern. When he examined the face, he found the holes had been drilled with no pattern other than assisting the jackhammer.

“I was previously faced with a similar situation in Sydney – took one look and said 'sorry, I can't help you with a mess like that' and walked away.” But now two men's lives were involved. No longer controlled trials, but stark reality. “I couldn't walk away from Todd and Brant.”

Management said all the relevant authorities had now reluctantly approved the use of RocKracker explosives but said the final decision could only be made by the trapped miners. They also only approved the firing of one 30-gram shot at a time.

Darren then spoke by a previously installed phone line to Todd and Brant for the first time, explaining who he was and that he wanted to start using explosives less than two metres away from them.

Todd was a shotfirer and knew exactly what could happen. “I was scared and I knew they were scared too,” Darren said.

After a brief time out, Todd came back on line to say yes, but only if he gave the countdown for each shot to be fired. This enabled the two to squeeze under a piece of roof mesh which up to then, was their only protection from falling rock and also to wrap blankets around their bodies.

Darren retreated back to the lower roadway and waited for the first countdown from Todd. The atmosphere for all of the team was absolutely electric.

Backing his experience, judgement and faith in his low energy explosives, Darren had to push the button knowing this could cause the roof to collapse. As the moment arrived Darren was alone, as everyone had moved well back from the tunnel mouth as a precaution.

“For a moment I was lit up like a Christmas tree with dozens of headlamps focussed on me from concerned rescuers as I fired that first charge.”

Darren was on the phone immediately and was relieved to hear Todd say 'Hey, you're a big girl – I've got a shotgun back home which makes more noise than that!'

The release of tension was immense. From that moment Darren was nicknamed 'The Gun' by the pair.

Then began the hard physical slog, which for Darren lasted 29 hours. As each shot was fired, he would crawl up the hole over the broken shards of jagged rock from the previous explosion, towing a 'drip tray' containing the cartridges and stemming packs for the next shot. Darren would then load the tray with the broken rock and it would be hauled back with ropes by the helpers below. Five tonnes of rocks were moved this way.
 
Whereas a lack of water had initially been a problem for the trapped miners, as the rescue progressed, due to roof movement what had previously been a precious drip had become a steady stream, which meant Darren was perpetually wet and with the rush of ventilating air, hypothermia became a problem.

There was also concern that when the breakthrough finally came, the loose floor below the miners could collapse onto the rescue team. They found it was possible to pass a hose through the communication tube for Todd and Brant to secure the loose floor with a relatively flexible grout.

Approximately 70 cartridges were used and when the final shot had been fired in the solid rock there was only 300mm of grouted rock separating the rescuers from the trapped miners.

Now, after the rescue was successfully completed, Todd and Darren still remain in close touch as friends, through the special bond they formed after all the countdowns to shot firing.

There were a lot of people who played a role in the Beaconsfield rescue, many of who will carry emotional scars for the rest of their lives, of the hundreds involved only one was called on to fire the first shot.

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