Pike River re-entry to be finished in six months, agency boss says

Tuesday, 29 December 2020

Carol and Steve Rose talk about the loss of their son Stu Mudge, and their journey in the 10 years since the Pike River Mine disaster

More than a decade on from the disaster, the Pike River mine re-entry will be completed and the mine handed over to the Department of Conservation (DOC) by June, the agency’s boss estimates.

Pike River Recovery Agency chief executive Dave Gawn said he expected re-entry and forensic work in the mine’s access tunnel will take another three months, followed by another three months of clean-up at the mine site.

It will then be handed over to DOC to be included as part of a new Great Walk.

The nine-kilometre Pike29 memorial track will link the mine site with the 55.7km Paparoa Track, which runs between Punakaiki and Blackball.

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Pike River Recovery Agency chief executive Dave Gawn says cleaning up the mine site is expected to take about three months.

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Part of a ventilation control device, or airtight steel doors, installed at Pike River to allow staff to go up to the roof fall at the top of the mine drift.

A memorial and information centre would also be built to commemorate the 29 men killed in 2010 and tell the story of the tragedy at the West Coast coal mine.

Gawn said recovery teams had reached a Rocsil plug 2.2km up the mine’s access tunnel (or drift). Rocsil is a concrete-like sealing resin that can be sprayed and then hardens to make a tunnel air-tight.

The agency was given a $51 million budget to recover the 2.3km drift to find any evidence as to what caused the 2010 explosions and recover any bodies found. So far, no bodies have been discovered.

Once agency staff returned to work in the new year they will install a ventilation control device, essentially a steel frame sprayed with Rocsil with an air-tight door.

That will allow them to tunnel through the plug and recover the final eight metres at the top of the drift. They will use breathing apparatus to examine the rockfall at the top of the drift, which is blocking the main mine workings.

Gawn speaking at an event to mark the beginning of re-entry.

Gawn said getting through the last 200m of the drift was slower and more difficult than anticipated because there was more damage and debris than expected.

The team has also found heavy pipes that needed to be secured.

Pike River fathers Dean Dunbar and Bernie Monk have theorised that the second explosion happened in the drift, an idea backed up by data analysed by electrical engineer Richard Healey.

Gawn said that was one scenario being looked at by police.

“We don't comment on the police investigation, but they are doing it very thoroughly,” he said.

Pike River Recovery Agency chief operating officer Dinghy Pattinson inspects roof bolts near the Pike River Mine portal.

Healey has called for the agency and police to put a robot and camera up a 30-centimetre pipe leading from the drift into the mine workings.

Police earlier said they were considering whether to drill new boreholes to look deeper into the mine. Stuff understands they would focus on an area at the coal face to see if it had collapsed.

A collapse there would have expelled a large volume of methane and caused an explosion when it met an ignition source.

Gawn said putting a robot through a pipeline was not a simple exercise because they are not intrinsically safe for underground mining.

Flames burn from a ventilation shaft above the Pike River mine after the November 2010 explosion that killed 29 men.

Although the atmosphere inside the mine is inert, approval would still be needed from WorkSafe to use such devices.

Gawn said the possible boreholes police were mulling over might extend the lifespan of the agency.

“We won't know that until what it is exactly that the police land on and once that review has been completed we will look at what the impact is on timelines on the agency,” he said, emphasising that his team was focused on finishing its job of recovering the drift.

They have been working in two 10-hour shifts, but that will soon be reduced to a single 10-hour shift, meaning some of the 28 mine workers would not have their contracts extended into 2021.

Both the agency and police intend to complete a “very thorough” investigation of an area known as pit bottom in stone because it holds electrical equipment that might reveal more about what happened in 2010.

Gawn says putting robots into the mine isn't a straightforward exercise.

Gawn said he had kept all family members informed of the team’s progress, and had worked with the agency’s family reference group, which represents 27 of the 31 families affected.

“It doesn't matter who you talk to within the families, they generally all want the same outcome – justice and accountability.”

Once the re-entry is complete, it will take another three months to seal the mine and clean up the site.

“Rehabilitation of the area is still a big task ahead. Picking up rubbish that's been there for years and years – everything from pipes to concrete pads, a couple of buildings and sheds.

“Rehabilitating the ponds to promote natural regrowth of the forest and the roads will have to be redone before we finish,” Gawn said.

DOC will also upgrade the bridges and turn the site into a memorial centre to be visited by walkers and bikers on the Paparoa Track.

“The memorial will be at the portal and the administration block will be a museum that will tell the story of Pike River. It will be a journey you can take from the gate all the way through,” he said.

Gawn will then look for new work opportunities, something he has been expecting to do since March.

“[This project] is genuinely challenging. It's a tight budget – we've had to manage it very carefully. But we’re getting there,” he said.