Creating a new small tunnel into the Pike River Mine drift is one of three re-entry scenarios that are considered by technical experts in Greymouth. By Peter Owens.
The Pike River Recovery Agency was set up by the Government earlier this year to plan a manned re-entry and recovery into the Pike River Mine drift access tunnel.
The agency is a Government department, comprising mining staff and administration/advisory staff.
It calls on the services of a technical expert advisory panel, and workshops include representatives from the Department of Conservation, WorkSafe, New Zealand Mines Rescue, New Zealand Police, family representatives and their own expert advisors.
The agency has been focused on the three re-entry scenarios signed off by the Minister in July. They include building a new two metre by two metre tunnel about 200 metres long and driven down to intersect at the pit bottom area; and re-entering the main drift as it is with no second means of egress (exit).
“A two metre by two metre tunnel, if it can be achieved, would provide ventilation, a second means of egress and quicker access to the areas of interest to assist with finding out what happened and recovering any remains,” says agency chief executive Dave Gawn.
“There are other options as well, including the drilling of a new large diameter borehole which would assist ventilation and possibly act as a means of escape. At this stage no final decisions have been made.”
Gawn adds that the input of ventilation and engineering experts, with the detailed chemistry and geological engineering knowledge, combined with hundreds of years of mining experience, has enabled the team to get closer to finalising a preferred option.
A concept plan drafted following an earlier four day workshop was sent to the Minister Responsible for Pike River Re-entry, Andrew Little, who gave the concept plan the go-a-head to proceed to the next stage.
Dave Gawn says contractors who carry out any work will also be involved in detailed recovery planning and risk analysis, as well as mine sealing and rehabilitation works at the completion of the project. A procurement process is underway to find the right contractor for that work, he adds.
“We need to continue our planning even while the Minister is making his decision about whether he’s confident that re-entry is possible.
“The Pike River families have been waiting for more than seven years now and it’s important that we keep the pace up, while not sacrificing any finer details around health and safety.”