14 Nov 2018

Pike River Mine re-entry: How it will happen

2:04 pm on 14 November 2018

Today the government announced it will proceed with the re-entry of the Pike River Mine which will begin in February next year.

The second drilling platform at the Pike River Mine near Greymouth.

The second drilling platform at the Pike River Mine near Greymouth. Photo: IAIN MCGREGOR / POOL / AFP

The Minister responsible for Pike River re-entry, Andrew Little, made the announcement at Parliament in front of a number of the families of the Pike 29.

In 2010, 29 men died following a series of explosions at the West Coast mine.

Three options were put on the table including building a new 2m by 2m tunnel, about 200m long, to the pit bottom in stone area; drilling a large diameter borehole; and re-entering the main drift as it is with no second exit.

A group of experts then considered the options and presented Andrew Little with a plan for safe entry to the mine.

Mr Little said he decided the Te Kāhui Whakamana Rua Tekau Mā Iwa - Pike River Recovery Agency, recommended course of action to enter the drift, using the existing access tunnel, was by far the safest option.

He said he required an additional $14 million from Cabinet for the plan to be enacted - the total cost of the project is $36m.

The plan will be split into seven phases and is expected to be complete by June 2020.

Before the first phase begins in February next year, preparatory work is being carried out by the PRRA.

That work includes the design and manufacturing of new emergency portal doors, the restoration of a high voltage power supply and the acquisition of a nitrogen plant that has been transported to Pike River and will be brought into service.

Over the next three months several additional small holes will be bored into the mine shaft to assist pumping and ventilation.

Once that's all complete, the first phase can begin.

The breakdown of each process

Phase one, February 2019: Breach the 30 metre seal and re-establish the 170m barrier.

Phase two, February-April 2019: Conduct forensic search 30m - 170m then remove 30m seal and deconstruct the water management infrastructure.

Phase three, April 2019: Remove the 170m barrier and progressively search and recover the drift.

Phase four June 2019: Establish seal and conduct detailed forensic examination.

Phase five, August 2019: Recovery and examination.

Phase six, December 2019: Reseal the mine, re-establish water management infrastructure and seal at portal, refurbish site for handover to DOC.

Phase seven, June 2020: Handover to DOC and disestablish the PRRA.

Key moments in the mine tragedy

  • 31 January 2018 - The Pike River Recovery Agency - Te Kahui Whakamana Rua Tekau ma Iwa, opens
  • 20 November 2017 - Labour government establishes stand-alone agency to start planning for manned re-entry of Pike River
  • 20 November 2017 - Labour government establishes stand-alone agency to start planning for manned re-entry of Pike River
  • 5 May 2017 Thirteen hours of Pike River footage released by police
  • 21 November 2016 - Pike River families furious at mine's closure
  • 17 November 2016 - Pike River re-entry 'lunacy' - PM
  • 12 May 2016 - Pike River mine Great Walk route finalised
  • 10 September 2014 - Two families of mine victims apply for a judicial review of the decision to drop charges
  • 4 February 2014 - Second phase of work to re-enter mine tunnel begins
  • 24 December 2013 - Payments begin from a special compensation fund set up after Mr Whittall's charges were dropped
  • 12 December 2013 - Charges against former Pike River Coal CEO Peter Whittall are dropped
  • 15 November 2013 - Legislation implementing health and safety recommendations passes its third reading in Parliament
  • 23 October 2013 - The Defence Force completes the first phase of the mine tunnel re-entry plan
  • 5 November 2012 - The Royal Commission into the Pike River Mine Tragedy makes its report and recommendations public
  • July 2012 - The sale of Pike River Coal to Solid Energy is confirmed
  • 10 November 2011 - The Labour Department lays 25 charges against Pike River Coal, Valley Longwall International Drilling and former Pike River Coal CEO Peter Whittall under the Health and Safety in Employment Act
  • December 2010 - Pike River Coal is placed into receivership
  • 29 November 2010 - Cabinet agrees to establish a Royal Commission of Inquiry
  • 24 November 2010 - The second explosion hits at 2.37pm. Police move from rescue to recovery operations
  • 19 November 2010 - The first methane gas explosion hits at about 3.45pm, leaving 29 men trapped