Opinion: Pike River mine no place for humans

David Bennett

Pike River re-entry was a high-risk election promise, writes David Bennett

It seems incredible to me that a government minister, Andrew Little, a former trade union official and former leader of the Labour Party, would now be leading the charge to enter the Pike River mine.

Surely the Government realises how much of a potentially dangerous move this is.
Let's remind ourselves of the facts ... 29 men died and two narrowly escaped after there was an explosion at or near the mine face. This was a mine being developed by a private company that had a right to mine a very high value coal in the West Coast of the South Island.

The problem was that the coal was very deep in the mountains and, to reach it, the miners had to dig a tunnel under a national park for some two kilometres before they reached the coal.

The problem was when the miners reached the coal. Something went wrong, and my guess is that there was failure around the electrical safety of some equipment once the methane gas in the coal was exposed. In coal mines, everything - ventilation systems, electric motors, drilling tools etc - must be of a very high standard to be safe.

Whoever gets the "job" of entering the mine will have to be dressed like firefighters. Modern fire crews are very conscious of the risks around explosive gases or even volatile flammable liquids.

So, apart from wearing what is known as level 2 clothing (multi-level fully fire/heat protective clothing, structural fire helmets over the top of Nomex balaclavas, gloves and boots), firefighters and rescue crews carry intrinsically safe torches and radios so as not to set the gases/flammable liquids off by carrying any tools that may create heat or a spark.

Mine "rescuers" will need to be wearing all this gear, which normally fire crews wear for only about a maximum of one hour. But, in this case, the mine rescue crews will also have to wear full self-contained breathing apparatus and other equipment such as gas detectors, various digging tools, cameras, specimen collection containers etc.

The normal expectation is the air in the self-contained breathing apparatus tank will safely last for 30 minutes. So, even if they use BA sets that have rebreathing ability (recycling the wearer's own waste air), there will need to be depots of air and other rescue/evacuation equipment to support this entry.

The distance to be walked in the Pike River mine in order to get to the coal face is about 2km, slightly uphill. There is no way a team of people going into this mine could reach the coal face without pre-preparation of supply depots, backup, and emergency evacuation provisions in support.

If there were to be another explosion of the magnitude of the last one, even this safety equipment would probably not protect the re-entry crew from fiery deaths.

I know a considerable amount about the protective clothing these people should be wearing, but a massive gas explosion, as happened seven years ago, would almost certainly overcome all this protective equipment. The problem will be that if air gets mixed with the methane, that's when the really serious problems may start.

Another complication is that what happened at the coal face is not exactly known. It is possibly a crime scene, so entry will have to involve police and other forensic investigators.

There have been suggestions of creating a special legal entity that will employ the mine rescue team and, presumably, be exempt from normal health and safety legislation.
Let's remember that it was following the Pike River disaster that the Government changed the workplace laws to hugely tighten safety for all workplaces. Some workplaces can be inherently unsafe, and good employers, and certainly the directors of private companies,
now have health and safety on the agenda of their meetings. Company management is charged with effective daily monitoring and visionary leadership with monthly reporting in order to prevent injuries.

The sad reality is that those miners are dead - we all saw the effects of the explosion in the video of the blast that came out the front portal and the flames that billowed from the escape hole. It is very likely that all that is there is ash because the heat of that explosion was effectively like a crematorium.

So what are the other options?

One option is simply to seal the mine and treat it as a tomb. Obviously no satisfaction for the families.

Another option was what the National Government was preparing - some sort of robotic device that could go into the mine to collect samples or transmit images. Preparing this device is obviously taking time, but should it succeed as a first attempt, it would not put a re-entry crew at risk.

Another option that I suggested to Bill English's office was to insert a pipe along the floor of the mine. In Australia, they do long-distance horizontal drilling into coal mines in order to capture the methane gas for sale and, apart from the debris on the floor of the tunnel, there may be no need to actually drill the pipe in.

Once inserted, through the pipe could go a gas detector to measure methane levels. Even a camera and lighting could be inserted, maybe even a micro-robotic device that could explore past the end of the pipe. Again, no risk to a re-entry crew. Only after that would I be risking real people in this mine.

Any politician who is prepared to put other people's lives at risk should be prepared to lead the charge into the mine. Election promises should be reconsidered in the hard light of post-election reality, Mr Little.

■ David Bennett is chief executive of Whanganui company Pacific Helmets, part of the safety equipment industry for 35 years and an exporter of protective equipment throughout the world.