Pike River mine crisis: Five things you need to know (Day 5)

Greymouth. This drizzly weather from Sunday has cleared and the forecast is good for the next few days. Photo / Mark Mitchell

If you haven't got time to read all our in-depth coverage of the Pike River Mine disaster, here's a quick summary of five key things you need to know today:


1. So exactly where is the rescue operation at now?

Police say the drilling operation to complete a 162-metre bore-hole is "progressing well" but it is still too dangerous for rescuers to enter the mine because of poisonous gases and possible "heating" underground.

Last night the drilling crew reached a depth of 142 metres before making contact with heavy rock.

The crew is expected to break through the rock this morning after changing to a diamond head drill to lessen the chance of explosion.

Once the drill breaks through into the mine, air samples will be collected and rescuers plan to set up a listening device and put a camera down the bore.

This could - if all goes well - be the point at which the 'green light' is given for rescuers to head in.


2. To wait or to rush in? The debate.

It's Day Five. Many above the surface are growing impatient and nerves are being frayed about the delays in implementing a rescue operation. Radio talkback callers are saying rash things like "let me throw a rescue pack on my back and I'll go down there, even if they're too chicken to go!".

All very gung-ho sentiments - but the reality is far more serious.

Experts from around the world seem to agree it would be a mistake to rush into a rescue.

Environmental engineer, Gavin Mudd, from Melbourne's Monash University says an operation like this takes time. He told Newstalk ZB it's important to follow mining protocols, and approach every question carefully and methodically.

Dr Mudd says issues including the possibility of residual combustion and how much methane is still in the air need to be considered and the wrong choice could easily lead to another accident.

3. Twin dangers of CO and CH4

Herald reporter Isaac Davidson has backgrounded the two dangers lurking far beneath the surface of a coal mine - carbon monoxide (CO) poisoning and methane gas (CH4).

Carbon monoxide may have been caused by the initial blast. The story explains its effects on the human body, and what needs to be done in the the event of exposure.

Methane - ever-present in coal mining operations - could cause a further explosion if it was (a) mixed with oxygen in certain levels and (b) ignited by a spark.

4. Conditions deep in the tunnel

What would the regimen be, for survivors of the explosion, over the last four and a half days? It's only speculation.

When they went into the mine for their shift on Friday, some miners would have carried water, but they would have had few other supplies for their 10-hour shift.

They will have taken their lunch with them, but they won't have taken much else.

The men walked between two and three kilometres into the mine and would have carried only the supplies essential for that day. This includes a self-rescue device that contains a short-term supply of oxygen, in case they are making their way on foot to an exit in choking smoke and dust.

But those canisters were only intended to give them enough time to reach a fresh air source, and would provide only enough oxygen to breathe for up to 60 minutes.

Surviving for any length of time would depend on getting to fresh air sources, experts say. If they can get to fresh air, they can survive for a reasonable amount of time.

5. The famous West Coast weather

At least the elements seem to be co-operating with rescue attempts, in a region notorious for heavy rainfall.

Conditions should be fine in the Greymouth area for the next few days, ensuring at least the weather won't hinder the Pike River rescue.

MetService forecaster Paul Mallinson said there was a ridge of high pressure for the next few days.

Mr Mallinson forecast today it would be generally fine with light south-westerly winds, tomorrow would also be generally fine with light winds, while Thursday may be patchy with a bit of drizzle.

He said the Greymouth region typically gets bands of rain and high fronts coming up the West Coast.

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