New Zealand - Pike River Explosion Royal Commission

[rob52]

pikeriver.royalcommission.govt.nz/

Royal Commission Report
 - Pretty damming.

"
pg42
Ventilation:
During the development of the drift a fan at the portal ventilated the mine. It was replaced in mid-2009 by a fan at the top of the ventilation shaft.

In mid-2010 a new main ventilation fan was installed underground next to the main vent shaft. It was designed to draw air into the mine from the portal and expel polluted air up the shaft and out of the mine. The fan was commissioned in October 2010. This is thought to be the first time a main fan had been located underground in a coal mine anywhere in the world. Some metalliferous mines have underground main fans, but they do not face a methane hazard. In locating the fan underground the company faced a number of challenges. The fan motor was not flameproof and had to be situated ‘in fresh air’ in an intake roadway, with the fan blades located in a return roadway to expel polluted air up the ventilation shaft. The fan was vulnerable in the event of an underground fire or explosion, dependent on a power supply cabled into the mine from the portal and inaccessible to electricians in the event of an underground emergency. It also experienced teething problems after it was installed.

Workforce:
There was also a staff retention problem. One example of this was the turnover of mine managers at Pike River. From September 2008 until the date of the explosion six men held the position on a permanent or acting basis. A seventh person, Stephen Ellis, was to assume the role, as soon as he obtained a first class mine manager’s certificate of competence.

Company Directors:
At the time of the explosion the board comprised John Dow (chairman), Raymond Meyer, Stuart Nattrass, Antony Radford, Dipak Agarwalla and Arun Jagatramka. Gordon Ward was an executive director from July 2006 until 1 October 2010. It appears that none of the directors had underground coal mining experience.

**************
Book of interest:
Tragedy at Pike River Mine: How & Why 29 Men Died
Rebecca Macfie
Paperback, Awa Press
isbn-10: 1877551902,

**************
Disgraceful really....
New Zealand drops Pike River mine boss charges
Former Pike River directors omit miner detail

Pike River Coal Mine Disaster 2010 | Third World Standards In a First World Country

Rob

[John]

Both main vent fans were installed at Boulby mine underground, one either side of No1 shaft forcing air up No1 shaft, they have lots of CH4, and were listed as a safety lamp mine. The motors and switchgear were on the intake side though, but the fans were in the return air. Both fans were 1350HP.
This has since changed to one fan on the surface forcing air down No2 shaft.
The reason originally for the two fans underground was due to the "tree huggers" noise pollution.

[John]

For those who have only worked in UK coal mining, the NCB in it's "wisdom" decided early on to make all switchgear, lights and motors flameproof, probably because the M&Q Act required that the air flow must be able to be reversed in an emergency.

Now I'm only guessing, that NZ mining law is similar to Australian law in regards to mining.
In NSW, flameproof equipment is usually only found withing 300 feet of a hazardous zone and in the returns. All conveyors outbye of the faces are all none flameproof, all lights are just drip and dust proof, and main underground switchgear outbye are standard heavy duty industrial.
Now in saying that, the law required that in the event of a main fan failure, power U/G had to be isolated automatically, so the main surface fan contactor was interlocked with the main surface U/G HV circuit breakers.
In the event of a fan failure, we were allowed a time period, if the fan hadn't been restarted in that time period, the Deputy's had to evacuate the mine of all men.