A World of Change

Brian Robinson explains why the time has come for the coal industry to look at advancing mine escape and rescue strategies

Reprinted with permission from Coal Magazine, December 2006 - January 2007 Edition

The world of mines rescue has changed more since the January 2, 2006, than it has say in the last 13 to 15 years, maybe even longer! Just why will be obvious when you look at your calendars and diaries, it was the date of the Sago explosion in West Virginia.

Until that fateful time, a lot of peoples concentration on coal mine fatality figures, explosions, fires or inundations of water went to China, where conservative estimates give a death toll of 5,500 a year. However, within the space of just a few months, there were quite a few incidents in the western world, that have woken people from their dreams, thinking "well, it can't happen here", well it did! If there are still mine managers around these days, thinking just that, they are delusional to say the least.

Just a quick review of some of the western world's coal mining incidents (one potash exception) that required the intervention of breathing apparatus equipped mine rescue teams will show you;

• Sago mine, West Virginia, January 2, explosion, 12 dead, room & pillar

• Aracoma mine, West Virginia, January 20, belt fire, two dead, longwall

• Esterhazy (Potash) mine Saskatchewan, January 28, underground fire (after hot-work), 72 rescued

• Mexico, February 19, explosion, 65 dead

• Darby mine, Kentucky, May 20, explosion, five dead

• Halemba Mine, Silesia, Poland, Nov 21, explosion, 23 dead (longwall)

There were more in India, Turkey and other countries also, however, the largest number of incidents and fatalities is obviously China.

China also possesses a very experienced mines rescue organisation, due to frequency of incidents!

GOLDEN APPARATUS

Before the beginning of this year, the two most recent items to come into mine rescue were probably;

• the introduction of the Draeger BG4 breathing apparatus in 1993, successor to the most widely used apparatus in the world, the Draeger BG174, and

• the introduction of Positive Pressure breathing apparatus by Biomarine in the early 1980's.

Actual techniques and equipment have changed little since the first rescue men descended Killingworth and Seaham collieries in the UK in 1880 wearing the first self contained oxygen breathing apparatus (the Fluess) after disasters there.

Mines rescue still involves a team or teams of workers, wearing a life support apparatus walking what could be long distances into the very hostile condition found after a mine explosion, fire, or gas outburst.

However, since the dreadful occurrences in the US, it has certainly stirred thinking a great deal, with such as the US 2006 Miner Act becoming reality after a knee jerk reaction, but it has also stirred the thoughts in far off lands, if it can happen in a first world country like the US, it could happen just anywhere, right?

The big things to emerge within the US will be the provision of more oxygen self rescuers or SCSR's, and refuge chambers to provide a better chance of survival for the miners underground in the event of fire or explosion, but also better planning to provide rescue teams at the affected mine quicker, and in larger numbers, to hopefully then affect rescue as soon as possible, again giving the miners a far better chance of survival. Also dictated for, mines should be provided with better communications systems, capable of withstanding the effects of fire and explosion, and by miners having tracking systems to enable pinpoint location of miners either who have gone further into workings seeking safety, or disorientated in smoke.

I have to say though, the priority of any miner should be to yes, muster at a safe(er) location such as a refuge chamber, but to then safely and quickly make their way out of the mine if at all possible. This is why, with good communications at these safe(er) points, it can inform the guys in trouble, your miners, there best way out according to reported conditions elsewhere. If it's possible guys, (after reporting your location, conditions, and travel route) don't hang around, get the heck out! In these circumstances, its often forgotten that the Sago mine explosion, a complicated room and pillar mine, and now infamous for the 12 deaths and Randy McCloy, the much reported one survivor in the crew of '2 Left' section, but this was also the mine where a bigger success occurred, where the other 16 members of '1 Left' section crew, who were also way inside the workings safely evacuated the mine in groups, using their oxygen self rescuers and heeding prior training in the mine layout etc. Sago was not just about the 12 dead miners, but about the guys who got out safely.

Again, this occurred at the Aracoma mine fire, a multi-entry longwall mine, in which two deaths occurred during the aftermath of a belt fire, the majority of the shift also safely evacuated the mine, showing at least some good training, miner perception, and leadership in difficult conditions.

SELF RESCUERS

Self rescuers are not new things by a long way, being developed in the 1930's, but only widely used since the late 1960's in the form of filter rescuers. The type that has to be carried by the majority of US coal miners is the '1 hour' person wearable SCSR, an oxygen producing unit rather than a filter. Larger, heavier, more cumbersome, and as recent experiences have shown, they require the wearer to know more of its working characteristics, otherwise they may think its not in fact working properly.

The jury is still out, quite literally in this situation, as in a number of cases, at more than one incident it was reported that a certain type of SCSR failed to function correctly, however the different schools of thought are;

• faulty equipment

• lack of sufficient training

• incorrect perception of just how and what an SCSR does.

NIOSH in the US are the publishers of the most useful and comprehensive research documents on SCSR's, RI9671 phases 8 & 9 being the latest. Within these latest documents, where they took rescuers that had been recently carried by miners underground, then very carefully looked into any damage, external and internal, and just how they would perform if they had to be used in anger.

For one manufacturers product it mentions a 10% failure rate in this, 31% in that, go to another manufacturer and we have a failure rate of 8%, and 5% in another test. Now, to a miner these figures should be like Russian Roulette, because you just don't know if the rescuer you have on your belt may have one of these faults, one of these percentile "failures", possibly until you need the thing to do what its designed to do, that is save your life!

Although these figures are failure rates during detailed inspection, and it may not result in malfunction, it need looking at. NIOSH have done the research into what goes wrong with them, its high time the manufacturers gave us a 100% reliable product.

I've experienced another of these products giving less than desirable service, dust in the hose/breathing bag on the first inhalation, again this doesn't inspire confidence.

So lets have a look at what can go wrong with an SCSR, or in its operation. The majority of these devices use a chemical, KO₂ or potassium super oxide, to remove exhaled CO₂, and produce oxygen, however this reaction takes a few minutes to get going properly, so most SCSR's are fitted with an oxygen starter, a device that when you pull an activation cord, sets off and introduces oxygen into the system quicker, so the user can breathe immediately, without delay from the chemical bed getting upto speed. It seems that;

a) maybe the starters didn't operate correctly

b) the guys weren't told to, or forgot to pull the starter cord

c) If this occurred, they should be also made aware to blow into the rescuer, and allow it time before expecting it to give full production of oxygen, in other words they were (rightly so too) panicking to get the rescuer on, and get out.

d) Maybe SCSR's hadn't been maintained correctly, or even designed/manufactured with the rough life of mining in mind.

Whatever the reasoning, more thought has to be given to providing miners with a proper escape device that works well, and improving training to correspond with this — five minutes in a mine office having a chat about it is just not enough!

I have to say also, that a '1 hour' device in the US, would only be classed as, say at most, a 40 minute unit in Europe, as a different oxygen uptake/air consumption figure is used to calculate the rated duration of an SCSR. The way it's measured in Europe has its flaws too, as it doesn't give a specific barometric pressure to test it at, so you could see a variation from an assortment of test elevations.

Any underground escape is never going to be easy, however, involving maybe a different route to normal, compromised vision and hearing due to dust, smoke and fire noise, as well as natural, gut wrenching fear/panic.

Historically a filter self-rescuer is simpler by design, easier to use, and more reliable than an SCSR. The reason SCSR's are dictated for in a US coal mine is so if the oxygen level goes below 19.5% after a fire or explosion, they would provide enough oxygen for an escape. At the Sago explosion, the CO figures show that the miners may well have been better off with a filter rescuer as opposed to an SCSR. It's a catch 22 situation really.

CHAMBERS

Refuge chambers can take the form of say a pre mined room, sealed off with walls to make it airtight, and a means of giving it fresh air or oxygen to sustain the miners inside. New means of generating oxygen and harnessing exhaled CO₂ now mean that refuge chambers can be completely independent from external sources, as such electrical power or compressed air ranges may well be in disarray after fire or explosion in a coal mine, and even consist of either a pre-stationed but movable steel chamber, or now even such as infl atable refuge chambers. It was by this method that the success story of the Esterhazy Potash mine rescue occurred this year, where during hot work, burning of bolts on a 40 cm polythene brine pumping column, an easy task, but the plastics ignited, not the start to your mining day that you really want. Under a disciplined regime, the workforce took to their many refuge chambers, sealed themselves in, and awaited the rescue team's arrival to put out the fire, ventilate the smoke logged mine, and allow the miners to return to surface. This major task though, involved some 14 rescue teams from several mines taking part in high levels of CO, and operating in bad visibility. It was further complicated by both power and telephone communications being put out by the fire. All that said, it was the major success in mine rescue this year for sure. It was also important to include this non-coal incident as it was a similar room and pillar mining technique, very much like half of the US coal mines.

THERMAL IMAGING

An item of equipment that may well have allowed the rescue teams to travel quicker in the poor visibility has been around for years, it's called a thermal imaging camera, fi re departments use them to very good effect, almost every fire truck has one these days. So why not mine rescue teams? One big thing is that they are not intrinsically safe (IS) approved, and not having this approval says it can't be taken into a coal mine in most countries. To my train of thought, if you have a fire, be it an open fire or a heating (spontaneous combustion), you already have your source of ignition, so providing gas readings are taken where the camera is being used, the IS would probably be the least of your worries. Fire departments don't worry about it not being IS!

Second thing is cost of course, these things being around US$10,800, or the same price as an extra set of breathing apparatus! I'm glad to say that the new regulations in the US recognises these facts and says that they should be available for rescue team use. Having placed them in non-coal operations, they are a must, enabling the team to travel in safety, and to locate the disorientated miners quicker, after all, that's what mine rescue is all about, right? This vital piece of proven rescue equipment just has to be recognised more widely, maybe even the manufacturers getting to work on a full IS spec unit.

Newer types of four-hour breathing apparatus are being released by Biomarine Inc with their Biopak 240R Revolution from the US, the German Auer/MSA International AirElite, and Polish firm Faser's W2000 apparatus, some stiff competition may be in for Drager Safety, one of the world leaders in the development and manufacturing of the highest quality safety equipment. My personal feelings are for a tougher, more robust unit, using the latest cooling devices and other enhancing features, but ensuring reliability in the harsh mining environment.

Some countries are also now using open circuit compressed air breathing apparatus, with twin cylinders giving a duration of around 90 minutes, but more simple and less costly than its closed circuit counterparts. Couple all of this together with realistic training that should be allowed and available for rescue teams to experience varying quantities of heat and poor visibility actually underground, and to use the specialist equipment to enable them to do the job eff ectively.

OTHER SUCCESS STORIES

Mines rescue hasn't just been about the use of breathing apparatus recently either. In 2002 the world received the news that nine miners were trapped by an inundation of water when the Black Wolf Coal Company owned Quecreek mine in Somerset County, Pennsylvania intersected the old unknown Saxman mine workings. Over several days, and involving the use of large diameter drilling rigs, the nine were safely brought to the surface. And in the non coal sector at two incidents this year in Tasmania, miners have been safely rescued after falls of ground, in one case after a lengthy two-week period cut off at the Beaconsfield gold mine. Of course such things can just as easily occur at a coal mine.

IN SUMMARY

So, a busy time in the world of mine rescue this year, a lot of tragedies, some success stories, and many, many lessons to be learnt, to be carried over into future mine emergency planning, and to put into future mine rescue training.

By Brian Robinson, United Kingdom, a leading expert in mine rescue techniques