Sandpit

I'm working in a very large sandpit. This was how my career was summarized by my loving friends and family. The fact that I'm no longer in contact with any of them is a completely different matter, of course :-).

The Sandpit I Call Home

Open cut coal mining is all about balancing the sand or dirt to get to the black gold underneath. I've only been at my new open cut mine for three weeks, but I've learnt so much already. The diagram below illustrates the basics of open cut mining (as seen through the eyes of a geologist :-).

Open Cut Coal Mining

The first stage is clearing the area (after the correct environmental procedures and plans have been followed). Then comes the removal of the overburden. There are different methods of open cut mining. For example, strip mining or terrace mining. The method used depends on the geology of the area. How deep are the coal layers? How many coal layers are present? Are the rock strata horizontal or at an angle? Are there any structural features likes folding affecting the strata?


One of the biggest challenges is to remove the dirt above the coal without damaging or destroying the coal and then to manage the space available for dumping the dirt. This is done by deploying the correct machinery to the right stage in the process. The dirt is typically moved to sites where the coal has already been removed. One big thing I've learnt is the dragline never touches the coal. It only removes the overburden. The bucket on the dragline is too rough of a tool and easily scrapes away valuable coal.


I sometimes feel a bit silly at work when I don't know what the hell is happening or what people around me are talking about. But, the guys I work with are amazingly helpful. The geologist I'm learning from has been sitting with me and slowly teaching me the modelling software and how open cut mining operates. It's been wonderful. And, I'm loving being in the sun.


So it is a bit like playing in a sandpit :-).

Taking Credit

Geology is easy. Being a geologist is tricky. The rocks have been the way they are now for millions of years - only our knowledge of what's beneath our feet changes. And that's where the tricky part comes in.

I've mentioned before the sometimes difficult relationship between the geologist and the engineers on a coal mine (Gaggle of Dykes). And more often than not difficult geological conditions are entirely your fault. Even though the rocks have always been like that, somehow the geologist is to blame. It is your fault if you didn't warn the production teams of the conditions ahead of time. But, the actual rocks? Definitely not.

I've had many issues underground around thick in-seam inorganics. These are sandstone lenses in the coal seam which are harder to cut and worsens the overall quality of the seam. Some stone layers can become thick quickly in a localized area and causes major problems with the crushing and transporting of the material underground. As the geologist, I can only predict what the stone will do. I cannot remove it. This is sometimes lost on the engineers.

Recently, I was underground with the foreman of the section. He took me all over, complaining about the unmanageable cutting conditions and how the huge stone layers were blocking his feeder breakers and chutes. He was ranting and then implored me: "How the hell I am suppose to cut this nonsense?" (I have censored his word choice slightly.) I very calmly replied: "With difficulty." His anger deflated immediately and he came back down to Earth. "That's probably the right answer to that kind of question," was his reply. He knew I could do nothing about the stone. His expression was quite hilarious though! I do think most of the guys get so much pressure from above that they just need to vent to an understanding person. I sometimes just fall into that role.

This kind of blaming happens quite often, so when you can take the credit for something, you should! We were busy with a large stoneworks project through a dyke and devolatilized coal (the intrusion had burnt the coal). Burnt coal is very soft and dangerous to mine through since it's so unstable. The plan was to drill boreholes to test for when we get into the normal coal again. We did a couple of samples and finally reached clean coal. When I shared the results, I was congratulated and patted on the back by everyone! It was so funny. I didn't magic the coal not being burnt - it's been like that forever. I only gave the laboratory results back. But, as I said, you get blamed so often for the state of the rocks that it was a welcome change to be congratulated.

At least mining is never boring :-).

Occupational Hazard

I got a hammer in the post this week. Now, to most people this would be an extremely weird comment. A geologist would simply reply: "Estwing? Wood or vinyl handle?"

Being a geologist brings with it a few eccentric behaviours. A case could be argued whether eccentric people become geologists or whether the job itself creates these weird traits. Take the hammer for example - not all hardware stores carry Estwing hammers so alternative options for getting a new one is necessary. And it is an essential tool for the working geologist. Actually, it's the only cool tool we use. So to compete with the engineers with their huge machines and power tools, you flaunt your special hammer whenever you can :-).

I keep a bag filled with PPE (safety clothes), a notebook and my hammer in my car in case I get called out to site. I was stopped one afternoon by the mine's security. They do routine checks to make sure no one is running off with copper or computers. I was not really paying attention to the guard's check until he called me over to where he was going through the bag. He lifted the geological hammer and stared at me with a frown. The one end of the hammer is like a pick and the other is blunt. I joked: "It's for self-defence." The guard was not impressed and I tried explaining that I'm a geologist and I used it underground. He just nodded and carefully put the hammer back. Since then, he's kept an eye on me.

Geologists also makes loads of jokes (puns especially) about different rocks. There's a running joke among my geology friends that there's a blissful state of mind a geologist will reach after enough experience where he'll be able to identify any rock type without even looking at it. This comes from the fact that we sometimes struggle to identify the basement rocks in our area while one of the oldest geologists in the office simply glances at it and gives an answer.

I mentioned before how engineers want a concrete answer, but because geologists work with limited data points you can never be one hundred percent sure. This does mean that you started speaking in options - On the one hand, the data could indicate this, but on the other it could point to something else. I heard another joke about this from a mining engineer the other day. He says that a engineer looking at a white horse from the side would exclaim the horse is white, but a geologist will say this side is white and can't be sure about the other. Quite funny!

All the above means that most geologists have some quirks, but are hilariously funny and get along with almost anyone. Get your own geologist friend as soon as possible! :-D

Not Underground

Typically, an underground coal mine runs continuously on a shift system. There's a day, afternoon and night shift and the productions and preparations teams will cycle through these shifts on a week to week basis. There could also be a long weekend where the entire mine is off the Friday and Saturday.

This means that most of the people that you as the mine geologist will come into contact with will be guys who are constantly underground and work shifts. To them, if you're not underground you're not doing any real work. The real work is done by the people in the face getting the coal out. Except if you're in financial or a secretary ;-).

This sometimes puts geologists in tight spots. A lot of what I do, is modelling on a computer, pulling out the relevant data from the model and getting the right info to the right people. You do underground mapping and inspections, but you don't work shifts 24-7. But, if you're not visible to the production teams (i.e. your customers), they will not trust your work or respect your opinions. I'm not saying work 10 hour shifts underground each day, but regularly weekly visits with the mine captains and shiftbosses are a must. Also, many production meetings will only need your input for maybe 10 minutes, but being there for the entire meeting shows that you want to and are part of the team.

It's a very tricky line between keeping everyone happy and still getting to your own work. Mynbou is nie vir sussies nie! (Mining is not for the faint-hearted :-)

Knowing People

I recently posted about the dynamics between engineers and geologists (Gaggle of Dykes). It can be quite a difficult work relationship to maintain, but definitely worth the effort.

I am changing jobs at the moment - not drastically. I'll still be a mining geologist at a coal mine, but I'll have more responsibility. The entire geology function will be mine and I'll report almost directly to the mine manager. This in itself is a bit daunting - I've always had a more senior geologist as a buffer between me and the higher management. This won't be the case anymore. The responsibility and accountability will lie with me.

Geez! I already sound like a manager! I made my friends promise me that they'll let me know when I turn into a full-blown manager who uses words like challenge, opportunity, alignment and leadership in every sentence. They are instructed to slap me back to reality :-).

I'm quite excited about the new job. It will be my mine and I will be able to make decisions and follow them through. Also, as I've been handing over to my replacement, I had a slight ego boost when I realized how much I actually know about coal geology and mining. But, knowledge will only get you so far. You can be the best geologist on the planet, but if you cannot communicate or work with people, you might as well stay underground.

Understanding people is probably 70% of the job. Of course you have to know what you're doing, but if you can't convey your opinions in the right way to the right people, nothing will get done and you'll end up very frustrated. I've seen how people can block others simply because they don't care for them much or because they don't understand how they work.

Luckily one of my many skills is people :-D. I've never realized how valuable such skills can be and I'm definitely not an expert, but making people laugh and listening to them does help to make the work go faster and easier. And if all else fails, chocolates and beer have always been known to help any relationship :-).

Gaggle of Dykes

There has always been a bit of a battle between geology and the production teams at a mine. The mining guys are mostly engineers and they want a full proof answer right now that will apply to the rest of the mining area as well. Geology isn't fortune-telling. We have a certain amount of boreholes (i.e. data points) which gives us an indication of the expected geology, but there will be some local variations. This leads to some very funny meetings and a bit of friction between geologists and engineers. 

Simplified geology showing horizontal sedimentary rock layers intruded by green dolerite.

Many geological terms are a bit strange to engineers. They only want to know if geology will affect production rates and how the bonus might then also be affected. The typical engineer doesn't care that it's an igneous intrusion and should be called a dolerite sill. To most miners any hard rock between him and his coal is a dyke.

This can cause a lot of frustration for a mine geologist. As a scientist, you want to be as accurate as possible when describing any geological feature. In meetings however, you easily lose the production guys if you mention too many detailed geological terms. It has become a bit of an inside joke among geologists at how far we can push this. We could be mentioning a gaggle of dykes or massive dolerite splays (all of which are completely incorrect and illogical) and no-one would pay attention or care. Does it stop mining? Yes? Then fix it! That's the more typical response :-).

The opposite to this is that some people get attached to a new geological term that they heard you say months ago and know everything is called a stringer of whatever. And since you're typically the lone geologists among tens of mining engineers, your voice does get drowned out a bit. Most of the time you try and be as accurate as possible and as simple as possible. Sandstone in the coal seam = hard rock in the coal, will use more picks on mining machine. Micaceous minerals in sandstone in floor of coal seam = soft floor, when wet machine will slip and cut into floor.

What many mining engineers love to do is blame geology. If their sections are not performing - somehow geology is responsible. This means that you develop quite a thick skin and you deliver your opinions with conviction. You are the geologist - your say on the rocks are final.

I must admit that not all mining engineers and production teams are like what I've mentioned above. Mostly it becomes more of playful teasing between the departments. I work very well with my production and engineering teams. They rib me for not working shifts underground and not seeing how thick the stone was becoming months ahead of time. I tease them with the fact that I can and often will change my mind - they have no such luxury :-).

Men & Material Shaft

An underground coal mine typically has 3 shafts - a men and material shaft (or main shaft),  a decline shaft and a ventilation shaft. The main shaft is a vertical shaft and has a large cage for getting people and machinery underground. The decline shaft runs at an angle to the coal seam and contains a conveyor belt system which removes the coal from underground. The ventilation shaft is used to get air underground and circulating in the correct manner.

 

I've mentioned previously, that I'm part of a shaft sinking project for a new underground coal mine to extend the mine's coal reserves. During sinking, the shaft bottom is blasted and the rock is removed. At first, this is simply done with frontend loaders. As the shaft becomes deeper, the top is lined with concrete to keep the shaft open and stable. To make this process easier, a stage is used. The stage is a flat metal plate which fits into the shaft and is lowered with winches. This allows people to work on the sidewalls and shaft bottom as the shaft gets deeper. During the lining of the shaft with concrete, the stage keeps a metal curb, which goes right around the shaft, in place into which the concrete is then thrown.

 

 

During this process of lining the shaft, the stage is kept perfectly still to ensure that the concrete lining is straight and vertical and has the correct thickness. This means that since the stage is not being winched up and down that the only way to get to the stage is by climbing down a rung ladder from the top.

 

Part of my job includes mapping and inspecting the sidewall of the shaft to make sure no major structural features are present that could cause rock falls (such as jointing and faulting). To not interfere with the production of the shaft sinking team, I inspected the sidewalls during the lining of the concrete ring which translated into lots of ladder climbing.

 

At first, it was fine since the shaft wasn't that deep. Later, it became quite a full-body exercise. The first step is to get into the harness which you can attach to the metal ladder to keep you from falling. I had to keep quite a game face on since a lot of the older men sometimes refer to me as girlie and I didn't want to give them any more reason to think I couldn't handle my job. Climbing down the ladder is just as bad as climbing up since you have to concentrate on not looking down and not slipping. You are wearing full PPE (personal protective equipment) which is definitely not the lightest clothing. Once you reach the shaft, you need to climb out from under the ring surrounding the ladder and onto the stage. This was very daunting the first time since you can see the shaft bottom below you and it's quite a drop.

 

Climbing back up was a mission. I was determined not to let the men see I was in any way tired, but when I reached the top, I realized my mistake. My arms and legs were so wobbly and tired that I barely managed to grab the railings at the top of the ladder. My hands flailed around for a bit and my only thought was that it would be beyond stupid to fall now that I've reached the top. Luckily after a few tries I grabbed hold of the railing and pulled myself up and out. Unfortunately, my adventures had not escaped attention. The stage foreman came over and said he saw my hands wildly waving around over the top of the ladder and wondered what I was up to :-). I felt a bit better, though, when the other surveyors and foremen who came up after me were just as exhausted as I was.

 

I became quite an adrenaline junkie after that first experience. There's something to be said for hanging on to a ladder with only a small harness clip between you and a very hard fall :-).

Darkness

Working underground ruins any plans of getting that summer tan quickly or keeping it through winter. Your wardrobe also doesn't help. For safety, you have to wear a full set of PPE - personal protective equipment. This consists of a one-piece overall (which you climb into), thick long socks, steel-tipped gumboots, gloves, hard hat, hearing protection, safety glasses, a cap lamp and rescue pack. The rescue pack provides a limited amount of air if there's an explosion or other emergency underground.

The main travel roads underground have lights and the entrance to the production sections are also lit up. There are substations and transformers underground which supply all the necessary power. But, in the old areas there are no road lights and it's quiet. You're far away from the mining machines and conveyor belts. Doing inspections can be quite surreal. The only light is provided by your cap lamp. Once you switch it off, it looks as follows:

It makes you feel quite insignificant when you realize you're hundreds of metres under solid earth and surrounded by rock and darkness.

I'm involved with a new shaft which is currently being constructed (i.e. shaft sinking). During the first 60 m of sinking, you climb down a rung ladder to inspect the rock layers which have been exposed. One late afternoon, I had to map the rock strata and check for any joints or faulting which can cause rock falls in the shaft. There were issues with the power and the stage in the shaft on which you walk around had no lights. Very creepy to know there's 20 m of open space below you to the shaft bottom and you only have a small circle of light to see with. The stage was filled with people waiting for the lights to come back on - they were sitting in total darkness with no cap lamps. My little light kept finding them and I had to keep myself from getting a fright each time I saw eyes looking back at me. Very creepy.

The darkness underground makes you appreciate a sunny day. But, when a power failure at home suddenly makes it pitch black, I get a twitch and an underground flashback :-).