Opal Mining Newsletter July-31, 2005 on Mining Underground for Opals in Coober Pedy

July 31, 2005

Opal Mining Update - No 51

Tunnel Machine is cutting well, now Blower problems

Looks like I have found why the teeth got messed up on that sprocket, as you know (if you have been with us from the start) when I did this machine up I went right through it as far as I could without pulling it completely apart and that chain box if you can cast your memory back was full of dirt and the seal was completely stuffed through old age and standing out in the weather for a long time, anyway I cleaned it all up and replaced all the bearings and ordered a new chain and fitted it and at that time there was no damage to any of the sprockets.

But when I put it all back together again the chain did stick in places as I turned it around, I thought at the time that because it was new and the gears may not have been lined up precisely due to some of the welding that the guy who built it had done, so I put the cover plate on and finished the job, now I have had this new gear come and it was right and wrong, right because it had 9 teeth but wrong because it was too thin by 1.5 mm. (60 thousands of an inch)

Now I have found out that there are English and American chains and also in the gears/sprockets, so when I asked Ross to order me a new length of chain, he of course ordered the American one which is the normal one we use here and as it turns out I had the English chain and sprockets, so the difference is that the chain width the links were not wide enough by 1.5 mm and not enough clearance for when it is running and so the chain has been catching on the sides of the teeth since day one, so I got caught out again.

Like I said it is a learning curve this game so many things here are built different ways with different parts, some people don't like spending money and use what ever is lying around even if it is second hand, I don't think that happened here with this machine, but is was built down in Adelaide by a engineer and then sent up here, that is why it has never been set up properly, had it been built here it probably had the American parts in it.

I have got a new length of the right chain coming along with another gear, Tuesday or Wednesday it should be here then I have to machine this sprocket out to suit a bearing before I can take it underground and then I have clean the box and gears before I can replace the parts and put the front plate on again, put some oil in and we are ready to go again.

So a couple more days of tickling up the machine and I will be ready for the new parts should they be ready by then and I have yet to still get a drill and I am chomping at the bit to see how I go with the machine on the level and in dry ground, looks like I may have to do another drive or finish one on the bottom level until I get this next shaft drilled, may even get 2 shafts drilled if it is going to hard to get a drill when I want one, all I have to do is work out in which area I will want go with the machine when I have finished working out the area around this next shaft.

It will be around 60 foot out, if it was not for the wet ground on the bottom level I would drill all shafts 90 foot apart, but it is hard to pull the wet or damp ground that far as the last drive I was in was 74 foot out and that was far enough, so 60 foot is just about right as I have to go past the shaft by the length of the machine which is 8 feet so to be able open up the area around the shaft for turning the machine in when starting new drives.

Here I have removed the old piece of runner that has a big piece missing from it on the corner, I had glued a piece on here if you remember but it finally got knocked off, so this was a good time to replace it properly, that's the new piece below in yellow.

Here is the job done, all bolted in, now as soon as I have the new gear and chain I have to clean the other side of this as this is the box that has the chain etc in it and it is still all dirty with the old oil that has run all over the place, still have to sharpen the teeth yet.

All the teeth have been sharpened and are ready to go, I am getting 2 shafts drilled on Thursday (tomorrow) and as of yesterday the new parts have not arrived so I am hoping that they arrive today for me and that I can finish the job off while the shafts are being drilled above.

Well you could have bet that something would go wrong now I have found a drill at last, it rained, yep hardly rains here at all and just when I need to go out on the field to drill shafts it rains, rained all day on and off mostly on but not heavy, lots of water around the town by the end off the day so no drilling today day and the drill is out at 11 mile parked and waiting for me to show them where to put the shafts, have to wait now and see if it stops tonight and if we can get out within the next day or 2, but they have forecast rain for tomorrow as well so we will just have to wait and see how things turn out.

Today the sun was up and I got a phone call at 8 am to be on the field by 8:30 to 8:45, I told them that I might get bogged with my little truck tires if it had rained a lot out there and that they might have to pull me through, but I just managed to get through on the road which is always bad after it has rained, as you can see below I did not have much traction left and was sliding all over the place.

The mud was even being squeezed out from between the rims, this is why when it rains here I do not go out on the field for at least a day after it has stopped raining to let things dry out a bit and as I was approaching the 11 mile field I thought I was running into a rain shower as that is what it looked like but turns out it was fog, could not see more that about 200 feet in any direction at that time.

Here the boys (Brothers) are setting up to drill the first shaft which went down with no problems as there was very few Jasper rocks below and close to the surface, I did not go underground while these was being done as I had to be there just in case they drilled anything up, I did want this shaft to stop at 75 feet so they did not cut the bottom level, but it ended up at 77 feet, but to my surprise they drilled up some trace from the 64 foot level and as you can see it is very foggy and but should burn off later.

This is the trace, 2 bits of green and some gray seam opal with color, not real good stuff but it is opal and with some color and the best part is that it is just in front of me below, the shaft should be around 3 foot or there abouts in front of the drive I am doing right now and the level in the face does not show anything at the moment but I am not far from a fault in front of me that I figger goes down to 72 feet so I should cut that soon, not sure when I will be opening up around this shaft so I can move the blower on it, but I will check again to see if the fault is within the next 12 feet in front of the shaft.

Here they are setting up on the seconded shaft to be drilled, the first shaft as marked is in front here and there is another shaft on the right here that I did not drill, but was done by somebody about 3 or 4 years ago when I pulled the pegs on the old claim, I will be also using this shaft in the near future as I mine for opal through out this area.

Here is what the drill looks like from the front and you can just see the small white dump behind the 4x4 which the shaft they have just drilled, here they are setting up for the seconded and this is just in front of a slide/fault to the left, which the main one where I am, there are more to the left and right of me, but I have a patch of virgin ground that has not been touched in the past because I think there was not enough activity in the ground with the wires showing slips and slides with the old time miners, us new ones have some different ideas and the only way to prove it is to tunnel it out and see which is what I am doing, slowly.

From this angle you can see where the blower is and there is a small dump right behind the bucket, this is the spare shaft I did not drill but will use and this shaft is being drilled is 65 feet from it and that shaft is 96 feet from the blower, so that makes this shaft some 161 feet out from the blower, so by the time I get to here I will have done a lot of work below on 2 levels and the slide/fault is about 20 feet to the left of photo, by the time I get here I will have to get another 2 or 3 shafts drilled to continue tunneling, but it will be a network of tunnels/drives below by then.

They drilled up these skin shells from the seconded shaft at the 75 foot level and it turns out that there is 2 levels down, don't know how far apart so one is what we call a squibby level (false level) wont know until I get there with the machine, no point in going down to check as it wont make any difference to me as I will still be driving to it with the machine in the future, but nice to know that the level is producing material and that there could opal around there somewhere.

Went back to work the next day after the shafts had been drilled and set up to go down but when I tried to use the winch there was no power, after checking a few things out I found that there was no power coming from the generator, so I could not go down and work, very frustrating as I wanted to get the machine finished today now I have the new chain and sprocket, I could have gone down using the petrol generator but I would have been only able to put the chain in, so I came home and went to see my friend Boro and ask him if he could come out and find out what the problem was, who would have thought I would get a breakdown on top of a breakdown.

When I have worked the last time (3 days before) I had no problems or indications that anything was wrong, in fact if it had broke down like this I would have had to climb the ladders to get out, then start the petrol generator to operate the winch and bring the seat up, oh well the electrics for you, never know when they will play up.

I got my friend Boro to come out and check what went wrong on the generator, turns out that a UDL circuit switch for the 240 volt power on the generator had packed it in, Boro had a couple of new spare ones back home, so he sold me one and I will put it on tomorrow.

Put the new UDL circuit switch on but still had a problem with it cutting out, turns out that I have 3 240 volt cables connected together down the shaft and water had got into where 2 cables are plugged together and was causing it to short out, fixed it by pulling all 2 leads up and running a 25 meter long one down the shaft so that will not happen again, will have to put a new socket on the generator and by pass this UDL circuit switch so I can just run the winch off it, so no matter what happens I can use the winch to get out of the shaft.

I have dropped the 500 watt light (twice) that is taken off the 3 phase (240 volt) that is on the machine and that trips out the 3 phase UDL circuit switch up top and I have to go up and turn it back on and I may drop a the other 500 watt light that runs off the lead that I have down the shaft and when it breaks the globe it could trip this switch out, don't want that to happen or I will have to climb the ladders to get out, hence the new switch socket on the generator.

Well we got going again and here we are back in action, I am just starting to break into the shaft in front of me here, the level or what I think is the level at this point is just in line with the tops of the 2 pick heads, I had gone only 2 foot 10 1/2 inches before I started to break into it, I said that it would be around the 3 foot mark so I was almost spot on, have to blame the driller for being out that 1.5 inches.

This is my new partner John, (76 years young) he cannot work by himself any more because of his health and they are some things that he cant do like drilling above his head, pulling dirt etc, so I asked him if he would like to work with me for a while and he said yes so today was his first day and I did appreciate him being there this morning helping to carry the pipes up the drive and set them all up again and now I have this tunnel machine we don't have to work that physically hard anymore, only now and again so we get plenty of rest leaning on the machine between putting a new pipe on, looking forward to the partnership and finding some opal to share with him.

Here I have stopped working and switched the blower off while I went up to put the tape measure down the shaft so we could see where we was regarding the 64 level and to my surprise I am 3 feet to high, the level is 1 foot below the floor, not that I picked up on that as I was doing the drive, all I saw in the wall was alanite and not much else but the level or what I thought was the level is to low anyway.

I was going to bring the machine back a bit anyway and take the floor down to bring this level up above the cutting head so I could see all of it in the face and right now that is about 2 foot low anyway so the real level is not that far from it and also this so called level is dropping in front of us so it may also up with the 64 foot level, anyway I have brought the machine back ready for tomorrows work and will take the floor down at least 3 feet, then when I am about 10 to 12 foot past the shaft I will bring the machine back and start opening up the surrounding area so I can move the blower on to this shaft and start driving and looking for opal.

This is the shaft we have connected to and John is down checking where the level is and if there is anything in it and also if there is anything else around that area that we should know about, so when any of you guys who are reading this feel down and tired of work, just remember this man at 76 and you may feel a bit better, you are never to old for anything, not here anyway

Here is John finished checking, he was down that long I was getting worried, I did have a peak over the side and can watch him at work but have to very careful that I do not disturb anything around the top of the shaft while he is down there, if a rock became loose and fell down it would cause him damage, so we stay away for the shaft while someone is down working for safety, you can see the blower in the background and from shaft to shaft it is 86 feet.

Here we are taking the floor down so we will end up about 4 feet deeper, you can see some dirt in the bottom of the shaft, this I had to put down with the front end loader to make sure that the hole was filled, I was not sure that the dirt from the tunnel machine as it was cutting would have filled the hole so the machine could travel over it, now I do was lucky though that I put down just the right amount or would have been if I did not have to go a bit deeper.

Now I have gone in a few feet and after slowly changed the angle as I went I am over the top and have started to take the machine down a bit more as I did not start far enough back down the drive when I started and so the pipes are sticking up in the air here and this can cause a problem so we have to keep our eye on the telescope as it gets caught as the tunnel machine pulls it forward and pulls the pipe out from the one behind it, loosing vacuum so I have to stop and connect them back up again, this has happened a few times already, wont be so bad after we put the next small pipe on and move forward.

Now we are over the hump and have just put the new pipe on, you can see the plastic pipe that I use for wet ground as a elbow ( or corner as we call them ) but comes in handy for this type of work for a short time, the pipe still has some elevation to it so I have to pull the telescope out a bit so I can move forward without any problems and when this has straightened out I will pull it out a bit more and so on until I don't need to do it anymore, now I have to drive some 12 feet past the shaft then I can start to open up to give me room so I can turn the machine around and start driving for a shaft in another direction and look for opal, John is just putting the light back on the wall.

Here I am just starting to open up, have started going in on the right side and now I am started on the left side, trying to see how wide I have to go to leave enough room to turn the machine around under the shaft, looks like I will have to go a bit wider yet, we have to jackpick in side of the drive on the floor so I can turn the machine a bit and start cutting into the side wall, it is a slow process as I can only take a small bite at first as the teeth have to cut sideways into the wall and the top of the cutting head starts to catch and then the head will jamb and I have to back off, just thinking may have to use the jackpick on this as well in future to make it easier on the machine.

I have gone a bit wider on the right side and on the left and am not far from finished opening up, this is the end of a days shift for me and will finish it tomorrow, looks like I have not gone wide enough this time will know for sure when I have finished and we are not on the level for sure, I think I was on it before and now that is one foot up in the roof.

Looks like my partner got it all wrong with the level and it could be that he did not understand me, when I said that the level is around the 64 foot mark, I think he must have thought that I said that it is at 64 foot and when he went down to check the shaft and as I had put the tape measure down to 64 feet he told me that I had to go down in the floor one foot, so a misunderstanding, now he knows that this is not the level at all.

So what I have to do now to get out of trouble is when I start this next new drive is to go up 2 foot in the first 15 foot I go forward and as I am driving to an old claim that has very little work done to it, a couple of small drives if I remember right as it is a few years since I was down having a look and there was some material around and there is some in the dump up top, so when I get there I will know for sure if I am right about the level and where it is then I will be alright for the working the rest of the ground around at this level, but if there is any opal right above me now I will not get it unless I want to take the roof down after I have finished all of the drives and I will only do that if I strike any opal in the immediate area as I start prospecting again.

Well here is the machine turned around ready for starting work, after we have done a small repair and greased it up again, there is not much room here and it was a bit of a squeeze in getting the machine in this position and I have just enough room to connect the plastic elbow on the back, but at least I can get a start but I am not pointed in the right direction, the machine needs to be turned around in the direction of the arrow or very close to it, so I have to do a bit of opening up in front of me so I can make more room for turning the machine around for the other drives that will be done from this shaft.

We have pulled the pipes and moved the blower onto the pad next to the new shaft but as I was checking it for being level (the blower) John looked up the pipe that goes to the hopper and saw a hole up there, now I know why I started to have trouble pulling the dirt I had started to loose vacuum, so I put the hand-winch that needed to be repaired on the back of the blower (I hang it on hooks) and we brought the blower back into to town and parked it outside my house until Monday when I can take it down to Ross's for repairs.

Got the blower into Ross's and started to pull things apart, as I was going to check the fan for wear, now I will pull it out as it has been 2 years since I last had it out so it must have some wear on it and now is the time to fix it, I also have a hole in the top of the fan housing that needs to have a patch put on it and when I do this I also weld inside to build up the area that has worn out to give longer life and for this I have to take the fan out anyway.

Now I have got the fan out and it has some very bad wear on it, lots of holes in the blades in fact, well past its time to be repaired and I would have also been loosing some vacuum or I should say not creating some vacuum through this wear, I will only be able to repair it this once as after this I will have to have a new one built, so if I am lucky it will last for 4 months or more.

Here is the fan on the bench ready for being welded, the blade you see here is one of 16 and the worst, most of them have holes in them where the dust has worn through and all have some wear on them that need to be welded, this I can do but Ross will have to balance it for me, this needs experience so it is his job.

This is the hole that has appeared in the top of the fan housing and is some 2 inches long, it has been getting bigger for a sometime, but I did not bother about it as it does not affect the vacuum, this is caused again by the dust that goes through the fan as it pushes the air out through the air outlet (chimmey) on the right, the fan has already created the suction and this is the waste air along with the dust that is being got rid off, so this hole was not that important to get fixed straight away, but as more have appeared its time to fix all.

This is the cover that bolts on the fan housing and connects to the 12 inch pipe that comes from the top of the hopper, this rim below almost touches the fan when it is running but does not affect the fan creating the vacuum needed to pull the dirt from underground, the holes again are made by dust in the air flow which is broken by the corner of the fan housing where the air outlet is creating a vortex, (whirling mass of air) I have to put 3 patches here and the one on the bottom left the patch will be put on the outside and I will have to do a bit of building up with weld here as it has started to scallop it out where the shinny path is so needs to be strengthened, wont take that long to fix.

I have now welded the fan cover above and when I welded the small outside patch on the hole on the bottom left the cover in that area buckled somewhat, so I will now have to wait until the fan is finished on the bench so I can take it in and straighten it out again with the help of the oxy torch, always something.

Here you can see we have put the MIG welding equipment up on the roof with the forklift, Ross is just checking out what is needed in the way of patch sizes and how many, then we will take the oxy torch up there, just the leads, so it can be used to help bend the patches into shape as needed, I will also be up there to assist Ross when he needs to have something passed to him.

This is number 2 patch that is being put on here and there will be another one just above this one and the bottom of it will overlap this one to give it more strength for the future punishment it will get, hopefully it will last a few more years before it has to be repaired again like this.

This is the badly rusted out part, did not know it was this bad until I got up and had a look here, Ross as hit it a few times with a hammer so it looks worse than it did when I first saw it, still plenty of strong material around it so patching it up is not going to be a problem, just Ross reaching it is a worry, so I will bring in my ladders form home for him to use so he can get up anther 2 foot higher to do the job.

This is the first patch which Ross can reach quite easily on his small stand, but the next one will be to the right of this and higher up as you can see above, this is the one he will have to use my ladders for and there is also a weld that has cracked on the top of the hopper, I will have to move the position of the blower for him to reach this one.

This is the last weld to be done on the hopper and it is all finished, the hopper that is, then it is my job to do the rest, I did not have the experience to do the hopper but the fan housing is up to me, so that is my next job, then the fan can be put back in and after I have straightened the fan housing cover, I can also put that back on and connect the pipe up to the hopper and all is done there, until next time.

I have bought (or will have) a second hand metal pipe like the ones you can see above some 6.6 feet in length, this is to replace the one that got stolen from me year before last when I was on holidays along with the elbow, (the short pipe in the photo below) this elbow has also to be replaced and that is to be made early next week, then I will be ready to take the blower back out to the field.

Once I am back on the field I will set the blower up on the new shaft and connect the pipes together down the shaft ready for starting work again with the tunnel machine, but before I can start work with it I have to replace a side rubber at the front of the tracks that ripped off, no big deal just the 3 gutter bolts that broke and that is done.

Then I have to grease the machine (6 nipples) as I must do after every drive, make a small adjustment to the cutting head and pull the pipes up from the last drive and place them at the top of the drive ready for use, then I can continue opening up in this other direction so I can align the machine correctly for the drive to the next shaft.

This next shaft is an old one from the early 1970's, it is an old claim that has not done a lot of work, just a couple of small drives, I was down a few years ago and they is or was some material in the wall here and there, I did pick a lot of it out then but did not chase anything or do any work and there is another just about 18 feet away that is not connected to this shaft but also has done a couple of small drives, this one is from the early 1960's and is a square shaft and has timber around the top and was worked with what they call a "York Hoist".

This York Hoist was a winch that was set up by placing a long solid bar or pole vertical in the ground and then they would place the winch set up over this bar and then anchor this bar with cables to the ground, much like a radio antenna and then this winch was run by a petrol engine, like what is on our petrol generators, this winch then would run a bucket up and down the shaft, the miners would have been a company of at least 3 men, one up the top to run the winch and empty the bucket an the other two below doing the mining and filling the bucket, then they would change over every so often.

Anyway I have to check it out in this direction to see if there is anything around and not just here there is plenty of ground to have a look at, a lot of the old miners missed out on finding some opal because they did not chase too far when they sunk shafts by hand, if they were not on opal straight away, the norm was whatever they went down in depth they would drive that distance underground having a look, could have been one drive but from what I have seen was to make 2 smaller ones about 30 foot in length and if they found nothing they would quit, as it used to take at least 2 weeks to put a shaft down by hand to a depth of 70 feet.

Hope you have enjoyed this issue and look forward to the next one, hopefully I will have some good photos to show you in the next issue, of opal with color of course, I am hoping that this will be a good year for us, but only time will tell, so stay with us over the next few months and find out what goes on in our part of the world. But normally it Patricia Until the next issue.........

Stay Tuned for the next Issue, who knows what I will have to report.

Until the next issue.........

and wish me lots of LUCK.

Cya Later, Stuart Bird.

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