if you just want to see how deep the shaft is, would a simple laser ruler do the trick?
Try the M24 or M24S but either way important to get quality batts like panasonic 3100/3400 mAh etc. Any XML grunter needs good high rating batts for good runtimes.
If you want even more throw get an M24 and send it to someone here on the forum to be dedomed. This will boost the stock M24s 82k lux to about 170k - all the distance you’ll ever need.
Tested two dedomed Maxtochs couple of nights ago. They really lit up the lux meter. M24 dedomed was 179k lux, and 2X dedomed read a cracking 256k lux. That’s serious throw……
How much more is the draw of the 2X vs the M24? I’m seriously considering one of those for dedoming.
Can’t remember offhand but I think it was:
M24 = 3 amps, 82kcd, 62mm head
M24S = 3.5 amps, 90-95 kcd, 62mm head
2X = 4 amps, 120kcd, 68mm head
I think…… If you want to mod a 2X there is a very god mod thread here somewhere. Tom E and others had lots of them over 350kcd.
I second that, Maxtoch SN6X 2X is for you, and it is not that much bigger than the M24S considering you are not going to mount it on a rifle, right?
If you want to have a neutral tint to deal with all the dust - dedome it to have more neutral tint and basically double the lux number. 
Definitely neutral white at least! Cool white tints don’t render colors very well.
I think the standard Maxtochs mentioned are actually a neutral white - certainly not cool white - no bluish tint.
Maxtochs rock. I recommend them. Either of the two mentioned would handle your tasks easily. For the money, can’t ask for better.
Mtnelectronics has it if you want aUS source.
http://www.mtnelectronics.com/opencart/index.php?route=product/product&path=80&product_id=365
I went ahead and ordered a MAXTOCH 2X. I’m looking forward to seeing how it works. It should be a massive upgrade in throw compared to the TR-J12. I’m using Panasonic 3,400mAh batteries so I’m good to go there.
As for the laser question, we do use a Disto laser rangefinder for depths. We need the light to ascertain the conditions in the shaft before we rappel down.
Thanks for all the feedback!
Can’t wait so see pics!! 
Wow!! That mtnelectronics price is very good for a Maxtoch M24. $62.50” !!!
Mtnelectronics gives a helluva description for the Maxtochs:
“A while ago, I began searching for a light to bridge the fit and finish gap between the so-called ”budget lights” and the much more expensive lights; with Maxtoch, I found what I was looking for! These lights don’t just bridge the gap—they close it entirely! I consider the overall construction of these lights to be as good, or better, than any of the more expensive lights I’ve ever seen. The fit, finish, and presentation of these lights is top notch, with AR lenses, copper MCPCBs, great reflectors, nearly flawless HA anodizing and machining, and XM-L2 U2 LEDs from the factory. These lights look the part as well as they play the part. These are truly premium lights.”
Bang for the buck…
If you want something really inexpensive to see down dark shafts, the Jacob A60 might be worth a look. Typically about $10 to $14, and IIRC it comes stock with like 60kcd of throw. It won’t wow anyone with lumens, but its narrow hotspot can shine a long way without a lot of spill up close to make the pupils contract.
I wonder how long or deep these mines are in general?
These mines are good places for taking beamshots, I hope you will post some beamshots taking in there and that would be quite unique! 
+1 and modded goes 200kcd :)
The shaft in the first picture is 900’ deep.
The 2X will put out alot less flood/lumens than the TR-J12, but its single emitter beam will travel quite a bit further. If you want more distance, ask one of the US guys to dedome it for you - then it becomes an exceptional thrower with round 1000m range in the right conditions. Costs nothing - just the price of post.
The 2X is overkill for this mine then! J)
Okay, I ordered a Jacob A60 too just for giggles. Kinda hard to pass up for $15.
The MaxToch M24 is right here in the US for a great price: mtnelectronics.com-M24. Richard (RMM) owns/runs it and is a BLF'er like the rest of us. Typical shipping is 2 days. He's got cells, chargers, etc. if you need them. Can't go wrong with this light or the vendor. I have the 2X and the M12, both older models, but both heavily modded. The M24 had many of my mods built-in now to the production model, directly from mudgripz, my, and other BLFer's suggestions.
You can use the rated kcd and throw distances specs as a reference, but not directly as it relates to lighting up a long shaft. 100 kcd is 632 meters, but that equates to 1/4 lux of light (moonlight level) at 632 meters. To get a 100 kcd rated light to light up an object at 1 lux means it's at a distance of 316 meters. So you would need close to 100 kcd to give the bottom of a 900 foot shaft 1 lux of light, that's assuming little interference in the air of course.
I see you ordered the M24 already and a A60 - both good choices. I would think you got the M24 by now if you ordered it from MtnElectronics - let us know what you think 
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The standard LED in the M24 is cool white, probably 1A, 1B, or 1C. The A60 is even a cooler white. Neutrals do have their advantages, but either light would have to be modded to get that.