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Copper Mine Dive

 

Mark crosses rain swollen river leading to mine shaftSaturday 26 Oct 2002, the date for my latest sortie into Coniston Copper Mine. This would be dive five in the mine, planned dive depth 237m. At this depth the original copper ore work face would join the main shaft, according to the mines original plans.  The four previous dives were carried out to obtain video footage and feel more comfortable with the 309m deep, 2m square shaft with its 9’c water temp and pitch black darkness. Finding buddies who would assist in diving the mine was almost as tricky as the dives themselves. The deep shaft is 300m back in a hill side, you have to cross a river to get to it, its totally without light and freezing cold ! (oh yeah and has frequent rock falls in places)  Christina Uwins (Medical student / Dive master) and Brian Gilgeous (commercial dive company owner who helped lift Donald Campbell's  BlueBird) were ideal for the job. Both had dived the mines before, both were experienced with technical diving, and decompression medicine and even better, both were free that weekend!

                       

Layout of Coniston Copper Mine  Jeff from the nearby RUSKIN museum, was a mine (free pun) of useful information. As the museum’s custodian he had access to articles and plans going back to the mid 1800’s, and was very helpful with his huge knowledge of the mine systems. The deep level mine had ceased work in the 1892 and had taken 5 years to fill up with water when the pumps ground to a halt. The hair raising stories of the copper mine workers 150 years back would send shivers down anyone’s spines.

  The weather that weekend was wet and windy; the mine entrance can only be reached by crossing a rain swollen river. Christina and Brian and I carried the equipment into the mine over 2 days in 6 hour shifts ! Carrying twin 20 litre tanks over rapids takes a lot of care.  When all the kit was in place, the deco tanks staged on lines, we exited the mine to relax and suit up before the dive.

  Dive tanks were a 20 litre  twin set of Trimix 5/76 bottom mix,  stage tanks of Trimix 14/50 and Trimix 20/30.  Brian would descend to 60m supply backup 20/30 and remove the used 14/50. Christina would descend to 40m with Nitrox 32 and 36. At 21m  a 20 litre stage tank of Nitrox 50 was pre staged together with a 7 litre of Nitrox 50. The 20 litre tank was to be used during in water recompression if the need arose. At 6m we staged a 12 litre twinset of oxygen with long hoses to reach the 3m 2m and 1m stops. Attached to the big twinset was the argon suit inflation, and battery packs for Otter Electric Suit Heater system and Abyss HID lighting. While kitting up a backup light fell into the void…never to be seen again.

  With the kit checks done, I slipped into the black water, the rain pouring like a water fall through the solid rock above, the visibility was nil near the surface. Descending through the darkness, I dropped to the first restriction at 30m. At various levels, the shaft has tunnels that join it where the copper ore vein was more closely followed. At 33m I placed my weights into one of these “crosscut tunnels”, as I didn’t need additional weight below this depth. I clipped my strobe at the cave entrance. Dropping down to 54m on trimix 20/30, I passed the next restriction and swapped directly to Trimix 5/76 bottom mix. It was very easy to breath so I turned in the resistance screw on the second stages and checked all venturi levers were set to the minus position to avoid free flows. I signalled back to the surface with 2 pulls for OK on the descent line.

Artist's sketch of pit entrance. Train tracks take ore out. Water drawn out from Pump 90metres up   The topside cover could watch my progress on the 6 foot square black water virtual “TV” screen in front of them. I would pull the line periodically to indicate my progress. At 150m and 7 minutes into the dive the next big restriction came into view, it was a solid staging platform covered in debris. I carefully started to remove the timbers and pile them up on one side so I could get past. At 160m and 9 minutes another pile of timbers stopped my progress and I worked carefully to remove them, the visibility was bad. I noticed a glow below me and was very surprised to see my lost TEC 40 divelight sitting back from the main shaft, glowing brightly. My primary light consisted a Suunto Navy 80 which was working fine and an Abyss HID light, which proved less than water tight at 130m. At this point I did a kit and self check. I was down to 170 bar and 2 Q40 headlights had gone to sleep, my head mounted chem lights had also split from the pressure and were all leaking green alien blood !  I checked my twin UK SL6’s and SL4 backup lights, they still worked fine. I felt no HPNS symptoms, only a dull ache in the spine area.

  I picked up the lost TEC 40 light and dropped further. The wooden floors were coming far more often than in the shallower areas, the next one just 7m lower at 168m.  This staging consisted of 2 solid diagonal timbers which each bisected the shaft. Large timbers lay loosely on top. I removed these.  Dropping through the gap I’d made caused my twin set to get wedged on something. I tried to pull back up but my side mounts were now below the level and I was stuck. Visibility was almost nil,  I shut my eyes to relax.   Alarm bells started ringing in the back of my mind. I was pretty much trapped. It was time to leave at 12 mins descent time, but I could afford another 7 min’s at this depth before the deco plan using the RGBM algorithm would be compromised.

  I tried to free myself upwards, but could manage nothing.  Concern flicked across my mind, I looked at my back gas contents gauge, it showed 100 bars. I slumped down and found my back tanks free but only going downwards. I dropped below the restriction, down to 170m now 17 min’s in and 70 bar left. I checked my isolator valve…maybe it was off, but no luck there.  I looked up at the underneath of the floor , looking for a way through. I moved across the shaft,  and put my hand up and started to fin up, the loose timbers lifted and with a big effort I was through.  The plan called for 147m by 20 mins. I got there almost on time and started the deep 30 second stops. My mind slowed down. The 15 metre END helped enormously.

Christina checks her twinset  The next stops trickled along, but, by 130m my back gas tanks equalised with the surrounding pressure, and would not supply gas. I turned on my left stage tank of Trimix 14/50. For some reason it free flowed violently, I put it in my mouth. Taking a breath I turned the tank off. This tank was to be used at 90m and shallower, but needs must so I used it.  With all the excitement I forgot about the next restriction near 120m. It wasn’t much of a restriction, taken on the correct side, but I ascended into the wrong side and was wedged in to the cross timber.

  On this mix, my equivalent narcosis value was 60m ish.  I had a stop here for a minute and used the time to signal to the surface I was trapped at 120m with twelve pulls of the rope. I got a response asking if I was OK.  I wasn’t, and definitely needed support diver Brian to descend earlier than planned, bringing the spare gas. There was no rope signal for this, so It didn’t happen. Id asked Brian and Christina not to attempt giving assistance below 60m, because of the restriction dangers at this depth.

  Dumping the gas from my wing and suit, I got free and headed up. With the free flowing reg still going it didn’t last as long as it should and by 100m the tank stopped breathing. I closed it and switched to my trimix 20/30. Every few breaths I would swap to my back gas to average out the high p02. All the stops over 30 secs were reduced to 30 secs, to reduce gas consumption, also, the planned max depth wasn’t reached.  By the time I reached 60m I was ahead of schedule by almost 10 minutes, Brian wouldn’t be coming for a while. It left me breathing whatever was left during the stops. At 60m I settled on top of the restriction here. I dumped all my wing gas and replaced it with exhaled trimix 20/30, this might be useful…soon !

  Brian showed up by the time I got to 40m.  I ascended up with him still breathing my 20/30 and Bottom left we see deep cut tunnel entrance (mine entrance). On hill top we see chimney of pump houseback gas till 21metres. The first tank on a rope appeared at 21m it was nitrox 50.  This stop at 21m I increased from 6 minutes to 40 minutes, an ounce of prevention here could save some trouble later on. During this stop Brian went up and Christina came down with some more nitrox 50. The rest of the stops went to schedule. The warm drinks she brought down with her were very welcome.

  At 6 metres  I moved onto oxygen for 30 minutes,  then 4 metres for 20 minutes and 3 metres for a further 30 minutes, every 15 minutes I would have an air break for 5 minutes. I chose back gas switching here but this was a mistake because of the really hypoxic trimix 5/76, after less than a minute of breathing this, I felt my brain and vision shutting down, so it was quickly back to the oxygen (note to self…only normoxic mixes for back switching). For the further air breaks I used some trimix 20/30 (the theories behind this, attempt to prevent Pulmonary related decompression problems and not simply buffer the CNS clock). A further ten minutes at 2m and ten minutes at 1m served to relax my bodies gas tissue tensions further, a useful technique id used before when forced to deco on back gas etc.

  After all this extra deco, I felt confident that the bends were not coming. With all the extra deco stops, it meant close on 240 minutes in the cold water. I was still warm and dry, my Otter dry suit worked perfectly. I had spoken with Otter a couple of weeks before and they mentioned a new Artic 300 under suit. I got one of these and was very pleased I did.  My support divers had “mere mortal” under suits and felt the cold pretty much throughout.

Blown up image of Old engine shaft.  Using the RGBM algorithm on this dive was totally in order (Ive since changed my mind on RGBM nonsense!), but in a low gas situation would be easy to compromise. The RGBM deep stops necessary to allow shorter shallower stops are mandatory. To have missed out any of the deep stops would radically increase the decompression schedule. When carrying out any Accelerated decompression profile such as this it is necessary to have a back up “traditional” profile and make provisions for the extra breathing gas that would be needed. While I’m a believer of helium being very much easier to off gas than nitrogen, I feel that proving myself wrong means the bends, hence the increased 21m stop time to offset the decompressing between 40m and 21m on incorrect gases.

In the past I have unknowingly tested algorithms on myself, but see no reason to do this now or in the future, (because im not getting paid for it and its total madness!) , unless in the relative safety of a research chamber. The way software providers offer products to customers to test on them selves is, in my opinion, criminal. 

Readers with a Central Nervous System Oxygen Toxicity calculator would see that my “CNS” loadings from this profile were over 200%.  Measures were in place to deal with the possible side effects. Minimally, I believe, all technical divers should abstain from any “diet” products for at least a month, be they drinks or foods. Artificial sweeteners / E numbers are known to be massive CNS exciters.

  Technical dives should be attempted by people on a “level playing field “. Divers should be fit, regularly doing aerobic exercise. They should avoid cigarettes /alcohol for months before a deeper dive and have no history of drug abuse.  If a technical diver benefits from diet fizzy drinks then they should exercise until they don’t!

  I would still like to explore this mine shaft deeper, but any further deep dives will need several clean up dives in the 170m range. The reasons for doing these deep dives are mostly for the exploration and adventure.  Another reason is to improve my teaching ability as a Trimix instructor trainer, how any instructor can teach without doing it themselves baffles me. The experience and knowledge gained from these dives is invaluable.

  I would like to thank Christina and Brian for their help and time. Also thanks to the International Technical Diving Association (www.ITDAHQ.com) at Fort William, Scotland for the donation of all the diving gases. Thanks to Kent Engineering for the supply of the super stainless exploration reels used, finally Otter dry suit’s for the loan of the electric suit heater system and thermal advice.

  Contact Mark@inspired-training.com

 

Donating Ingot to Jeff at Ruskin Museum  Here I am Donating a 60kg Copper Ingot to Jeff at Ruskin's Copper mine Museum. The Ingot lifted from a ship wreck called the Jean Marie (locally called "The Copper Wreck". The Copper Ore from Coniston was often shipped to France for processing into Ingots and then shipped back to the UK. The Jean Marie was sunk by U-boat UC-18 (WW 1). This U-boat lies in 60metres depth, west of Jersey, about 20 nm west of the Copper Wreck.

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