Saturday 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 hillside, 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 / Divemaster) 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!
Jeff from the nearby Copper mine's 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 1800Ős, and was very helpful with his huge knowledge of the mine systems. The deep level mine had ceased working in 1892 and
had taken 5 years to fill up with water when the pumps grounded 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, Brian and I carried
the equipment into the mine over two days in six 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 twinset 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.
"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..."
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 waterfall through the solid rock above and 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 is 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.
The topside cover could watch my progress on the six foot square black water virtual "TV" screen in front of them. I would pull the line periodically to
indicate my progress. At 150m and seven minutes into the dive the next big restriction came into view, and 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 nine minutes another pile of timbers stopped my
progress and I worked carefully to remove them, but 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 of a Suunto Navy 80 which was working fine and an Abyss HID light, which
proved less than watertight at 130m.
At this point I did a kit and self check. I was down to 170 bar and two 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, and 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 two 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 minutes descent time, but I could afford another seven minutes 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 and 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 minutes in and 70 bars left.
I checked my isolator valveÉmaybe 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.
The next stops trickled along, but by 130m my back gas tanks equalized 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 I needed to use 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.
