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Copper
Mine Dive
 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 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!
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.
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.
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
 back
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.
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
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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