Story 11. The Sudden Demise of Lake Turnbull

Lake Turnbull.

Allan Turnbull approached me one morning after we had a huge rain storm overnight.

There is now a bloody huge lake directly in front of my bloody ore body we are going to fire and "I don't want it ending up in the bloody water can you get rid of it before we let the bloody shot off"? he asked.

I put Allan's job on my growing list, one job was to move some of the overburden that lay spread over the access road to the same ore shot that had been fired the previous day effectively preventing all vehicle access to the lake.

Two hours before the shot was due the lake still remained untouched, this had been caused by other problems delaying me gaining access to the area.
Allan approached, expressing some concern regarding the possibility of the water ruining his bloody ore.

Knowing there was no way I would be able to do anything to remove the water until I had access I was in a bit of a bind.

In the powder magazine we had a large roll of sheet explosive about a meter wide and four meters long and around 15-20mm thick, this had been kept in storage for years and was simply taking up space in our storage, it was once used to shock harden the crusher jaws.

Taking to it with a panel saw It cut it into 20 or so 50mm wide four meter long strips. These long strips were unrolled and after folding a corner and placing an instantaneous detonator inside the folds, it was then laid out under water and held down with a rock or two on the bottom of the shallow lake, a delay was then wired with two lines into the ore shot, the second line ran direct from the initiation point with a matching delay in case there was a fault or break in the line of the original initiating underwater shot caused by a wayward rock breaking the line.

The idea was to detonate the shot in the lake 250milli seconds prior to the ore body going off.
Hopefully it would be enough to enable the water to be thrown clear before the ore body landed in it.

Blast time was scheduled to coincide with lunch time and with all the equipment clearing the pit we made final preparations for the blast.

With the pit cleared sirens and flags up we were making the last check that the pit was safe to fire the two shots.

As the safety vehicle passed my observation spot on its way out of the pit thus indicating all was ready, I waved my hard hat to indicate to the shot firer inside the safety bunker located inside the pit it was safe to now fire the shot.
Allen walked up to stand along side, instantly noticing the large untouched lake still directly in front of his precious ore body.

I thought you were going to get rid of that bloody water he said slightly louder then necessary to make his concern felt.

I noticed the shot firer had acknowledged my waving hat by waving his back and had disappeared inside his bunker.

Watch carefully I informed Allen.
A second or two later the lake suddenly erupted instantly became hidden in a cloud of steam, the ore body then went off and the entire view became hidden in an expanding cloud of steam and dust that quickly filled the pit.

We stood in silence, waiting for the visibility to clear.

Finally the dust moved on, the ore body appeared dry, the lake had vanished, the entire pit seemed fresh and clean as water ran down haul roads and dripped off the pit walls.
Allen turned to me and smiled, Good work, exactly what I would have done, he said as he walked off.