Thunder Shaft!
- Thread starter zomjon
- Start date
crickleymal
New member
That's a cracking name for our toilet.
AR
Well-known member
Without having the relevant PDMHS bulleting to hand, I think it was recorded as somewhere in the 150' region, going to either water or a load of gungy toadstone clay dependant on weather conditions with nothing going off it. I don't recall seeing anything to rig off at the top but it's a while since I was last in there.
History Trog
Member
The reference to the article about this level (properly called Bonsall Leys No. 2 Level) is:
Flindall, R.B., and Hayes, A.J., 1971. The Adit Workings on the North Side of the Via Gellia. P.D.M.H.S. Bull. Vol. 4 Pt.6 pp429-450.
I wrote that article and have recently been compiling a report on the history of mining in that area.
The 150 feet deep turn (called by the spar miner Cyril Maddocks in the 1950s the Thunder Shaft) was on Flixen Rake but it was always blind (even when it was first sunk) and there is nothing to be discovered really in the level at all. I wrongly stated in the article that the raises no doubt went in stages up through the toadstone to the surface but they would be blocked by collapse. In fact, the raises lead only into short trial levels just below the toadstone.
The only air flow in this long level seems to be that originating from a three inch wide open rift in the right wall of the level about 15 feet before the final forefield. The sound of falling water can be heard faintly in the distance (or at least it could in the 1970s), which is surprising because the overlying toadstone keeps all that strata very dry. There must be some sort of fault to allow the water to penetrate. There is a moderate airflow into the rift in summer. I cannot understand why the miners did not investigate this as it could lead to some sort of vein or cave. This point is about 250 feet below the surface of Bonsall Leys.
Flindall, R.B., and Hayes, A.J., 1971. The Adit Workings on the North Side of the Via Gellia. P.D.M.H.S. Bull. Vol. 4 Pt.6 pp429-450.
I wrote that article and have recently been compiling a report on the history of mining in that area.
The 150 feet deep turn (called by the spar miner Cyril Maddocks in the 1950s the Thunder Shaft) was on Flixen Rake but it was always blind (even when it was first sunk) and there is nothing to be discovered really in the level at all. I wrongly stated in the article that the raises no doubt went in stages up through the toadstone to the surface but they would be blocked by collapse. In fact, the raises lead only into short trial levels just below the toadstone.
The only air flow in this long level seems to be that originating from a three inch wide open rift in the right wall of the level about 15 feet before the final forefield. The sound of falling water can be heard faintly in the distance (or at least it could in the 1970s), which is surprising because the overlying toadstone keeps all that strata very dry. There must be some sort of fault to allow the water to penetrate. There is a moderate airflow into the rift in summer. I cannot understand why the miners did not investigate this as it could lead to some sort of vein or cave. This point is about 250 feet below the surface of Bonsall Leys.
History Trog
Member
I only noticed the noise of the water because I was by myself on one visit. It may only be a slight trickle of water. I did look in the roadside entrance in the Via Gellia (Bonsall Leys No. 1 Level) to judge if that could be the exit point for the spring but could not detect any airflow associated with the water. I am not an expert on hydrogeology.
There may have been an old shaft at that point through the toadstone on Parsons Rake (the vein followed in the last part of Bonsall Leys No. 2 Level), which may have let the water through the toadstone.
I should have made it clear in my earlier posting that there were old (18th century) shafts from the surface intersected by the No. 2 Level at the end of the entrance crosscut and also near the Thunder Shaft but they are so thoroughly blocked somewhere that there is hardly any airflow from them. There were also several raises made from No. 2 Level to test the veins just below the toadstone but none amounts to very much.
There may have been an old shaft at that point through the toadstone on Parsons Rake (the vein followed in the last part of Bonsall Leys No. 2 Level), which may have let the water through the toadstone.
I should have made it clear in my earlier posting that there were old (18th century) shafts from the surface intersected by the No. 2 Level at the end of the entrance crosscut and also near the Thunder Shaft but they are so thoroughly blocked somewhere that there is hardly any airflow from them. There were also several raises made from No. 2 Level to test the veins just below the toadstone but none amounts to very much.