Tue 23rd Feb 2016
Duncan Price, Sarah Payne, Duncan Simey
Surveying the mine
Duncan P offered to survey the mine for us.
He took GPS readings of the shaft entrance, and our best estimate of where Tankard Hole entrance was located and aims to combine them on a single survey.
He's used the Tankard Hole survey provided by mrodoc to create a 3D representation in his survey software, so we should be able to tell which way we need to go and how close we are.
All excellent news and we are all waiting with eager anticipation for his findings.
It will also be interesting to hear where Duncan P thinks our mine fits on his Brown Trouser scale.
He had a small wall of stacked deads collapse on his shoulders, and if it hadn't been for a natural arch in the wall preventing a major collapse we'd have probably abandoned surveying at that point.
Discussion in the Hunters indicates this is a long way from being the most scary place he has explored, but it's not 'that' stable either. I think he described it as 'interesting'.
Part of the problem is that this isn't virgin cave which he has a good feel for; things are only as stable as the miners bothered leaving them, and things that appear stable may not be.
Sarah helped with the surveying while Duncan S ferreted around with the can of smoke trying to make some sense of the draught.
Despite rising air pressure from an approaching high pressure system, there was noticeable air movement in the mine. The usual suspects were still draughting well, but the shock discovery was a hole Duncan had previously discounted which had the strongest draught of the night. The big pile of stacked deads in the furthest chamber has a sort of ramp running up the back that curves around from the chamber via a natural arch, the draught was from the entry to this curved ramp. At this point we have no idea where the draught is coming from, but it looks like the miners didn't stack the deads right up to the back wall for a reason. This definitely needs investigation!
The other puzzle is that we still don't know where the draught goes to. Very little of it is blowing up the shaft.
The other activity Duncan S performed was to dig out one end of the double ended rift feature we are now calling Crystal Rift. This is the draughting rift in which Sarah had spotted a large slab of crystals during our previous session.
With access now available, Sarah recovered the slab of crystals. The main slab is still at the bottom of the Pit, but she brought out a chunk about the size of two house bricks which we proudly displayed in the Hunters to much Ooooo-ing and Ahhhh-ing. It's a vein of Calcite crystals several inches thick and looks beautiful.
We also have good samples of the soft yellow rock littering the mine, and the even softer burnt orange rock found in occasional corners. The soft orange rock is quite heavy; maybe it is Iron?
On the previous trip we removed the cap from the Pit in the furthest chamber, this photo is looking straight down the Pit. Sarah is perched on a ledge less than half way down keeping out the way of Duncan P surveying at the bottom. You can see his Peli case in this shot, it's about 3m from the opening into the Pit.
Another view into the Pit. Sarah is looking at the far wall which isn't stable and must not be touched.
A close up of Duncan P writing his survey notes at the bottom of the Pit.
Regardless of what Duncan P's survey shows, the next phases are as follows....
1) Dig out the bottom of the shaft. The mud is horrendous and the squeeze through the mud will make working beyond the shaft problematic. It should be straight forward to sort this out!
2) Remove a good chunk of the debris cone in the first chamber. This is debris from Hole 1 and we are wondering if it is covering another way on; we still don't know how the draught is leaving the mine (it's not by the shaft). It will also make the first chamber a more pleasant place to be
3) Stabilise the stacked deads Duncan P demonstrated are not as stable as we had thought. This is important as they hang over the Well (one end of Crystal Rift) and are (were!) the obvious step up into the way on to the far chamber and the Pit (the other end of Crystal Rift). All our draughting leads rely on this wall being stable!
The above steps ought to keep us busy for quite a few sessions, during which we need to monitor the draught to see what other surprises it reveals and to help decide where to attack next.
