The Cheddar Caving Club was responsible for creating the link between Bath Swallet and Rod’s Pot (after work by other clubs) creating an entertaining through trip on Burrington Combe, in the Mendip Hills, Somerset. The next logical step was to attempt to link Rod’s Pot with its neighbour the opposite side; Drunkard’s Hole.
http://www.mcra.org.uk/registry/sitedetails.php?id=45
http://www.mcra.org.uk/registry/sitedetails.php?id=5
http://www.mcra.org.uk/registry/sitedetails.php?id=10
I was involved in the dig for a while in Rod’s Pot starting at the bottom of what was known as the ‘Blind Pots’. This progressed horizontally for a short while before a route was excavated vertically upwards to enter a small chamber. From here further digging occurred in the upwards direction.
At a similar time myself and my regular caving partner began re-examining a few areas of interest in Drunkard’s Hole, a short section of passage was found after climbing up an ever tightening aven and a dig was started here feeling that we were heading right for our dig in Rod’s Pot.
Whilst we thought we were heading in the right direction it is hard to know for sure. I purchased a Disto x310 and the conversion kit which allows accurate and fast cave surveying to be performed. The goal was to establish the distance between the two digs in the cave to motivate us to further our efforts (after all we had dug an estimated 120 m of passage in Rod’s Pot and the gap between the two caves was thought to be about 80 m in a straight line).
Arriving early before each digging session I set myself the task of surveying between both entrances on the surface so that the data collected in both caves could be accurately linked. Lengths of PVC pipe stuck into the ground were used to clear the vegetation acting temporary survey stations.
The process was completed three times to check the accuracy of the work; misclosure between the traverses was within 0.2 m in the horizontal plane and within 0.3 m in the vertical plane.
Now the task of surveying from both cave entrances to the dig faces was all that was required, this took a few trips in both caves to achieve and was a good excuse to escape the physical work of digging, bagging, dragging and stacking of mud in its various forms.
A no frills approach to the survey was taken meaning that only centre line data was recorded to speed up the process in what are difficult size and shaped passages to accurately survey.
The results were suprising, both ends of both digs in Rod’s Pot and Drunkards Hole were still separated by over 50 m horizontally despite over 120 m of passage having been dug from solid mud fill.
Not long after the surveying was completed we retired to the Crown Inn at Churchill for the final time and focused efforts elsewhere thwarted by the complex geology of the Mendip Hills.