Post date: Aug 23, 2010 7:04:07 PM
Cavers: Les, Aileen, Al
Having caught an ear infection from the static duck in Creevy Cave the previous day the diving plans for Blackburn were put on hold and Les and Aileen were free to enjoy their first trip to the cave unencumbered by wetsuits and diving equipment. Instead i brought a crowbar so that we could take a look at the choke blocking access to the main downstream section of the cave.
The trip through the cave was uneventful and as enjoyable as ever, although that enjoyment is tempered somewhat by the unpleasant cobble floor one has to crawl over in places. There was a little more water flowing into the cave than previously, and i also noted that our hydrological engineering of the previous year was holding up well and now diverting all the water further down the passage - the sump here was dry but it is completely choked.
Reaching the boulder choke i took a look at it, but nothing had moved since Artur and i had dug it last summer. There were two possible ways to dig - squeezing vertically over the first big boulder through a tight z-bend into a small chamber and then hopefully continuing upwards; or, squeezing horizontally between the boulder and the right-hand wall. Les decided the latter was the most favourable, and started digging. The crowbar could be used as a poking stick and then hook to safely dislodge and remove the boulders behind. We each took a turn, and soon we had passed from mostly boulders and some gravel to a mostly gravel section, which was quickly scooped out (a kibble would have helped here). It became apparent that the left wall was as steep and unstable gravel slope, with a small gap between it and the right wall (or ceiling). As a long term solution some shoring along this side would be necessary, or the next flood will bring it down, if a digger doesn't. We proceeded with caution, and eventually began digging mostly in boulders again. The old branch that Artur and i had used was redeployed to give some more distance from falling rocks, however i had a close escape when one rolled down the slope to where my head had been a second before. After about an hour and a half digging we had made good progress of about 2.5 to 3 metres. We think from the stratified nature of the choke and the fact that we are now digging in boulders again that the choke is not that big; in the latter stages of digging more organic flood debris was also apparent among the boulders, possibly washed upstream from the waterfall during a flood. It is possible to hear the waterfall faintly beyond the choke.
Al