A few weeks ago, some loose cobbles were reported to CNCC at the base of the Lancaster Hole entrance pipe. We immediately issued a warning on our website and via social media channels.
We have since (30th October) received the following update from a volunteer team who went to investigate:
Yesterday whilst on a trip down Lancaster Hole myself and a friend saw the loose cobbles mentioned by the CNCC recently, they where immediately at the base of the concrete tube and had previously been cemented in place but appeared to have slumped, upon closer inspection we noticed a very large amount of infill behind the cobbles that was not at all stable and was only held in place by good fortune, it included a very large boulder that was 100kg+, we trundled what we could whilst their (one kick was all it took) and abandoned our trip as we didn’t fancy getting underneath it all.
We returned tonight and dealt with the big boulder which is now in pieces at the bottom of the pitch.
We have cleaned up as best we can but there is still a large amount of infill (probably used to backfill around the tube) that could be an issue if it became loose.
Cavers should remain aware and vigilant if going down Lancaster Hole… I don’t think that digging more of it out is the answer as where do you stop? There is quite a lot of it.
Our Chairperson has invited those involved in installing the current entrance pipe several years ago (who will have a more in-depth understanding of what lies behind/underneath it) to have a look and see if it is something they can help with or provide additional suggestions. Of course, the CNCC will provide whatever input we can.
For now, anyone descending Lancaster Hole, must do so with extreme caution and check for anything loose under the pipe that may fall during a descent. If the situation presents an unacceptable hazard, do not descend whatsoever and report your observations to us.
If you do decide to descend, we suggest ensuring each individual is fully clear of the entire shaft (i.e. positioned well away from the bottom, along the passage towards Bridge Hall) before the next person even comes down the pipe from the surface.
In particular, any groups visiting with novices should be particularly aware; It may be sensible to put a Lancaster Hole trip on pause and instead enjoying one of the many excellent other 'simple SRT' potholes in the area until the situation has improved.
Keep an eye on our website, social media channels or the current UKCaving thread for further updates.
Update 15th November 2022:
We are pleased to say that a RRCPC team have been to have a look at the situation at Lancaster Hole.
The conclusion is that a little work below and behind the current entrance pipe is needed because the fill (mud, cobbles, gravel etc) has deteriorated and will continue to do so. Therefore, matters are only likely to get worse unless the void is dealt with and stabilised soon.
There is still a risk of material coming loose from here, so continued caution is needed. A decision to descend should be made following careful inspection and use of your own judgement as to whether it is in a safe enough state.
A reminder of this has been attached to the lid for now for anyone who does not follow CNCC social media.
The CNCC has offered to fund any materials needed for this work, and we will keep you informed. Thanks to the RRCPC volunteers for taking this on and keeping us informed.