Are we talking about the same shaft, the one in clay chamber? IIRC its only 3 meters deep, then an awkward slither a couple of meters to the letterbox with a drop down into a mined passage a few meters long before popping out into Streamway Chamber?The ladders are shot, got couple of metres down before running away. Might be ok with an electron or SRT.
There was a fixed metal ladder I think.
John Taylor was the diver inserted into the downstream sump, on 9th October 2011.
Nickergrove Streamway was regained on 10th May 2011, we called on JSB with the news afterwards. I seem to remember picking up a speeding ticket on the way home that night.