Okay, okay it's not a total collapse.  Just a sizeable block had fallen out of the roof in the washed out shale band between the first and second pitches and settled like Damocles Sword above the second pitch.  A little jiggling got it safely down the second pitch where it made a mess and blocked the descending crawl (since unblocked).  Two more blocks lying in the shale band, so take care peeps.

Interestingly, despite the dry weather recently, the water levels didn't seem particularly low (I only went as far as the 6th pitch).  And even the fixed rigging didn't appear to have been used since my last visit a year ago, the crawl below the dig shoring didn't need any excavation.  :-\

Ian.