We've been for another look now that the snow has gone. More debris appears to have come down since January.
In summary, there has been a spectacular mud and rubble avalanche on one side of the large shakehole resulting in a large diseased tree being uprooted on the one side causing it to topple over into the adjacent field. In the process it demolished the fence by the wooden gate providing the usual access to the cave at the lowest point of the shakehole on top of which some of this avalanche has come to rest.
We weren't in caving gear, as the photo shows, but a large amount of sticky mud and debris was nevertheless moved aside to reveal the scaff frame thus giving us a sideways view towards the top of the shaft which had been (and still is) roofed over with a sheet of corrugated iron and consequently is mud free. We then covered over the square frame with material to hand. It needs a robust lid made of closely spaced scaff bars that can simply be lifted off when cave access is required, and probably I'll see to fitting that, and this will better protect access when there are further surface movements.
The next caving group needs to bring a bucket and short rope to remove say 15 buckets of sticky mud from the ledge immediately under the square opening so this material doesn't fall any deeper before anyone ventures into the shaft proper. But I don't think there will be any more than nuisance amounts of debris in or at the bottom of that, so it should be quick to regain access to the passages of interest.
