Upper Gallery-Cohesion Sump-Toadstool Aven - Phil Wolstenholme

Present: Phil Wolstenholme, Dominika Wróblewska

This trip was all about doing some new stuff - we've all noticed how fantastic the slabs in the Upper Gallery beyond Mucky Ducks sound when you walk on them - big clonking crockery-type sounds, interspersed with really deep booming ones and tiny clatters on top. So we decided to do something about it - Dominika brought in a digital sound recorder with a couple of mics, which fitted perfectly in my Peli drill case for the Wallows and Mucky Ducks. Once past these watery obstacles, we got to work recording a huge variety of noises from the slabs - my favourite is a huge chunk in a 'diamond' shape that pivots in the middle, despite it probably weighing 300kg. You can easily rock it and move it around, and the variety of sounds it makes is incredible - like a tunable log-drum, or a giant bizarre marimba.

Incidentally, such things exist - the US composer Harry Partch, about 60 years ago, decided that the conventional 12-tone musical scale beloved by western music was rather boring, so he invented a 43-tone scale to use instead. Naturally, no instruments existed for this scale, so he had to build all those too, many of them percussion instruments. The music was very strange, but strangely endearing, and many of the sounds he produced are very reminiscent of the Upper Gallery slabs. We also manage to capture some great dripping sounds, walking over gravel, through puddles, etc. So she now has a huge library of very high-quality noises to begin the 'Peak Percussion Opus' - or something. Edgard Varèse was also very fond of percussion composition, but I digress...

Once satisfied, we made our way into Pickering's Passage - our recent trip into Moss Chamber had reminded me that I hadn't yet seen Cohesion Sump or Toadstool Aven, and with the only obstacle being Cohesion Crawl (how hard can it be?), we went for it. On a plain crawling trip, with no baggage, it's a reasonably entertaining and slightly gymnastic crawl. With a large bag stuffed with very inflexible Peli cases, it's not so much fun, and there was a lot of grunting whilst we hoofed it round corners and unsnagged it from rocks - the two diagonal squeezes in the middle proved to be particularly irritating. I can't imagine the entertainment dragging diving cylinders through this. But eventually all passages must come to an end, and we flopped out above Cohesion Sump, looking very dark and mysterious as it plunged down into murky green water, on this day about 3m below overspill level.

We took some photos and then decided to 'have a quick look' at the Toadstool Aven situation before committing to taking the camera kit up. We knew there were a few rocks to get over, but had no idea they would be that big, or that many, and by the time we'd got past them all, we'd lost 15 minutes, and I'd also lost the enthusiasm for going back down to drag the bag up again! So we topped it out and then obviously found the magnificent flowstone humps, bumps and slopes that gave the aven its name. Absolutely beautiful, and I was already regretting leaving the bag behind, though in reality it would have slowed us down even more. Dominika immediately got sketching while I scanned the aven with all my lights on. The roof is clearly not solid, being composed of boulders, mud and gravel cemented in place with flowstone - it's gorgeous and terrifying in equal measure - I can only wonder what's above it, and at what point the giant boulders fell in - it must have been before the flowstone formed but long after the aven itself, as they're all fairly sharp-edged, whilst the cavern walls are smooth. Incidentally, the very gnarly and rather unsafe rope-loops provided for climbing over the big slab could be improved upon, so that's another Peak job to add to the list!

On the way down, we popped into the very large and very pretty side-passage, and followed it to its conclusion - an enormous ramp of flowstone blocking the way on, and a very puny and futile attempt at banging through this with snappers was only too apparent, especially as 100m of rusty bang-wire has (somewhat predictably) been left behind. We didn't have any spare bag space, or we would have brought this out, but if anyone else goes in soon, it's there. I did pull a bit out of Anniversary Aven too last time, but there's still more in there that needs bagging-up. All this done, we slithered back through the boulder choke and set off back down the passage, now made slightly easier by the downhill slope (never really noticed it was uphill on the way in, but it explains why it was so miserable). We didn't really struggle after that and made it out well before our allotted time to have a chat with TPot and Irene. Another very good trip.