WHERE THE CAVES ARE - The Caving Regions > Portland

Persil gets longer (well a bit)

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tim.rose2:
The return to caving on Portland...

Persil rift, discovered in the early 1980's is a short but sporting rift which previously ended at a 'flowstone blockage with a view beyond'.  It was proposed to be the continuation of Grand Canyon in Ariel Cave and hence has potential to provide a back door to Portland's best cave.  I first visited this site around 15 years ago and although at the time I had zero interest in digging, decided it was a good idea to return with a hammer and chisel.  After about 10 min effort and no progress I then confirmed digging really wasn't my thing and gave up.  The others with me had even less enthusiasm.  In the preceding years I occasionally mentioned the place to others on Mendip who likely digging but nobody seemed to bite and take the job on.  I can't say I regularly visited the cave in the preceding years but probably racked up 10 or so visits as people either wanted 'a short trip somewhere different' or some ladder practice on the 8 m pitch.  Having decided digging wasn't so bad after all, and taken on a couple of projects on Portland I though it best to have a look at the end of Persil again.  Sometime last summer a group of 5 of us headed into Persil, climbed up and down the flowstone many times (the rift is around 10 m high at the former end) and eventually decided on attempting to break through at floor level.  An hour later we decided the flowstone was in fact steel reinforced high strength concrete impregnated with granite and gave up.

Following the easing of lockdown, myself and Mike agreed to meet on Portland for a digging trip and we both thought Persil would be the ideal place as there's loads of room at the end (vertically) and essentially only one person can work at a time so a great choice for a group of 2.  We'd been talking about a return but never got around to it.  Equipped with a selection of chisels, hammers, plug and feathers and the drill we set to.  Taking turns to 'beat the crap' out of the flowstone, eventually after around 3 hours the first bit succumbed to our abuse.  Fortunately the next couple of sections gave way easier and after a further hour taking in turns to abuse the cave we managed to wriggle through.

Mike set off first and had the pleasure of being the first to explore around 20 m of sizeable (for Portland) rift which was extremely well decorated.  At the far end we quickly and minimally scrapped out a tube we could both just about fit through to find a small terminal chamber with the route ahead thoroughly blocked with mud and flowstone.

We returned a few days later with Gaynam to enlarge the route we'd dug past the flowstone, enlarge the tube to the end and also to start digging at the terminal chamber.  Again this worked ideally as we had 3 locations and 3 people.  The enlargement work proved successful, however the end looks like a long term project.

Naturally we needed to know whether the extension lies anywhere near Grand Canyon and hence one further trip to survey the cave was undertake.  The good news is that we've halved the distance between the two caves and Persil is heading straight in the right direction.  The bad news is that there's still around 20 m to go.  Now bear in mind the 'view beyond' at the end of Persil had been known for 40 years and nobody had done anything about it during that time.  Furthermore, I'm guessing the cave probably sees at most 1 group a year - what's the chances of coming out after surveying the discovery to find another caver equipped with digging kit to 'have a go at the flowstone end!'.  That was certainly a surreal moment.  Pity really, if we'd been a couple of weeks later we'd have been saved the effort.

I've not yet finished drawing up the survey, but there are photos (many photos)...

I'll start with the former end of the cave:



Which is now looks like this (I've pretty much settled on the unconventional feet and arse shots rather than faces!):



And then onto the pretties around the corner...



















And in true Portland style every new piece of cave has a dodgy boulder:



The tube to the final chamber:



Pretties in the final chamber:





And apparently there's no formations on Portland!  Well they are there, just hidden.  One thing I've always admired with the formation on the island is the breath of colours.  There's very little white stal but a quite amazing range of orange, yellow and reds.  Just out of interest, can anyone shed light on the greys?  There's more nearby in Ariel but otherwise seems to be limited to that part of the island.

PeteHall:
Good write-up and good pictures! Thanks for sharing  :thumbsup:

Mike mentioned this place the other week and pretty much convinced me that I ought to make the journey down to Portland some time :)

tim.rose2:
You'd be very welcome.  Plenty of places to find more cave, just need some enthusiastic folk!

Ed W:
Excellent result Tim!  I also tried to enlarge this back in the 90s, but like you came to the conclusion it was armour plated!  Dom Sealy did manage to get through the initial flowstone constriction (he was REALLY good with squeezes) but no further.

Another bit of the jigsaw comes into place, and another entrance to Blacknor a definite possiblity.

tim.rose2:
Not sure I'm going to believe anyone who tries to tell me stal is delicate anymore.  Nothing which takes 3 hours of more or less continuous hammering to get it to crack through having been initially drilled and partially split with plug and feathers is delicate in my mind.

Well here's a bit more of the jigsaw...

I've plotted the centre line data for mine and Mike's survey of Persil in blue on google earth and then sketched an overlay of the useful part of Ariel Cave in Red / Pink based on Mike Reads excellent survey.  The phreatic tunnels are red and the rifts pink.  The rift in Ariel which Persil appears to be heading straight towards is Grand Canyon.



I've also updated the Portland website with further photo's and description:
https://sites.google.com/view/the-caves-of-portland/persil-rift

For those who follow my ramblings and interested, mine and Richard's 'end of Steve's' dig aims to join the rift in the bottom left corner of the picture above.  I dream of the 'in Persil out of Steve's' trip. 

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