• Hello From Descent

    The publication date for issue 289 is the 10th of December, meaning subscribers should receive their copies during the week leading up to that date. It is also available from caving suppliers such as Inglesport and Starless River, or from our new website

    New Descent board here:

Huge 'sinkhole' emerges in Bexleyheath

Cantclimbtom

Active member
Yea if it connected to others it would certainly need massive amounts of vibrators to get into all the pockets , main issue I think they would face would be not being able to go inside ! In the ideal world you would enter and build walls and do it in sections and then sort of shim pack the very top like you do when under pinning.

Even with a lot of plasticiser and vibration, you may find that some chambers the roof is higher than the bottom of the entrance shaft, so you might leave unfilled pockets

RoofCrumble_small.jpg


This pic shows a smaller chamber with its roof a fair bit above the highest point of the entrance shaft connection which is about 2 foot above the camera lens and for perspective about the same height as the top of the arch in the background.
Also it illustrates how 🤬 unstable these things are. Yes that big mound of rubble in foreground used to be the roof. I wasn't feeling all warm and happy taking that pic! Don't sneeze too hard 🤧
 

sjt

New member
I think a bell pit is exactly that, a bottle/bell shape hole. Shouldn't be too hard to fill just drop some hard setting slurry down it.

But the distinctive feature of Dene holes (although there are several designs/variations) are that it's a shaft and at the bottom then there are chambers laid out radiating from the shaft a bit like a double clover leaf shape. In some cases connecting to other Dene holes accidentally, or in case of Thurrock intentionally (don't know if that is original construction or more modern digging?). That would be much harder to fill without leaving voids.

Nowadays the open ones are gradually filled in. People seem to find them irresistible to throw dog waste bags over the fence. How public spirited of them :(
There's an inscription next to one of the cut-throughs saying it was done in 1884, but whether that's authentic I don't know
 

Cantclimbtom

Active member
There's an inscription next to one of the cut-throughs saying it was done in 1884, but whether that's authentic I don't know
Thank You! somehow I missed that, I think I was getting jittery from the pitter patter of "rain" (sand and pebbles) in the shaft area which I take as a very bad omen underground. I wonder if the stacked block "sculpture" is the same age. Thanks for the 1884 tip - when you know what to search for it is much easier to find things. I'd say that date is very likely genuine.
Which tunnel is that engraved by (I have a mind to go back some time, so no worries if you don't remember). There was a sudden flurry of exploration, both learned and best of all... mischievous, in the 1880s. I'm grateful to the diggers because the air was safe (meter) but a bit of LEL kicked up (methane?) at times, I'd rather not explore places if H2S, CO2, CH4 are being spicy so a bit of airflow is always good in my book ;)

EXCURSION TO THE DENEHOLES OF HANGMAN'S
WOOD, NEAR GRAYS THURROCK, ESSEX.
(In connection 7uitk tlte Essex Field Ctub.)
IITH AND 12TH AUGUST, 1893.
Directors:-T. V. HOLMES, F.G.S., AND W. COLE, HON. SEC.,
E.F.C.
(Report by T. V. HOLMES.)

<previous text removed> "...The Essex Naturalist for January and February,
1888. It is gratifying to be able to state that Prof. T. G. Bonney,
in acknowledging the receipt of a copy of the Denehole Report,
remarked that he thought our conclusion that the Hangman's
Wood pits had been originally used mainly as granaries a very
probable one; adding that subterranean granaries resembling
them existed in Syria.
It was a matter of considerable interest to the Directors to
note the changes that had taken place since the conclusion of
the exploration in 1887. For their tunnels had allowed currents
of air to pass through many pits previously closed and stagnant.
No appreciable change for the worse, however, seemed to have
been caused by the ventilating currents, though much harm had
resulted from the mischievous stupidity of unauthorised persons
who had visited the pits..."
 

Cantclimbtom

Active member
There's already a lot of dene holes around this area. We found a large one in joydens wood. It was fenced off with a tall metal fence and we would have been interested to take a deeper look but it was full of dog poo bags 🤮
Just on the off chance I pass the area on my travels in the next few months, can you give any rough description of whereabouts that fence was? Did you get a good look from inside the fence and it's definitely not explorable... Or is it still worth a look?
 

sjt

New member
Thank You! somehow I missed that, I think I was getting jittery from the pitter patter of "rain" (sand and pebbles) in the shaft area which I take as a very bad omen underground. I wonder if the stacked block "sculpture" is the same age. Thanks for the 1884 tip - when you know what to search for it is much easier to find things. I'd say that date is very likely genuine.
Which tunnel is that engraved by (I have a mind to go back some time, so no worries if you don't remember). There was a sudden flurry of exploration, both learned and best of all... mischievous, in the 1880s. I'm grateful to the diggers because the air was safe (meter) but a bit of LEL kicked up (methane?) at times, I'd rather not explore places if H2S, CO2, CH4 are being spicy so a bit of airflow is always good in my book ;)

I can't remember exactly which one, it's on the main route between the 2 shafts afaik, but easily missed if you're not looking out for it.
Funny you say that about the gas, I was sure I had a little flare up when testing in one of the chambers which had a load of rotting timbers in the bottom, but thought nothing of it at the time.
 

Attachments

  • 20220831_124307.jpg
    20220831_124307.jpg
    206 KB · Views: 27

Keris82

Member
Just on the off chance I pass the area on my travels in the next few months, can you give any rough description of whereabouts that fence was? Did you get a good look from inside the fence and it's definitely not explorable... Or is it still worth a look?
I can't remember exactly where it was, it was quite a while ago. It's a tall metal fence near a footpath. You could jump it if you don't mind dodging all the poo bags!
 

NigelG

Member
I don't know the area and consensus strongly suggests a collapsed denehole.

If though it is natural, Graigwen points to a possible cause - the chalk.

This is subject to dissolution forming "pipes" - roughly vertical shafts usually tapering downwards; into which overlying sediments can eventually collapse. Left to themselves they gradually settle into being conical depressions of, usually, quite modest dimensions.

The heathland of East Dorset holds a huge number of these, mainly just small dolines; though one near Bere Regis, and called Culpepper's Dish, is a steep-sided cone some 15-20m deep and over that in top diameter.
 
Top