Thrupe Lane Swallet

Has anyone got any news regarding an update on how things are going with Thrupe after it was closed dues too flooding etc?

I had a look on the CSCC web site, but could find nothing on there mentioned since last year.

Cheers
Tim

 
Thanks Cap'n ...much appreciated.
Wish I was closer to help!......I may be over again in the next few weeks (during the week), if so, I'll give a shout out if help is still needed.

How much work has got to be done, do you know?

Tim
 

cap n chris

Well-known member
ATLAS are the people to contact! (I just heard about it today as had volunteered to assist if diary allows, which it sadly doesn't this week).
 

Maj

Active member
Ah, update, yes!
Not much to say at the moment, except that the Thrupe stream has temporarily been diverted to leave the entrance of Thrupe Lane Swallet dry. A temporary stemple has been installed in the adit above the entrance shaft to which we will attach a pulley for hauling up bags etc. So Wed evening, about six of the ATLAS team are going to start clearing out washed in stream debris etc. We will concentrate on the Ferret Run and below, this Wednesday, probably leaving the assault on Bamboo Aven area (down the Railway Series) for another day since that is far less stream dependant. A couple more hands could be useful on Wed evening. PM me if interested in assisting.

Maj.
 
Hi Maj,

Many thanks for the update on the situation.

We come on over to Mendip pretty regular, so, when I am next on my way, I will PM you before hand and see if I can be of any help.
As I live in West Wales, it's a bit tricky for this week, but I'll check with "she, Who must be obeyed!" as to when we are due over next.

Thanks again for the update

Tim

 

Thrupeman

New member
There seems to have been a bit of a lack of up to date info on whether Thrupe Lane Swallet has been re-opened or not. I'm happy to report its open for business once again!

The clearing operation on Wed 17th Sept resulted in several bags of washed-in debris, comprising mostly of logs and branches being hauled up to the surface from the start of the Ferret Run.

The bottom of  Perseverance Pot was found to have silted up causing the connection through to Slit Pot to be more constricted.

Cowsh Crawl had also silted up and was a duck about 2ft -3ft deep with about 1ft of air space. Some initial work has been done here to lower the water level by excavating the floor on the far side but a lack of suitable digging tools on the night resulted in only a few inches drop in the water level.

Most of the flood stream appears to have flowed down Bridge Rift & Avalanche Pot - this hasn't been checked as yet.

Its assumed that the cave beyond Butts Chamber has not been adversely affected by the flood.

The Railway Series and Plaster Passage, near the cave entrance, had obviously taken a big stream and was well scoured out and washed clean.  As a result the 'Sand Crawl' before Bamboo Aven was completely choked with sand and much effort was expended in bagging up as much as possible and hauling it to the surface.  Much sand remains, although the way is now open and its a case of pushing through as before.

The route into High Atlas via Chimney Pot was not checked but was assumed to be open as the flood had flowed across Bleak Hall and on down the Old Wells Road. This was completely blocked at approx 1/3 of the way down thus losing the further reaches of the OWR and the Bone Aven extension.

At the time of writing most of the Thrupe stream has been diverted into the Hobnail Hole dig area resulting in a completely dry TLS entrance shaft for a change.  Some water has now started flowing along to TLS as well but is sinking earlier along the cliff face leaving the entrance shaft still dry.

Enjoy!

Clive
 
Thanks for the update Clive, it's much appreciated

Unfortunately, My wife's ill health has dictated that we haven't been over to Mendip recently, so I  haven't been able to offer my assisitance.

To you and all the team involved, a huge well done and a big thank you to you all  :bow:  :beer: :clap: Without cavers like yourselves, where would we all be!
A Brilliant job well done too.

Thrupe is one of my Favourite trips on Mendip, so am glad it's back open for business

Many thanks guy's and Gals <;-0)

Tim
 

Thrupeman

New member
Thanks for the kind comments Tim....

Since writing that TLS is open again, we have been at work in Hobnail Hole close by.  The recent rains have caused the stream to rise appreciably so much so that that our work underground in Hobnail would have been under a waterfall!  So, we have dammed off the route the stream was taking into Hobnail and returned it to its normal flow to the TLS entrance area.

This is only a temporary dam and would easily be removed by a party wanting to go down TLS but it would, of course, mean damming and diverting the full Thrupe stream back into Hobnail which would be a bigger job.

So at the moment its a very wet descent of the lower part of the TLS entrance shaft again.....

We have now broken up and removed the large boulders which had fallen from the cliff-face into the streambed by the TLS entrance.  Furgling with a long bar caused the whole stream to dive underground at this point but that was only temporary.  This didn't seem to affect the flow of falling water into the TLS shaft though.

More news as and when!

All best

Clive
 
Great little vids Maj....

Certainly looks slightly interesting on the entrance eh!

That must have been pretty awkward to clear with that flow of water to deal with!

Great work peeps

Tim
 

Maj

Active member
Thrupe Lane Swallet update.

ATLAS are still currently digging Hobnail Hole therefore the Thrupe stream is still entering Thrupe Lane Swallet. Since the stream level is very low, although a little showery the Ferret and Perseverance Pot are passable at present without the need to divert the stream.

Over the last couple of years the stream has deposited a large quantity of gravel and cobbles on the far side of Cowsh Crawl, turning what used to be a damp muddy crawl into a duck with barely enough space to keep your head above water.
On Friday 12th June three members of ATLAS/MNRC descended Thrupe Lane Swallet and cleared a large quantity of gravel etc. from beyond Cowsh Crawl to increase the air space. Two large boulders weighing in at a guesstimated total of 2 tons that had allowed the gravel bank to build up were also moved. Cowsh Crawl, although it will remain as a Duck in all but drought conditions, is unlikely to develop into a sump which was a possibility before if left unchecked.

Most of the gravel, cobbles and rocks shifted were either stashed just beyond or washed down Bridge Rift. There will however be some gravel and possibly the odd cobble that didn't quite make the descent, but still intends to. A few flood pulses should help them on their way. In the mean time care should be taken if planning to descend Bridge Rift and Avalanche Pot.



Maj.

 

Maj

Active member
The situation in Thrupe Lane Swallet remains pretty much the same. In winter and during wet weather there is quite a large stream flowing down the entrance shaft making it impassable. But at present there is a small stream flowing down. It is probably passable but this will depend upon the stream flow and the weather conditions at the time and how wet you're prepared to get.

The ATLAS diggers are still currently digging Hobnail Hole each week during the day, usually Fri or Sat, but occasionally Thurs or Sun. The Thrupe stream can be diverted down Hobnail Hole, but we would first ask if you could let the ATLAS diggers know. There are a number of active ATLAS members spread across the Mendip clubs, so it shouldn't be difficult to contact one of us. If we know in advance we may be able to divert the stream for you before an intended trip. It only take 5-10 mins to divert the stream and again to divert it back after your trip. 

Under no circumstances should the stream be diverted down Hobnail Hole if the Hobnail Hole gate is open. Hobnail Hole can easily be seen as you cross the stile in the dry stone wall between the layby and copse. It is a horizontal grill on the opposite bank of the stream, with the sole of a hobnail boot attached to the tree that over hangs the entrance :).

The work we carried out to Cowsh Crawl in June last year has worked well. On a recent trip the duck had been reduced to a 150mm deep puddle, although its depth may fluctuate it should not now sump and is unlikely to reach a depth of 300mm even with a large stream flowing down the entrance shaft and on down
Perseverance Pot.

Maj.
 

Maj

Active member
Last night (Monday 23rd May) three member of ATLAS descended the entrance of Thrupe Lane Swallet after first diverting the stream down Hobnail Hole. The team headed off down Plaster Passage into the Railway Series. Note that the remains of the old wooden tramway mentioned in MU5 no longer exist due to have been washed out by the various floods in recent years.

As expected the sand crawl approach to Bamboo Aven was once again blocked with gravel and silts (previously cleared to a caveable size in Oct 2014). After about an hours digging, this was once again passable. This now means that High Atlas is again accessible, entrance stream conditions permitting.

The route on through Bleak Hall and down the Old Wells Road is much as reported back in Oct 14. Approximately the last 3-5m of the end of the OWR (not 1/3 of the way down as previously reported) remains silted up with a small air space where a small stream will occasionally flow, and there by blocking the way on to Bone Aven. This could potentially be dug out in the future, although any spoil would probably need to be hauled back to Bleak Hall to prevent it washing back in during future flood events. Even then, future floods may still wash in mud and silts that line parts of the OWR.

Final task after exiting TLS was to divert the stream back down Hobnail Hole.

Maj.
 

Maj

Active member
Update re Thrupe Lane Swallet.

The recent flooding has once again overwhelmed Thrupe Lane Swallet totally submerging the entrance. Thrupe Lane stream also washed a lot of shingle and silt down stream and deposited it in the depression and approach to TLS to a depth of about 1ft. Over the last few weeks members of ATLAS plus friends spent a couple sessions diverting the stream down Hobnail Hole and clearing the debris from the the approach to TLS. Further clearing is still required and ATLAS have scheduled another session for Fri 30th Dec.

We have currently left the stream flowing down Hobnail Hole which means TLS entrance is dry and accessible therefore open for caving. I dare say in a few weeks time we will recommence with stabalisation work in Hobnail Hole and will send the stream back down TLS. If I remember I will update when we do, but I would recommend getting in touch to confirm the latest state of play if you are planning a trip later in January and beyond.

Without carrying out this clearance the TLS gate may become blocked and access very difficult.

15726854_1167038586720783_9085211843751856162_n.jpg


Dave.
 
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