Author Topic: Majlis Al Jinn - an awesome cave  (Read 2705 times)

Online Badlad

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Majlis Al Jinn - an awesome cave
« on: December 08, 2016, 01:35:08 pm »
A few weeks ago I visited Majlis Al Jinn in Oman.  This amazing cave lies 1400m up on the Selma Plateau some 100km south of Muscat.  The cave has been known since the 1980’s as one of the largest underground chambers in the world.
 
Our group was there as part of a project to create 3D laser scan imagery of all the world’s big chambers.  Our aims are to discover just how big these spaces really are, which is biggest and why, to create amazing digital imagery and to provide data free of charge for any further work.  Of course we get to travel the world and see these awesome places for ourselves. Majlis was the 12th chamber we have visited and one of the most spectacular. 

Despite the difficulty of access, it is up a very steep 4x4 track, I have several friends who had visited the cave in the past.  Members of the Buttered Badgers a few years ago and friends who worked in Oman in the 1990’s all reported what a great cave it was.  The cave is characterised by big exposed pitches and daylight which unusually reaches into all corners of the huge chamber.

Unfortunately the cave had become popular with adventure groups, in particular Red Bull sponsored base jumps and roof climbs and that has led to its complete closure by the Omani authorities.  Check out the base jumping on this clip.



Needless to say a lot of diplomacy was required to get the cave opened up for our project.  We are fortunate that Andy Eavis is part of our core team and managed to meet with Omani officials ahead of our visit.  We were also greatly assisted by Steve and Kath Jones who now work in Muscat and together they received extraordinary permission to descend the great hole.

By now Andy, myself and Roo Walters, our third core team member, are used to travelling through the airports of the world with the $100,000 3D ‘camera’ and its powerful batteries.  Always there are some issues, usually batteries, to work through but we have always arrived at destination relatively intact.  This was tested as we passed through Doha and Roo was called aside just as we boarded our flight as there was a problem with his hold baggage.  It looked like he would miss the flight but just before the door closed they let him back on.  No problems with the scanner but his spare Scurion batteries this time.  On into Muscat and Roo is again stopped.  This time it is the scanner.  Hours go by as we negotiate its entry into the country with the help of Steve. 

 
Rough camping! with First Drop entrance just behind the big tent.                                           Going over the edge

The next day we are up the plateau in convoy with our Omani hosts who hope to descend the cave themselves.  They are quite disappointed to find that we plan to descend on ropes and not by winch.  Again we are fortunate as Steve has recruited the help of Joe Daniels of Twenty3 Extreme and with his friends Mike and Pavel he has already rigged two different routes into the chamber.  ‘First Drop’ is the classic 120m freehang down the widest of the three entrances.  Cheryls Drop is much deeper at 160m and drops out of a rift in the centre of the chamber roof.

I made a couple of drops down the 120 which was quite a thrill in my standard caving kit on shiny new rope.  As soon as you are over the edge the walls ease away and disappear completely 20m down.  Everything is lit up by the daylight and by mid-morning sunbeams arc across the floor from First Drop. Then as they fade out more appear from the Asterisk Entrance, another less popular route into the cave.


A panarama of the chamber taken by Chris Haigh on the Badgers trip.  Left with the rope visible is First Drop, right is Asterisk Drop and from the cross joints in the middle of the roof is Cheryls Drop.

There are no ways out of the chamber to distract and scanning goes without a hitch.  Probably our most efficient trip yet, as the two talus slopes and relatively flat floor area mean the laser coverage is good and we wrap up after only thirty odd scans.  The big benefit of the daylight means we can use the scanner’s own camera which sits atop the machine.  The photos are calibrated to the scans which then colour texture the point cloud and we can get proper coloured scanned images.  This is all Roo’s department and he now makes this techy stuff look easy – which I’m sure it isn’t.

   
Beams hitting the ropes hanging from the roof of Cheryls.                 The scanner with camera atop.

Also with us is Carsten, did I mention him.  He is a professional photographer who has taken to following us around.   His photography is legendary appearing in the ‘big mags’ of the world which we look forward to seeing.  In the meantime we must amuse ourselves with his antics and shepherd around his huge bags of kit.  A massive drone is pulled out of an enormous case and he flies it around the chamber trying to capture a nervous Kath midway up the 160.  We chuckle when on manual flying it reaches a ceiling at 50m height and whilst Carsten tries to work out why, it comes within inches of crashing into the wall.  Mike’s warning the only thing to save it.  There are shots of sunbeams and danglers in the spotlights to follow, but we are also in Oman during the ‘super moon’.  This is wonderful for our three nights camping out under the stars, gathered round the fire with a barbie and a beer – magic indeed.  This isn’t enough for Carsten and Joe who head down the cave at midnight to photograph the chamber lit up by moon beams.  Apparently successful at the limit of the camera’s sensor.

Hot but pleasant in the day and very cold at night.  No problem for those of us who read the briefing and brought warm sleeping bags and duvet jackets.  Not so warm for my tent companion shivering in everything he owned and a summer bag.  A lesson to be learned for sure when you are going up a mountain but only check the weather forecast at sea level on the coast.


One of Roo's maps created with the scan data.  Our camp and some houses only 30m above the chamber roof.
 
With all the kit and faff going down the cave there was a lot to haul the 120m back to the surface.  We had a 3:1 stretched out across the surface to assist with this and it proved pretty efficient.  Prussiking times varied widely as did the age of our team.  Joe manged an incredible 12 minute ascent whilst whilst most of us were a leisurely half hour.  I missed out on the last days caving and my chance to do the 160m drop when I rolled my ankle on a boulder walking about on the surface.

Our trip finished back in Muscat where we held an evening’s presentation on Majlis and our project to an invited audience of 130.  The presentation was organised by Steve and attended by Royalty, government officials, geologists, adventurers, both Omani and ex pat alike.  It all went down very well and hopefully will have refocused attention on a remarkable cave.  We hope that it will soon be possible to open the cave again for others to enjoy – responsibly of course.

   
The audience ready for the evenings presentation.                               The authors ugly foot

The stats show that at 4.19 million cubic metres Majlis is fifth largest chamber in the world. This may change as we are still to visit La Muneca in Mexico and Ghar e Doser in Iran next year.  Max dimensions are 318x244x134m and a floor area of 66.5 K m2.  Or in other words BIG.

A huge thanks to everyone who helped us out.  The map, stats and fly through were produced by Roo who really is the most important member of our team.  Collecting the data in the field is the easy part – doing anything with it takes a lot of hard work post caving.  Cheers.

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« Last Edit: July 14, 2017, 09:06:27 pm by Badlad »

Offline aricooperdavis

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Re: Majlis Al Jinn - an awesome cave
« Reply #1 on: December 08, 2016, 01:42:25 pm »
That looks absolutely superb - I've never seen 3D scans that really add something more than the usual photos, but that video is incredible! Congratulations to the team, I'm well impressed :clap2:

Online Roger W

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Re: Majlis Al Jinn - an awesome cave
« Reply #2 on: December 08, 2016, 03:18:08 pm »
 :clap2:  :clap2:  :clap2:

But a cave that big must surely go somewhere?

Is this a job for some mature Mendip moles?



"That, of course, is the dangerous part about caves:  you don't know how far they go back, sometimes... or what is waiting for you inside."   JRR Tolkein: "The Hobbit"

Offline droid

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Re: Majlis Al Jinn - an awesome cave
« Reply #3 on: December 08, 2016, 06:24:55 pm »
Roo's looking good. Pass on my regards please.  :)
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Online Badlad

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Re: Majlis Al Jinn - an awesome cave
« Reply #4 on: December 08, 2016, 06:31:28 pm »
Roo's looking good. Pass on my regards please.  :)
He'll be reading this  :coffee:

Online Fulk

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Re: Majlis Al Jinn - an awesome cave
« Reply #5 on: December 08, 2016, 08:10:11 pm »
Hi Badlad, have you 'done' Torca del Carlista? If so, how big is it, and where does it come in the 'big list'?

Online Badlad

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Re: Majlis Al Jinn - an awesome cave
« Reply #6 on: December 08, 2016, 09:08:23 pm »
Hi Fulk

Yes we visited Carlista last Easter on a trip which took in the Verna too.  I'm afraid the Carlista is surprisingly small by volume but still a pretty big footprint.  The Verna was larger than expected at almost twice the volume.  Verna has a good shape with the high point around 198m floor to roof.  In the Carlista the highest part of the chamber is the pitch and it tapers to nothing on the sides.  I'll get the latest table and publish it on here for you to see.

There is a coffee table book due out on the Carlista in which Roo has written a chapter  featuring our scanning.  Here is a video of Roo's work with the scan data so far.

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Online Fulk

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Re: Majlis Al Jinn - an awesome cave
« Reply #7 on: December 08, 2016, 11:02:09 pm »
Gracias, hidalgomalo.

Offline chunky

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Re: Majlis Al Jinn - an awesome cave
« Reply #8 on: December 08, 2016, 11:42:24 pm »
Fantastic write up of an amazing project. Thank you for sharing. Looking forward to seeing and reading of more in the future!

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Online Fulk

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Re: Majlis Al Jinn - an awesome cave
« Reply #9 on: December 09, 2016, 08:53:09 am »
Hi Badlad, you've spoilt my day; I'll have to stop telling people I've been to the biggest cavern in Europe.

Seriously, though, I'll echo chunk's remarks – it's an amazing project, with spectacular results. Well done all.  :thumbsup:

Online Badlad

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Re: Majlis Al Jinn - an awesome cave
« Reply #10 on: December 14, 2016, 10:33:34 am »
Fulk and all.  Apologies for being the bearer of bad news but our new 'largest' list shows the Gran Sala in Torca del Carlista is 2.14 million m3 which is likely to drop it down to 11th by volume once the last two chambers are completed.  (Salle Verna is 3.65 by comparison)

The good news is that at 87.09 thousand m2 it places it third in the largest footprint list.  (Salle Verna is 43.47)

So in one sense you can still say you have been to the largest chamber in Europe  ;D

 

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