Cave diving rescue in France

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Re: Cave diving rescue in France

Postby self-deleted_user » Nov 11, 2010 4:01 pm

I"m trying to picture things...can someone explain visually (i get theoretically what it is) a sump is in the context of this cave rescue? I thought sumps were like, where the water flows out and it'll resurge somewhere. Multiple sumps needing dives that are deep sounding though? LIke, big water filled pits inside the cave? Sorry if these are dumb questions, I'm still learning different terms and stuff and it seems often two very different looking things are covered by the same term.
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Re: Cave diving rescue in France

Postby Phil Winkler » Nov 11, 2010 4:07 pm

Perhaps the easiest definition of a sump is a portion of passage completely filled with water connecting two air filled passages. A terminal sump (or syphon) is one with only one air filled passage leading to it. The depth of the sump may vary widely, too.

Does this clarify it?
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Re: Cave diving rescue in France

Postby self-deleted_user » Nov 11, 2010 4:17 pm

Yeah that helps. So basically, yeah, the conditons of the sump itself is a huge variance (eg. it could be 500 feet long and 100 feet deep, or it could be 5 feet long and 2 feet deep) so long as it is a fully water filled passage with air on both sides (or if terminal one side).
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Re: Cave diving rescue in France

Postby Phil Winkler » Nov 11, 2010 4:30 pm

You got it, Amy. See, those 2 years in 6th grade still pay off! :tonguecheek:
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Re: Cave diving rescue in France

Postby wyandottecaver » Nov 11, 2010 4:34 pm

also, in this context there are "hanging" sumps. A normal sump is generally at or near the base stream or water level. it is generally not possible to pump these down unless there is very low water flow. A hanging sump is elevated above the base level or stream, kind of like the J trap in a sink. it fills up during high water or from water flowing downward in the system during rains but isn't constantly replaced by flowing water and thus can generally be pumped out.
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Re: Cave diving rescue in France

Postby self-deleted_user » Nov 11, 2010 4:46 pm

OHHHHHH thank you wyndotte that realllllllllly helps because yeah i was trying to figure out next how you stop the water from flowing back in as you pump it out! Phil - I prettymuch skipped 6th grade :P
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 12, 2010 5:27 pm

There has not been an official update for yesterday Thursday Nov 11, but unofficially, I read that Sump 2 was found to be impenetrable, clogged with sand at a depth of 4 meters. Therefore, to keep going, this sump will need to be pumped out and emptied of its sand. What a terrible setback. As I said, this was still not officially announced by the Speleo Secours. I am leaving for the weekend and will update you again on Sunday evening.
-Yvonne
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 14, 2010 9:16 pm

From Spéléo Secours:
On Thursday, Nov 11, the first teams in had to check the reinstallation of the phones and to make sure that Sump 1 was emptied. The team was kept to a minimum so as not to unnecessarily raise the level of CO2 between the two sumps. In the meantime, the divers got their gear ready for diving through Sump 2 in order to do a reconnaissance beyond, whether underwater or in air-filled passage. If the latter were the case, they took along the necessary instruments to verify whether the air they would encounter beyond the sump is breathable or not. The 2 divers and 8 sherpas entered the cave around 2 pm. Once at the bottom, the first diver entered into the sump and after only 12 feet, at -3 feet of depth, he was stopped by a sand plug with only 6 to 8 inches of water at the ceiling. Three times, the two divers tried unsuccessfully to pass through the sump. Around 4 pm, the surface is called with the news. Right away, technical solutions to this new setback are discussed, with the supposition that this sump could be similar to Sump 1. The divers and support team return to the surface.

On Friday, Nov 12, everyone is looking for new ideas. One of them is a bit ambitious. It’s necessary to pump out Sump 2, but since it’s not possible to get through it, there is no way to pump it out downstream. Therefore, the choices are to pump out the water to the outside, or to store it underground. In the end, the best idea is to build a dam capable of holding back a large quantity of water. It needs to be able to hold back the active stream’s water (2 liters/second) and in addition, to hold the water that will be pumped out of Sump 2. The idea is not to empty out the sump, unless it happens to be very short. It’s mainly to evaluate its dimension and how it reacts. The floor of the sump, being filled with very compacted sediment, could also be dug in order to increase the height of the passage.

Once this idea was adopted, the pump and accessories capable of pumping water up to the dam had to be procured. Then it was necessary to figure out the best location for the dam, and to calculate its capacity. The equipment was bought. The dam was positioned upstream in the main stream. Taking into account its height, just over 2 feet, the capacity was about 20 cubic meters (5300 gallons). Four-inch steel rods were used as the support structure, anchored in the opposing walls. Bags filled with sand and cobbles were positioned against this metal barrier. As in any dam, the bottom was built thicker than the top, and an overflow incorporated. Then the pump was installed, as well as the hose 180 feet upstream to the dam. By end of the afternoon, the set up was ready. The divers returned to the bottom, and started the pump. Two other people were at the dam to oversee the operation. One team was at Sump 1 to keep an eye on its level. Once all was set, the operation started in this order:
1. Sump 1 is fully emptied.
2. The dam is sealed.
3. Sump 2 is pumped into the dam.
After some electrical snafus due to the ambiant humidity, the complex system functioned. After about 1.5 hours of pumping, the level of Sump 2 was lowered by about 4 feet. The divers, helped by two cavers, dug in the entrance of the sump. Since the sump’s level went down quite a bit, it was thought that it is reletively short. The divers tried again to get through. This time, they got an additional 3 feet. But the distance between the ceiling and the floor is still only about 4 inches.
That evening, the entire team, quite tired, left the cave. Even though the sum seems to block the efforts for now, a fissure found a bit before and on the left of the sump was found. The objective for the next few days will most likely be in this direction.

-Yvonne
(P.S. There is no Sunday morning update for what was achieved on Saturday.)
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 15, 2010 10:40 am

On Saturday November 13, the plan was to widen the fissure found just before Sump 2 in the hopes that it might bypass it. In order to do that, it was necessary to improve the air quality at the bottom of the cave. The large air hose needed to be lengthened to reach Sump 2. While this was being procured, a fan was placed at the entrance of Sump 1, and the oxygen level returned to normal. A team then started enlarging the floor of Sump 1 with explosive charges to facilitate passing through there. That took a few hours.

Finally enough air hose was found and a team of 8 cavers started installing then assembling the pieces of the huge “plastic snake”. The air hose now reaches to the top of the 5-meter drop just above Sump 2. The teams of diggers started their widening efforts and managed to enlarge the fissure over several meters. All night long, these teams took turns working, but finally, the last team was forced to give up: the fissure started going up, pinching out without any hope of continuation.

On Sunday morning, November 14, the last of the diggers came out of the cave, all very tired and somewhat depressed by the outcome. Another idea needs to be found. The weather is not cooperating: rain is in the forecast. As a preventive measure, a team needs to go reinforce the piles of debris at the bottom of the pits, since a new flood would have a devastating effect on these stashes if they were not secured. Tarps, fencing, steel cables are fixed over the piles. This lasts all day Sunday, and finally all the pit bottoms are safe.

With this primary mission accomplished, a new experiment can be tried: forcing a discharge hose through the constriction at Sump 2. With a lot of luck, it would possibly come out on the other side, since it’s estimated that Sump 2 is short. Once the hose is pushed in over several meters, the pump would be started to see if the water level drops in the sump. That could rapidly empty the sump. If that does not work, pumping out the sump upwards to the dam will again be done, and hand digging of the sand and sediments will restart when the water level is lower. The sediments will be stored into large, tough bags. This operation will be repeated after every time the sump is emptied. If the weather cooperates, work will start on Monday late morning. If a lot of rain falls on the plateau, this operation will of course be postponed.

At the Thursday meeting, it was decided that the current operating system would be extended, i.e. work will continue on a daily basis until at least November 28. Teams of participants are therefore asked to organize within their regions in order to schedule work days.

On Friday afternoon, Eric’s wife and son, Evelyne and Arthur Establie, visited the site of the Puits de Ronze together with some family members. They were shown the maps of the cave as well as updated on the progress in the cave. The mayor of Labastide de Virac then organized a moving ceremony at the Court House. Evelyne and Arthur thanked everyone for their help and solidarity. They talked with members of the Fédération Française de Spéléologie and the Spéléo Secours Français. Their strength and desire to see the work come to a successful ending was a lesson for all and increased their determination to succeed in this mission.

-Yvonne
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 17, 2010 10:31 am

The attempt to force-push a hose through Sump 2 was unfortunately unsuccessful, but another attempt is planned. However, the weather was not favorable on Monday Nov 15. It rained overnight and water started flowing in the stream in front of the Command Post. Therefore, operations were not possible in the cave. Work was done at the surface, organizing, improving the area, etc. A team went to continue the digging efforts in the sink where the stream that passes in front of the Command Post goes underground. This sink, located near the upstream end of the Dragonnière de Gaud, is not very engaging, but no lead should be neglected.

(There is no update for Tuesday’s efforts yet.)

-Yvonne
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 18, 2010 11:45 am

(I edited this post to fix the dates. -Yvonne)

Update for Tuesday and Wednesday Nov 16-17:

On Tuesday, Nov 16, the Puits de Ronze was inspected to see if there was any damage after the strong rains. Except for one damaged rope, all seems OK until Sump 1. The pumps are put into the water and pumping starts. It takes longer than normal. After two hours, the level is still high. Finally Sump 1 is emptied. This wasted time was due to the rupture of a little barrier that keeps the active stream from coming back into Sump 1. After being repaired, the barrier now diverts the water again directly into Sump 2.

A team goes to check the main dam. It needs to be emptied. The flow is much stronger than last week. Pumping it out is not feasible today, and besides, there are issues with the telephones. Everyone returns to the surface, hoping for a quick drop in the water levels. Outside, the shelter for the turbine is being improved. It had broken down due to the wetness. The roof is replaced by a solid and waterproof one, and now properly protects the turbine and the electric panel.

On Wednesday Nov 17, a new pump was installed in Sump 1. It is equipped with a way to start the pump before the team enters the cave, which will save time. Once the first team got beyond Sump 1, they checked on the dam. All was well, but it needed emptying. Once that was done, Sump 2 was now ready for the attempt to pump it out to the downstream side. However, another problem got in the way: water found its way into the aeration hose. Oxygen levels drop, and the hose needs to be made more waterproof. An hour later, it was fixed and the oxygen level returns to 20.5%. The phones function well. The pump in Sump 2 was put in operation, but the level goes down little. On the other hand, the dam is filling up much too fast. The level of Sump 2 went down by 16 inches, whereas before, it had gone down by 48 inches. The flow is still too strong and some other solution needs to be found.

Another alternative is to pursue the lead in the middle of the 20 m pit, a tight tube that was nicknamed “the Bousier”. The plan for tomorrow is to go down and see how much flow is in the main stream passage. If it’s still too strong, then enlarging will restart in the Bousier. This could be a good option while awaiting a significant drop in the water levels.

A team also continued digging in the sink on the surface. The entrance is now open. About 6 feet in, it appears that the fissure is promising and it’s considered an alternative.

-Yvonne
Last edited by yvonnedroms on Nov 19, 2010 12:41 pm, edited 2 times in total.
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 19, 2010 10:53 am

(I edited this post to fix the dates. -Yvonne)
On Thursday November 18, the weather was good and the ground was drying out. The first team in went to check the pump at Sump 1. The automated system worked well, and the water level is coming down in the cave. As planned, the team resumed widening the narrow passage near the top of the 20 m pit. A few meters were gained. The second team of the day went to Sump 2. Again they tried to push the discharge hose through the sump, but after various unsuccessful attempts, the idea was abandoned, and the team returned to the surface. On the way out, they cleared the debris from the Bousier passage.

For the past few days, the idea of pumping Sump 2 directly out to the surface has been studied and several solutions were found, but the theory remains the same: the water needs to be pushed up 150 meters (500 feet) vertically, then released far downstream from the entrance of the cave. Sumps 1 and 2 will be emptied into the dam. Because of the sediments and sand, the water will need to settle before being pumped up. The dam will serve that purpose. A high pressure pump will push the water out of the cave directly, or, if an appropriate pump is not found, a relay pump will be installed at the -75 meter level.

On Friday, this equipment will be procured, allowing for the cables and hoses to be installed in the cave this weekend. The plan is to install the pump at the beginning of next week.

A map of the cave is at http://ssf.ffspeleo.fr/images/stories/s ... ZE%204.pdf

-Yvonne
Last edited by yvonnedroms on Nov 19, 2010 12:37 pm, edited 1 time in total.
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 19, 2010 11:00 am

It's possible that I'm a day off on the posts. The way it's posted on the Spéléo Secours page is a bit confusing. The posts are written partially as if it was that day, partially in the past, etc. I wish they would put dates within the posts, instead of in the title only. So the dates for this week, above, may actually be a day later...
-Yvonne
(Edit: I think I fixed the time frame. -Yvonne)
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Re: Cave diving rescue in France

Postby Chads93GT » Nov 20, 2010 10:00 pm

Keep up the good work with the updates.
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Re: Cave diving rescue in France

Postby yvonnedroms » Nov 21, 2010 6:23 pm

On Friday, November 19, digging continued in the Bousier passage, and another attempt was made to empty Sump 2 but again it failed due to there not being enough time or storage capacity in the dam. This was probably the last attempt with the currently available techniques. Pumping the water out to the surface is now the only solution possible to overcome this obstacle.

The Bousier now has 25 feet of open passage. It’s heading south, not exactly in the right direction, but it’s important to find out where this narrow tube is going.

Work at the insurgence is also progressing and that dig is now 10 feet deep. The fissure is dividing into various passages, but a larger void seems to be felt.

Technical studies on the feasibilty of pumping upwards from -500 feet were completed during the day.

Water samples were collected for analysis at the entrance of the Dragonnière, and a team was tasked with collecting samples at the bottom of the Puits de Ronze above the dam.

The weather forecast for Saturday was not good, so a team was sent down during the night from Friday to Saturday to bring out sensitive equipment, and to protect what couldn’t be brought out.

(no update for Saturday yet)

-Yvonne
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