The oxygen content in Tham Luang cave is low, along with four 1.7 km long cave sections that require swimming and diving. Therefore, the rescue operation requires a lot of oxygen tanks for divers and school children.
According to the previous report of the rescue force, the oxygen content in the cave was sometimes only 15% compared to the standard of 21% to ensure human health. This is one of the reasons why more oxygen is needed for the campaign.
According to the US Federal Aviation Administration, if the oxygen level falls below 16% of the standard, symptoms such as headache, nausea, drowsiness, rapid breathing, slurred speech, and impaired thinking will appear. In some cases it can even lead to death.
Dinko Novosel, president of the European Cave Rescue Association, said the oxygen content in the cave at 15% was a dangerous problem. This oxygen level is enough to sustain life but makes it difficult to exercise.
Rescuers deliver oxygen tanks for the rescue operation. (Photo: AFP).
The rescue team moved to the place where the football team was stuck in the direction of the current, so they had to move a lot, leading to needing to breathe more. The water level in the cave has largely dropped to a wading level.
However, four sections of the cave are 1.7 km long, from the command post in cave No. 3 to “Nern Nom Sao slope” , where the team is still stuck in deep water and needs to swim, a part needs to be dived.
This part of the cave is forced to use an oxygen tank because the oxygen content in this area is quite low. Earlier, a diver died at this section from running out of oxygen, showing how dangerous a cave rescue is and how important a backup oxygen tank is.
According to Sport Diver, a website that specializes in sport diving, a standard oxygen tank has a life time of about 60 minutes or less, depending on the user and the depth of the dive.
Most of the cave from the forward command post to the location where the team was stuck had to use oxygen tanks to swim and dive. (Graphic: Bangkok Post).
It took about 6 hours for the rescue team to move from the main entrance to the location where the team was stuck. So each diver needs about 6 oxygen tanks. Thirteen world-class divers and Thai SEALs were sent to rescue the team. They need at least 78 oxygen tanks, not counting the oxygen tanks for the students.
In addition, cave diving is very dangerous, unlike scuba diving, if something goes wrong, you can come to the surface. In the dark flooded cave, all must depend on the backup oxygen tank. The rescue team must arrange many oxygen tanks along the way out to promptly replace when needed. That is another reason why the demand for oxygen tanks is so high.
Before that, the rescue force had moved a large amount of oxygen tanks arranged along the rest stops in the cave, but most of it was used for resupplying necessities, installing ropes and communication equipment in the cave and first rescue.