In the early hours of May 16, Adrian Ballinger, founder ofExpeditions, was making his way up the North Side of Everest with 13 Sherpaand 13 clients when their oxygen tanks started to hiss and roar, expelling all their precious oxygen into the thin air.The team was at 8,500 meters when, in quick succession, 10 of their 39 oxygen-bottle regulators failed spontaneously and without warningwithin threeminutes, according to Ballinger.
The regulator controls the flow of oxygen between the bottle and the mask. If it fails, there will be no oxygen flowing into the mask.Several of the Alpenglowguides and Sherpas gavetheir working regulators to the clients, then the groupdescended together. Jim Morrison, a client on the climb, that a Sherpa on the team“just took his mask and handed it to me. We descended and shared the one mask, me on it and him refusing to take it.”All clients, guides, and Sherpaarenow at or below Camp II and safe.
Ballinger says Alpenglow was usingregulators at the time.I've personallyused SO systemsseveral times with complete success. When I spoke with Ballinger by satellite phone Wednesdaymorning, he was quickto say he was not criticizing the company, but that he wanted to get the word out about the malfunction he experienced. Before Wednesday,he said he hadused SO for sixyears with no problems.After we got off the phone, four more SO regulatorson the Alpenglow expeditionfailed,according to Ballinger. Over the course of the morning, two other teams—Transcend and Furtenbach—would also report failures of SO regulators, but both had enough spares to continue their climbs.
At 10 a.m. local time, Alpenglow issued the following statement:
Both of our Alpenglow Expeditions teams, along with other teams on Everest, were utilizing an industry standard supplemental oxygen system during their summit push. When multiple of the team’s oxygen bottle regulators malfunctioned, the team made the difficult decision to stop their summit push and return to lower elevation.
Since this time, it has become apparent that a defective batch of oxygen bottle regulators was released. Multiple teams using the same device have experienced similar oxygen system failures. There are no reported injuries at this time.
In my experience, this level of regulator failure is extremely rare. There may be one or two that fail each season, but not 10 simultaneousblowouts like Alpenglow experienced. I havefound these devices to be abit fragile, and when I'vescrewed the regulator onto the oxygen bottle atanincorrect angle, the sealcan leak. If either dirt or water gets in the seal, it can also cause problems. That said, I'm not suggesting operator error by the extremely experienced Alpenglow team (or by Transcend and Furtenbacheither).
On Wednesday morning,I spoke with Neil Greenwood, the director at Summit Oxygen.“It is very difficult to ascertain the cause ofsuch a failure at this time without being able to inspect the equipment,” Greenwood says. “The manufacturing and testing process of the regulators has not changed and all of the regulators supplied to Alpenglow for the 2018 season had been previously used.The connection and disconnection procedure of the regulator to a cylinder is particular to this application and if the dynamic O ring is broken in theprocess it can cause problems, however, I suspect this is not the case in this situation.”
“Based on the information we have from Adrian, Isuspect that the pressure relief valvehas functioned,” Greenwoodcontinued. “The PRV is a safety mechanism to protect the low pressure side of theregulator from high pressure.If this is the case, we will need to investigate what caused the pressure to increase and thus the PRV to function.I'm extremely glad to know thatall the team members are safe.”
According to Ballinger, his team extensively tested the regulators before summit day and did not find any issues. “We tested every reg and mask at 6,400 metersbefore taking them uphill,” Ballinger says.“This problem did not manifest until very high on mountain.”