In the early hours of May 16, Adrian Ballinger, founder of听听Expeditions, was making his way up the North Side of Everest with 13 Sherpa听and 13 clients when their oxygen tanks started to hiss and roar, expelling all their precious oxygen into the thin air.听The team was at 8,500 meters when, in quick succession, 10 of their 39 oxygen-bottle regulators failed spontaneously and without warning听within three听minutes, according to Ballinger.听
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.听Several of the Alpenglow听guides and Sherpas gave听their working regulators to the clients, then the group听descended together. Jim Morrison, a client on the climb,听 that a Sherpa on the team听“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.”听All clients, guides, and Sherpa听are听now at or below Camp II and safe.听听
Ballinger says Alpenglow was using听听regulators at the time.听I've personally听used SO systems听several times with complete success. When I spoke with Ballinger by satellite phone Wednesday听morning, he was quick听to say he was not criticizing the company, but that he wanted to get the word out about the malfunction he experienced. Before Wednesday,听he said he had听used SO for six听years with no problems.听After we got off the phone, four more SO regulators听on the Alpenglow expedition听failed,听according to Ballinger. Over the course of the morning, two other teams鈥擳ranscend and Furtenbach鈥攚ould also report failures of SO regulators, but both had enough spares to continue their climbs.听
At 10 a.m. local time, Alpenglow issued the following statement:听
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鈥檚 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 simultaneous听blowouts like Alpenglow experienced. I have听found these devices to be a听bit fragile, and when I've听screwed the regulator onto the oxygen bottle at听an听incorrect angle, the seal听can 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 Furtenbach听either). 听
On Wednesday morning,听I spoke with Neil Greenwood, the director at Summit Oxygen.听“It is very difficult to ascertain the cause of听such 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.听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 the听process it can cause problems, however, I suspect this is not the case in this situation.”
“Based on the information we have from Adrian, I听suspect that the pressure relief valve听has functioned,” Greenwood听continued. “The PRV is a safety mechanism to protect the low pressure side of the听regulator from high pressure.听If this is the case, we will need to investigate what caused the pressure to increase and thus the PRV to function.听I'm extremely glad to know that听all 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 meters听before taking them uphill,” Ballinger says.听“This problem did not manifest until very high on mountain.”