Everest oxygen week, Part III of III
11:38 a.m. EST Jan 29, 2004
In the final installment of ExplorersWeb’s interview with Neil Greenwood, the creator of a new ‘demand’ based oxygen setup for Everest, Neil talks about the weight of the system, how long it lasts, safety, regulation, where to buy it, and more. Next week, the Everest oxygen series continues with first hand impressions of how an early version of the system worked on last spring’s successful UK Royal Navy/Marines Everest expedition.
One of the advantages that Neil points out below, of the demand system, is efficiency – A 3L bottle on the Summit setup will last the user over 20 hours, whereas a 3L bottle on the Poisk setup will last 6 hrs.
ExWeb: How does the weight compare between the Summit Oxygen system and Poisk?
Neil: The Poisk cylinders are extremely light and an empty one weighs slightly less than one of ours. The lining on the Poisk cylinders is titanium, which in most places is only 1.5 mm thick; this is where they save their weight. They may also explode if punctured, not something you want on the mountain. The valve has the threads on the outside leaving them open to damage and they lack an ‘open’ or ‘close’ mechanism, which again saves weight, but presents other problems mentioned earlier.
ExWeb: How long will one bottle on your system last, and how does this compare to Poisk?
Neil: One of our 3-litre cylinders will last 32 hours at a flow rate of 2-liters per minute, this is based on a climber breathing at a rate of 14 breaths per minute. This will alter depending on the flow rate they use and their breathing rate, we advertise 22 hours 30 mins for planning purposes, allowing for a safety margin. All this will be explained to the climber before they embark on their expedition. It is simple to work out and each cylinder comes with an endurance table on the side for quick reference. As far as the endurance of a Poisk cylinder is concerned: If it has been filled to the correct pressure it will last approximately 6 hours at 2-liters/minute.
ExWeb: What does this mean in terms of a weight difference, how does your set-up compare to the weight of Poisk’s, looking at the whole picture of an expedition.
Neil: One of our cylinders when full weighs 3.35kg. Part of this extra weight is due to the extra oxygen in the cylinder, the rest is down to the cylinder valve and cylinder which each weighs slightly more than Poisk. When the endurance is compared to that of Poisk cylinder though, you will see the true benefits. For the British expedition this year; if they had used Poisk they would have needed 144 three-liter cylinders, which equates to 388 kg of cylinders to be moved up the mountain.
With our system they only needed 39 three-liter cylinders equating to 130kg of equipment to move up the mountain. It also allowed them to use just one cylinder from the top camp to the summit and back again. They climbed on a flow arte of no less than 3-liters/min and at times 6-liters/min. In addition no cylinders got left en-route and they saved 45 minutes by not having to change cylinders.
ExWeb: What type of O2 is in your cylinder?
Neil: We use aviation oxygen, which is slightly drier than medical oxygen, preventing it from freezing the working parts of the system. When cylinders originally arrive from the Poisk factory they are filled with aviation oxygen, however, when refilled in India, the grade and type of oxygen is unknown. I do know also that no license exists in India to refill cylinders above a pressure of 207 bar.
(Editor’s warning: If new, or refilled from the factory in St. Petersburg, Poisk bottles are tested and filled with aviation oxygen to spec, however, not all Poisk on Everest is from the factory. Some Poisk bottles are illegally refilled in India. There is no regulation and testing for those bottles, nor is this in accordance or affiliated with Poisk in any way.)
ExWeb: What difference will there be using a drier air in terms of function of the system – lots of user complain of a dry throat?
Neil: It will reduce the possibility of the vapor freezing on the mechanical parts of the system. It won’t have any affect on the climbers because the oxygen is only dosed as the climber inhales. There is no constant flow of oxygen (as with the Poisk system), which is what normally dries out the throat etc.
ExWeb: How will the system be regulated; are there any safeguards so people know exactly where their bottles and system came from?
Neil: All servicing, maintenance, and cylinder refilling will be conducted by us. If a company purchases equipment from us they will return it to us at the end of the season to conduct this servicing and for clients who hire it we will conduct it as part of the hire package. Companies who do not return it for servicing will be listed on our website as not having the equipment regularly maintained.
The servicing is not an opportunity for us to extort money from clients, we must protect our reputation, our product and public liability insurance and ultimately we have a duty of care to our customers. If the equipment is not maintained correctly it will start to fail thus endangering climbers. The cylinders are fitted with microchips to keep maintenance and ownership records, as does the Pulse Dose Meter. We can also spray cylinders different colors to denote their ownership.
ExWeb: Is there anyone slated to use it this year?
Neil: We have had a lot of interest, but most people are still unaware of its existence, don’t fully comprehend how it works, or simply don’t realize the benefits. However, we do have a number of people hiring and buying the system for the 2004 season, we are also loaning equipment to other companies who want to try it first.
ExWeb: Where can someone get the system?
Neil: They can hire or purchase it direct from us. We encourage people to phone us and discuss their requirements or concerns. We will arrange for the equipment to be collected in Kathmandu alternatively they can export it themselves but we’ll probably be able to do it cheaper because of the quantities involved.
ExWeb: Thanks a lot Neil!
3L bottle – 615 USD, 3345g, 22.6 hrs of use on 2L of flow (20 breaths per minute)
Regulator & Dosage Regulator – 1680 USD (210g + 200g) = 410g
Total weight: 3755g
Total cost for 1 setup: 2295 USD
Refill from Summit 100 USD
3L bottle: 310 USD, 2600g, 6 hrs of use on 2L of flow
Regulator: 300 USD, 350g
Total weight: 2950g + mask
Total cost for 1 setup: 660 USD
Refill from Poisk: 120 USD
Summit: 22.6 hrs of O2 = cost of 2295 USD and weight of 3.8kg
Poisk: 24 hrs of O2 = 1540 USD and weight of 10.8kg (1 regulator and 4 bottles)
All information in comparison from respective company’s websites.
Image of Dave Pearce, who summited Everest last year with the Summit Oxygen system, courtesy of rneverestnorthridge2003.com.