Mask and regulator
You can find masks and regulators on the
second hand market in Kathmandu, or you can rent it from your trekking
agency. Itís expensive and not reliable.
Our recommendation is that you get new gear from POISK. It's US
250-380 a set, depending on how many you order, and definitely worth the
money (you can sell the gear too after the expedition).
a commercial expedition in 1996, Tina was provided with a mask, used
just a couple of days earlier by Becks (the climber with severe
frostbites that eventually lost his nose). The mask was still covered
with his blood. She was advised to clean it out with snow at C2. You
don't want that!
The supplementary oxygen supply system is
roughly built as follows:
It is an ultralight 3-liter or 4-liter (new) cylinder, pressured to 320
The pressure will however decrease with temperature.
Testing the bar reading in a cold BC is thus not a good idea.
bring a handheld scale instead (shop for it at game fishing stores for
instance) and check the weight stated on the bottle. Neither altitude
nor temperature affects the weight.
A 3-liter bottle weighs around 2,6 kg when full. Approximately 1060
grams out of that is oxygen (this will vary between individual bottles).
We weigh the bottles simply to make sure that they are full.
Now, we need to calculate the duration of the bottle for our climb.
The flow control measures usage in liter/minute, so it is easier to
calculate in liters per minute, rather than counting on the consumption
A 3-liter bottle holds about 720 liters of oxygen.
During the climb, you will vary the flows between 1, 2, 3 or 4 l/m.
Even though it is possible, don't go higher than flow 4. Oxygen becomes
toxic and dangerous at that rate. The flow set by you will determine the
duration of your bottle.
We stated that the bottle holds 720 liters of oxygen. If you breathe
from it at the rate of 2 liters a minute - the 720 liters will be gone
after 360 minutes. Thatís 6 hours.
Should you use 3 liters a minute, the bottle goes in 240 minutes, or
4 hours. At 4 liters a minute, the bottle consequently empties in 180
minutes/3 hours. On the other hand, a flow of one only, will last the
bottle for 720 minutes - 12 hours.
you do these calculations at 8500 meter, after 30 sleepless hours, and
20 hours of climbing? Good, you need to!
Fitting the gear
- On top of the bottle there is a valve. Keep it protected from dust
and damage at all times.
- Fit your regulator to the valve.
- Put the regulator on half a liter flow, before you screw it on.
- After that, screw like crazy (if you are to slow you will lose too
much oxygen). The escaping pressure will produce a loud noise.
- Close the regulator.
- A hose is attached to the regulator. Be careful not to step on it,
especially with crampons on. (The hoses can be made to order by POISK.)
- The hose is provided with a flow control. This view meter tells
you that the flow is actually on.
- A Bar meter is fixed to the regulator. It shows how much oxygen
there is left in the bottle.
- The regulator, being placed on top of the oxygen bottle, will be
carried high on your back, inside the pack were you canít see it.
- Reading the bar meter from that position while climbing is a real
hassle. For that reason, a climbing partner usually performs the
reading. (On the recent hose version from POISK, the bar meter has
been removed from the regulator and is placed on the hose, towards
your chest. This new position of the Bar meter seems excellent to us.)
- The other end of the hose fits onto a mask. These masks were
originally developed for Russian fighter pilots! Prepare for it to fit
badly and constantly clogging your glacier glasses. Get the mask prior
to your climb and try it out.
- The mask is not constructed for the extreme cold at Everest and
will tend to clog. Squeeze the rubber parts once every thirty minutes
while you are climbing, and you should be OK.
The oxygen is very dry and could damage your
face. In 1998, Tina got severe frostnip in her face from using the
oxygen - see picture. Prevent this by using some moisturizing cream on
your face prior to putting on the mask. (Even though the lubricant will
freeze on your face).
When and how much?
Most climbers start using oxygen at C3.
The main reason being that it will give you a good night's sleep (on
flow 1 liter or less) before the long, strenuous summit attempt. Also,
you will try out the gear and get used to it well in time. Using oxygen
to Camp 4 gained Thomas only one hour of speed, compared to when he went
without. Yet, it left him less worn for the summit attempt.
Furthermore, you might have to stay at C4 for 2 nights
if the weather is bad and you need to preserve your strength. Staying in
shape by using oxygen from C3 is a good strategy towards your optimal
chance of a summit. The use of oxygen below C3 is of minimal benefit.
will start using oxygen at C4. At that altitude you should use a rate of
one l/m while resting/sleeping. If you are weak, don't hesitate to put
it up to two liters until you feel better. The main reason for weakness
is however not lack of oxygen but lack of fluid. Try to drink 1 liter of
water upon your arrival to camp, and another 3 liters before the climb.
Bring 2 liters of HOT liquid for the climb, keep it in your down suit
- never in the pack (it will freeze in no time).
When leaving for the summit, you should calculate for at least 18 hours,
to be on the safe side. Head out at around 11 PM, arrive at South Summit
by 7 AM and the main summit at 9 AM. This is considered a very good
time. If the snow is just little deeper and the wind just a little
higher, you could just as easily summit at 12 or even 2 PM. Never ever
summit later than 2 PM! Allow 4 to 6 hours for descent.
If staying one hour at the summit, we are looking at a
time span of 15 to 21 hours. If your average use of oxygen is 2,5
l/m, youíll need at least 4-5 POISK bottles to be sure.
But how much do climbers actually bring?
Well, considering that up to one third of all climbers
get into oxygen trouble up there, they are either bringing to little or
using too much.
So, letís say that you bring (or are provided with) only
2-3 bottles of oxygen (funny we should use THAT figure...).
If you use 2 liters a minute, 2 bottles will last you
for 12 hours.
hours without oxygen, on the climb down, when you are the most tired Ė
will be a chilling fact!
Sure, perhaps youíll be really disciplined and use only
one l/m at some parts, but that will just call for 3 l/m on the hard
parts, since youíll get worn. You will still end up on the average 2
liters a minute consumption. Expect many hours without oxygen on your
climb down - just when you are at your worst! This is the time when
climbers die most often.
3 bottles would rather be the minimum and that is what
the Sherpas normally bring for themselves. If you are an experienced and
altitude strong (which is not equivalent to sea level strong) climber,
three bottles could be OK.
Most people should however bring 4 bottles and still be
careful with the usage. With an average of 2,5 liters that will last for
19 hours. In most cases that will bring you up and down safe.
We try to bring 5 bottles each if possible. That gives
us a good margin of safety. The extra bottle is only going to Balcony
(8500-m/28000 ft) for rescue. High up, weíve been able to offer climbers
in trouble spare oxygen because of this and that is a nice feeling too.
It is just a spare bottle, but could mean the difference of your or your
Finally, an important fact to be remembered in all this
is also that bottles occasionally brakes on summit attempts.
Running out of oxygen
pilots, who reach altitude of 8000-m/26000 ft without supplementary
oxygen, will fall into coma within 4-8 minutes.
For you likewise, running out of oxygen at a very high
altitude means big, big trouble. It's like going in to a wall. You can
not compare yourself with someone climbing without oxygen for the entire
climb. They have adjusted their bodies gradually, whilst yours will have
If you are on the ridge (8750-meter/28700 ft) and the
oxygen is gone, your chances of returning alive are slim and the chance
of returning without frostbite almost nonexistent.
Don't trade US 250 against your life! Bring an extra
bottle and save yourself or someone else.
To be safe, we need around 2-3 bottles from C3 to C4
(including sleep), 2 bottles at C4, 4-5 for the summit push and two
spares. That totals 12. If you are up for another attempt you need at
least another eight. That totals twenty.
The cost for this will be around US 300 each bottle or
US 6000 in total. Invest this money and sell what you are not using upon
Check the prices at