Doing Denali Light: Post-Trip Report and Gearlist

It IS possible to climb Denali using lightweight techniques! Agnes and Matt discuss their gear and provide detailed gearlists.

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by Agnes Stowe with Matt Hage | 2007-08-29 00:00:00-06

Doing Denali Light:  Post-Trip Report and Gearlist

Introduction

For most people climbing Denali (aka Mt. McKinley) is no easy task. A vertical rise of 18,000 feet makes it bigger than Everest. It is no wonder that Denali means “the high one” in the Athabascan language. With backbreaking loads of 100 pounds (45 kilograms) or more the haul to the summit is grueling for even the fittest climber, but as Matt and I proved on this trip, it’s not so miserable with a lighter load. In a mere 3 hours Matt and I trucked into the first camp at the base of the ski hill at 7800 feet (2377 meters) with half the load of a typical climber and plenty of energy to spare. We could not go any further until our bodies acclimated. We set up camp and tried to “chill” in the heat of the day when afternoon temperatures can swelter to 100 °F (38 °C on the lower glacier. Perhaps our two most unorthodox items - at least for this type of climbing - were our 20 ounce (567 gram) packs and 2.5 pound (1.1 kilogram) tent. For most climbers on Denali, these two items alone can weigh from 15 to 20 pounds (6.8 to 9.0 kilograms), while these two items weighed only 4 pounds (1.8 kilograms) for us. By taking techniques from ultralight backpacking and alpine climbing, we manage to put together a 30 pound (13.6 kilogram) kit (base weight plus non-worn technical gear) not including food and gas.

The Gear

To jump directly to the gear lists and weight summaries click here.

Our Golite Gust packs, at 20 ounces (567 grams) with no bells or whistles fulfilled our volume (5000 cubic inches, 81 liters) needs - they carried a lot of goose feathers. I rigged a sternum strap to help adjust the pack under load. We pushed the pack’s 30 pound carrying capacity limit, which helped us keep our loads honest. Early in the trip when the pack was maximized and we were pulling sleds the thin unpadded waist belt made our hips tender. We were thankful to be caching the sleds at the 11,000 foot (3352 meter) basin camp, especially after the hard second day around Kahiltna Pass with high winds.

The high winds persisted at the 11,000 foot (3352 meter) camp, putting our small tent to the test. The Stephenson Warmlite tent (2.5 lbs, 1.1 kilogram) was designed over 40 years ago and today is still one of the lightest high quality mountaineering tents on the market. The tent depends on its aerodynamics to withstand high winds with no guylines attached. As is expected in such cold conditions, condensation formed on the inner walls. The condensation accumulated primarily on the single-wall end sections rather than on the double wall section over the sleeping bag area. This minimized the dampness of our bags.

Another fairly unconventional item that we included in our shelter system was an 8 x 10 foot (2.4 x 3.0 meters), 14 ounce (397 grams) Integral Design Siltarp. Part of Integral Design’s “fast and light,” line this ultralight waterproof nylon tarp was great as a vestibule or awning. During high winds, we setup the Siltarp as a huge vestibule with snow walls digging down to make a cubbyhole great for cooking or just hanging out. Most of the time we did not so much encounter wind but intense sun instead. Using our poles and snow walls, we created a front porch (awning style) that allows us to stay out of the hot tent but remain protected from the blaring sun. The tarp was probably the most admired commodity on the mountain.

When it came to choosing technical gear, we had to ask ourselves, “what can we get away without?” and “what can’t we do without?” One thing we noticed was that many climbers carried excessive amount of technical gear: miles of cordalets, numerous screws and slings, and carabiners galore. The National Park Service provides fixed ropes and permanent pickets at all the technical locations leaving you to provide basic gear in case of a self-rescue situation. We reduced our technical equipment to two pickets, one ice screw, two Mammut Specter slings, two Petzel Tiblocs, and six CAMP Nano carabiners per person (Note:

The West Buttress does not have a high avalanche danger, so we decided we could “do without” an avalanche beacon. A probe, however, is useful for finding crevasses.

Choosing snowshoes instead of skis was a no-brainer for us. It is hard to pull a sled when you’re roped together on skis going downhill. Snowshoes are also lighter. Backpacking Light supplied us with Northern Lite snowshoes that worked great for travel on the lower glacier. We cached the snowshoes along with the sleds at the 11,000 foot (3352 meter) camp. Dependable footing is critical when one slip could be fatal so steel crampons were necessary. On the other hand, self-arresting on blue ice is challenging even with the best of ice axes so we felt safe with lightweight aluminum alloy CAMP USA XLA ice axes, which also assisted with the headwall climb above 14,000 feet (4267 meters).

Multi-purpose items and simplicity were the keys to our cooking system. All our meals were of the “just add hot water” variety, which allowed us to bring one four-liter cooking pot to melt snow for the two of us. Our MSR XGK stove provided the BTUs required to melt large quantities of dry snow in a short amount of time at high elevations. Some of our favorite parts of our kit were our homemade insulated yellow buckets. We purchased 32-ounce Nalgene containers that we insulated with blue foam and duct tape. The buckets were used for both hearty meals and hot drinks. We even used them to cook our Mountain House Pro-Pak meals with an extra half cup of rice. They were easy to clean too - just add water, cover, and shake.

Our sleeping setup was nothing fancy, but it was one place we did not want to skimp. After a bit of research, we chose REI 20-below Sub Kilo sleeping bags. The Sub-Kilo’s specs were comparable to bags costing twice as much. A basic blue foam pad cut to length served as both bottom insulation and as our “blue foam couch” under the front porch. Lastly, a ¾-length ultralight Therm-a-Rest provided a little more insulation under the torso.

When worst comes to worst you want to be warm. A good sleeping bag is one thing, but great layers are equally if not more important. It is crucial that when conditions become desperate you can throw on all your layers and keep moving until you can make camp. Matt and I tested our layering system on a 30-below ski tour in late February so we were confident that our clothing would see us through the Denali attempt. Key pieces included MontBell UL Down Inner Pants (7 ounces, 198 grams), Patagonia Specter Pullovers (6.5 ounces, 184 grams), Intuition Denali Liners (8.5 ounces, 241 grams), Patagonia Micro Puff Pullovers (12 ounces, 340 grams), and MontBell Ventisca down parkas (26.5 ounces, 751 grams). The Intuition Denali Liners are half the weight of standard double boot liners and thus dry quickly. This is important because you want your sweat-soaked liners to dry and not freeze overnight. The Patagonia Specter pullover was light and worked well for protection against any precipitation or wind. Finally, a down parka with a hood that you can throw on over all your layers when things turn for the worst is crucial, and the MontBell proved to be a good choice.

The Regrets

In the end, the only item we wished we had carried was a full-size snow shovel. The Snowclaw shovels are light and useful but when we could not poach a prefabricated tent site, building snow walls and digging out a site through hard ice layers was strenuous and back-breaking.

Conclusion

Slow and light is the only way I go anymore for mountaineering expeditions; not that I know any other way. It just seems like an unnecessary burden to carry a monster load when you can do it just as well carrying half the weight. Hopefully, all of you will find some ways to lighten up on your next mountaineering expedition.

Gear Lists

Agnes’ Gear List
FunctionItemWeight
Clothing wornouncesgrams
Patagonia Tights6.6187.11
Patagonia Capilene 2 Zip Neck5.0141.75
Patagonia MW Capilene Tee3.496.39
MH Windstopper Fleece20.0567
Patagonia Spector pullover6.2175.77
Patagonia Dimension pants20.2572.67
Koflach Degres boots60.61718.01
Intuition Denali Liners7.6215.46
OR Expedition Gaiters9.6272.16
Smartwool liner socks2.673.71
Smartwool socks3.290.72
Smartwool hat2.468.04
Patagonia Liner Gloves1.234.02
BD Shell Gloves3.496.39
Smith Empire sunglasses w/ case 2.673.71
Clothing Worn Total Weight154.64382.91
Other Clothingouncesgrams
Patagonia MW Capilene Tights (2)9.0255.15
Under Armour Long Sleeve6.0170.1
Patagonia Capilene MW Long Sleeve6.0170.1
Patagonia Micro Puff pullover10.8306.18
Montbelll UL Inner Down Pants5.8164.43
Montbell Ventisca Down Parka26.8759.78
Seirus Balaclava2.673.71
Comfort Skins Neck Gaiter1.234.02
Camp Booties14.8419.58
Integral Vapor Barrier Socks2.468.04
Bolle Goggles52
MH Subzero Down Mittens11.0311.85
Patagonia Liner Gloves1.234.02
Smartwool liner socks2.673.71
Smartwool socks3.290.72
Other Clothing Total Weight103.42931.39
Sleeping Systemouncesgrams
REI -20 Sub Kilo Short57.01615.95
Thermarest 3/4 UL 15.4436.59
Blue Foam Pad7.8221.13
Sleeping System Total Weight80.22273.67
Shelterouncesgrams
Stephenson Warmlite 2RL (shared)--
Integral Design Siltarp16.0453.6
Snow Stacks (7)9.0255.15
Snowclaw6.2175.77
Mammut Probe (shared)--
Shelter Total Weight31.2884.52
Cooking Systemouncesgrams
MSR SGK w/ Kit20.0567
OR Bottle Parka (2)18.4521.64
Nalgene (2)13.6385.56
33 oz MSR Fuel Bottle15.6442.26
Open Country 4L11.4323.19
Utensils2.570.88
Cooking System Total Weight81.52310.53
Packing Systemouncesgrams
Golite Gust w/ straps (S)20.0567
Paris Expedition sled (modified)24.0680
Packing System Total Weight44.01247
Technical Gearouncesgrams
BD Whippet20.6584.01
Camp USA XLA 210 (60cm)8.8249.48
BD Sabretooth Crampons36.21026.27
BD Bod17.8504.63
Camp Nano Carabiners (6)7.2204.12
Petzel Tibloc (2)2.879.38
Mammut Spector Slings (2)1.336.86
BD Express Screw 45.6158.76
Rope48.01360.8
Snow Picket 2'14.0396.9
Northern Lites Snowshoes43.01219.05
Technical Gear Total Weight205.35820.26
Other Essentialsouncesgrams
First Aid Kit4.0113.4
Toiletries6.0170.1
Repair Kit (shared)--
Freshetta1.028.35
Reading Book2.056.7
Other Essentials Total Weight13.0368.55
Consumablesouncesgrams
Food411.911677.37
Fuel128.03628.8
Water (1 liter)32.0907.2
Consumables Total Weight571.916213.37
Matt’s Gear List
FunctionItemWeight
Clothing wornouncesgrams
Patagonia Activist Tights8.6243.81
Patagonia Capilene 1 Tee4.5127.58
Lowe Alpine Midweight Top8.4238.14
MH Windstopper Fleece23.0652.05
Patagonia Spector Pullover6.8192.78
Marmot Precip10.4294.84
Lowa Denali Plastic Boots65.21848.42
Intuition Denali Liners10.8306.18
OR Expedition Gaiters12.2345.87
Smartwool Liner Socks3.599.23
Smartwool Socks4.0113.4
Wigwam Stocking Hat2.056.7
Patagonia Liner Gloves1.234.02
BD Shell Gloves3.496.39
REI Glacier Glasses w/ case4.6130.41
Clothing Worn Total Weight168.64779.81
Other Clothingouncesgrams
Patagonia Tights8.6243.81
Under Armour Long Sleeve7.8221.13
Patagonia Capilene MW Long Sleeve7.2204.12
Patagonia Micro Puff Pullover12.0340.2
Montbelll UL Inner Down Pants7.2204.12
Sierra Design Down Parka27.0765.45
MH Balaclava1.439.69
Columbia Neck Gaiter1.542.53
OR Camp Mukluks15.2430.92
Integral Vapor Barrier Socks2.468.04
Uvex Goggles6.0170.1
OR Mittens10.2289.17
BD Liner Gloves2.262.37
Smartwool Liner Socks3.599.23
Smartwool Socks4.0113.4
Other Clothing Total Weight116.23294.27
Sleeping Systemouncesgrams
REI -20 Sub Kilo Regular60.01701
Thermarest 3/4 UL 15.4436.59
Blue Foam Pad8.4238.14
Sleeping System Total Weight83.82375.73
Shelterouncesgrams
Stephenson Warmlite 2RL44.21253.07
Integral Design Siltarp (shared)--
Snow Stacks (shared)--
Snowclaw12.0340.2
Mammut Probe7.0198.45
Shelter Total Weight63.21791.72
Cooking Systemouncesgrams
MSR SGK w/ Kit (shared)--
OR Bottle Parka (2)18.4521.64
Nalgene (2)13.6385.56
33 oz MSR Fuel Bottle15.6442.26
Open Country 4L (shared)--
Utensils2.570.88
Cooking System Total Weight50.11420.34
Packing Systemouncesgrams
Golite Gust Pack (M)20.0567
Paris Expedition sled (modified)24.0680
Packing System Total Weight44.01247
Technical Gearouncesgrams
BD Whippet20.6584.01
Camp USA XLA 210 (70cm)10.0283.5
BD Sabretooth Crampons33.8958.23
BD Alpine Bod Harness14.0396.9
Camp Nano Carabiners (6)7.2204.12
Petzel Tibloc (2)2.879.38
Mammut Spector Slings (2)1.336.86
BD Express Screw (2)5.6158.76
Rope48.01360.8
Snow Picket 2'14.0396.9
Northern Lites Snowshoes43.01219.05
Technical Gear Total Weight200.35678.51
Other Essentialsouncesgrams
First Aid Kit-0
Toiletries-0
Repair Kit6.0170.1
Pee Bottle2.262.37
Reading Book2.056.7
Other Essentials Total Weight10.2289.17
Consumablesouncesgrams
Food411.911677.37
Fuel128.03628.8
Water (1 liter)32.0907.2
Consumables Total Weight571.916213.37
Weight Summary of Matt’s Gear
Total Weightounceskilogramspounds
Total Weight (Worn/Carried)359.910.222.5
Total Base Pack Weight329.39.3420.6
Total Weight Consumables (Sled)571.916.2135.7
Total Initial Weight (Pack + Sled)901.225.5556.3
Full Skin Out Weight1261.135.7578.8
Weight Summary of Agnes’ Gear
Total WeightounceskilogramsPounds
Total Weight (Worn/Carried)368.910.4623.1
Total Base Pack Weight343.59.7421.5
Total Weight Consumables (Sled)571.916.2135.7
Total Initial Weight (Pack + Sled)915.425.9557.2
Full Skin Out Weight1284.336.4180.3

Citation

"Doing Denali Light: Post-Trip Report and Gearlist," by Agnes Stowe with Matt Hage. BackpackingLight.com (ISSN 1537-0364).
http://backpackinglight.com/cgi-bin/backpackinglight/hage_stowe_denali_light_post_expedition.html, 2007-08-29 00:00:00-06.

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Doing Denali Light: Post-Trip Report and Gearlist
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Jon Rhoderick
(hotrhoddudeguy) - F - M

Locale: New England
Re: Gearlist for timeframe on 09/02/2007 17:54:53 MDT Print View

Robert stated earlier that this is obviously not a winter gear list, so what else would you need for that? Vapor Barriers? huge down jacket? I recently pulled up two old articles that a related to such cold weather hiking and climbing. 6 years ago there was an interview with an adventure racer named Bill Merchant, who said he wore a down jacket and a 400 weight fleece all the way down to -50! Granted he also was OK with leaving out a pad for his lightest outdoor trips, but it suggests that leg insulation really isn't nearly as important as the upper body. Also the fleece is much better against conductive heat from sitting down at breaks. Another article, the arc alpinist review had a section in which the designer Don Johnston took this 20* quilt to 0 degrees in a freezer, with little leg insulation, and only his feet were cold. Obviously thermal conductivity operates differently at -50 or -40 than at 0 degrees, but would booties help stretch a "lighter" expedition bag with 30 oz or less fill? Another place to look at is Andrew Skurka's Icebox trip, where for 16 days he endured low temperatures, and put much more emphasis on vapor barrier clothing than the Denali expedition, helping preserve the little down he had and keep himself warmer in the long term.

So with these thoughts, would you really need that much for a colder expedition? I obviously have no experiance with any of these environments, but I hope some people who do could debate that.

Matt Hage
(mattagnes)

Locale: Alaska
Re: fixed lines and tiblocs on 09/02/2007 18:02:24 MDT Print View

I don’t think there is a need for a full size ascender on the West Buttress head wall. Petzl’s Accession weighs in at 6 oz compared to just over 1 oz for a Tibloc. The fixed lines are fat and they can be icy. But the angle is far from vertical (50 degrees) and you should just be using the fixed lines in place of a running belay. We were able to use the Tiblocs with no problems this season, though the lines did fill ‘em up. But the next option is to not use an ascender at all. Just attach two opposed carabiners to your daisy chain for an improvised via ferrata. Clip the fixed line and climb the up the section using your axe and crampons. Get to the next picket, sink your axe self belay style and clip around the picket. If you or your partner are to loose their footing, the ensemble of fixed ropes is very dynamic.

Tjaard Breeuwer
(Tjaard) - MLife

Locale: Minnesota, USA
Windstopper Fleece on 09/02/2007 19:10:51 MDT Print View

How did you use the windstopper (I assume they were jackets)? And wich ones were they?

I had kind off come to the conclusion that WS is not breathable enough for high energy moments and to heavy/warmth for low activity moments.

How did this work out for you?

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
No Overboots? on 09/03/2007 16:56:53 MDT Print View

I am no expert, but if we do a little thought-experiment, let’s say a person who has no overboots is climbing up Denali, and at Denali Pass it is calm, sunny and a mild 0 degrees F. Then, at the “Football Field,” the wind has picked up to 20 MPH, and it is minus 20. On the summit, the wind is 30 MPH, the temp is minus 30. Back down to the “Football Field” and it is cloudy, with winds at 40 MPH and the temp at minus 40. The climber only has Koflach Degre boots, with no overboots or even super-gaiters. They say a much warmer boot is the Koflach Arctis Expe, and even warmer is the La Sportiva Olympus Mons. At Denali Pass there are several lenticular clouds above the summit, like a stack of pancakes, and it is minus 60 with winds at 60 MPH, and from a non-expert’s point of view it looks like frostbite with amputation of some of the toes for anyone wearing Koflach Degre boots with no overboots.

Edited by RobertM2S on 09/03/2007 17:18:35 MDT.

Matt Hage
(mattagnes)

Locale: Alaska
Re: No Overboots? on 09/03/2007 19:24:57 MDT Print View

Hey Robert,

What you have described is deteriorating weather conditions during a summit bid. This happens often high on Denali and has turned me around on two occasions. Twenty mph winds at 20-below put the wind chill temp into the danger zone (-48). Thirty mph winds at -30 are just brutal at -67. You will also begin to suffer from low visibility when winds on the upper mountain approach 30 mph. Forty mph brings a full lenticular on top. My personal cut off is around 15 mph at 15-below (-39).

Overboots are the norm for the West Buttress and I’ve carried them on every other trip. For our Denali Light excursion we used Intuition Denali liners, which offered a greater ‘R’ value than the stock Koflach booties. We also packed vapor barrier liners for our feet that could add about 10 degrees to our insulation. Our decision going to the mountain was that if the conditions are too cold for this set-up, then we don’t go. My partner and I don’t have any biz jacking around above 18,000 ft in conditions colder than 40-below. The human machine doesn’t produce heat as efficiently at these altitudes and the risk of frost bite is too high. We actually had a guy in Anchorage show off his frost bitten toes from this season. Not only did he have his overboots, but also 75-pounds of the lightest mountaineering gear known to man. Sometimes I wonder if overboots give a false sense of security to Denali climbers.

Our safety depended on being able to move fast in response to changing conditions. In my opinion, overboots create a hazard for the dog-tired climber descending from Denali Pass. This is a high accident area with many fatal falls. We also wanted to keep pack weight down so not to bring ourselves to exhaustion. Once the decision is made to descend, Agnes and I want to be able to move quickly and safely to a lower elevation.

MH-

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Overboots on 09/03/2007 20:43:18 MDT Print View

Matt: What if we modify the thought experiment a little, and it is a balmy zero at the summit, then at the "Football Field" on the way down it is 20 MPH at minus 20. That's colder than your personal limit, but you're already trapped above Denali Pass. Then at the pass it is 40 MPH and minus 40. My question is, how do you know the weather won't fall below your limit AFTER you're way high on the mountain and it is too late to fall back?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Overboots on 09/03/2007 20:56:28 MDT Print View

Robert asked:

> how do you know the weather won't fall below your limit AFTER you're way high on the mountain and it is too late to fall back?

Short answer: you can't know in advance. That's mountaineering.

Better answer: read the weather forecast in advance.

Longer answer: one can be awful determined when heading downhill in deteriorating conditions! I've seen people running DOWNHILL at 5,000 metres...

"We took risks, we knew we took risks, but things have come out against us. Therefore we have no cause to complain."
Scott, Antarctic.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Risks on 09/03/2007 21:13:34 MDT Print View

Roger: They say that fast and light is often safer than slow and heavy, but when you can buy much warmer footwear which is only slightly if any heavier, why risk your toes with flimsy boots? When Reinhold Messner soloed Everest without bottled oxygen, he garnered huge bragging rights in the climbing community, and for those who care about that (not me) it was worth risking everything. But summiting Denali via the West Buttress garners you no bragging rights in that community, so why take huge risks? (You will take some risks unless you stay on your couch.) The Oly Mons boots only weigh about 6 pounds a pair, and they include built-in gaiters. P.S. In my arrogant opinion Robert Falcon Scott was a stupid fool and an arrogant idiot. He refused to learn from the Inuits how to travel in cold conditions, so instead of being towed by sled dogs like the successful Amundsen, he post-holed it on foot.

Edited by RobertM2S on 09/03/2007 21:16:54 MDT.

Thomas Tait
(Islandlite) - F

Locale: Colorado
Fast on 09/03/2007 21:40:16 MDT Print View

>one can be awful determined when heading downhill in deteriorating conditions! I've seen people running DOWNHILL at 5,000 metres...

I guess that is the FAST part of "Fast and Light"

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Risks on 09/03/2007 23:23:31 MDT Print View

> In my arrogant opinion Robert Falcon Scott was a stupid fool and an arrogant idiot. He refused to learn from the Inuits how to travel in cold conditions, so instead of being towed by sled dogs like the successful Amundsen, he post-holed it on foot.
This has been said before. :-) But it's a great quote.

As to boot warmth - I do wonder that people never discuss the leg insulation when discussing boots. A boot can NOT keep your foot warm; it can only slow the loss of heat. The only significant source of heat for your feet is the blood coming down your leg. So there is a huge difference between warm legs and cold legs.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Re: Re: Risks on 09/04/2007 00:00:15 MDT Print View

You're right, Scott was great at talking big. He should have been a politician rather than an explorer, where he just winged it. As to leg warmth, what is your opinion of using down suits, which tap body warmth from head to torso to legs? Impractical due to having to go to the bathroom?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Risks on 09/04/2007 03:51:26 MDT Print View

> what is your opinion of using down suits, which tap body warmth from head to torso to legs? Impractical due to having to go to the bathroom?
I don't think toilet problems are that bad. Drop flap designs are well known, after all. You have to just grin and bare it ... (sorry).
A problem, or rather a question, is whether it is cold enough that you don't sweat much. Sweat plus down is not good. Even in the Antarctic people often go without down suits when they are working hard. Good wind resistance is often as or more important.

On which point, it is worth noting that the wind chill factor may be over-emphasised. It applies to exposed skin. It does not apply to the outside of dry windproof clothing. There the ordinary ambient temperature applies.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Down Suits on 09/04/2007 06:32:45 MDT Print View

Yes, I hear that many Everest climbers have their down suits carried to high camp by Sherpas, and don't actually wear them while actively climbing until the final summit push, because it is too warm lower down. (How fun it must be to "grin and bear it" on the South Col.) As to wind chill when not naked, that's an interesting question, and not being an expert, I don't really know but I would guess there is SOME effect: the wind must strip away any micro-climate that tries to form one or two molecular distances above the surface of the boot or garment. In a dead calm, I would guess that this very thin layer of air could be warmed up somewhat, and maintained with electrical forces between the molecules of the garment and molecules of the air. (I'm jusst blowing smoke out my butt, ignore it.)

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
D on 09/04/2007 06:35:47 MDT Print View

I'm getting interference from the morals computer program.

Edited by RobertM2S on 09/04/2007 06:39:02 MDT.

Robert Mohid
(mohid) - F
Re: Re: Risks on 09/04/2007 09:30:38 MDT Print View

I think the critical thing about boots that's being missed is that your feet are one of the key culprits of heat loss as they are in constant contact with the ground. Agree the only source of heat is the blood from your legs, but that the significant source of heat loss is the ground.

Overboots are a pain, and might not be worth the extra warmth if your crampon footwork is critical, but as to why they didn't suit up with oly mons instead of tested gear they already have is most likely a budget issue athan anything else.

Matt's tactics are fair in stating that if he felt conditions were too much for his gear, he would not go. That's his call and it's a reasonable one.

And quoting Scott on risk managment is like quoting Mengele on medical ethics. It's in bad taste.

Robert Mohid
(mohid) - F
Wind chill on 09/04/2007 09:35:59 MDT Print View

Keep in mind that wind chill affects ANY evaporating surface, not just bare skin.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Re: Wind Chill on 09/04/2007 10:37:06 MDT Print View

Would there be different wind chill charts for different surfaces? For example, wet cotton would evaporate faster than skin or Gore-Tex, hence the chilling effect attributable to just the wind would be different? If so, what surface did they use to fill out the standard wind chilll charts, bare skin?

Robert Mohid
(mohid) - F
Wind chill on 09/04/2007 11:27:56 MDT Print View

The wikipedia link to wind chill has some information on how the values were orginally calculated as well as the math involved. The original values were based on the measured effects of wind on a plastic cyninder.

http://en.wikipedia.org/wiki/Wind_chill#Formulae_and_tables

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Official wind chill on 09/04/2007 11:36:55 MDT Print View

Yes, but that is old data. Wikipedia on Wind Chill: “In 2001 the National Weather Service (NWS) implemented the new wind chill index, used by the US and Canadian weather services, which is determined by iterating a model of skin temperature under various wind speeds and temperatures… Heat transfer was calculated for a BARE FACE [my emphasis] in wind, facing the wind, while walking into it at 3 mph (1.37 m/s)… The 2001 WCET is a steady state calculation (except for the time to frostbite estimates [4]) There are significant time-dependent aspects to wind chill, for cooling is most rapid at the start of any exposure, when the skin is still warm… The method for calculating wind chill has been controversial because experts disagree on whether it should be based on whole body cooling either while naked or while wearing appropriate clothing, or if instead it should be based instead on local cooling of the most exposed skin, i.e. the face.” This seems to say that a climber swathed in down clothing and gloves, neoprene face masks, goggles and double mountaineering boots was not considered when making up the Weather Service wind chill charts. Their charts are based solely on the “bare face.” I didn’t see any information on charts to tell us how wind adds to the chill when we are bundled up with lots of clothing.

Robert Mohid
(mohid) - F
Wind chill on 09/04/2007 13:05:29 MDT Print View

With regards to calculating effective windchill on fully clothed climbers I don't think the official charts will be of any help.

The emphasis was on developing a model to calculate perceived windchill in a way that would be practical for people in the outdoors. So in that respect it's backwards. They agreed by consesus on what would be most usuable (bare face) and then proceeded to model that scenario.

The only work that seems to focus on the more basic aspect of windchill is dr Osczvski's work. But then again, the focus is still specific to specific applications.

http://en.scientificcommons.org/randall_j_osczevski