Blizzard Bag testing format

The recent post re: Blizzard Bags resulted in the US distributors kindly sending one for examination. Longtime members will recall the group input on condoms for emergency canteen. A series of posts resulted in a remarkable document. I thought we would use this method again. I will post preliminary information so we all have the same vocabulary. If I make any mistakes forum members can point them out. We will first discuss the mechanisms of heat loss and generation, a history of the space blanket, and finally ( hopefully on what I can assemble) a review of the Blizzard Bag and any market competitors in term of materials etc. There are a few known and not so well known products that may be usefull additions to an emergency system we can discuss. Finally a appraisal of performance and specific use and value. I will also be invitng the makers to answer any questions.

Cody's book title says it all. We like this very thin microclimate of a wet 98.6 around us. We eat. Dieticians call this caloric intake; French toast,eggs,bacon and coffee, or a Mainstay bar spiced with tobasco sauce and Earl Grey Tea,in extremis Dead seagulls, ants and filtered water, Yum Yum The second method is external; a fire, radiated heat from rocks storing solar energy, chemical heat packs. The third option is kinetic energy, creating heat through exercise, aka flapping your arms while walking in circles, hopefully until you stumble upon a camp with a fire cookinig French Toast.

There is quite a good informative document about sleeping bag performance at

www.mammut.ch/mammut/uploadedFiles/Sleep%20Well_Pt1_E.pdf

It is quite a good introduction into the subject.

We have 5 mechanical processes, CCRRE- something I start to utter when I'm cold. Convection is air ( wind) on the skin speeding up evaporation beyond the optimal exchange to maintain that 98.6 Cody explains. Conduction is the loss of heat through contact with a colder surface. Think of the girl who turned you down for your first dance. Radiation is normal heat loss from the body. Think of it as a gas tank slowly emptied with normal driving and we know needs refilling ( french toast.) Respiration is heat loss through breathing. This is why people from cold climates have different noses from people in hot, at least until we all started dating pretty girls from all over and the irish great grandmother got hot and cold. Evaporation, a scientific term for perspiration AKA sweat: The normal cooling of our body to maintain, once more 98.9 degrees. Speed it up or slow it down and we are in trouble.

"Clothes make the man. Naked people have little or no effect on society."- Mark Twain. Everyone knows the 3 basic layers of clothing,right? We have an evaporative layer next to the skin to move perspiration off our body and avoid overheating and chilling. Next is insulation, materials that trap warm air. Finally we have a barrier layer to prevent rain and/or wind from further chilling and to keep that warm air and optional moisture in. All garments and shelter assemblies can be categorised into these three layers.

In 1964 Nasa developed a thin ( @ .20 Micron) plastic sheeting coated with powdered aluminum. We don't know if it was the same team that developed the Magnesium bar. The first use was in space suits with @ 27 layers.The material will reflect 80-90% ( depending on the source) of radiant body heat. Remember, these suits had external heating units in a closed and regulated environment. The 'Space Blanket' entered the civilian market as a lightwieght emergency item in an open and very unregulated environment called Mother Nature. It's that very compactness and wieght that make it an attractive option. But is it a blanket? A 6 point Hudson's Bay blanket is THICK. It has lots of air pockets ( loft)in all that wool to hold warm air.A single unit of space 'blanket' has none. Coupled with the fragile, almost single use material, space blankets are more properly space sheets. They make a good outer barrier to ward off wind and rain, or would if designed as an enclosed unit ( what Blizzard bags and a few others have done.)They have found some favour as PART of improvised shelters to improve campfire efficiency. The danger lies in their promotion as a convenient placebo. A person not interested in personal safety is going to think this handy, $3 item in the glove compartment is a Hudson's Bay Blanket. There's a anecdote about a cowboy caught in a Blizzard in the 1880s with only his thin 'fish' rain slicker for protection. He barely rode back to his ranch. His bunkmates asked him if the fish helped any? " If I had two of the blankety-blank things on I would have freezed to death." Is there a valid role and place for this material? We will try to find out with testing.

As for suggestions, I'd like to see it compared against a couple of benchmarks:

1) No bag.
2) A 'traditional' single walled bag as a control.

-john

I would second that suggestion but add a 3rd control,

3) A Rab Quantum Top Special bag at 300 gms and a Pacific Outdoor Equipment Insul Mat Uber Lite at 250 gms.

What would really be interesting would be test Army Ranger Ricks Mylar Blanket and 9 hr Candle method.

The bag arrived today. The unit is nicely vacuume packed in a durable, double layer of thick plastic bagging. I was about to cut it open with my knife and recalled the canadian crash where lack of knives kept needed gear inaccessable. I noticed a small slit in the packaging material highlighted in red. My nieghbor, a senior with arthritis was able to tear open the outer, and tougher bag with effort. I opened the second with a good tug. Then I read the instructions, brief but always helpfull to read first and it says " TEAR AT RED LINES TO OPEN." As an aside, if you are carefull and don't destroy the outer packaging a very tough water container can be fabricated by carefully resealing the top over fire. The bag itself is very generously sized lengthwise and my 6'2" frame will fit with full head coverage. The three layer laminate is sealed into a tube, the bottom gathered into a taper, glued and locked with a zip tie. It's not going anywhere and is very secure.Topside, there is a nice toggled drawstring of braided cord positioned on the lengthwise seal. The seal may cause a loss in insulation, not dissimilar to sleeping bags with the zipper covered by a flap. The instructions next tell you to CAREFULLY expand the bag by stretching it sideways. Well, mea culpa I again had my nieghbor help and her clenched fist tore off a palm sized layer of the outer laminate with a finger size hole fully tearing through the second and third. This did give a 'window' to constuction and revealed the horizontal, thread sized elastic and the two thick cellular construction. Next I'll climb inside.

As it happens, I won one of these in a competition when they first came out. Interesting idea that will help to keep you warm provided that you do everthing you can to help. Like get out of the *&^%$ wind! And put some insulation underneath you.


Space blankets do have their uses. Just so long as you treat them as a cheap expendable. They are above all things a vapour barrier. Weatherproof a shelter, cut up and use to line that hole you are going to hot rock boil some water or melt some snow in. Radar corner. Signal kit? Reflective layer for your desert survival shelter to help reflect the sun. Take four branches, one mylar blanket and some duct tape and hey presto! One Bloody Big Signal Mirror. One thing that they are is tough. Need to patch that hole in the hull? Double or triple a blanket over the hole and tape it down. You could even use one or two as a sail in a pinch. It might not last long, but so long as it does the job for just long enough, who cares? Use your imagination.

There seems to be an ethos on the forum of refusing to use something because its not exactly stellar at it's advertised purpose. I can live with loosing a nights sleep because they are not exactly quiet. Can't say the same thing about hypothermia.

The generous length is countered by a close fit. Anyone who uses a mummy style bag will be used to this, and for thermal efficiency small is beautifull. The horizontal elastic works well to maintain 'drape.' No, we are not on Saville Row. Drape is a material's ability to naturally cling to and move with the wearer. This is one of the major advantages of Down and Lamilite. Space blankets have a reputation for being noisy affairs.This is only of concern if the user is trying to get vital sleep. The Blizzard bag was significantly quieter, no doubt in part to the construction.The air cells were easily pulled to capacity. This is a mechanical effort on the user's part, no passive regaining of % loft in x minutes as with a lightly shaken down bag. At this point I repaired the tear with duct tape. The website claims it's wind and waterproof. I would assume this means rain,sleet and melting snow. I went one step further, and with worried looks from my nieghbors slipped into the swimming pool @ the 4' level. 15 minutes later I was still dry. I allowed the bag to air dry in our hot summer sun. Instructions for repacking bag are to again pull lengthwise to reform the pleats and at home a towel and vacuume cleaner.I was skeptical, seeing more pleats than a Highland kilt. Following the instructions, one can indeed repack almost as perfectly as the vacuumed unit at home.It's a matter of deliberate effort, and even a sloppy field repack reduces the bag to easy stowage and carry.

On one occasion I was out in a fishing boat most of a chilly spring night due to wind and a cantankerous outboard of a now-discontinued line that I and others called the Curse 'N Carry. I had a space blanket in the tackle box, and I agree with Leigh - it was much more comfortable with it than it would have been without it. It blocked the wind, shed the spray (when the motor occasionally decided to work and I pounded into a chop for a few minutes at a time), and reflected some body heat. I did have a foul weather jacket on, and there's no doubt that helped. But so did the space blanket. So, I have one in the car bag and two in the BOB, as backups to my backups, if you will.

Frank2135

There is a story of some Inuit suddenly trapped on a breaking iceflow seperated from their dogsleds and supplies. Survival depended on the chance of currents either pushing the flow back to shore or out to sea and death. What did the Inuit do? They went to sleep, reserving their strength. They woke up to the flow hitting the shore, using their guarded reserves of energy to recover the sleds. Ever look at the advertising for space blankets? I think the same consultants for mattress companies are responsible. Conversely,most illustrations for survivors are somebody huddled fetal like and bug eyed in anticipation of Bart the Bear to come charging out of the darkness into a charge dropping hit from a .22 survival rifle. We have 3 digit temps here, hardly optimal testing conditions. But I went to my cooperative butcher shop's walk in freezer today and climbed into the blizzard bag wearing smartwool, woolen pants,shirt, mittens and a balaclava. I almost died of sunstroke making the 10 minute drive I spent @ 20 minutes getting slightly chilled and then climbed into the bag.I was comfortable enough to fall asleep for 2 hours. I only woke up when an employee, unaware of my presence thought I was a wierd deerbag and tried to move me. After he calmed down, I remained in comfort for another 3 hours. My test ended when the shop had to close.I'll report my observations in the next post.

This brief assessment was hardly laboratory or even in the true conditions I'd like to test. But for what it's worth here are my anecdotal observations. Obviously this is no arctic rated sleeping bag and in a blizzard as named I'd love to have a vacuume packed down or Lamilite bag. But for many good reasons apart from performance we can't always have one, or a dozen if needed.The Blizzard Bag takes a material with obvious shortcomings and a mixed reputation with users and with a little thought produced a well made and thought out unit.The simple instructions are common sense not always commonly found with users.In spite of managing to damage it straightaway the bag was deployed and repacked 5 times, kept me dry in a swimming pool and performed in a cold environ well enough to enable comfort and rest.One of the premises of such bags is the vapor barrier startegy. Simply put, your warm sweat stays inside and you remain warm, if soggy. The Achille's heal of this theory is the very rapid cooling once again outside- potentialy dangerous for a casualty. The bag did produce this effect, but suprisingly not as pronounced as my experience with commercial VB products.I'm guessing the active realignment of the air cells helps vent excess moisture out the adjustable top. It's forte is compact and light wieght with a useable performance. The price, at least from our US distributor is easilly competitive against traditional blankets or inexpensive sleeping bags. Again, the compactness is an attractive feature if your restricted by logistics. I would toss in a short length of Duct tape for possible tears a watch cap or balaclava and some dedicated or expedient ground insulation. I used a newspaper and plastic bag for mine. Again, In temporary conclusion until I can play with it this winter, the Blizzard Bag can fill a very usefull function in your strategy and kit. Think of it as part of a SYSTEM you can assemble easilly and depend on for more than one deployment.

How would you rate it against a current U.S. Mil-spec poncho liner and a Rab Vapour-rise bivvy bag? Which is my preferred daysack combo.

Rating one 'system' vs another is tricky. The Blizzard Bag and it's mates are primarily an emergency system with acceptable performance in a very compact unit. If I am a mountain rescue tech racing to a avalanche that injured 12 people obviously 12 Bags in my rucksack have greater potential value than one or two vacuume packed sleeping bags. Or if I am a day hiker with limited kit but unlimited foresight a unit in my daysack is good insurance. Emergency service users will use such a unit once and discard. A civilian can use this in emergencies or simple preference and expect a usefull lifespan. I have deployed mine every afternoon, taken a cat nap and repacked it. I don't know as of yet a reasonable service life vs a poncho, bivi bag etc. If you have a dedicated lightwieght setup stick with it. If you foresee any scenario where a easily packed unit could be handy consider Blizard bags. Performance is vastly improved over a placebo space blanket.

Wow! I thought I would check back and see if anyone had followed up my original Blizzard Bag post. This is a pleasant suprise.

They sound ideal for throwing in the car for those unexpected stuck in a snow or a jam in winter situations and are then likely to get transfered to daypacks etc as necessary.

I look forward to hearing the winter testing feedback in due course.

OIMO

I wonder how would Blizzard bags compare to Heatsheets bivvies and blankets?
One thing I noticed is Blizzard bags and blankets are significantly heavier then Heatsheets.
Blizzard bag (12.3 oz) vs Heatsheets Bivvy (3.9 oz)
Blizard blanket (18.7 oz) vs Heatsheets blanket (2.9 oz)

However, it seems like the Blizzard products are also warmer.

Would this be the general consensus?

How much does a USGI poncho liner weigh? I was thinking that they might be fairly heavy since they're synthetic not down.

They are very light, I don't know the exact weight but I carry one in my bob and have a hard time telling the difference in wight with or without it.

not to deviate from the topic, but I felt this appropriate since red flare brought up heat sheets(tm).

I was in Texas this past weekend teaching some classes. Several of us rode in together on Thursday, but arrived late.

instead of setting up camp in the dark we decided on star shelter (sleep under the open stars). A big ground cloth was set out to accomodate 5 of us. A variety of pads were laid on top as were the types of bags with varying degrees of insulative properties. The only one without a bag was me.

I've spoken with Alex (Red Flare) and told him him I like heatsheet so much I use it as part of a 3 season setup. Of course, three seasons in California is far differrent than in Wyoming, or in this case Texas.

That first night was so cold. it dipped into freezing temperatures before we went to bed, as was evident by some heavy frost on the pads and bags.

come bed time, I pulled out my sleep system: Thermarest, Ultralight Pad; One AMK, heatsheet; one US, poncho liner.

Some of the other instructors kidded with my choice of sleep gear, but I assured them if I really got cold I would snuggle up with them... LOL!

The ponchliner went on me first followed by the Heatsheet as a shell, silver down. I did this to prevent from waking up in a puddle of water from condensation build up by using the liner as a barrier... worked like a champ

while it was cold outside, I managed to sleep soundly except for not having a pillow. At one point I decided to get up grabbed my daypack and returned to bed with my improvised pillow... it worked decently!

The next morning, everyone was sharing their experiences with the cold. From what I can gather, based on comments and remarks, I was the warmest of the lot, and that is a lot to say considering I'm only about 9-10% body fat.

The next night. I tried using the same setup in the hammock, but really was cold all night. I do think, however, it had something to do with the fact I was sick that day and didn't eat anything all day, let alone before bed, to keep my furnace burning.

On night 3 I changed tactics. I wrapped the Heatsheet on the outside of the hammock, silver in, and used my thermarest, along with the liner, inside

I did experience a bit of a cold shoulder, but other than that, I slept soundly. The next morning provided the evidence as to the reason for the cold shoulder. The heatsheet slipt away from the right side of the hammock, the cold shoulder side.

What I took away. Set up properly it can work and work well, but to be comfortable, in that temperature, you need more.

Alan
[url=survivalbiz.com]survivalbiz.com[/url]

Alan,

Sounds like a good time. You got to be here during the best weather we've had all year!

-Blast