Posted by Jerry Wigutow on Jul 14th, 2014
I have for 20 years written about sleeping bags created by government employees and the fact that whatever these people have created has never performed in the field at the intended temperature rating. The primary reason is the fact that these people ignore the temperature and use what is called “clo value” for their rating. “Clo” I believe comes from the word clothing and has no value! But, the people who create insulated products for military personnel to use, in my opinion, do not care if the products work or not.
In April 2013 I wrote a commentary about Natick Labs looking for a -20 degree sleeping bag for the Marines. They purchased an Ultima Thule from me and tested it. The “clo value” they came up with was about 10 and that is the highest “clo value” that they ever registered. But, I was not to receive a second order for any quantity. In my June 2014 commentary I wrote about the direction that Natick Labs took with respect to making a bag using a lamination process of sorts to accomplish the task of making a -20 degree bag. As I said then what they came up with will not perform for the task at hand.
Since the publishing of the June 2014 commentary I have received some very interesting information. The cost of the bag to me is $223.00 without the compression stuff sack. The compression stuff sack will probably cost about $20.00. I was very surprised to be told of these two weeks later. The other information I received was of even greater interest, as it has to do with the temperature rating and use.
I quote; “Protection from 3 to 15 degrees Fahrenheit is achieved when using the Outer Sleeping Bag (OSB) inside the 3S bivy when wearing maximum to medium clothing layers, respectively (see 6.1) and without a tactical shelter. Protection from -12 to 5 degrees Fahrenheit is achieved when the OSB is used over the inner 3S sleeping and inside the 3S bivy when wearing maximum to medium clothing layers, respectively (see 6.1) and without a tactical shelter.”
When I researched the national stock number 8465-01-608-7503 to see if there was a 6.1 explanation, I could not find one. However, what I did read was the following; I quote: “Outer bag sizing-internal outer sleeping bag must be large enough to use it over the 3S sleeping bag; external sleeping bag dimensions cannot be too large to cause tight fit inside the bivy; outer bag attachment-outer components can be handled as A single item for field expedient use and storage.”
It stands to reason when the two bags are used in concert they should fit comfortably inside of each other as well as inside of the bivy bag. This single bag is referred to as an “Extreme Cold Weather Sleeping Bag”. What is not noted is its temperature capability or even the “clo value” which is what they prefer to use.
What this information is telling us is far different from what the initial bag is supposed to be capable of performing at: -20 degree Fahrenheit as a low temperature. By their own admission the bag does not perform at that temperature as a stand-alone product nor does it perform to that temperature when it is combined with the existing center zip bag and bivy that are already in the system. The powers at Natick rejected my bag after they tested it because my bag the Ultima Thule actually performed by itself at -20 degrees F, but we know it performs at temperatures lower than -20 degrees F, as the Navy discovered -35 degrees F. Also, if it was their intension—as it appears it was—to have a two bag system, all they had to do was resurrect the initial system I built for the Marines in 1993; which was the Ultra-Light FTRSS (over bag). This system is rated for -20 degrees F and I have personally used it at -30 degrees F.
Further information that I have received states and I quote;” For best results, the bags should be stored loosely in a well-ventilated area (or bag) when not in operational use.” Or and I quote; “the loss of loft has much to do with the way the bag is stored; we don’t recommend storing the bags in the compression stuff sacks for long periods of time, especially if they’re damp or soiled.” Considering that they are using continuous filament fiber just as I do, I don’t care how long the bag is kept in its stuff sack because I know that the loft of the bag will not be adversely affected since I vacuum pack them under about 20 tons of pressure for the Air Force survival kits and we know the loft returns after years of being in the vacuum packed state. In addition the dampness or soiling are not a consideration, as it also has no negative affect on the performance of Lamilite insulation.
Aside from the fact that the bag or bag system isn’t rated for -20 degrees F a more serious problem exists. As we have read they the creators of this system want the individual Marine to wear several layers of clothing. Since these people are Marines they will be using these bags when on missions, peace time or combat time does not matter. The Marine will be moving or very active and as such will not be getting into the sleeping bag without clothing. All of the moisture that the individual has been generating all day is trapped within the clothing that is being worn. Aside from the material absorbing the Marines body heat the moisture trapped in his clothing will also be absorbing his heat. Remember water in any of its forms absorbs heat better than any other entity on the planet, so the end result is going to be a Marine who gets cold quickly.
So much for government created sleeping bags.