Military sleeping bags are a relatively recent development. The comfort of the ordinary soldier in the field was not a priority for armies until the 20th century. Even in World War II, blankets or a simple mummy bag was the usual sleeping gear, even in very cold weather. Specialized mountain troops had the first sleeping bags designed in modern terms.
Tenth Mountain Division soldier in the snow with his M-1942 Mountain Sleeping Bag on a bed of pine boughs, Camp Hale, CO, 1943-1944.
Prior to World War II American soldiers were issued blanket rolls. This consisted of several wool blankets and a ground sheet to roll it up in. The Blanket, Wool, OD, M-1934 was the basic "Army Blanket" and each soldier had at least one issued. In cold climates as many as five blankets were issued to each man. These were combined with the Roll, Bedding, M-1935 or a Shelter Half which could also be used as a ground cloth or, with another soldier, make a tent. The blankets and items such as socks and underwear all were folded into the roll, following a carefully defined procedure drilled into the soldiers in Basic Training. For sleeping, it was unrolled and made into the best arrangement for the conditions.
World War II Mountain Sleeping Bag
M-1942 Mountain Sleeping Bag, Water Repellent Case, and Carrier. Photo: Philadelphia QM Depot.
By the outset of World War II, sleeping bags of varied design had been in use for many years by mountaineers and sportsmen generally. The strengths and weakneses of the designs were well known. It was assumed by the Quartermaster engineers that a sleeping bag would replace blankets for mountain troops. The mountain soldier would ordinarily have to carry their sleeping bag and it was therefore essential to make it as light as possible and small enough in bulk to fit into the Mountain Rucksack. It must, at the same time, be durable enough to stand rather rough treatment and warm enough for sleeping in fairly severe cold. It must be so designed that the soldier could get out of it quickly in an emergency. As in the case of the sleeping bags for Arctic use, the design problem was complicated by the fact that there was a shortage of down, the material most favored as a filler.
The "mummy" type of sleeping bag, shaped to fit the body, had been gaining favor among mountaineers for several years, as against the more usual rectangular bag. The mummy bag was considered more efficient, used less material and was less bulky. A sleeping bag of the mummy type, consisting of inner and outer shells and an attached head canopy, was designed for the ski troops in 1941. This rather complicated design was thoroughly revised and then further refined in the next year, partly with a view to simplifying the whole sleeping bag program by providing units that could be used by all troops operating in cold climates.
The mountain sleeping bag developed in 1942 was designed to be issued to mountain troops as an item complete within itself. Combined with an additional outer case, it became a new Arctic sleeping bag.
The mountain bag consisted of a single case filled with a down and feather mixture, with a pear-shaped face opening and a full mummy shape. A slide fastener with a quick release device permitted the bag to be opened almost instantly down the front to about half its length. The casing was made of water repellent balloon cloth. There were new and unusual features in the design. The stitching which bound the casing to the filler did not go all the way through, like quilt stitching. Instead, it fastened the casing, by alternating inner and outer lines of stitches, to a diaphram of cheesecloth which separated outer and inner layers of the filler. This technique avoided lines of cold penetration through the stitiching, which had been criticized in earlier models. The closing seam was reinforced against cold by the addition of a tubular secion of filler placed tight against it.
A waterproof carrying case was issued with the sleeping bag. The sleeping bag was placed in the case when not in use. The case could also be used as an added foot covering in extreme cold. There was an insulated, inflatable sleeping pad (air mattress), for additional warmth and to protect the sleeping bag from wetness when camping on ice or snow. Finally, there was an outer water repellent case for additional warmth when a tent was not used. [ Source: QMC Historical Studies No. 5, Feb. 1944 ]
The mountain sleeping bag (and Arctic version) had tie straps attached to the foot of the bag. These straps could be pulled through matching holes in the foot of the cover to get the bag and cover aligned. The two parts could be rolled up together and the ties used to secure the roll. "US" was stenciled on the outside of the cover so that it would show when rolled.
Bag, Sleeping, Arctic, M-1942
The Bag, Sleeping , Arctic, M-1942, consists of two down and feather filled cases for use in extreme low temperatures. The inner bag is mummy shaped. A full length zipper is used to close the quilt shaped outer bag. A waterproof wrap case, with flaps and tie tapes, is provided for carrying both rolled bags. Also issued under the same stock number is another Bag, Sleeping, Arctic, consisting of two mummy shaped down and feather filled bags and the Case, Water-repellent, for the Bag, Sleeping, Mountain, described above.
With a waterproof cover, this system is suitable for use in extreme low temperatures with the Bag, Sleeping, Mountain, used as the inner bag, and the outer bag is of similar design and construction. Tie tapes on the foot of Bag, Sleeping, Arctic, extend through openings in the bottom seam of Case, Water-repellent, to hold bags in a compact unit when rolled. A waterproof cover is provided to protect the bag.
Case, Water-repellent, for Bag, Sleeping
The Case, Water-repellent, for Bag, Sleeping, is made of poplin and provides a wind resistant cover for any one of the Bag, Sleeping versions. That is, it is ordinarily used with all sleeping bags. In warm weather, where little protection is needed, the case may be used alone. Two openings in the seam at the foot of the case allow the tie straps on sleeping bags to be drawn to the outside to hold the items in a compact unit when rolled. The Case, Water-repellent was also used for decades as the outer case for newer model sleeping bags (see below). The case was issued in two sizes, regular and large. It is common to find these covers with dates in the 1940s through 1960s, manufactured by "Boyd and Gould" among others. Markings are stamped inside, along the button or laced opening, or may be in the form of a sewn-in label.
World War II Infantry Sleeping Bag
Early in the War, the pre-war blanket roll continued to be used, the same situation as with other equipment. By 1944 troops were issued a mummy shaped sleeping bag made of blanket material: the Bag, Sleeping, Wool type 27-B-317. This sleeping bag was used with the standard water-resistent case to create a lightweight and reasonably warm sleeping bag suitable for the ordinary infantry soldier.
The material of the Bag, Sleeping, Wool was the same color wool fabric as an Army blanket, but a little heavier. A long quick-release zipper ran the length and the head was enclosed in a hood shape. The mummy shape saved material and weight compared to carrying several blankets and was warmer due to its one piece construction. By using it with or without the case the soldier could adjust to the daily temperature changes, at least until it got very cold.
The Bag, Sleeping, Wool had two labels sewn in. One had standard instructions for care and use while the second, smaller label had contract, manufacturer (e.g. "Woodbury Mills" or "Selig Mfg") and date information. The dimensions were about 84" long and 28" at the widest point. According to Raymond Roy, former Worsted Superintendent at American Woolen Company, World War II brought government contracts for enough cloth to make "3,000,000 sleeping bag lining cloths, and 4,841,200 finished GI blankets (among many other things)."
These sleeping bags were issed to troops during World War II through the 1950s and continued to have a place as a liner for other bags for very cold conditions.
Sleeping Bag, Mountain, M-1949
Label, zipper, and lacing of Sleeping Bag, Mountain M-1949 Click photo for larger image.
Building on the success of the 1942 Mountain and Arctic sleeping bags, in 1949 the Army issed the Sleeping Bag, Mountain, M-1949. This mummy shaped, feather filled bag had a heavy zipper closure with quick release. It was intended to always be used with the same Case, Sleeping Bag M-1945 outer water-repellent carrier as the earlier sleeping bags. It was issued in two sizes, regular and large.
The M-1949 sleeping bag was issued for years, through the Vietnam War. It is common to find bags dated in the 1960s (if dated at all). The label sewn in at the head gave instructions for use including to lace the liner onto the sleeping bag, as shown in the photo. The outer liner had a set of eyelets that matched eyelets along the zipper line, as well as snaps that can be used to form a wind resistent closure. A length of olive drab parachute cord can be used to lace the outer water-repellant case to the sleeping bag itself, to form one unit. Other instructions included "avoid sweating" and to spread a poncho under the bag to protect from moisture, as well as to put padding, a pneumatic mattress, boughs or other materials under for insulation. Click on the photo to see a larger, readable version.
Updated models of the M-1949 Mummy Bag
In the 1970s (?) the M-1949 sleeping bag was replaced by a new system of sleeping bags, still very close in design to the M-1949 Mountain bag. These were the Bag, Sleeping, Intermediate Cold Weather (ICW) and Bag, Sleeping, Extreme Cold Weather (ECW) as follows:
15 deg. F
-20 deg. F
Water repellent/Wind Resistant Case
Draw string hood
Quick release zipper closure w/snap cover
100% Waterfowl Down
7 1/2 lbs
7 1/2 lbs
The dimensions of a sleeping bag are hard to measure since it is soft and the width varies. These sleeping bags are approximately 85 inches long x 35 inches wide at the shoulders, suitable for someone up to about 6 foot 2 inches tall. When rolled up and tied, the bag measures approximately 21 inches long x 12 inches in diameter.
Note: ECW bag has cotton balloon cloth inner panel with polyester 6 oz. batting filling. The ICW bag may have feathers and down, depending on the year of manufacture.
Pneumatic Mattress and Sleeping Mat
The World War II pneumatic mattress went through several design changes and material upgrades through the Vietnam War. The Vietnam era Pneumatic Mattress was an inflatable, coated fabric mattress, ridged with side panels. The colour was olive green (US Army shade 207). These were designed to be inflated by mouth but took too long to blow up and later deflate not to mention it was prone to puncture.
The pneumatic mattress was replaced by today's polyfoam mat, green/gray or olive drab in color, with two roll up straps attached. The mat measures 23 5/8 inch wide, 73 inches long, and is 3/8 inch thick. (NSN 8465-01-109-3367 or 3369) Available from Amazon.com as the military sleeping pad.
Another innovation was the Pad, Sleeping, Self-inflating, (manufactured by Therm-a-Rest) that rolls up into a two inch diameter cylinder but inflates to be as comfortable as the foam mat. It weighs about 2 pounds and self-inflates as soon as unrolled if its valve is open.
Extreme Cold Weather Sleep System
The Sleeping Bag, Extreme Cold Weather (ECW) (NSN 8465-01-033-8057) was replaced by the Extreme Cold Weather Sleep System (NSN 8465-01-306-2681) which was in turn replaced by the Modular Sleep System described below. The components of ECW Sleep System are not interchangeable with the components of the Modular Sleep System. The ECWSS is a rare item.
Modular Sleeping System
The Modular Sleeping Bag System is current issue in the early 2000s. It is a four-component system:
Sleeping Bag, Patrol (30 to 50 deg F), MSS Green NSN 8465-01-398-0685
Sleeping Bag, Intermediate (30 to -10 deg F), CW, MSS Black NSN 8465-01-398-0687
Compression Stuff Sack, Black NSN 8465-01-398-5428
The four components can be ordered together by the single number NSN 8465-01-395-1154.
Colder temperatures can be managed by using multiple components, hence the name MSS. Putting the Patrol and the Intermediate sleeping bags together provides insulation to at least minus 30 degrees Fahrenheit for a soldier dressed in polypropylene expedition weight undershirt, drawers and cushion socks. Protection to minus 50 degrees Fahrenheit is possible for a user wearing various layers of ECW clothing inside both bags.
Except for the compression stuff sack, the components are also produced in extra-long, 14 inches longer than the above standard size bags. The extra-long components were ordered individually with their own NSN's:
The recommended sleeping system is the Extreme Cold-Weather Sleeping Bag (NSN 8465-01-033-8057), on top of a polyfoam sleeping mat (NSN 8465-01-109-3367). The MSS ECW combination can be used instead of the ECW Sleeping Bag.
Layers of tree boughs or mats under the sleeping bag help prevent heat loss to the ground. The sleeping bag should be shaken out before using to add air to the lining, which improves its insulation.
In tents, soldiers should sleep in long underwear and socks with all other clothing hung up to dry. In improvised shelters, only boots and the outermost clothing layer should be removed. Place clothing under the sleeping bag where it can add insulation without accumulation moisture from the body. Ice should be removed from vapor barrier boots, and they should be wiped dry on the inside and, if possible allowed to air out before putting them on again. In extreme cold, a balaclava or some other head cover should be worn while sleeping to protect the ears, neck and face. The arctic mittens can be worn on the feet while inside the sleeping bag to help keep the feet warm. The head should not be put inside the sleeping bag, since moisture from the breath will accumulate in the bag.
Air out the sleeping bag as often as possible to evaporate moisture.
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