Military Modular Sleep System

The US Military Modular Sleep System is designed for Cold and Wet environments, which is what a Washington State Winter is.  These systems are heavy and bulky, but work very well in the winter and can be found for discounted prices if you keep your eyes open for sales or eBay postings. 

Military Modular Sleep System (MSS)

The military system is designed for use by the military in harsh, wet and cold environments.  In extreme conditions, this bag should keep you alive.  It is a bit overkill for what we do, but is nice to have when everything is soaking wet and cold. 

Some of our former military Adult Leaders prefer this system for Winter Outings.  They are heavier than civilian systems, but will keep you warm in extreme conditions such as when you are soaked to the bone. 

About the MSS:

• Uses a Modular 2 bag + waterproof Bivy system

  • Like layering of clothing, you can use one bag or multiple bags depending on environment

• Expensive and heavy/bulky - a least compared to down or a 20° bag

• NSN 8465-01-445-6274

• Find in Army surplus stores - sometimes new

• Watch out of counterfeit ones and used ones that are worn out (missing seam tape on bivy)

Modular System Components

Shown: TII MSS Inner Bag, TII MSS Outer Cold Water Bag and TII Bivy Cover
Image Source: tennierindustries.com

Generation 1 Modular Sleeping System

• Military modular system uses 3 bags that snap together

  • Introduced around 1996

  • Intermediate Cold Weather Bag

    • Color: Black

    • Maybe equivalent to a 10 or 20° bag?

    • 4lb 6oz

    • NSN: 8465-01-398-0687

  • Patrol Sleeping Bag

    • Color: Green

    • Used alone or as overbag

    • Maybe equivalent to a 40° bag?

    • 2lb 5oz

    • NSN: 8465-01-398-0685

  • Gore-Tex Bivy Cover

    • Color: Woodland Camo

    • 2lb 3oz

    • NSN: 8465-01-416-8517

  • Poncho Liner

    • Often added by soldiers to their system

    • Around 22-23 oz

    • Use alone in 50°F and above or add to poncho or in sleeping bag

  • Storage Bags

    • Large Compression Stuff Sack 

    • NSN: 8465-01-398-5428

US Military Improved 5-Part ACU Digital Sleep System

• • Introduced around 2007

  • Improvements were made to the fill material to make it lighter and compress smaller

    • Can be compressed into smaller bag

    • IMSS weighs about 1-2 pounds lighter than the MSS

    • Has a lower temperature rating

      • Note that a new rating doesn't always mean better performance

      • IMSS system uses less insulation than MSS

  • Intermediate Cold Weather Bag

    • Color: Urban Grey

    • Lighter but warmer?

    • 3lb 10oz

    • NSN: 8465-01-547-2694

  • Patrol Sleeping Bag

    • Color: Foliage color

    • Used alone or as overbag

    • Maybe equivalent to a 40° bag?

    • 2lb 7oz

    • NSN: 8465-01-547-2706

  • Gore-Tex Bivy Cover

    • Color: ACUPAT

    • 1lb 14oz

    • NSN: 8465-01-547-2644

  • Storage Bags

    • Small Compression Stuff Sack

      • NSN: 8465-01-547-2656

    • Large Compression Stuff Sack 

      • NSN: 8465-01-547-2670

TII Multi-Season Sleep System

• • Newer System by Tennier

  • TII MSS Inner Bag

    • 3 Season Inner Bag

  • TII MSS Outer Cold Water Bag 

    • Extreme Cold Weather (ECW) Outer Bag

  • TII Bivy Cover

  • Poncho Liner

    • Around 22-23 oz

    • Use alone in 50°F and above or add to poncho or in sleeping bag

  • Storage Bags

    • A Small and a Large Compression Stuff Sack are standard

    • Optional Waterproof compression Stuff Sack

    • Optional Mesh Bag

Gore-Tex Bivy

• • Used in each generation of the Military systems

  • Can't be beat in wet weather, except maybe by a tent

  • Bivy will keep you dry, protect you from wind and adds about 10 degrees to your bag's temperature rating

  • It is Waterproof - even on wet ground/snow and in pouring rain without cover (if used correctly)

  • This is an excellent addition to your sleep system when snow camping

Military Modular Sleep System Ratings

It is vital to note that the US military uses a completely different system to rate their sleeping bags than ISO.  They provide a range of what soldiers can survive for 4 hours in.  Survival rates are NOT the same as limits used by ISO and most civilian gear manufactures. 

Per Tennier

• When the two "Multi-Season Bags joined w/o Bivy"

  • T Comfort: -10°C / 14°F

  • T Limit: -18°C / 0°F 

  • T Extreme: -40°C / -40°F

Military Rating per Cold Region Operations Manual

• • Reference: ATTP 3-97.11/MCRP 3-35.1D/FM 31-70/FM 31-71 Cold Region Operations JANUARY 2011

    • The modular sleep system is designed for a temperature range of 50°F to -40°F (10°C to -40°C)

      • At the low end of this range, individuals will only stay comfortable for about four hours of sleep

      • As they sleep, they compress the sleeping bag material causing it to lose its insulating properties

      • If needed, individuals exit the bag and shake it to restore the insulating properties. Individuals should fluff it before entering. 

    • Units use the patrol bag (green with foliage green) when temperatures stay above 30°F (-1°C)

    • They use the intermediate cold weather bag (black or gray-green) when temperatures fluctuate from 30°F to -10°F (-1°C to -23°C)

    • In temperatures below -10°F (-23°C), personnel insert the black or gray-green bag into the green bag and snap and zip them together

    • The double bag works inside the patrol base cover for a temperature rating of -40°F (-40°C)

    • The newer ACU has a bag style rated to -45°F (-43°C)

    • Soldiers and Marines should wear no more than a single base layer inside the bag

Manufacturers of Modular Systems for Military

The US Military System is made by Tennier.  There are other comparable systems made by other companies. 

Tennier Industries:

• • Contractor that makes Sleeping Bags and other textiles for US military

  • You can purchase bags and other gear directly from Tennier

    • tennierindustries.com

    • Better prices can be found from retailers

    • Note: Surplus will cost a fraction of retail prices (new or used surplus)

    • Note: when shopping for used gear

      • Inspect the bivy cover to make sure seam tape is intact

      • Check out bag to make sure it isn't worn out, torn or soaked in blood (real thing)

      • Wash before use

Wiggys 

• • Wiggys makes something very similar

  • Temperature Rating: 0°F (or whatever you select)

    • +20º (-20º FTRSS) "Ultra Light" Sleeping Bags

    • 0º (-40º FTRSS) "Super Light" Sleeping Bags

    • -20º (-60º FTRSS) "Ultima Thule" Sleeping Bags

    • -60º (-80º FTRSS) "Antarctic" Sleeping Bags

  • Fill: Lamilite with Climashield

  • US made custom bags

  • FTRSS - Flexible Temperature Range Sleep System

    • Allows you to zip two bags together for modularity 

    • Similar to Military snap-together system

  • wiggys.com

  • Wiggy states that he invented the modern military sleep system and that his Super Light FTRSS are better than the system made by Tannier

Snugpak

• • UK Company that makes military gear for the UK

  • Similar 2-bag system that zips together

  • Fill: Softie Premier, 100% Polyester

  • Bag 1: use in above freezing temperatures 

  • Bag 2: use in temperatures down to -10°C.

  • Combined with zippered baffle: conditions down to -20°C

Look Alike Systems

• It really shouldn't be that hard to make a comparable system

• There are systems out there that look the same, but don't have a seam sealed bivy

• These should be avoided