The British Army sleeping system is modular. You choose a sleeping bag for the conditions, such as the heavy Arctic bag or the lighter medium weight modular bag, and zip it inside a waterproof, breathable Gore-Tex bivvy bag. Each bag packs into its own compression sack. In colder weather, the issued Modular Sleeping System nests a lighter and a heavier bag together inside the bivvy bag.
- The Arctic sleeping bag is the heaviest, warmest bag in the range and comes in Large size.
- The medium weight modular bag is the lighter, more packable option for milder conditions.
- The MTP Gore-Tex bivvy bag is a waterproof, breathable cover that goes over any of the bags.
- Compression sacks come in four sizes. From largest to smallest: Arctic, medium weight, lightweight, jungle.
- Ground insulation matters as much as the bag. Use a sleeping mat or camp bed underneath.
What are the parts of the British Army sleeping system?
| Component | What it does | Where to find it |
|---|---|---|
| Arctic sleeping bag | Heavy insulated bag for the coldest conditions | Arctic sleeping bag |
| Medium weight modular bag | Lighter bag for milder conditions, or the inner layer of a nested system | Sleeping bags |
| Gore-Tex bivvy bag | Waterproof, breathable outer cover | MTP Gore-Tex bivvy bag |
| Compression sacks | Squeeze each bag down to fit in a bergen | Liners and compression sacks |
| Mat or camp bed | Keeps the cold ground from drawing heat out of you | Camp beds and sleeping mats |
How does the Modular Sleeping System work?
The idea is that one set of kit covers a wide range of conditions. As issued, the Modular Sleeping System combines a lighter bag and a heavier bag, which can be used separately or nested one inside the other, plus the Gore-Tex bivvy bag over the top. In milder weather you carry only the lighter bag and the bivvy bag. As it gets colder you add the heavier bag, or use both nested together for the most warmth.
This saves weight and space. Carrying the warmest possible bag for every trip means hauling bulk you do not need for most of the year. The modular approach lets you pack for the conditions you actually expect. We do not publish temperature ratings for surplus bags, because a bag's real-world warmth depends on its condition, what you wear, your mat and your own metabolism.
What is the Arctic sleeping bag?
The Arctic bag is the heavyweight option. It is a large, bulky bag for the coldest conditions, and it comes in Large size. It needs the biggest compression sack in the range, and even compressed it takes up a large share of a bergen. For kit carried in a vehicle or used at a fixed camp, the bulk matters less.
| Grade | Arctic sleeping bag price |
|---|---|
| Super Grade | £59.99 |
| Grade 1 | £49.99 |
| Grade 2 | £19.99 |
Super Grade is the cleanest issued stock with minimal use, Grade 1 has light wear and Grade 2 has heavier wear but is fully usable. See surplus grades explained for more.
What is the medium weight modular sleeping bag?
The medium weight bag is the lighter part of the modular system. On its own it suits milder weather and is much easier to pack. It can also be used as one layer of a nested system when conditions get colder. Its compression sack is smaller than the Arctic one, which leaves more room in your pack for food, water and clothing.
What does a bivvy bag do?
A bivvy bag is a waterproof, breathable cover that zips around the outside of your sleeping bag. It keeps rain, dew, frost and ground moisture off the bag while letting water vapour from your body escape, so the insulation stays dry. It also cuts wind and adds a little warmth. Many people sleep in just a bivvy bag under a basha instead of carrying a tent.
| Grade | MTP Gore-Tex bivvy bag price |
|---|---|
| Super Grade | £49.99 |
| Grade 1 | £34.99 |
| Grade 2 | £19.99 |
You can compare other options in our bivvy bags collection.
Which compression sack fits which sleeping bag?
Each issued bag has a matching compression sack. They are sized, from largest to smallest, for the Arctic, medium weight, lightweight and jungle bags. If you use a sack that is too small, it will not close. If it is too big, it will not compress the bag properly.
| Compression sack | Size | Price |
|---|---|---|
| Arctic | Largest | See collection |
| Medium weight | Second largest | £9.99 |
| Lightweight | Third | £2.99 |
| Jungle | Smallest | £2.99 |
Compression sacks are also handy for clothing and spare kit. A lightweight or jungle sack makes a cheap way to pack a spare layer tightly in a bergen.
How should I store and care for a military sleeping bag?
Compress the bag for carrying, not for storage. Leaving insulation squashed for months can reduce its loft, so at home store the bag loose or hung up in a dry place. Air it after every trip so body moisture can dry out before you put it away. Inside the bivvy bag, a liner helps keep the sleeping bag clean between washes.
Frequently asked questions
What sleeping bag does the British Army use?
The British Army has used a modular system. It pairs a lighter and a heavier sleeping bag that can be used separately or nested together, inside a waterproof, breathable Gore-Tex bivvy bag. The heavyweight Arctic bag is also widely available as surplus.
Can you put one military sleeping bag inside another?
Yes. That is the principle behind the issued Modular Sleeping System, which nests a lighter bag inside a heavier one for colder conditions. Make sure the inner bag is not squashed so tightly that it loses its loft, because compressed insulation keeps you less warm.
Do I need a bivvy bag if I have a tent?
Not always, but a bivvy bag still protects your sleeping bag from condensation dripping inside the tent and from damp ground. Without a tent, a bivvy bag under a basha is a light, low-profile shelter that many soldiers and campers prefer.
What is the warmest British Army sleeping bag?
The Arctic sleeping bag is the heaviest bag in the range and is designed for the coldest conditions. We do not quote temperature ratings, because real warmth depends on the bag's condition, your clothing, your mat and whether you use a bivvy bag.
Which compression sack do I need for an Arctic sleeping bag?
The Arctic bag needs the Arctic compression sack, which is the largest in the range. Smaller sacks, such as the medium weight, lightweight and jungle sacks, are sized for lighter bags and will not close properly around an Arctic bag.
How quickly will my sleeping bag be dispatched?
Orders placed before 1pm Monday to Friday are dispatched the same day. UK delivery is free on orders over £100, and you have 30 days to return an item. See our store facts page for full details.
Written by the Raid Supply team, who grade every item by hand in Buckinghamshire.