Join Date: Oct 2001
You will likely be afforded two types of sleep at military simulation: planned, and unplanned. Planned sleep will occur when your unit is rotated out of action for rest. Unplanned sleep is the result of your unit identifying a time when a reduced level of alertness is acceptable or required. These times may include situations where you are placed in a LP/OP overnight, or holding a defensive line in force with good fields of visibility. Your sleeping gear needs to allow you to sleep with a degree of comfort and get real rest. However, it is important to remember that you may need to go from sleep to fighting in seconds. In some cases, you must pack and be mobile in less than a minute. Your choice of sleeping gear will greatly impact your ability meet both the rest and action requirements placed upon you at 24-72 hour simulation.
Things to Consider
- Weight and Volume
- Sleeping gear, like shelter, can consume the majority of your pack space and weight if allowed to do so. Most inexpensive zero degree bags will be up to 20L in volume and can exceed 3kg in weight. Many people won’t compromise on sleeping equipment comfort, but combine that with a desire to save money by buying an inexpensive system and the weight and volume requirements skyrocket.
- Temperature Range
- Whatever the weather report says, assume it will be 10°C colder. Sleeping gear has to keep you relatively warm. Compromises can be made here if you’re willing to deal with some discomfort over night.
- Water Resistance
- How well does your sleep system deal with water. Even drybags can leak, and a sleep system set up on the ground may receive splashes from rain or become dew-covered overnight. A down sleep system will not retain warmth if wet, and must be protected.
- Setup/Takedown Time
- Can you easily set up and take down your sleep system? If suddenly called to action, how quickly can you get out of it and into the fight? How quickly can you pack it and bug out if required?
- Shetler Choices
- In some cases you may be able to compliment your sleep system with shelter. A bivy or tent may reduce the need to use waterproof sleep gear. The protection of shelter may also help reduce the necessary temperature rating as you’re protected from the wind. Conversely, no shelter means you need to choose some extremely good sleeping kit.
- Clothing Choices
- You spend all day wandering around in insulating layers. If you’re taking them off only to replace them with the warmth of a sleep system, you may be wasting the space in your bag. Remember that any insulating layers you pack can be used to supplement your sleep system. In some cases, you may be able to replace the need for a sleep system all together with your clothing choices.
- Sleeping Pad
- To prevent heat loss through conduction, you need to place an insulating layer between you and the ground. Sleeping pad can be inflatable, closed cell foam, or a combination of the two. It’s important to consider the ‘R’ value of the pad, which will inform you how well the pad insulates. Some are larger and heavier than others, and tradeoffs are made between size, comfort, and price.
- Sleeping Bag
- It is impossible to list all possible sleeping bags options. A good primer on what to look for in a sleeping bag is available at Outdoorgearlab.com. Ultimately you’ll have to choose between down and synthetic insulation options. While regular down packs down very small and is very lightweight, it is susceptible to moisture. Synthetic is warm when wet but can’t hope to beat the compressibility of down. Colour choice may be important if you don’t plan on using a bivy bag or tent. Snugpak is one of the retailers offering a good selection of military sleep systems. Sleeping bags can be extremely bulky and heavy, or small and lightweight, but the cost and temperature rating will vary just as drastically. Being inside a sleeping bag may limit your mobility.
- Poncho Liner
- The poncho liner, ranger blanket, or woobie, has always been a staple of military rucksacks. It is a simple blanket made of nylon or polyester with an insulated fill. While it is not ideal for very cold weather, it will work well in warm and cool conditions if combined with layers. They come in a variety of colours, and a number of companies make commercial versions with more insulation. They pack down reasonably small but may not be as small as the most lightweight and expensive sleeping bags. Being synthetic, they are more likely to hold heat when wet. Finally, because it is a simple blanket, it does not limit your mobility like a traditional sleeping bag.
- An alternative to a dedicated sleep system is simply packing additional layers of clothing. The ECWCS and PCU systems will enable static operations down to -40 degrees. The benefits of sleeping in layers is that your reaction time and capabilities are not hindered. While multiple layers can begin to dominate the volume of your pack, they are not single purpose items. Clothing layers can be added or removed at any time to increase comfort based on the mission.
- Sleeping Pad
- To prevent heat loss through conduction, you must separate your sleep system from the ground. Again, there are too many to list, but OutdoorGearLab has a solid primer on sleeping pads. Military options exist from companies like Klymit and Thermarest.
I chose to use existing clothing layers that I’d already packed, and supplement them with a Kifaru Woobie. The Woobie is a poncho liner or Ranger blanket. It is small, light, and easy to deploy, and more importantly, easy to stow. It takes seconds to cram it back into your ruck and you’re ready to roll. It doesn't restrict your movements the way a sleeping bag will and won't trap you if you're bumped in your NDP. It doesn't quite provide the same insulation that you get from a sleeping bag as it does not readily seal around your body to keep the warmth in. However, it is large enough to share with a team member which provides opportunities for more warmth.
Using clothing layers means that I’m not carrying any single-use insulation in my ruck and I can save that space for mission critical gear.
The Z-Lite pad comes in coyote brown, and is a good way to get you and your gear up off wet or cold earth. It doesn’t have a high R value though, so I supplement with a Klymit Recon X-Frame stuffed inside my bivy. This combination does a sufficient job with cool to cold weather.
- Layers with Light Sleeping Bag, Neo Air Pad (Ray)
Like Sean I like to use my additional layers when possible to beef up my insulation while resting. I do try to ensure that whatever layers I am resting in are dry however, as moisture is the number one killer of warmth. While synthetic retains heat better in moisture, down compresses better for packing. My go to bag is a small down bag rated to around +5 Celsius that packs down smaller than a nalgene. When combined with dry layers and a bivy I’ve had comfortable sleeps subzero.
For additional warmth, my sleeping pad has a layer of mylar in it that reflects body heat back. I usually like to keep my mat inside my bivy to minimise heat loss. As a final tip, I find placing an air activated hand warmer inside my sleeping bag while it’s packed in my pack makes it much nicer to crawl into and saves wasting body heat to warm up the bag.
"Solving an imaginary world's contrived and over dramatic problems... 6 millimeters at a time."
Last edited by Bravo One-Six; February 3rd, 2016 at 22:36..