I have been researching and testing hammocks over the last few weeks and I would like to share what I have found. Please bear in mind that this is my myopic view from a newbie's perspective.
I was researching other equipment on the Web and was checking prices at Campmor.com and I saw a very basic hammock for $15 and bought it on impulse. I had seen occasional posts on hammocks on BPL and references to the HammockForums.net Web site and wanted to try one. The ability to camp in steep, rocky, or wet terrain had its appeal and I never have slept well on the ground. While waiting for the $15 hammock to arrive, I did more research and ordered a Hennessy Expedition Zip model hammock and some suspension hardware.
I wanted a hammock for day hikes and multi-day trips. As I mentioned, campsite selection is increased. You are off the ground, so steep terrain, low brush, roots, rocks, mud, and even running water can be dealt with. All that is needed are two anchor points roughly 6 feet off the ground and 12 to 15 feet apart. Two trees are the typical anchor points, but rocks, cliff faces, posts or other solid anchors can be used with the proper hardware. There are some models that can be used on the ground like a hooped tent or bivy.
Hammocks can be low impact shelters. Wide web straps have been developed for anchoring to trees without damaging the bark and most setups use 2 to 6 stakes. The ground is only disturbed by the camper's footprints and a few stakes; the usual compression of soil and plant life is avoided.
Weather and insect protection can be excellent. Some manufacturers have complete, coordinated systems incorporating insect screens and tarps, or you can build a system from components and select the tarp size you prefer.
The real appeal for me is the comfort of sleeping in a hammock. Surprisingly, you don't lay in a curve– the sleeper lays diagonally and rather flat and the lower back is well supported. Of course there are no rocks, sicks, or uneven ground to cause discomfort.
Some of the components overlap with ground-based camping gear. Quilts work very well with hammocks and conventional sleeping bags can be used. Sleeping pads can be used, but there are hammock-specific systems for insulation. Tarps are used extensively, with cat-cut models being on the top of the list, with a range of sizes and the same fabrics you are used to seeing with ultralight backpacking– PU coated, silnylon, spinnaker cloth, and Cuben fiber tarps are all well represented and the same strengths and limitations exist. Some of the hammocks are an asymmetrical design so the tarps for them may look a little different. The larger cat-cut tarps are in the 10'x12' range and can be used for conventional ground pitches.
The bottom insulation systems are mostly made from the same materials you are familiar with in ground camping. Some hammocks have a double bottom and a pad can be used between the layers. Other systems use quilts with down or polyester fill and have all the same issues you are used to with quilts and sleeping bags. It was a surprise that hammocks need a fair amount of insulation on the bottom. You are up off the cold wet ground, but there is still a lot of convection loss to the air and most hammock bodies use breathable fabrics. As with ground camping, any insulation between you and the hammock body will be compressed and lose its value, so some sort of additional insulation is needed when temperatures are below 70F. Condensation and vapor barrier techniques are much the same as with ground camping.
You can buy hammocks as a complete, coordinated system or purchase separate components. The coordinated systems can be used with other components and customized to the user's needs. Weight issues are much the same as your ground-based gear. Multiple use, high-performance materials, and minimalist designs all come into the picture. There are bare-bones hammocks that run 7 ounces and complete systems getting into the 4-5 pound range.
Examples of coordinated systems are brands like Hennessy or Clark hammocks. They come with hammock body, a suspension system to attach it to the trees, a tarp, and extra covers and insulation accessories. Other manufactures offer components and you can mix items to make your own system. You can buy suspension hardware, a hammock body with or without an integrated insect net, separate insect nets, tarps, topside quilts, and bottom insulation.
User weight is an issue with hammock systems. Fabric weight, construction, and suspension systems all factor into the total capacity of the hammock. There is a range of sizes available to suit the weight and height of the user. Weight limits run roughly 200 to 300 pounds with the majority being in the 225 to 250 pound range. You will see hammocks with light fabrics and basic suspensions given the same capacity as ones with much heavier fabrics and obviously more robust suspension. My guess is it more legal than scientific. Caveat emptor! The rule with hammock users is "don't 'hang' farther than you want to fall" — or what you don't want to fall on. Most setups are at chair height, which aids getting in and out of the hammock and using the hammock as a lounge chair. Most users frown on rigging in high places. You can fall out of a hammock in your sleep, but it is usually difficult and rare. Big wall climbers use hammocks and remain in their harness while sleeping.
Hammock bodies are made from nylon or polyester fabric and are typically breathable. Some inexpensive (and lightweight) hammocks are made of parachute-like fabric, with some of the high-quality cottage-made examples using 1.2oz to 1.7oz nylon and single or double layers. Some hammocks are a simple rectangle with a channel sewn in each end and gathered with climbing-quality rope or a carabiner. Other methods use gathered fabric with a whipped end– wound with line and tied. It is possible to make a usable hammock by tying a knot in the fabric and tying the support lines below the knot. The sides of the hammock are typically a simple hem. The channels and seams for a gathered end are usually triple- stitched for strength and safety. Those of you who sew shelters, packs and sleeping gear would find it very easy to make a basic hammock. Most hammocks have a banana shape and are anchored at each end. Some manufacturers use an asymmetrical design, with extra fabric for the user's head and feet to allow a more comfortable diagonal position. Laying on a diagonal is flatter and supports the lower back and legs. Bridge hammocks have some sort of spreader bar at the ends and a flat area for the user to sleep; they allow the use of conventional pads and mattresses for insulation.
For insect protection, some models use integral zippered screens much like a double wall tent; others use a separate bag or sock arrangement with a zippered entry or gathered ends with typical no-seeum mesh.
The suspension is where the hammock is attached to the tree or other support. Some use a climbing-quality rope that is integrated into the body of the hammock; others use a high-performance line like Amsteel Blue or Dynaglide in a an adjustable loop called a whoopie sling. Web and buckle systems are used too. Most users use a web sling around the tree to attach the main suspension and tied directly or using a climbing carabiner or proprietary hardware.
Tarps are much like you are used to seeing with conventional shelters. The smaller tarps are used in a diamond pitch; the larger tarps are pitched as an A-frame. Some of the larger tarps have sections that can be closed as doors and some have accessory beak-style doors available. Fabric choices are identical to ground shelters, with silnylon, Cuben, PU-coated and spinnaker cloth versions available. All the strength and weaknesses found in ground tarp fabrics apply to hammock shelters. Flat tarps can be used, but the vast majority offered are catenary cut. Some are attached to the ridge line that is part of the existing hammock system. Most are pitched using lines attached to tie-outs or a separate ridge line. The bottom edges use guy lines and stakes like conventional shelters.
On the underside, some manufacturers offer a bottom cover or weather shield. They are usually silnylon. There can be condensation issues, as a closed environment is created with the warm sleeper above and layers of insulation between. Hennessy offers their SuperShelter that incorporates a silnylon cover and a shaped open cell foam insulation layer, used along with a space blanket between the hammock bottom and the foam.
For me, bottom insulation is the dirty little secret of hammock gear. If you think you can buy a hammock with a tarp and use your existing sleeping bag and pad, you are partly wrong. Hammocks are cold when used below 70F– there's just no way around it. Granted, they come to us from tropical cultures, where the cooling is a benefit, but for temperate climates and at altitude they need some help. Pads will work, but they detract from the comfort of laying on the hammock surface and they need some help– a typical 20” wide pad won't cut it. A 24” pad will get by and one that is 66' long (or more), 32”-36” wide at the top and 18” at the foot end is better. Speer Hammocks developed a nylon sleeve for sleeping pads called a Segmented Pad Extender or SPE, that uses a standard 20” wide CCF or self-inflating pad, along with 5"x19" sections of CCF pad in sleeves on each side to insulate your arms and shoulders, which can get cold when the sides of the hammock compress your sleeping bag or quilt.
A popular bottom insulation system is a quilt that hangs below the hammock on shock cords, called an under quilt or UQ. Construction materials run the same gamut as quilts and sleeping bags, with down or polyester-based fillers and sewn-through or baffle construction. Under quilts can be full-length or partial. Users have used under quilt systems in sub-zero conditions with appropriate topside insulation. One YouTube video shows a user with a system that was warm at minus 26F! Search YouTube for “hammock shug” for a very entertaining and informative series of videos on hammock camping. Shug (like "sugar") really does know his stuff with hammocks and he is quite the clown.
Another bottom insulation option is a “peapod” that is basically a sleeping bag with openings at both ends and slips completely over the hammock. Some are like a semi-rectangular bag and others have a face opening like a mummy bag and draw closed at the top end.
Alternative bottom insulation options include the Hennessy foam/space blanket/weather shield option that I mentioned, and an Insultex-based system is offered by Molly Mac Gear.
On the top side, quilts and sleeping bags are used. It can be a tussle getting into a mummy bag in a hammock and quilts are an easy solution. The same issues exist with bottom insulation compressing as with ground camping. The same fabrics and fillers are used and your ground camping quilt is identical to those offered for hammocks, with an open bottom and a footbox.
That's what I know so far. I have tested a basic system in my yard in moderate conditions. I slept better than any other night outdoors on the ground. I am still working out bottom insulation options, with the SPE, a Z-rest pad, space blanket and a multiple-use poncho/weather shield. I am using a Hennessy Expedition Zip model hammock system and I have the larger Hennessy Hex tarp for harsher weather. I have modified the Hennessy suspension with whoopie slings, carabiners, and custom 1”x8' polyester webbing tree straps.
Resources:
Forums:
http://hammockforums.net
Hammock manufacturers:
Clark Jungle Hammocks :
http://www.junglehammock.com
Claytor Hammocks :
http://www.mosquitohammock.com
DD Hammocks :
http://www.ddhammocks.com
Eagles Nest Hammocks
http://www.eaglesnestoutfittersinc.com
Grand Trunk
http://www.thetravelhammock.com
Hammock Gear
http://www.hammockgear.com
Hennessy Hammocks
http://www.hennessyhammock.com
Ticket To The Moon Hammocks
http://www.ticketothemoon.com
Speer Hammocks
http://www.speerhammocks.com
Trek Light Gear
http://www.TrekLightGear.com
Warbonnet Hammocks
http://www.warbonnetoutdoors.com
Accessories:
2Q & ZQ Hammock Specialties (Hennessy Bugnet Zipper Mods)
http://www.2qzqhammockhanger.com
Arrowhead Equipment
http://arrowheadequipment.webs.com
Jacks-R-Better
http://www.jacksrbetter.com
Molly Mac Gear
http://www.mollymacgear.com
OES Tarps
http://www.outdoorequipmentsupplier.com
Tree to Tree Trail Gear
http://www.tttrailgear.com
Whoopie Slings
http://www.whoopieslings.com
