Alpine Hammock Product Specifications
Before we started to build our Alpine Hammock we wanted to better understand the product specifications of similar items on the market; namely hammocks and bivy sacks.
To inform our design we took an analytical look at over 45 backpacking hammocks, over 40 bivy sacks, and a variety of accessories, analyzing ten metrics to describe each product: cost, weight, seasons (3 or 4), number of poles, size (length/width/height), stuff size (volume), top material (for bivys) and bottom material (hammocks and bivys). We also took notes on online reviews for each product from multiple gear websites to get the pros and cons from a user's perspective.
Here's a screenshot including some of our research:
This research as well as our own gear testing in New England and Colorado has led us to our current design.
The but net is not attached to the pole in this picture, but there is a piece of velcro sewn into the bug netting that will attach to the pole to keep the material off your face. I'm using a Big Agnes Air Core sleeping pad in this setup and have the unzipped rainfly rolled and secured to one side
The alpha-prototype specs are as follows:
- Weight = 1.4lbs (without suspension but including the pole)
- Seasons = 3 (spring, summer, fall, although we have ideas in the works for a winter version)
- Number of Poles = 1 (you can easily use it without the pole to save on weight)
- Length = 98 inches (comfortably fits up to 6'4" tall, ~188cm)
- Width = 40 inches
- Height (rainfly above your face) = 6-10" in Bivy Mode and 16-20" in Hammock Mode
- Stuff Size = 9" x 7" x 6"
- Top Material = waterproof breathable fabric
- Bottom Material = silicone coated (waterproof) ripstop nylon
Our current stuff size is 9" x 7" x 6" and our next prototype will include a built-in stuff sack as opposed to the Sea to Summit bag shown here
Future Design Considerations:
In terms of material choice, for the top we are currently using Gore-Tex but are testing out two other waterproof breathable materials as well which might be lighter and potentially more breathable.
For the bottom material we initially tried 1.1oz silicone coated ripstop nylon, but it became obvious very quickly that this material would not be durable enough during use as a bivy sack. So we're looking at a range of coated ripstop fabrics that will endure abrasion as a bivy but also be comfortable as a hammock. This will invariably increase the weight of our 1.4lb alpha prototype but our goal is to end up with a product as close to 2lbs as possible. From our research, a target weight of 2lbs would put the Alpine Hammock slightly above the average weight of bivy sacks (1.5lbs) and far below the average weight of the traditional backpacking hammock/bug net/rainfly combination (3.3lbs, assuming you bought each item separately).
From using the product ourselves and from feedback we've received from other outdoor gear aficionados, we've realized that our hammock width is too narrow. It operates well as a bivy sack but as a hammock it can be a little tippy. So we'll be increasing the width of our hammock significantly to help make it act more like a hammock. From our research we found hammocks that ranged from 48" to 100" so there is a wide margin of possible widths. Ultimately we'll choose a width that is comfortable for one person to sleep in with a flat lay.
Ridgeline - We have been testing out various ridgeline ideas which might allow us to get rid of the pole all together. A ridgeline down the center could help pitch the rainfly more like a tent and thus helping to shed water in a more efficient manner while keeping the fabric off both your face and and your feet.
Stuffsack - Right now our stuff sack is a generic Sea to Summit stuff sack but in our next iteration we will include a built-in stuff sack in the foot of the Alpine Hammock so that the shelter can be packed up quickly and easily.