The Cowboy Rope Bridge Hammock (Grizz-Inspired)
Well, no one gave me a Multicam bridge hammock for Christmas, so I made one myself...
Here was my result, dubbed the "Rope Bridge" in reference to its integrated Amsteel suspension (see details below)...
Type: Single-layer bridge camping hammock with double-layer end caps and integrated Amsteel suspension
Materials: 1.5 oz Multicam ripstop nylon, 1.3 oz Coyote Brown ripstop nylon, 300D pack cloth, 3" poly grosgrain ribbon, 7/64" Amsteel Blue, Mara 70 poly thread
Dimensions: 80" long, 48" arc length at head/foot, 34" wide at center, 36" spreader bars at head/foot
Weight: 20 oz (574 grams) total, 11 oz hammock only, 9 oz spreader bars
Context:
I had some serendipitous remnants in my fabric box, chief among them an odd 3-yard piece of 1.5 oz Multicam ripstop nylon. It was too short to build a gathered-end hammock, my daughter already has a junior-sized (9-foot) Multicam Epsilon hammock with a zip-off bug net, and I had already made a top cover from the same material for my 11-footer. What to do?
Bridge hammock!
No matter how I enjoy my various gathered-end hammocks or how many I build, the idea of bridge hammocks has continued to maintain a certain allure; with their interesting alternative geometry, fascinating engineering details, and promise of a flat, comfortable lay, there are many aspects to building, detailing, and camping with one to occupy the mind of a thinking man like myself. That said, the available commercial bridge hammocks have never quite piqued my interest, primarily because they tip the scales at a margin I consider uncomfortable beyond what my various GE camping set-ups weigh, and since I don't hike with trekking poles, I have to factor in spreader bars on top of the hammock itself...
The lightweight bridge hammock alternative was to build one based on one of the various DIY models based on plans available here on Hammock Forums. Two very intelligent and prevalent do-it-yourself designs stand head and shoulders above others in terms of popularity.
Bic has distilled down the myriad complexities of building a basic bridge hammock to a simple set of easy-to-follow instructions using a one-piece hammock body and readily available supplies including some ingenious Dutch bling, and in a short series of detailed videos he takes you through the process by the numbers. (I watched them all several times!) There are a number of highly successful DIY bridge hammock projects presented here on HF based on his design...
https://www.youtube.com/watch?v=XXlSA9shWJc
https://www.youtube.com/watch?v=aitA0XHq6QE
https://www.youtube.com/watch?v=ANG-nVU8LPM&t=2379s
However, I was looking to accomplish this build in my down time during the holidays from materials I had on hand, and Bic's hammock called for some of Dutch's titanium tidbits that I didn't own.
This and other reasons led me to the grandmaster himself, GrizzlyAdams, who has spent years developing, refining, and presenting to the public his plans for the legendary GrizzBridge hammock over several project generations, the most recent of which, the Ariel, possessed some ingenious engineering details that inspired me to build my own "K.I.S.S." ("Keep it super simple") rendition of his design. I had successfully copied some of Grizz's other gear designs, and I had enjoyed all of his "Professor Hammock" video offerings on YouTube, so I devoured all of his instruction on building the various generations of the GrizzBridge, up to and including the Ariel.
https://www.hammockforums.net/forum/...ridge-(part-1)
https://www.hammockforums.net/forum/...Endcap-Origami
https://www.hammockforums.net/forum/...ee)-Gone-Loopy
https://www.hammockforums.net/forum/...and-Deployment
https://www.hammockforums.net/forum/...idge-the-Ariel
https://www.youtube.com/watch?v=Qhw2g5hJMJM
https://www.youtube.com/watch?v=e8rWcwUsoP0
Of course, part of the beauty of DIY projects is the intrinsic improvisational nature that they possess; you can start with the thoughtfully laid-out plans for the GrizzBridge Ariel and then personalize it, picking and choosing features while still respecting the overall design ethos. Other than its remarkably light weight, there are two landmark features of the Ariel: 1) an innovative recessed spreader bar design for a flat lay with meticulously calculated end cap extensions and 2) a precision-spliced all-Amsteel suspension that accepts the spreader bar tips in gaps in the cord between locked brummel pairs. The former feature, recessed spreader bars, did little for me, since I wasn't keen on dealing with the proximity of the bars over my head and feet, so I eschewed it for more conventional bar placement out by the end caps and relieved any potential for shoulder squeeze by increasing the arc length of the hammock body at its widest points on the ends. However, the latter feature, the Amsteel suspension with folded cord channels sewn to the hammock body, spoke to me, not only because of its elegance but also because I didn't have to buy fancy titanium fittings to form the corner junctions where webbing and rope come together on more conventional bridge hammocks. My choice to deviate from the Ariel's recessed bars meant that when I copied Grizz's cord suspension, I needed to modify his recipe for the spliced cord suspension to make the main cords running along the edges longer to accommodate the increased arc length between the bars. My other departure from the Ariel design was to revisit the way the Amsteel was attached to the long edges of the hammock body. In his video Grizz details his elegant method for salvaging wide strips of fabric with selvage edges and using them to construct sturdy, multilayered folded channels for the Amsteel cord. There is a lot of precise measuring, ironing, and pinning, and sewing involved, including adding a long length of inline bias tape. I applied my "K.I.S.S." maxim here to formulate an alternative with far less elegance but adequate practical utility, and I instead used a couple of rolls of 3" grosgrain ribbon I had on hand as an expedient practical alternative for a triple-stitched folded suspension channel.
Construction Steps:
1) I folded the fabric carefully into quarters (two perpendicular folds) and marked out the end cuts and parabolic suspension arcs, along with a 1" seam allowance around the entire perimeter; with these measurements made -- 82" long, 50" wide at the ends, and 36" wide at the midpoint (i.e., 7" deflection on the side cuts) -- I cut out the hammock body. I sewed small triangular reinforcement patches to each corner where the suspension would eventually exit.
2) One original feature I decided to add to my hammock design was double-layer end caps to serve as storage pockets, so I cut out a total of four parabolic pieces to terminate the hammock body, a outer pair from 1.5 oz Multicam fabric to match the hammock body and an inner pair from 1.3 oz ripstop scraps left over from my sock project. These were approximately 38" wide and 14" deep including allowances, with an arc length to match the 48" ends of the body blank. I cut them out and roll-hemmed the straight edges, and then I basted the layers together (one outer to one inner) along the curve (wrong sides touching) to make a pocket-style cap for each end.
3) I cut and tapered six sections of 7/64" Amsteel Blue cord for the suspension according to Grizz's instructions, excepting for increasing the length of the main sections by approximately 14" to account for my spreader bar location. I had an arc length on the sides of the hammock of 82" compared to the Ariel's 68", so I cut two 100" lengths of cord for the main body edges and four 49" lengths of cord for the suspension triangles, splicing them with great care to form four precisely placed gaps for the spreader bar tips. All the remaining cord ends received 1" spliced eyes to allow them to connect to a Dutch Bridge Hammock Whoopie Hook. (See Grizz's engineering video for the arithmetic and details on where and how to execute the spliced connections.)
4) After verifying that my spliced cords were the correct finished length, starting at one corner of the hammock body, I wrapped the fabric tightly around the Amsteel and trapped it in a tight channel running the entire arc length with a single row of stitches, not really for structure, but to secure the cord in position on the channel. Then, starting from the same corner, I folded the 3" grosgrain ribbon over the edge evenly and formed a second folded channel layered over the first. Again, I used the zipper foot up against the Amsteel for the first pass, and then I sewed to more parallel rows of stitches, one at the inboard edge of the ribbon, and one splitting the difference. I then repeated the entire operation on the other side. To complete the suspension connection, I stitched directly through the Amsteel, connecting it to the two-layer channel for 6" in from every corner.
5) To complete the hammock I sewed the end caps on with French (standing) seams to the inside and the top edges folded in, both for a neat finished appearance and to aid in retention of items placed in the storage pockets.
Total cost of the build, including the spreader bars, was about $60!Total build time was about 5 hours.
I was particularly pleased with the finished weight of just 20 ounces for the Rope Bridge hammock, nearly half of which is accounted for by the four sections of Dutch .665" Easton aluminum spreader bars. I have already ordered some .490" Easton aluminum poles (about $20 plus shipping) as a lightweight alternative, and if they have adequate load capacity, they will bring the total pack weight of the Rope Bridge down to one pound!
I've done some moderately rigorous test hangs in this hammock to date. So far I like it best with suspension angles of 30 degrees on each end and a point-to-point distance (i.e., effective ridge line length) of 128" on the suspension triangles. It handles my 175 pounds easily in bounce tests so far, and I would rate its capacity conservatively at about 225 pounds. The lay is super-flat and comfortable; my relatively broad shoulders aren't squeezed, and my 6'2" frame has plenty of room to stretch out and find relaxed positions for casual lounging. The end pockets are voluminous, and the one above your head is extremely convenient. Time and testing will tell, but I feel confident I am going to enjoy it. I will watch the long edges and corners carefully for signs of wear. I will probably add a Lash-It ridge line soon. Future upgrades may include pocket modifications or a zip-off bug net, once I have had some hang time in it to assess my needs. (As an alternative, I may just make a separate bridge version of my full-enclosure sock/net design to use with the Rope Bridge instead...
(I also had a crazy idea based on one of Dutch's concepts, adapting this bridge hammock design to convert to a gear skin backpack (possibly using the spreader bars as a rigid frame...).)
I would like to express my sincere thanks (and perhaps also apologies) to GrizzlyAdams. Despite holding a doctoral degree from a major university in a scientific field, I am probably not really a true "quant", but I am definitely "quant-conversant" and "quant-friendly", so I really do enjoy the "mathemagical" asides and other peripheral vignettes you provide in your videos. Much obliged, sir! All your work and generous contributions to this community are truly appreciated...
Please feel free to inquire or comment below, and thanks for reading this project report.
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Originally Posted by zukiguy
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