Grass Ropes The Human Rope-Making Machine As published in the Bulletin of Primitive Technology, Fall 2011
Article by Thomas J. Elpel, with photos by Thomas J. Elpel and Dan Westfall.
Grass ropes are a fun and easy activity for any group of people, from adults to kids as young as 7 or 8 years old. Building the rope requires teamwork and cooperation. Testing the strength of the rope through games of tug-o-war is an opportunity for great camaraderie and raucous competition. All can be accomplished in less than an hour.
My interest in grass ropes grew out of frustration in trying to teach kids how to make cordage with traditional fibers like dogbane or stinging nettles. Cordage-making is essential to many other skills, used for everything from trap strings and snares to fishing line and fish nets, hammocks, bow and bowdrill strings, woven bags, lashing, sewing, and tying things up.
Yet, cordage is a complex skill, which requires fine dexterity to initially separate the fibers from plant stalks and subsequently to spin those fibers into quality cordage. It can be quite an accomplishment for a kid to make just enough cordage for a bracelet. And, as essential as cordage may be, we seldom found any more appropriate application for it in our youth programs.
I figured that kids could get much more excited about cordage if we could scale it up to a size they could manipulate and play with. Making ropes from grass seemed like an ideal way to go, if we could figure out a good system for making them.
I remembered seeing primitive rope-making machines in Richard Graves' book, Bushcraft: A serious guide to survival and camping, which I owned as a teenager. According to Graves, a one-inch diameter, three-strand green grass rope can take 100 to 250 pounds of strain. Palm fibers are good from 650 to 2000 pounds, while sedges are good for up to 2,500 pounds. According to Graves, "Double the diameter quadruples the breaking strain. Halve the diameter, and you reduce the breaking strain to one fourth." I once tried building Graves' rope-making machine as a teenager, but found it a bit beyond my limited skills as a craftsman.
However, it occurred to me while working with kids, that with enough hands working together, we might be able to form a human rope-making machine. We experimented with a class of kids and quickly spun up our first two-strand rope. It was a huge hit, and the kids had a blast playing tug-o-war with the rope. We've made many grass ropes since that time, experimenting with different grasses in different seasons. For easy manipulation by hand, we keep each strand at least one inch thick, forming a rope at least two inches in diameter.
Generally speaking, any green grass, preferably more than two feet tall, will work for grass ropes. Dry grass can work if it is not too brittle.
Grass cuts are a likely hazard while collecting the grass, but not likely while making or using the rope. Therefore, each person should wear at least one glove while collecting the grass. I keep a bucket of otherwise mismatched or worn-out gloves on hand for activities such as this.
To pick the grass by hand, grab a handful near the base of the stalks and thrust straight downward (keeping the grass vertical) to help break the stems, then rip the handful out horizontally. Optionally, grass can be cut with sheath knives, if the group has them. You can also use grass clippers and cut enough grass for the whole rope before the activity begins. One big garbage bag stuffed full is adequate to make one grass rope.
To make a grass rope, start by laying the grass out in two parallel lines, like train tracks. Each side should be uniform in thickness and about an inch thick when squeezed in the hand. For additional strength (optional), go down each row and shuffle some of the grasses back and forth, so that the fibers are well mixed from end to end.
Next, line up the whole rope-making crew shoulder to shoulder in two lines facing each other beside the grass. Put a capable or experienced person at the beginning of each line as designated line leaders. It is possible to make a rope with only three or so people on each side, but more is better. Ideally, there should be enough people to pick up both long lines of grass.
Ask each line to step in towards each other, so that the lines are about two feet apart. Next, demonstrate the rolling technique. Start one line rolling the grass "away" in unison. Stop them when they have the proper technique. Then have the other line roll their grass "toward" themselves. Both lines of grass should be rolling the same direction, but the hand motion is different since the people are facing each other.
Now, bring both lines together at the head of the rope. Pick up a handful of additional grass and kink it in the middle to make a "V," connecting both lines of grass. Start rolling both lines of grass. The two line leaders control the thickness of the strands as they come together. Stop the group as necessary to add or remove material to keep both sides uniform. The two line leaders move with the rope as the two strands are twisted together. Other people in the line will get squeezed out as the line leaders take over their positions.
An additional person is needed to help hold and turn the new rope. It should slowly spin in the same direction as the two lines. Turning the rope will help keep it tight, so it won't unwind on one end while it is being wound up on the other.
If there were not enough hands to pick up all the grass at the start, then send anyone who gets squeezed out to the end of the line to pick up more grass to add to the rope. If all the grass is up in the air, then send the extra hands to the completed portion of the rope to help keep it spinning.
When the grass is used up or the rope is long enough, then stop and tie an overhand knot at the end to keep it from unraveling.
The strength of the finished rope depends partly on the quality of the grass, and particularly on the uniformity of the rope. The rope is only as strong as its weakest part, which can be exceptionally weak if one strand is thick, with the thinner strand wrapping around it. But these ropes can be amazingly strong if uniformly made from end to end.
The best way to test them is in games of tug-o-war. We have had some ropes that could not be broken by a class of thirty 5th graders. We had one rope, made of long, thin mountain grasses that could not be broken by a similar number of adults.
Grass ropes can also be tied from a tree branch to make a good rope swing. The longevity of these green grass ropes is limited. They typically dry, shrink, and break within a couple of days. But you can have a screaming lot of fun with them while they last.
For longer-term ropes, look for non-brittle dry grasses or sedges that can be twisted without breaking. Grass ropes were commonly used for building suspension bridges among the Inca of Peru. One bridge, the Q'eswa Chaca (or Keshwa Chaca) is still rebuilt every year according to ancient customs.
References:
Richard Graves. Bushcraft: A serious guide to survival and camping. Warner Books. 1978.
_____. "Inca Rope Bridge." https://en.wikipedia.org/wiki/Inca_rope_bridge. September 19, 2011.