Photo: Michael Smith (flickr)
A hammock in the shade makes a fine reading spot on a hot day, but how tightly you hang it could be more than a matter of taste. A tight hammock makes a flatter surface, but a loose hammock is stronger and less likely to break.
How To Hang A Hammock
To see why, imagine a hammock hung very loosely in a U-shape between two trees. Set up this way, the ropes connecting the hammock to the trees will be almost vertical. If it were possible to get the ropes completely vertical, they would have to be just strong enough to hold the vertical force of your weight.
If you hang the hammock more tightly, the ropes now attach to the trees at an angle closer to the horizontal. The ropes still have to support the vertical force of your weight, but now they are also pulling horizontally against the two trees. So instead of one vertical force, there is now both a vertical and a horizontal force.
Let’s say the hammock is hung so that each rope attaches to the trees at a forty-five degree angle — in other words, at an angle half way between vertical and horizontal. At this point, the vertical and horizontal forces on the rope will be equal.
If you weigh one hundred and fifty pounds, then the hammock has to support both that weight vertically and an additional hundred and fifty pounds horizontally. As the hammock gets closer to the horizontal, your weight, of course, stays the same, but it creates a greater and greater horizontal force.
A hammock may be comfortable if it isn’t hung in a U-shape, but the closer it is to a U-shape, the stronger your hammock will be.