Custom tent calculations
When Deborah started building the first tent, she was single. By the time it was finished, she and I had met and were considering marriage. We quickly found the tent too small for both of us, a week's food, clothing, music, and musical instruments. So we built a larger tent in 1996.
If we had just increased the radius at the shoulder without making the center pole longer, it would have significantly flattened the roof, and since the angle of the roof is the same as the angle of the guy lines, we would have covered most of the encampment with our guy lines. So we increased the radius at the shoulder only slightly, to 5', the radius at the ground to 6', the height to 11' (still wheelbarrow handles, with a longer sleeve), and most significantly added a second center pole 5'6" away from the first to give an oval shape.
At right is an illustration,
from King Rene's allegorical book Le Coeur Empris (early 15th c.),
of a whole encampment, mixing oval and round tents.
At left is a similar illustration of a military encampment, painted some time between 1328 and 1344. (Click on the picture for more details.)
And at right is a closer look at one of the tents in King Rene's book; again, click on the picture for more detail.
A number of people have asked me about the construction of the edge of the
roof. Below are two diagrams: one illustrating how the roof, the buttonhole
strip, and the dagged or fringed valence are sewn together, and one
illustrating how all of these and the buttoned-on wall fit together in use.
Here's the tent after the first phase of going up (or before the last phase of going down): we place the center poles, put in stakes for two outer guy lines at a suitable distance collinear with the bases of the poles, and four others perpendicular to that line. This phase requires three people, or two if one of them is strong enough and has long enough arms to hold both center poles at once.
At the time this photo was taken, the pink cap wasn't actually sewn onto the roof yet (one of those things that didn't quite get finished before Pennsic). As one might expect, it blew around a bit in the wind. It is now sewn down all the way around.
In the second phase of going up, we stake out the rest of the guy lines. Unless there's a lot of wind, this phase only takes one person, perhaps a second to help measure distances and angles.
After this, we need only attach the walls, which as before hang from a reinforced strip near the edge of the roof. We're not sure whether it's better to have buttons on the strip and buttonholes on the walls or vice versa, but important: make sure the walls are inside the strip, rather than outside. This way any water that seeps in through the seam where the strip attaches to the roof will fall on, and run down, the outside of the wall, rather than falling straight down onto whatever you've left near the walls.
The final result appears at right.
Again, the fabric is cotton duck or twill, heavy for roofs and walls and lighter for stripes and valence. All ropes are 3/8". We transport the roof and walls in most of a car-top carrier, while the poles and hardware (along with clothes, furniture, food, cooking equipment, and musical instruments for two for a week at Pennsic) fit inside a Ford Escort hatchback. We can still use the rear-view mirror.
And here's the tent, lying in a heap on the living room floor.
A problem we observed over the first few years this tent was in use is that the guy ropes, which were passing through buttonholes in the valence, tended to tear those buttonholes open, enlarging them to fist-sized or larger. So in 2001, we removed the old valence (recycling the blue fringe) and made a new one with leather grommets for the ropes to pass through. Such grommets appear in a number of medieval sources, e.g. this 14th-century picture with a horse and a chessboard. (I also have a nice painting, due to Simone de Martini (1280-1344), showing grommets, but haven't scanned it yet. Watch this space!)
Since there were 16 guy ropes, and each had 4 crow's-feet, there were a total of 80 grommets to attach. Only the grommets for the main guy ropes were in fact finished in time for Pennsic 2001, so we set up the tent without the crow's-feet. It held up perfectly well, but showed more visible sagging between the guy ropes. (Photo not scanned yet.) As of this writing (October 2001), we're adding another 32 grommets, so as to have 3-fold (not 5-fold) crow's feet, which (we hope!) should be enough to eliminate this sagging.
Another result of the experiment was the removal of the 1/2" "spreader rope" which had run all the way around the shoulder of the tent, trapped between the guy ropes and the shoulder seam. It had served as an anchor to which to tie the crow's-feet, but in their absence it proved more hindrance than help. With the return of (3-fold) crow's feet, we anticipate anchoring them with wooden toggles inside the valence, rather than tying them to a spreader rope. Watch this space for updates. Back to Pavilions Page