The torsion catapult, or mangonel, was one of the most common siege weapons of the Middle Ages. This device used the potential energy stored in twisted rope to hurl projectiles such as heavy stones at enemy fortifications along a shallow trajectory. Although the machines themselves could be large and complicated, the mechanical principles which underlie the torsion catapult are simple. With simple materials and a few basic tools, you can build your own miniature mangonel.
Things You'll Need
Wood: square rods, flat sheets and dowels
Screwdriver or hammer
Small screws or nails
String or twine
Small cup or basket
Cut the pieces of your mangonel from wood using a saw. You need two long sections, a slightly shorter length for the arm and five short pieces. The arm should be about five-sixths the length of the long sections. If your long sections are 1 foot long, the arm will be 10 inches. The short pieces should be half the length of the arm. You'll also need two triangular supports. The supports should be slightly taller than the short pieces.
Attach a short piece to each long section at right angles. The point of attachment should be as far from the front of the long section as the base of the triangular support.
Screw or nail the triangular support to both pieces. This will give them added rigidity.
Lay out two of your short pieces perpendicular to the long sections. Place the long sections on top of them so that they form a rectangle, with the short pieces connecting the front ends and back ends of the long sections. Screw or nail them in place.
Screw or nail the last short piece to the tops of the two uprights, creating a crossbar.
Drill a hole in each long section, halfway along the base of the support. The two holes should line up squarely. Make them as large as you can without damaging the structure of the long section. Drill a hole near one end of the arm. It does not have to be quite as large as the holes in the long sections.
Cut a long piece of string or twine. The length will vary with the thickness of the string and the size of the mangonel but could be up to 10 yards for a foot-long catapult. Attach a length of wire coat hanger to one end of the string. Tie the other end to a short dowel or a pencil.
Thread the string through the hole in the long section, using the wire like a sewing needle. Thread it through the hole in the arm and then out through the hole in the opposite side. Loop it around another dowel or pencil and thread it through again in the other direction.
Repeat this process as many times as you can fit the string through the holes. On the first three passes, thread the string through the hole in the throwing arm. After that, pass the string under the arm, out the other side, around the dowel, back in, over the arm, and so on, alternating over and under the arm with each pass.
Tie the string off on the dowel when you can no longer fit the string through the holes. Tighten the string by twisting the dowels on each side toward the front of the catapult.
Attach a small container, such as a cup or basket, to the other end of the throwing arm. If you haven't got one that fits your projectile, you can make one out of scrap wood.
Insert a screw hook into the head end of the throwing arm. Press the arm down to see where it lines up with the long sections and insert a screw hook into each of these so that all three are in a straight line. Run a length of wire through the three hooks.
Place your projectile in the cup or basket. Pull the wire out of the hooks, and the throwing arm will snap forward, launching the projectile.
Always wear safety eyewear when building your mangonel, especially when using the saw.
Do not launch projectiles at people or breakable objects.