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How to Build a Catapult With Lashings

Catapults were invented by the Greeks, modified by the Romans and used extensively in siege warfare in Medieval times. A wide variety of everyday useful objects can be created using just wood and rope if you know the proper lashing to use. This catapult project requires two main lashing techniques: square lashing and diagonal lashing, although you'll probably use a few other knots along the way as well.

Things You'll Need

3 - 8-foot spars or saplings--as straight as possible (front face)
4 - 12-foot spars (back brace)
1 - 15-foot spar (throwing arm)
1 - 3.5-foot spar for the pivot bar
1 - 50-foot-long, ½-inch rope
7 - 10-foot pieces of ½ rope for the lashings
Hammer and nails
Small basket or large coffee can

Instructions

- 1
  Lash together three 8-foot spars for the front triangle (or front face). Use square lashings to connect the bottom spar to the two upper spars and diagonal lashing to connect the apex of the triangle.
- 2
  Begin with the square lashing. Start with a clove hitch on the spar that will be closest to the ground, leaving 12 inches of the free end. Then, lash it in front of and over the top of the second spar, then behind the upright spar and down in front of the second spar. Finally, take it behind the upright spar immediately above the clove hitch. Continue for at least three more turns around each spar. Frap the lashing by drawing the running end two times around the lashing turns, that is, between the spars. Finish off with another clove hitch on the upright spar.
- 3
  Start the diagonal lashing with a timber hitch. Follow the timber hitch round for three turns and then reverse and make three turns around the other fork. Secure the lashing by adding a clove hitch.
- 4
  Lash two 12-foot back brace spars to the front face of the catapult. Two of the spars should be fastened to the front face about two-thirds of the way up. Use square lashings to connect these two spars to the front face.
- 5
  Fasten another two 12-foot spars at the bottom of the front face using square lashing. These four spars are then lashed together at the apex of the triangle using a diagonal lashing.
- 6
  Attach the pivot bar to the bottom of the throwing arm about 2 feet up from the end of the throwing arm. Use square lashing to connect these two spars.
- 7
  Attach the pivot bar to the front face on top of the two back brace spars that are attached about two-thirds up the front face. Lightly lash the pivot bar to the front face -- do not connect it so that it cannot move, you need to leave it room to move. Use the hammer and nail to attach the tin can to the end of the throwing arm.
- 8
  Nail the pulleys to the bottom spar of the front face, one on each side. Connect the middle of the launching rope to the end of the throwing arm using a clove hitch.
- 9
  Run the two ends of the launching rope through the pulleys and lay them back beside the two back brace spars. Your catapult is now operational.

Nature