Play Catapult

A torsion catapult, or mangonel, is a type of catapult used frequently in Medieval siege warfare. The mangonel works by twisting up a rope as tight as possible on the end of a throwing arm. When the torsion in the rope is released, the throwing arm shoots whatever it is holding with great speed and power.

Rope Spring Power

The torsion catapult was invented by the ancient Greeks around 300 BC. The torsion catapult is based on the concept of the rope spring -- a rope coiled so tightly that it produces tremendous power when released. A torsion catapult looks much like any other type of catapult, with a throwing arm attached to a large base to provide stability and a large wooden beam to stop the throwing arm so that it shoots the projectile rather than slamming into the ground. Between the two sides of the catapult base is a length of rope, which can be wound tighter and tighter by a winch. This is what provides the torsion for the catapult.

Effectiveness

Although they had actually been invented centuries before by either the Greeks, torsion catapults or mangonels were not widely used in early Medieval warfare. Their first known use in England was in the Siege of Dover in 1216. From this point on, however, they were widely used. A mangonel was extremely powerful, capable of hurling a rock the size of a human head at the speed of 100 mph and for distances of up to 1,300 feet.

Projectiles

The mangonel was generally used to throw large rocks but could also be used to throw a wide variety of other items, depending on the ingenuity of the user and the availability of materials. Hot sand, when thrown, would find its way between the gaps in the armor of a defending knight. Diseased corpses could be hurled to spread infection in the enemy camp -- an early form of biological warfare. Burning tar could be thrown as a medieval equivalent of napalm.

Disadvantages

The torsion catapult did have some disadvantages. If the rope spring got too wet, it wouldn't work, so any day of heavy rain could earn the defenders of a besieged castle a day of respite from the attacks of the mangonel. In addition, the accuracy of any siege weapon depends on determining a precise range from which to shoot. However, the mangonel didn't shoot with consistent power because no one could be certain to put the exact same amount of torsion on the rope each time it was used. The mangonel would not be effective at consistently striking the exact same target such as a particular tower in a castle.

In the era before the use of gunpowder weaponry made them obsolete, castles formed the indispensable heart of warfare in Europe. Their construction was one of the primary expenses of any government, and no warlord could be successful without the skill and technical know-how to be successful at siege warfare. One of the primary goals of siege warfare was to break down the stone walls of the castle. For this purpose, large mechanical devices were constructed to fling stones at the high walls. Among the most successful of these was the trebuchet, a type of catapult, which used the power of a falling weight to swing the throwing arm from which the projectile would be propelled. A small model of a trebuchet will provide a look into the rich history of Medieval Europe.

Instructions

1 Cut two 1.5-foot lengths and two 2-foot lengths of 1-by-2 lumber. Lay one of the 2-foot lengths on your work surface with the 1-inch side facing down. Lay another parallel to it so that the outside faces of the two pieces are 1.5 feet apart. Apply glue to their ends and link them together at the ends with the 1.5-foot pieces to form a 2- by 1.5-foot rectangle. This will be the base of the trebuchet model. Hammer a finishing nail into each joint, and attach a pair of bar clamps to hold the parts together as the glue dries. Allow this assembly to dry before removing the clamps and continuing.
2 Cut two 2-foot lengths of 1-by-2. These will be the support columns that hold up the arm of the trebuchet. Use wood glue and nails to fix them to the insides of the 2-foot base sides halfway between the narrow ends of the base. Clamp the support columns in place with spring clamps. Cut two more 1-by-2 segments long enough to connect the 2-foot sides of the base together. Glue or nail the pieces to the inside of the base on either side of the support columns, which helps to hold the support columns upright. Viewed from above, the base should be a rectangle with its long sides connected together by four lengths of wood -- the two at the ends and the two that are helping hold the support columns in place. Use clamps to hold all the pieces in place as the glue dries. Allow the glue to dry before removing the clamps and continuing.
3 Cut four lengths of 1-by-2 long enough to connect the corners of the base with the support columns at a point 1 inch below their tops. These diagonal pieces will help keep the support columns from shifting forward and back when the arm of the trebuchet swings. Each piece should start at a corner, rising to meet the support column on the same side of the base as the corner from which it originated. Cut the ends at a diagonal so they can meet at the tops of the support columns; don't extend below the bottom of the base in the corners. Fix them in place with glue and a single nail at each end, and clamp them until the glue dries.
4 Drill a 3/8-inch hole in the top of each support column centered 1/2 inch from the top. These holes should allow a dowel to connect the two sides of the model together, forming the pivot for the arm of the trebuchet. Cut a 1.5-foot length of 3/8-inch dowel to serve as the pivot.
5 Cut a 3-foot length of 1-by-2. This will be the arm of the trebuchet. Drill one 3/8-inch hole through the 2-inch side of the arm, 1 foot from one end of the arm, and two 1/4-inch holes 1/2 inch in from each end of the arm. The larger hole will be where the pivot goes through, and you will use the smaller ones to attach the weight that pulls the arm and the sling that throws the projectile.
6 Cut out a 3- by 12-inch section of strong cloth (nylon will do well) to make the sling. Cut a 2-inch line in the middle of one of the 3-inch sides to make two "tails" on the sling. Tie these through the hole in the end of the arm that is 2 feet from the pivot. Hammer a nail into this end of the arm so that 3/4 inch of the nail projects from the end surface. Use wire clippers to cut the head off the nail, so that it is a smooth shaft. Cut a small hole in the far end of the sling, which will fit over the nail.
7 Attach the arm by putting the dowel (pivot) through one of the support columns, then the hole in the arm, then the other support column, so that an equal amount of excess dowel projects from each support column.
8 Cut a 1- by 1-foot section of fabric to use as a pouch for the weight. Cut a hole in each of the four corners. Place the weight (a brick or pile of fishing weights works well) on the center of the fabric and gather it up around the weight. Cut a piece of string, and push the end of it through the holes in the corners of the cloth. Put the other end of the string through the hole in the end of the arm that doesn't have the sling attached to it, and tie the two ends together.
9 Cut a 4-inch by 2-foot section of cardboard and position it so that it runs on top of the base components down the center of the long axis of the model. Staple it in place.
10 Fire the trebuchet: first push the end of the sling with the hole in it down over the end of the nail at the end of the arm. Holding the sling-end of the arm down near the ground, place a stone, marble or other projectile in the sling and lay the sling on the cardboard strip running down the middle of the frame. When you let go of the arm, the weight should pull its end down while the other end flings the projectile. If the sling lets go of the projectile too soon (the projectile flies in too high of an arc or even backwards), bend the nail forward slightly. If it releases too late (the projectile flies too low or strikes the ground immediately), bend it back.

Catapults were often used in medieval times as a form of weapon in battle. These weapons allowed warriors to fire upon their opponents from further away or to launch projectile weapons over high castle walls. While catapults are no longer needed for the purpose of fighting a battle, you can create your own model catapult to show how the original weapons worked. One of the ways you can build your own catapult is to use a metal hanger and spoon to launch your projectile.

Instructions

1 Cut the wire hanger at one of the bottom corners. Make a second cut next to the curved hanger portion at the top. Make the second cut on the side of the curved portion away from where you made the first cut. This removes one entire side of the triangle, as well as the curved hanger.
2 Set the flat bottom portion of the wire hanger on the piece of cardboard or wood to serve as the base. The angled portion of the wire hanger should be facing up. Tape the wire hanger to the base with duct tape.
3 Position the spoon along the angled portion of the wire hanger so the spoon extends beyond the cut end of the hanger with the spoon portion facing toward the ceiling away from the wire piece. The handle of the spoon and the wire should overlap. Tape the spoon into place by wrapping duct tape around the spoon handle and wire.

A catapult, or trebuchet, uses a counterweight to fling a stone or rock. The catapult has a long arm with a heavy weight on one end and a sling on the other. The weight falls, pulling the other end of the arm up. The sling rotates around the catapult vertically, going over the top of the catapult. One end of the sling unhooks from the arm and the rock is thrown down range. Loading and firing a catapult should be done safely.

Instructions

1 Aim the catapult by sighting along the trough or tray where the sling rests and point it toward the target. Catapults must be aimed using two components: direction and range. Sighting along the tray will give you the direction. Range must be determined by trial and error.
2 Calculate the range of the throw. Catapults have an ability to throw rocks high and short or midway and long. The angle of the peg and the length of the sling determine the trajectory of the throw. Bending the peg toward the back of the catapult will result in a late release of the weight, which means the rock will be thrown low and short. Bending the peg away from the back will give the shooter a high, short shot which will drop down on the target. It might also send the stone straight up or backward. Beginning users of the catapult should always use the neutral setting of the peg. This produces a shot that leaves the sling at a consistent 45-degree angle.
3 Arm the catapult. Pull the long arm of the catapult down and hook it into the trigger attached to the frame. Ancient catapults used horses or men walking inside large barrels like those used by hamsters for exercise to pull the arm down.
4 Load the catapult. Place the rock or other object in the sling and lay it down along the trough. Hook the end of the sling onto the peg or notch at the end of the long portion of the arm.
5 Pull the trigger and watch the rock slide along the trough and gain speed as it is lifted in the air and flies down range.

Making a rat-trap catapult is not just an inexpensive and entertaining project that you can do with your kids, but an opportunity for an impromptu physics lesson where you can explain about motion, forces, levers and energy. The catapult will cost around $5 to make and take 10 to 15 minutes to construct. The kids can use marshmallows, screwed-up scraps of damp newspaper or pieces of candy as ammunition and have competitions to shoot the furthest and/or most accurately.

Instructions

1 Remove the trigger mechanism, which is to one side of the central spring, using pliers and a screwdriver, if you need one, to prise the mechanism away from the base. Also remove the trigger arm. This usually fixes across one half of the engaged trap to hold the square trap wire, or snapper, in place.
2 Pull the snapper up from the base and place a tongue depressor underneath its width. Adjust the depressor so that the side nearest the top of the snapper lies flush along the top wire. Centralize the tongue depressor so that equal lengths jut out on either side of the snapper and secure it in place with duct tape.
3 Take a second tongue depressor and tape it so that it vertically crosses the first one at the bottom and, when the snapper is vertical, this depressor is too. Use plenty of duct tape to firmly secure the construction.
4 Tape the handle of a plastic spoon along this depressor leaving its bowl jutting out above the top. The back of the spoon rests against the front of the depressor which faces away from the snapper. Use many layers of tightly wound duct tape to create a firm bond.
5 Pull the snapper back against the resistance of the spring using the sides of the horizontal depressor to help you. For maximum firepower, pull the construction back fully so that the snapper is in its usual position when the trap is engaged. Press down on the horizontal depressor while you load the spoon bowl with ammunition. Hold the rat-trap base flat on the work surface with one hand ensuring that it is not in the way of the firing mechanism. When you are satisfied, release the firing mechanism.

Catapults are devices used to hurl objects a great distance. They were invented by the Greeks, and used as effective war weapons against enemy fortifications throughout the Middle Ages. Catapults used a winch system to create tension in an arm holding a catapult basket. The basket was filled with stones and when the arm tension was released, the rocks would race toward a target at great speed. Modern-day replicas of catapults come in three basic designs with three unique basket types. If you already have your model catapult built, the time is right to add a basket in one of these three styles.

Instructions

1 Carve a bowl-shaped depression directly into the end of the catapult's throwing arm. The objects to be thrown can be placed inside this depression. This basket type is used for a fused-arm catapult where the basket and arm are made of one piece.
2 Attach a wide plastic, wood or metal bowl to the end of the throwing arm to create a catapult basket with greater capacity than the fused-arm catapult's depression basket. Drill through the bottom of the bowl and attach the bowl to the throwing arm with screws. Do not use nails or glue because nails will pull out over time and most glue won't hold, as the force generated by the catapult is considerable.
3 Assemble a sling out of sturdy cloth such as burlap or nylon. Cut the cloth into a square and cut holes about an inch from each of the four corners. Tie a piece of rope between the holes in the corners on one side of the cloth and tie another piece of rope between the holes in the corners on the other side of the cloth. The resulting creation will resemble a hammock. To use a sling basket on your catapult, the throwing arm must be altered. Insert a round dowel through the width of the throwing arm at its end. Hang the sling basket from this dowel. Secure the loops of the sling by using additional rope to tie the loops to the dowel.

Catapults have been used throughout history to launch heavy objects into an enemy's camp and hurl items long distances and over walls. Building your own catapult is a perfect science experiment for learning about tension and seeing firsthand the power that it can create. You can make a simple cotton ball catapult using some basic materials that you may already have in your home. Once you gather your materials, the entire process should take less than five minutes.

Instructions

1 Cut off the top of a small box. A long tissue box works well for a catapult. Just use a box cutter to remove the top of the box where the tissues come out, cutting right at the edges. Turn the box upside down. This will be the frame for your catapult.
2 Make a cut into the box just big enough to insert your spoon handle. The cut should be about 2 inches from one end of the box. Slide the tip of spoon handle into the box. Tape the spoon into place by turning the box on its side and wrapping masking tape around the tip of the handle inside the box. Then, wrap masking tape around the spoon handle outside of the box, just above the top of the box. This will keep the spoon from sliding down into the box as you use your catapult.
3 Attach two rubber bands to the spoon. Wrap each rubber band around the handle of the spoon and pull one end of the rubber band through the other end to hold it into place.
4 Attach the rubber bands to the box. You can either tape the rubber bands to the edge of the box on the outside, or you can cut small slits in the box right at the edge and tuck each rubber band into a hole. Place your slits about 1 inch to either side of the spoon. Pull each rubber band so that it gives just enough slack for the spoon to stand upright. Tape the rubber bands to the box. If you have made slits in the box and tucked the rubber bands in, you will be taping them to the inside of the box.
5 Launch a cotton ball. Just place a cotton ball on the spoon, pull it back until it nearly touches the box and release. You have made your very own cotton ball catapult.