Mandi Glauser's Research

My Research

All research was done by me, Mandi Glauser. I also made the trebuchet that I tested my theories on. The design for the trebuchet came from the article"WarSerpent" by Paul Schmidt

Original Research

Below is a paper I wrote after physicaly conducting my own research

How Far Can You Go?
	Trebuchets are medieval siege weapons that were used to damage and knock down castle walls; they were also used to throw dead cows, manure, or spoiled meat to create disease within the castle walls. Nowadays, trebuchets are used as a form of entertainment. Full scale Trebuchets are used to through pianos, cars, and anything else a passionate demolitionist wants to destroy in a show. There are also competitions on how far a home made trebuchet will fire certain objects. But what will get the furthest possible launch? 
You can not just build a trebuchet and expect it to launch perfectly and as far as possible without making adjustments. There are many changeable factors to the trebuchet that will determine the furthest launch. The changeable things are: sling length, release hook angle, wheels, no wheels, lever arm length, counter weight arm length, lever arm pivot height, counter weight drop height, counter weight- weight, fixed counter weight, hinged counterweight, projectile weight, and projectile shape. All of these may affect the trajectory of projectile. Some of the factors of the trebuchet can not be modified after the trebuchet has been built such as: the lever arm length, pivot height, wheels or no wheels, fixed or hinged counter weight. If you wanted to test the differences between these factors you would need to build about six or seven different trebuchets specifically for one or two of these changes. Then you need to make sure all the other factors are the same such as the wood used, the same size wheels, or the 
	For now let us focus on only a few factors such as the counter weight, sling length, and the projectile weight. You might hypothesis that as with one sling length and one weight of projectile but a changing counter weight would throw the projectile further as the counter weight becomes heavier. Possibly due to the fact that the extra weight on the end would make the lever arm swing faster. In most cases you would be right in thinking this. There may be a factor or two else where on the trebuchet that will change the range of the ball at certain counter weight measurements.
Like a baseball outfielder throwing a ball to first base faster is not the only way to get the ball there; you need height also. In Physics, which has a lot to do with trajectory, fast low ball will not get very far. The sling length might play a key role in this situation. I have found a heavier weight longer sling will go much higher than a heavier weight shorter sling.
Now that we have found that more weight and a longer sling works better, what about the projectile weight? On a longer sling you need to lessen the projectile weight. But not too much for you need the weight of the projectile to act with the centrifugal force pushing outward to launch the projectile. The centrifugal force will also affect the sling too much length the sling will carry the projectile too long and plant it into the ground a few feet in front of your trebuchet.
Out of these factors and what happens when they are changed we may come to a conclusion. The more counter weight is better, this we know for sure. The more counter weight we add we need to add some more sling length. The more sling length the less the projectile should weigh. But we want more centrifugal force so we need to keep the projectile heavier and therefore the sling a little shorter. So slightly heavier counter weight, with a middle range sling length, and a middle range projectile weight should give you a good long trajectory. But don't forget about those other factors that could be changes so my suggestion on finding the perfect trajectory and longest range would just be trial and error.

Below is the data I collected wen doing my research.

Research paper

Below is a paper I wrote after researching through the internet and magazines

All About Trebuchets
Trebuchets, what are they? I had not even heard of a trebuchet until the summer of 2005 when I went to an engineering course at the University of Idaho. During the course, I learned what they were, how they worked, and how to build one. If it weren’t for that course, I might have looked at one and called it a catapult. In ways they are, but they are not the same thing.
The trebuchet and the catapult are both medieval siege engines. But a difference between them is the catapult’s projectile is placed in a hollowed end of a long beam, while the trebuchet’s projectile is held in a sling. The sling ultimately provides more energy to the projectile. Another difference is that the catapult gets its power from stretched rope or other sinew, while the trebuchet gets its power from the direct downward pull of gravity acting on a weight attached to a lever. The motion of the trebuchet is the key to the trebuchet’s potential, but the lock is the structure.
The trebuchet is a simple structure consisting of two A-frames supporting an axel. Around the axel pivots a lever arm. One end is shorter that carries weight; and on the other, much longer end is a sling carrying a projectile. 
How it works is like the see-saw (a type 1 lever). In its resting position the lever arm is straight up due to the counter weight which is on one end. The workers of the trebuchet would “caulk” or prepare the trebuchet for firing using a windlass (a pulley system) on the longer end of the arm to bring it down. Then someone would set the trigger, usually a pin through loops in rope on both the bottom of the trebuchet and the lever arm. “When the trigger is released, the counterweight begins to drop. This moves the other end of the arm very quickly and the projectile in the sling is dragged along underneath the machine…Centrifical (the correct term is actually centripetal) force holds the sling taunt as the sling swings out ….Forces try to straighten out the sling and eventually the loop on one end slips off the hook. The projectile is no longer held in the pouch and so continues on its way down range.” (Geiselman)
 The trebuchet was used to hurl stones, dead animals, and even dead humans at or into castles or fortified towns. The stones were used to demolish the walls of the castle, or to destroy the enemy’s artillery. The dead animals and humans were used for biological warfare. “…in 1345-46, the trebuchet’s contribution to biological warfare had perhaps its most devastating impact. As Mongol forces besieged this Genoese outpost on the Crimean peninsula, the Black Death swept through their ranks. Diseased corpses were then hurled into the city, and from Kaffa, the Black Death spread to the Mediterranean ports of Europe via Genoese merchants.” (Chevedden 66-71) The human bodies were also used in physiological warfare as the enemy would throw the ambassadors and the fallen warriors of the town under attack back at the town.
Before I learned all of these amazing facts, I had only heard of catapults. No history class mentioned them. I might have seen one on the history channel but I never watched the history channel very much. I think one of the first times I encountered a catapult was on a computer game. The game was partly for learning purposes so it explained to me that a catapult was a weapon used in the early days, in Europe, to knock down castle walls, or to fling things over the castle walls and into the castle. In the game that I had been playing, the intention was to fling ‘Hyperman’, who had been changed into a four eyed cow, over the castle wall to save his friend from the evil Entrobe. I had strange games, I know. Later, I would sometimes see them in movies such as “The Scorpion King.” And without realizing it, I witnessed a trebuchet throw a grand piano in the TV series “Northern Exposure.” Then I saw the same movie clip in one of Mr. Foote’s science movies. But with all these random glimpses and short explanations I had never found out all about them, until July of 2005.
I had applied and been accepted to the University of Idaho’s JEMS (Junior Engineering Math and Science) summer workshop. There I studied and constructed a working trebuchet. At that workshop I learned that trebuchets were used in Europe but came from China. They use the potential energy of a counter weight to throw a projectile when the weight is dropped. Unlike the catapult which uses the potential energy of wound rope or some thing similar. A full scale trebuchet could throw a three hundred pound projectile three hundred feet. I learned of the projectile’s trajectory through the air and the effect of air resistance on the projectile. I learned the drop height of the counter weight affected the speed and force of the projectile. At one point, the other students and I were given a kit to make a model trebuchet and an assignment to alter the changeable factors on it to see who could make their trebuchet fire the furthest. In my half of the students, I achieved the second furthest. 
At JEMS, I focused on how it worked and how to make it efficient. But I did not learn much about its history. Since JEMS, I have decided to explore more in depth into the trebuchet for my senior project in high school. I have researched more into the history of the trebuchet.
There were three kinds of trebuchets. One was the traction trebuchet. The traction trebuchet was the earliest. It worked by tens to hundreds of men pulling on one end of the lever arm where the counter weight would normally be while another group of men held the sling and projectile until ready to release building potential energy. This trebuchet was found in the Mediterranean area. The traction trebuchet evolved into a hybrid between the traction and the later and more efficient version- the counter weight trebuchet. The counter weight trebuchet made it the trebuchet famous.
The origins of the name trebuchet: “The word trebuchet came into English from an Old French word, which at first meant to stumble or trip, a compound of tres, over, with buc, body or trunk.” (Quinion) “During their heyday, trebuchets received a lot of attention from engineers-indeed the vary word ‘engineering’ is intimately related to them…. a common term for them was “engine” (from ingenium, “an ingenious contrivance”), and those who designed, made and used them were ingeniators.” (Chevedden 66-71) 
The one of the earliest types of catapults was the arrow catapult. It was capable of shooting a large number of arrows at once. Other forms of catapults were the Greek ballistae and the Roman onager. The ballistae looked much like the catapult you might think of when someone says catapult. The trebuchet came later. 
 The trebuchet was invented in China around the third to fifth century B.C.E. or the years 300- 500 B.C.E. In the 500s the trebuchet was used by the Islamic armies in Arabia. This started a migration of the design westward. The Mongols used the trebuchet in their conquest. The Mongols had hired Chinese engineers to build and operate the machines. Proof was the Mongol forces used the trebuchet to spread the Black Death epidemic into Genoese.  
The design then reportedly spread to Europe and into the hands of the French and English around the twelfth or thirteenth century (1200- 1300). At some time in the 1300s Edward I was thought to have used a trebuchet in his Scottish campaign. The only certain thing about the weapon was its name: the Warwolf. The trebuchet continued to be one of the favorite siege weapons even after the invention of the cannon. “…the cannon was for a long time not considered a replacement and the two artillery pieces were often used along side each other.” Such occurrences were recorded around the1400s.
The trebuchet was used for the last time as a siege engine in 1521 by Cortez during the siege of Tenochtitan (Mexico City). Cortez’s ammunition was running low so he took a suggestion to build a trebuchet. It took his men days to build it. Finally when it was ready Cortez loaded the trebuchet. The first throw the stone went straight up into the air and came smashing back down on the trebuchet destroying it.
Later in 1851 Napoleon III built a trebuchet it had an arm 33ft in length with a counter weight of 10,000 pounds that threw a 50 pound cannon ball 600 feet. But the trebuchet was unbalanced and sometimes the projectile flew backward.
Today in modern times trebuchets have been recreated for amusement and to discover historical times. Hew Kennedy from Shropshire, England made a full scale twenty ton trebuchet. He shows off his home made trebuchet regularly. He throws numerous things such as: a grand piano, 1975 Hillman (a small British car), many dead pigs, and a few dead horses. How does it work?
“How it works seems simple enough. The heart of the siege engine is a three-ton, 60-foot tapered beam made from laminated wood. It's pivoted near the heavy end, to which is attached a weight box filled with 5= tons of steel bar. Two huge A-frames made from lashed-together tree trunks support a steel axle, around which the beam pivots. When the machine is at rest, the beam is vertical, slender end at the top and weight box just clearing the ground.” (Mapes)
	What would you do with a trebuchet these days?
“Last year Mr. Kennedy walked onto the English set of the Kevin Costner Robin Hood movie, volunteering his trebuchet for the scene where Robin and his sidekick are catapulted over a wall. ‘The directors insisted on something made out of plastic and cardboard,’ he recalls with distaste. ‘Nobody cares about correctness these days.’”(Mapes)
There are also many other trebuchet fans out there. Ron Toms from Los Angeles California builds trebuchets for a hobby. He has thrown pianos 400-500 feet or watermelons with another trebuchet 300-400 feet. There are around 300 people registered in the International Registry of Hurlers on the internet.
Schools are studying it and encouraging students to do the same. Like the JEMS summer workshop did The Wright State University designed a competition for it. “The Wright State University Trebuchet Competition was first held in 1999 as a competition to see who could build a trebuchet that could throw the farthest distance and with the most accuracy. The first competition was held in Wright State's Student Union as part of the National Engineers Week festivities and the TEAMS (Tests of Engineering Aptitude, Mathematics and Science) competition.” (Unknown)
The trebuchet has survived history as tools and now as amusement. It influenced words, other tools and now it has influenced me. The trebuchet is a wonder and humans will continue to study it. I hope someday I may make a hobby out of making trebuchets, or studying the past when trebuchets dominated war.
Reference list

(Mapes)
Mapes, Glynn. "Giant Medieval War Machine Is Wowing British Farmers And
Scaring the Sheep." The Wall Street Journal : .

(Quinion)
Quinion, Michael. Weird Words: Trebuchet. 28 Aug 1999. 18 Mar. 2006 <http://www.worldwidewords.org/weirdwords/ww-tre1.htm>.

(Geiselman)
Geiselman, Kevin A. Trebuchet Physics. 27 May 2002. 18 Mar. 2006 <http://www.tasigh.org/ingenium/physics.html>.

(Vick)
Vick, Andrew. Trebuchet: Bibliography. 01 May. 2000. 19 Mar. 2006 <http://web.grinnell.edu/techstudies/vick/treb.html>.

(Payne-Gallwey)
Payne-Gallwey, Ralph. History Of The Trebuchet. 18 Mar. 2006 <http://www.redstoneprojects.com/trebuchetstore/trebuchet_history.html>.

(RLT.com)
The International Registry of Hurlers. 18 Oct. 2005. 19 Mar. 2006 <http://www.trebuchet.com/registry/display.php>.

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