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1. http://www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

Catapults
Catapults were the first form of field artillery used during battles by the Greeks. They were used as "seige" machines. The word "seige" means the surrounding and blockading of a town or fortress by an army trying to capture it.

The word Catapult comes from the two Greek words "kata" and "pultos". "Kata" means downward and "pultos" refers to a small circular shield carried in battle. Katapultos was then taken to mean "shield piercer".

The Ballista
The first catapults used by the Greeks were based on the bow and arrow but of a much larger size. The "Ballista" was the name given to the first Greek Catapult. It fired spears instead of arrows and its bow worked very differently from a normal bow.

The Ballista worked like the small wooden propellar and rubber band air planes that children play with today.

 

 

2.

 

3. Catapults were used in WWI by soldiers to shoot poison-gas bombs and grenades at enemy soldiers. To do this, the soldiers devised a catapult made of a thin, strong tree with a pouch fastened to it. The ammunition would be loaded into the pouch. The tree was pulled back and released; launching the ammunition.

Catapults are used at present times to launch airplanes off of the decks of aircraft carriers and to launch gliders into the air. The plane is either launched by a large elastic band or propelled along tracks and then released.  http://icatapults.freeservers.com/uses.htm

By the third century BC, two main types of catapults were standardized. One was called the euthytonon, which was used for shooting arrows. The second was called the palintonon, which was used for throwing stone balls at the enemies.   http://www.ic.sunysb.edu/Stu/ntheohar/great distance.

 

4. A device qualifies as a catapult if it takes a force applied to it and projects an object out and into the air. 

 

5. Arrows and stones were used to harm enemies during war.  They also used catapults to launch firry objects into the campsite of the opposing side. 


History
Catapults were invented about 400 BC in the powerful Greek town Syracus under Dionysios I (ca. 430-367 BC). The Greek engineers first constructed a comparatively small machine, the gastraphetes, sort of a crossbow. The gastraphetes was powered by a specially large composite bow. The military effect of the new weapon during the siege of Motya (Sicily) 397 BC encouraged the Greek engineers to enlarge the machine further. They put a larger gastraphetes on a carriage and added a windlass to cock the heavier machine. Certain physical barriers prevented further enlargement of the composite bow. Therefore in mid-fourth century BC torsion springs were introduced instead of the composite bow. The torsion spring consisted of a bundle of rope made from horse-hair or sinew. Such a spring could be enlarged indefinitely. The new catapults were equiped now with two torsion springs powering the two arms of the catapult. Very soon the new design superseded the old gastraphetes machines. Alexander the Great already employed torsion spring catapults on his campaigns. All Hellenistic armies and all powerful Greek cities soon owned a park of torsion artillery. Inscriptions from the Chalkothek  on the Acropolis of Athens first mention torsion spring catapults there about 330 BC. - In the 3rd  century BC the two main types of catapults were standardized:  the euthytonon for shooting arrows and the palintonon for throwing stone balls. They now could be built after the standard calibration formulae layed down in contemporary technical treatises. In this form Carthage and Rome also adopted the heavy weapons. - This type of Hellenistic torsion artillery still was employed under Augustus, when Vitruvius wrote his work. About 100 AD the Romans redesigned the torsion artillery, developing quite different new arrow-shooting machines. They are first shown on Trajan´s Column in Rome. The new catapult types remained in use until Late Antiquity. In this period also another type of  stone-thrower was employed, the onager.

Representations in Ancient Art
There are only few representations of arrow-shooting catapults in ancient art:
        Balustrade relief from the Athena sanctuary, Pergamon; 2nd century BC (Berlin, Pergamon Museum)
        Cupid gem; Late Hellenistic or Augustan (from the Tommaso Cades collection)
        Relief from Rome, Armilustrium(?); Flavian (Florence, Palazzo degli Uffizi)
        Relief on tombstone of Vedennius, Rome; end of first century AD (Rome, Musei Vaticani)
        Several reliefs on Trajan´s Column, Rome.
Photos of the reliefs are reproduced in:  Schramm 1918   -  Marsden 1969  -  Baatz 1994 (see bibliography)
No representation of a large, stone-shooting machine is known so far.

 

Recent Catapult Uses

Catapults were used in WWI by soldiers to shoot poison-gas bombs and grenades at enemy soldiers. To do this, the soldiers devised a catapult made of a thin, strong tree with a pouch fastened to it. The ammunition would be loaded into the pouch. The tree was pulled back and released; launching the ammunition.

Catapults are used at present times to launch airplanes off of the decks of aircraft carriers and to launch gliders into the air. The plane is either launched by a large elastic band or propelled along tracks and then released.

 The catapult was invented around 400 BC in Greek town Syracus.  However, it was not the catapult we generally think of upon hearing the word Catapult.  The very first catapult invented resembled a crossbow.  It was called the Gastraphete, and it was operated much like a crossbow.  Loading or reloading however took more effort than today’s crossbows.  The Gastraphete had to be pointed at the ground and the operator would push down with all his weight.  The Greeks, impressed by the destructive power of this new weapon, created a bigger version of the Gastraphete.  This was called a Ballista and it was used as a defense weapon against raiding armies, rather than offencively.  In order to reload this massive machine, the force needed would take many men; therefore they built a crank on the end that only needed one man or two.  The crank would be turned pulling back the rope of the Ballista putting it in the ready to fire mode.  The force needed for the Ballista to operate correctly is torsion.  Torsion is when the rope of the Ballista is twisted to generate the force.  The rope will get tighter, when released the force will propel the dart or arrow forward.  The missile was propelled with such force that it could take out several armored men in one shot.                       

 

 

 

 

 

 

 

 

Ballista
The oldest form of catapult used in siege warfare. The Ballista is best described as a giant crossbow which fired spears instead of arrows. There were many types of Ballista that were popular with the Greeks and Romans, but the one thing they have in common is that they were all powered by twisted sinew ropes. The ballista was accurate and could fire spears a great distance but they were difficult to build and they were limited to hitting only what they could see.

Ballista

Mangonel
Also called the Onager, was developed by the Romans. It had one throwing arm who's end was connected to a base by twisted sinew ropes similar to the Greek's Ballista. It was light, easy to move and could throw rock as well as fire. It was inaccurate however. Both the Ballista and the Mangonel are called Torsion Machines because they are powered by a twisting force called Torsion

Mangonel

Trebuchet
Traction Trebuchet - Used people power to haul down the shorter end of the beam, which in turn flipped up a sling that was connected to the longer end. As the longer end reached its apex, the sling opened releasing a large stone or other object.

Counterpoise Trebuchet - Worked the same way but a counterweight was used on the short end of the beam. To fire it they pulled the long end of the beam down and then released it. Both types of Trebuchet are Non-torsion Machines.

Counterpoise Trebuchet

 

          

 

 

 

 

 

 

 

 


Slingshot


Aircraft Catapult


Catapult Watch

 


1.      First known use of the catapult

Catapults were invented about 400 BC in the powerful Greek town Syracus under Dionysios I (ca. 430-367 BC). The Greek engineers first constructed a comparatively small machine, the gastraphetes, sort of a crossbow. The gastraphetes was powered by a specially large composite bow. The military effect of the new weapon during the siege of Motya (Sicily) 397 BC encouraged the Greek engineers to enlarge the machine further. They put a larger gastraphetes on a carriage and added a windlass to cock the heavier machine. Certain physical barriers prevented further enlargement of the composite bow. Therefore in mid-fourth century BC torsion springs were introduced instead of the composite bow. The torsion spring consisted of a bundle of rope made from horse-hair or sinew. Such a spring could be enlarged indefinitely. The new catapults were equiped now with two torsion springs powering the two arms of the catapult. Very soon the new design superseded the old gastraphetes machines. Alexander the Great already employed torsion spring catapults on his campaigns. All Hellenistic armies and all powerful Greek cities soon owned a park of torsion artillery. Inscriptions from the Chalkothek  on the Acropolis of Athens first mention torsion spring catapults there about 330 BC. - In the 3rd  century BC the two main types of catapults were standardized:  the euthytonon for shooting arrows and the palintonon for throwing stone balls. They now could be built after the standard calibration formulae layed down in contemporary technical treatises. In this form Carthage and Rome also adopted the heavy weapons. - This type of Hellenistic torsion artillery still was employed under Augustus, when Vitruvius wrote his work. About 100 AD the Romans redesigned the torsion artillery, developing quite different new arrow-shooting machines. They are first shown on Trajan´s Column in Rome. The new catapult types remained in use until Late Antiquity. In this period also another type of  stone-thrower was employed, the onager.

 

2.      Types of Catapults

Ballista/Traction Trebuchet

Tension Catapult

Counterweight Trebuchet

Torture Catapult

 

http://www.barrie.org/MS_Science/bridges.htm

http://www.trebuchet.com/plans.html

 

 

3.      Catapults were used in WWI by soldiers to shoot poison-gas bombs and grenades at enemy soldiers. Catapults are used at present times to launch airplanes off of the decks of aircraft carriers and to launch gliders into the air. The plane is either launched by a large elastic band or propelled along tracks and then released.

 

4. A catapult is any device that launches a projectile under its own power, and is flung not struck


Charlie Dickhaus

Ryan Delehanty

 

1. The first known use of the catapult is by the ancient Greeks who used a ballista sort of device to hurl shafts of wood at enemies. The traditional form of catapults did not come around until the Romans. The catapult reached it peak in popularity until the dark ages.

http://www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

2. The three different designs are the catapult, the trebuchet, and the ballista. The catapult uses a wound rope to sling an arm into an unmoving bar the arm stops but the projectile continues. The trebuchet uses weights to pull on the short side of the arm causing the long side to move rapidly. A sling is used to throw the projectile. A ballista uses tension from wound rope to hurl a wooden shaft.

http://www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

3. Catapults are siege weapons used to do significant damage, especially to building, from a large distance. Now they are almost entirely obsolete and used mostly for entertainment.

http://home.t-online.de/home/d.baatz/catapult.htm

4. A catapult is a device that uses weights or tension from ropes in a simple lever system to hurl a projectile.

5. All kind of projectile were used including boulders, shrapnel, and corpses (which were used to spread disease.)

http://home.t-online.de/home/d.baatz/catapult.htm


This pages shows the basic physics formulae for ballistic projectiles. The projectiles are assumed to be shot at a 45 degrees (for best range) or 90 degrees (for best height) angle, from ground level.

The formulas assume there is no air resistance. Also, for very high velocity projectiles (>1000 m/s) these formulas are not appropiate anymore.

When shot upwards:
 

max. height = 0.5 * v * v / g 

Example: at 36 Km/hour (10 m/s), this gives max height=0.5*10*10/9.8=5.1 meter.

time of flight = 2 * v / g

Example: at 36 Km/hour (10 m/s), this gives time of flight=2.04 seconds

launch velocity = 0.5 * g * (time of flight)

Example: 5 seconds time of flight gives 24.5 m/s (88 Km/hour)

launch velocity = square root (2 * g * height)   

Example: 10 meter height gives 14 m/s (50 Km/h)

range = 0

 

When shot at a 45 degree angle:
 

max. height = 0.25 * v * v / g 

Example: at 36 Km/hour (10 m/s), this gives max height=0.25*10*10/9.8=2.5 meter.

time of flight = 1.41 * v / g

Example: at 36 Km/hour (10 m/s), this gives time of flight=1.44 seconds

launch velocity = square root ( g * range )

Examle: if range=35 m, velocity=18.5 m/s (67 Km/h)

launch velocity = 0.71 * g * (time of flight)

Example: 5 seconds time of flight gives 34.6 m/s (124 Km/hour)

launch velocity = 2 * square root ( g * max height)  

Example: 10 meter height gives 19.8 m/s (71 Km/h)

range = v * v / g or 4 * max. height

Example: 100 Km/h (27.8 m/s) gives a range of 79 meter

range = 0.5 * (time of flight)2

Example: 5.5 sec flight time gives a range of 148 meter. Warning: mind the air resistance


v=velocity
g=gravity (between 9.78 and 9.83 m/s2, or 32.2 feet/sec2)

Additional formula:
1 m/s=3.6 Km/hour
1 m/s=3.281 feet/second=2.24 miles/hour
Energy = force * distance = mass * g * height = 0.5 * mass * v * v

Note that all of the above formulas are irrespective of the units you use; put feet and pounds in and you get feet and pounds out.

                                                                                                                                                                                                                                                                                               

History


Catapults
Catapults were the first form of field artillery used during battles by the Greeks. They were used as "seige" machines. The word "seige" means the surrounding and blockading of a town or fortress by an army trying to capture it.

The word Catapult comes from the two Greek words "kata" and "pultos". "Kata" means downward and "pultos" refers to a small circular shield carried in battle. Katapultos was then taken to mean "shield piercer".

The Ballista
The first catapults used by the Greeks were based on the bow and arrow but of a much larger size. The "Ballista" was the name given to the first Greek Catapult. It fired spears instead of arrows and its bow worked very differently from a normal bow.

The Ballista worked like the small wooden propellar and rubber band air planes that children play with today. To see an animation of how the plane uses "torsion" to turn its propellar, click the button below.

The Greeks would twist "sinew ropes" with a "twisting" piece of wood, and then use the "twisting" piece of wood as half of their bow. They would add a second set of twisted ropes and a second piece of wood and the other half of the bow. They would then tie string to the ends of each "twisting" stick to form the bow. To see a diagram of the Ballista's parts, click the button below.

A crank mechanism was added to pull the bow string back. They would then load a spear, release the string and the spear would be launched. It was an extremely accurate catapult but was difficult to build and you could only shoot at what you could see.

The Ballista, or "shield piercer", was invented because normal arrows would not peirce enemy shields. The Ballista's spears would easily pierce those shields at a far greater distance that normal arrows would travel. The Ballista was later adopted by the Romans.

 
The Mangonel
Because the Ballista was difficult to construct, the Romans developed the Mangonel. It got its power from twisted sinew ropes just like the Ballista, but instead of two arms it used only one. It is the type of catapult that we are most familiar with. It was very light and easy to move because the Romans added wheels. The Mangonel was easily constructed on the battlefield and it could hurl rocks, burning objects or most anything they could find. It was the most common catapult used during the Medieval Period and its only problem was that it was not very accurate.

 
The Trebuchet
It is beleived that the Trebuchet originated in China around 300 BC. Its use in Western Europe can be traced to the crusades of the 12th century. There were two types of trebuchets.

1.     The Traction Trebuchet used people as a power source. The people would haul down the shorter end of the beam which flipped up the longer end. A sling was attched to the longer end of the beam. As the longer end reached its apex, the sling opened releasing a large stone or other object. The traction trebuchet was good for throwing incendiaries and heads.

2.     The Counterpoise Trebuchet replaced the people power with a weight on the short end. The longer end was pulled down, lifting the weighted end. Upon release, the weight pull down the shorter end down and the longer end swung up. A stone was released from the sling at the apex of the swing.

The catapult was slowly replaced by gunpowder artillery during the 14th and 15th century.

 

 

 

 

http://www.madison.k12.wi.us/toki/catapult.htm

http://icatapults.freeservers.com/spring.htm


www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

 

www.medinfo.ufl.edu/cme/grounds/sinnott/slide14.html

 

History

Catapults were invented about 400 BC in the powerful Greek town Syracus under Dionysios I (ca. 430-367 BC). The Greek engineers first constructed a comparatively small machine, the gastraphetes, sort of a crossbow. The gastraphetes was powered by an especially large composite bow. The military effect of the new weapon during the siege of Motya (Sicily) 397 BC encouraged the Greek engineers to enlarge the machine further. They put a larger gastraphetes on a carriage and added a windlass to cock the heavier machine. Certain physical barriers prevented further enlargement of the composite bow. Therefore in mid-fourth century BC torsion springs were introduced instead of the composite bow. The torsion spring consisted of a bundle of rope made from horse-hair or

sinew. Such a spring could be enlarged indefinitely. The new catapults were equiped now with two torsion springs powering the two arms of the catapult. Very soon the new design superseded the old gastraphetes machines. Alexander the Great already employed torsion spring catapults on his campaigns. All Hellenistic armies and all powerful Greek cities soon owned a park of torsion artillery. Inscriptions from the Chalkothek on the Acropolis of Athens first mention torsion spring catapults there about 330 BC. - In the 3rd century BC the two main types of catapults were standardized:  the euthytonon for shooting arrows and the palintonon for throwing stone balls. They now could be built after the standard calibration formulae layed down in contemporary technical treatises. In this form Carthage and Rome also adopted the heavy weapons. - This type of Hellenistic torsion artillery still was employed under Augustus, when Vitruvius wrote his work. About 100 AD the Romans redesigned the torsion artillery, developing quite different new arrow-shooting machines. They are first shown on Trajan´s Column in Rome. The new catapult types remained in use until Late Antiquity. In this period also another type of stone-thrower was employed, the onager.

http://home.t-online.de/home/d.baatz/catapult.htm

 

The Greeks, impressed by the destructive power of this new weapon, created a bigger version of the Gastraphete.  This was called a Ballista and it was used as a defense weapon against raiding armies, rather than offencively.  In order to reload this massive machine, the force needed would take many men; therefore they built a crank on the end that only needed one man or two.  The crank would be turned pulling back the rope of the Ballista putting it in the ready to fire mode.  The force needed for the Ballista to operate correctly is torsion.  Torsion is when the rope of the Ballista is twisted to generate the force.  The rope will get tighter, when released the force will propel the dart or arrow forward.  The missile was propelled with such force that it could take out several armored men in one shot.      

 

There were many other variations or upgrades to the Ballista.  They were made bigger, easier to move around, and could throw things farther and heavier.  However, they all used the same premise.  They used tension, torsion and gravity to propel objects.  The catapult we think of upon hearing the word "catapult" uses tension or torsion to propel its ammunition.  There were many variations of catapults using this method of propulsion.  The Traction Trébuchet for example used tension.  It consisted of a long flexible piece that was held by many men while the other end was bent back by another man to place a stone that was used as the ammunition.  The tension generated by bending the flexible part was what propelled the stone.  This was useful in storming castles because it was very mobile.  However it only could use small size stones and the force was not strong enough to inflict a lot of damage or go a long distance.  It was used to eliminate guards on the castle wall.  But it was still difficult to enter a fortified castle.  The only way for the invading forces to enter the castle would be through the main gate.    

http://pages.emerson.edu/students/Carlo_Lim/catapults/Catapults.htm#Ballista/Traction

http://tc.education.pitt.edu/library/Catapult9-02.htm

 

http://depts.washington.edu/chinaciv/miltech/catapult.htm

 

http://apphysicsb.homestead.com/catapult.html

 

http://pages.emerson.edu/students/Carlo-Lim/catapults/Catapults.htm


Maria Toro

Brooke Hillebrand

 

October 7, 2003

 

1. http://www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

Catapults were the first form of field artillery used during battles by the Greeks. They were used as "seige" machines. The word "seige" means the surrounding and blockading of a town or fortress by an army trying to capture it.

 

2. http://web.grinnell.edu/techstudies/vick/cat.html

Two-cubit arrow-shooting catapult

370 metres

Three span arrow-shooting catapult (based on the remains found at Ampurias)

305 metres

Small stone-thrower (with a 1.5-mina stone)

184 metres

Small stone-thrower (with a 1-lb. lead shot)

over 300 metres

Smaller onager

over 200 metres

Larger onager

over 300 metres

 

Probably an onager.

 

Ballistae

 

3. http://web.grinnell.edu/techstudies/vick/cat.html

Catapults such as the ballista were intended for use directly against troops, as very large bows that could pierce a shield and still have enough energy to do damage to the sheild's holder. At the siege of Jerusalem in A.D. 70, stone throwers were used: "'and their impact was not only irresistible to the front rank, but also to the men behind, to a considerable distance'. At 400 yards, the one-talent shot ploughed its way through several ranks."[Marsden 95] These catapults were land-based, but catapults have found use on ships. During an attack on a Rhodian harbor, " [Demetrius] put on board his ships, preparatory to attacking the Rhodian harbour, 'those of his three-span arrow-firers that shot the furthest' ([greek translation ommitted]). When actually inside the harbour, he hindered the Rhodians, who were trying to improve their fortifications in that area, by firing at them with 'the lesser arrow-firer capable of long range' ([greek translation ommitted])."[Marsden 89]

Catapults reached their peak of development around 200 B.C., when they were understood well enough to have mathematical formulas that predicted their power based on their size; after that, development ceased during the early middle ages like so many things. It was rediscovered by 1050 and was enjoying much popularity. [Van Creveld 32-2] As with many technologies, there were those who objected (on grounds other than they didn't have them): "In Western civilization until about 1500 A.D., the most important reason why some weapons were considered unfair was because they enabled their users to kill from a distance and from behind cover. The victim being unable to retaliate, such weapons obscured the vital distinction between war and plain murder... [An example was] the catapult, which was perceived as a device that would render valor superfluous in war."                                                                      

4.      The basic characteristic of a catapult is that it is used to sling projectiles across a large or small area. 

5.      The different kinds of projectiles used may vary a lot.  Examples are baseballs, rocks, cannons, golf balls, and anything that does not react a lot to air resistance.

 

 

 

The Crazy Catapult

GET READY . . .

 

  1. Make the arm. Stack two jumbo sticks together. Measure and drill a hole centered 1/2" from one end. Use saw to cut a one-inch long x 1/8" wide horizontal slit centered through both sticks at opposite end. For arm grippers, cut 1-1/4" from each end of regular craft stick. Cut short piece of craft stick for spacer. Sandwich grippers and spacer between arm pieces while gluing together. Cut ends of grippers should be at a slight slant 1/2" apart with first gripper 1/2" from slot, between arm pieces. Position spacer 1/2" from holes at opposite end of arm. Break off spoon handle leaving 1-1/2" of the handle. Glue handle into slit in arm. Set aside.
  2. Assemble the catapult. See Figure and Photo. Glue two jumbo craftsticks (uprights) perpendicular to the base opposite each other 3" from one end. Glue two jumbo craftsticks at an angle on each side for stabilizers as shown in photo. Let dry. Drill one hole 1/2" from top of stabilizers on both sides. Cut dowel in half. Slide one dowel through the holes and glue into place. Drill a hole in each upright 2" from bottom. Slide remaining dowel through one side of upright, then through the hole in the catapult arm, then through the other upright. Glue into place.
  3. Attach the firing mechanism, load, and FIRE! To attach clothespin, position clothespin so it will grasp the end gripper when arm is in down position. Insert screw through spring in clothespin. Turn screw into board. Attach rubber band to top dowel using a lark's head knot. Slide opposite end over arm between grippers. Velocity can be adjusted by placement of rubber band. The further back on the arm the rubber band is placed, the more momentum. Push arm down until end of gripper fits inside of clothespin. Catapult is ready to fire!

 


                                                            Assignment No. 1

1.  Catapults
Catapults were the first form of field artillery used during battles by the Greeks. They were used as "siege" machines. The word "siege" means the surrounding and blockading of a town or fortress by an army trying to capture it.

The word Catapult comes from the two Greek words "kata" and "pultos". "Kata" means downward and "pultos" refers to a small circular shield carried in battle. Katapultos was then taken to mean "shield piercer".

URL: http://www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

 

2. The Ballista
The first catapults used by the Greeks were based on the bow and arrow but of a much larger size. The "Ballista" was the name given to the first Greek Catapult. It fired spears instead of arrows and its bow worked very differently from a normal bow. The Ballista worked like the small wooden propeller and rubber band air planes that children play with today.

The Mangonel
Because the Ballista was difficult to construct, the Romans developed the Mangonel. It got its power from twisted sinew ropes just like the Ballista, but instead of two arms it used only one. It is the type of catapult that we are most familiar with. It was very light and easy to move because the Romans added wheels. The Mangonel was easily constructed on the battlefield and it could hurl rocks, burning objects or most anything they could find. It was the most common catapult used during the Medieval Period and its only problem was that it was not very accurate.

The Trebuchet
It is believed that the Trebuchet originated in China around 300 BC. Its use in Western Europe can be traced to the crusades of the 12th century. There were two types of trebuchets.

  1. The Traction Trebuchet used people as a power source. The people would haul down the shorter end of the beam which flipped up the longer end. A sling was attached to the longer end of the beam. As the longer end reached its apex, the sling opened releasing a large stone or other object. The traction trebuchet was good for throwing incendiaries and heads.
  2. The Counterpoise Trebuchet replaced the people power with a weight on the short end. The longer end was pulled down, lifting the weighted end. Upon release, the weight pull down the shorter end down and the longer end swung up. A stone was released from the sling at the apex of the swing. The catapult was slowly replaced by gunpowder artillery during the 14th and 15th century.

URL: http://www.newton.mec.edu/Brown/TE/CATAPULTS/Catapult_history.html

In modern times, the basic trebuchet design has been updated to be more efficient and more powerful. These trebuchets are mostly used for study and entertainment, and the occasional pumpkin chucking competition!

In modern times, the word catapult can be used to describe any machine that hurls a projectile. This can include a slingshot used to hurl pebbles, a machine that launches airplanes off aircraft carriers, or even a watch that flings BBs!


Slingshot


Aircraft Catapult


Catapult Watch

 

 

 

 

URL:  http://www.catapults.info/

4. Catapult - A military machine for hurling missiles, such as large stones or spears, used in ancient and medieval times; A mechanism for launching aircraft at a speed sufficient for flight, as from the deck of a carrier; A slingshot.

URL: http://dictionary.reference.com/search?q=catapult

5. Balls, rocks and stones, Teters (Ha Ha J, shrapnel


                                                                                                                        Ike Chang

                                                                                                                        Eric DeWitt

                                                                                                                        Wesam Ead

                                                                       

                                                                                                                        10-6-2003

 

Catapult Research

 

  1. The first known use of a catapult.
    1. Catapults were invented about 400 BC in the powerful Greek town Syracus under Dionysios I (ca. 430-367 BC).

 

 

 

 

 

 

 

 

 

 

 

  1. Different types of catapult designs.
    1. Slingshot used to hurl pebbles, a machine that launches airplanes off aircraft carriers, or even a watch that flings BBs

 

    1.    

 

 

  1. Uses of catapults throughout history to the present.
    1. The catapults use has evolved throughout times, from the Roman to hurl rocks at enemies, with different projectile in the catapult. It can be uses for many different things. Hunters use slingshot to knockout small animals, Navy uses catapult to launch airplanes from the deck of a naval carrier, and during medieval time, ship were also mounted with catapults to attack ships, land alike.

 

    1. Catapults also has changed throughout history of mankind, in its present state, catapults has transformed into artillery, which is also a long range weapon against the enemies.

 

  1. What qualifies a device as a catapult?
    1. A catapult that allows a projectile to launch from the stand at an instant accelerated velocity. The purpose is to let a projectile to gain speed in short period of time.

 

  1. Types of projectiles used and why.                                                       
    1. Human in medieval time to spread diseases into siege castle.

 

    1. Airplanes to launch in short distance.  

 

    1. Flaming projectiles were also placed in the catapults as a mean of mass destruction against raids of men from armies.

 

    1. Pellets are used to shoot at small animals.

 

    1. Any other objects that user wishes to toss.

CATAPULTS

  PRIMITIVE WEAPONS OF MASS DESTRUCTION

 

 

 

 

 

 

What is a catapult ?

 

A catapult is a mechanism used to throw missiles in ancient and medieval warfare. At first, catapults were specifically designed to shoot spears or other missiles at a low trajectory. They were originally created from ballistae and trebuchets, both of which were large military engines used to hurl stones and other missiles, but these distinctions later blurred.  Later, larger catapults mounted on a single arm also hurled stones, pots of boiling oil, and incendiaries at a high trajectory. They were used to attack or defend fortifications. Catapults were widely employed in siege warfare, but with the introduction of artillery they passed from use. In the 20th century, catapults using hydraulic pressure were reintroduced to launch aircrafts from warships.


How does a catapult work?

There are several different technologies that fall into the "catapult" category. They include the catapult, the ballista and the trebuchet. The catapult is the winched-down bucket that people normally think about when they hear the word "catapult".  A ballista is a very large crossbow.  A trebuchet is a weighted beam that swings a sling carrying the projectile

Both catapults and ballistae work by storing tension either in twisted ropes or in a flexed piece of wood (in the same way an archery bow does, but on a larger scale).

A trebuchet tends to be easier to build because it consists of a pivoting beam and a counterweight that rotates the beam through an arc.

Catapults can launch things a fair distance -- 500 to 1,000 feet (150 to 300 meters) is common. It is surprising how much energy they can store. The gears are important, because they create a winch. The winch allows a person to put a great deal of energy into the catapult over a period of time. Then all of the energy releases at once, throwing the projectile.

 

How the trebuchet works

 

 

 

 

 

Figure 1.
This diagram shows a trebuchet shortly after the trigger has been released. The shot is in the sling and is beginning to slide backwards along a launch trough. The trough is put there to guide the sling and prevent it from getting caught up in the trebuchet's framework. In the early part of the launch all the shot's motion is horizontal and this speed will contribute to the rate at which the sling is going to be whipped around the end of the trebuchet’s beam later.

 

 

 

 

Figure 2
Here the trebuchet beam has rotated and of course the end holding the sling has risen. The shot has been pulled down the trough and is now speeding backwards, but it has also been lifted up and clear.  Now, any weight which is tied by a length of rope to the end of a rotating beam is going to swing out – inertia in action.  Our shot's motion has this effect plus the speed it has already acquired. The result is that the sling will rotate around the end of the beam

 

 

 

 

Figure 3.
If your trebuchet's release mechanism is the ring over a prong or hook, it is going to release the sling as soon as the angle between the sling ropes and the arm is straight enough for the ring to slip off the prong.

 

 

 

 

 

 

Figure 4.
Finally, the follow-through .   It's not as much as you might imagine.
If you had the weight fixed rigidly to the end of your trebuchet’s beam you would have a simple pendulum and it might well oscillate until it eventually came to a stop. The design shown in figures 1 to 4 uses a free-swinging weight and the interfering motions pull up the beam in a series of jerks and starts.


 

HISTORY

        Catapults were invented about 400 BC in the powerful Greek land of Syracus. The Greek engineers first assembled a relatively small machine called the gastaphetes, which is known to many people today as the crossbow. The gastaphetes was mainly powered by a large composite bow. The Greeks had much success with this primitive weapon, which urged them to create a larger and more powerful version of the gastaphetes. In doing so, they placed a larger gastaphetes on a carriage and added a windlass to cock the heavier machine. Eventually the Greeks came to a sudden halt due to physical barriers, which prevented them from enlarging the weapon even more. Therefore, they were forced to get rid of the composite bow and replace it with torsion springs. The torsion springs were introduced around the mid fourth century BC. The torsion spring was composed of a bundle of rope made from horsehair. The spring had many advantages, one of which that it could be enlarged indefinitely. The new catapults consisted of two torsion springs, one for each arm of the catapult. The creation of this deadly weapon took the place of the old gastaphetes and many other weapons in which they used for battles. Many great leaders, such as Alexander the Great, admired the catapult greatly and made it part of his artillery for his campaigns. Soon thereafter, many other armies and powerful Greek cities owned parks filled with torsion artillery. By the third century BC, two main types of catapults were standardized. One was called the euthytonon, which was used for shooting arrows a great distance. The second was called the palintonon, which was used for throwing stone balls at the enemies. From then on these weapons could be built by using the standard formulae that was laid down in contemporary technical treatises. Therefore, Carthage and Rome adopted these mass destructive weapons.  Around 100 AD, the Romans restructured the torsion artillery in which they developed many new forms of arrow shooting machines. The new catapult types remained in use throughout the Middle Ages, where another type of stone-throwing catapult was formed called the onager.

 

 

 

 

 

MODERN DAY USES OF THE CATAPULT

 

The first case of catapult technology returning was in a small children’s toy.  It consisted of a Y shaped stick and a piece of rubber.  It was used to throw small stones.  It worked by placing the stone on the rubber, pulling it back generating tension, then when released the rubber would snap back into it’s original form, prior to being stretched and the stone would be thrown.  This toy is known today as the slingshot. 

 

Another form of catapult technology appearing after the Middle Ages is known as “Langley's Catapult Device”.  Samuel P. Langley was the chief competitor to the Wright brothers.  Langley’s aircraft, known as the Aerodrome, was propelled by a spring-powered catapult.  It worked by attaching the Aerodrome to the end of the spring, the other end held stationary.  The Aerodrome would then be pulled back forcing the spring to stretch, which is also tension.  When released the spring would snap back, the force in which would create enough speed to launch the Aerodrome into the air.  This device in theory would have worked.  However, during the second test the spring caused the Aerodrome to crash right after takeoff. 

 

The Wright brothers had their own catapult, which used gravity.  It consisted of a single guide rail, a series of ropes and pulleys, and a 500-pound weight that would be secured on the top of the metal tower.  It works just like the counterweight Trebuchet.  The only difference is that it is only needed for generating speed.  When the counterweight is released it will pull the aircraft generating enough speed to be able lift the aircraft off the ground, thereby having the aircrafts engines take over to keep it in the air. 

 

There are other modern day uses of the catapult.  During World War I and World War II, soldiers tossed grenades using a form of the tension catapult.  Aircraft carriers use catapult technology to launch the planes from the deck of the carriers.  This device uses compressed air rather than gravity, tension or torsion.  The term catapult is modified in today’s world.  It does not have to be launched by gravity, tension or torsion in order to be a catapult.  Any device that can project an object a great distance in a short amount of time can be considered a catapult.