siege-engines-msg - 1/10/08 Catapults, trebuchets. Period and modern. Tabletop models. NOTE: See also the files: crossbows-msg, p-archery-msg, archery-books-msg, c-archery-msg, crossbow-FAQ, arch-books-FAQ, pottery-wepns-msg, slings-msg. ************************************************************************ NOTICE - This file is a collection of various messages having a common theme that I have collected from my reading of the various computer networks. Some messages date back to 1989, some may be as recent as yesterday. This file is part of a collection of files called Stefan's Florilegium. These files are available on the Internet at: http://www.florilegium.org I have done a limited amount of editing. Messages having to do with separate topics were sometimes split into different files and sometimes extraneous information was removed. For instance, the message IDs were removed to save space and remove clutter. The comments made in these messages are not necessarily my viewpoints. I make no claims as to the accuracy of the information given by the individual authors. Please respect the time and efforts of those who have written these messages. The copyright status of these messages is unclear at this time. If information is published from these messages, please give credit to the originator(s). Thank you, Mark S. Harris AKA: THLord Stefan li Rous Stefan at florilegium.org ************************************************************************ Military Engines <Son> Inasmuch as you seem to think that you have described most of the weapons which are convenient to have in naval warfare or in fighting on horseback, I will now ask you to say something about those which you think are most effective in besieging or defending castles. <Father> All the weapons that we have just discussed as useful on ships or on horseback can also be used in attacking and defending castles; but there are many other kinds. If one is to attack a castle with the weapons which I have enumerated, he will also have need of trebuckets: a few powerful ones with which to throw large rocks against stone walls to determine whether they are able to resist such violent blows, and weaker trebuckets for throwing missiles over the walls to demolish the houses within the castle. But if one is unable to break down or shatter a stone wall with trebuckets, he will have to try another engine, namely the iron-headed ram, for very few stone walls can withstand its attack. If this engine fails to batter down or shake the wall, it may be advisable to set the cat t to work. A tower raised on wheels ~ is useful in besieging castles, if it is constructed so that it rises above the wall which is to be stormed, even though the difference in height be only seven ells; but the higher it is, the more effective it will be in attacking another tower. Scaling ladders on wheels which may be moved backward and forward are also useful for this purpose, if they are boarded up underneath and have good ropes on both sides. And we may say briefly about this craft, that in besieging castles use will be found for all sorts of military engines. But Whoever wishes to join in this must be sure that he knows precisely even to the very hour when he shall have need for each device. Speculum Regale FROM: Simon the Strange SUBJECT: War Engines * Original: AREA.... MENSA * Original: FROM.... Bruce Wilson * Original: TO...... Dave Aronson There was a front-page feature story in the July 30 Wall Street Journal that might be of interest to you and other SCA types: "A Scud It's Not, But the Trebuchet Hurls a Mean Piano" "Giant Medieval War Machine Is Wowing British Farmers And Scaring the Sheep" It seems some guy in England's managed to build a full-size (some 4 stories tall) working trebuchet and uses it to hurl grand pianos, small cars, and animal carcasses across the British countryside. Some British parachutists want to try it, but the acceleration is 0 to 90 mph in 1.5 seconds and produces centrifugal force of 20 Gs, which may be enough to burst human blood vessels. One of his incentives to build the thing was a "nutter cousin" in Northumberland who made a small trebuchet he used to hurl porcelain toilets that'd been soaked in gasoline and set afire. The article said that a local paper had headlined the story "Those Magnificent Men and Their Flaming Latrines." :-) ------------ * Origin: Aronson Consulting: TIDMADT 703-370-7054, voice x6508 (1:109/120) From: JRECHTSCHAFF at hamp.hampshire.EDU Date: 13 Nov 91 22:48:00 GMT Organization: The Internet Greetings unto the Rialto from Lyanna ferch Gwynhelek, Concerning Siege Engines (also written by Pierre) The trebuchet is basically a counter-weighted lever. The potential energy of a weight is released across a fulcrum (pivit point) to import kinetic energy to a projectile lodged at the far end of the lever. It follows that the greater the weight the less the friction, the lower the lever, the greater the mechanical advantage. The lighter more streamlined the projectile, the greater the thrown distance. The weight must fall through an arc to translate potential to kinetic energy. It's vertical acceleration (ignoring friction) wil be 9.8m/sec. squared. Now it will take a while for the weight to reach it's terminal velocity. Aha! You say blinded by a brilliant flash of the inuitively obvious. To get maximum acceleration my trebuchet counter-weight must fall "x" feet which means that this sucker has got to be tall. Tall equals big. How big? Try 120-150'. (See The Wall St. Journal Tuesday 31, July for an excellent article on a piano throwing modern trebuchet.) Now the overall height can be reduced by digging a pit between the uprights, but physics is still physics and you still need clearence for the weight so about 120' is it. Needless to say the greater the mass (the more accelerated the counter-weight) the more convinient - try depleted urainium. Seriously, the most readily available wieght is lead. Don't start messing around with old batteries - nasty stuff can happen to you and mother earth. A ton or two works well. The longer the lever arm the better. Now we're into materials. I happen to have an 80' ash pole but I like it in it's present form - as a tree. Old growth spruce is hard to find. You're best off laminating (laminating is period) up a pole from close grain spruce. Consult a wooden boat maker. If you are building a machine you now have two uprights (telephone poles are OK) about 6 to 8 feet apart, (obviously this isn't very portable), a very long lever pivoting on trunions across the top of the uprights and a counter weight fastened (hinged is best) to the short end of the lever. You now put a cup on the throwing end of the lever sufficient to hold a dead horse or a prisoner-of-war of choice. (See projectile below) You collect a bunch of serfs, haul the long end down with a rope, load, and have everyone let go. (In addition to a dozen rope burned palms, you let the end of the rope loop around your ankle and neatly amputate it. See trigger mechanisms) Assuming you have a pivoted or off-center counter- weight the lever rotates from about 180 degrees (pointed down) up through 0 degrees (pointed up) over to 270 degrees (where the projectile falls onto the ground) on down to the ground where it shatters while pegging the idiots standing there (remember the trigger crew?) or rebounds and jumps on its trunions or if your lucky, pendulums for a while. Obviously you need to stop the arm at some point. The theretical ballistically optimum turning point is 45 degrees. In practice however, this does not allow for sufficient fall of the counterweight, for friction etc. A practicle point is at about 30 degrees. The stop must be strudy well padded and well braced lest the lever frame shatter. This gives rise to an old medieval saying, "It is easy to build something that fires once building one that fires twice is something else." If the frame is built on skids the azimuth can be changed, if it is (was) more usual it is anchored to the ground, the azimuth is fixed. Range can be altered by changing the release (trigger) point or by building up the stop padding. (Throw a few more sheep skins on the stop.) Range can be increased by a third by use of a sling. The sling is one-half the length of the lever and rides with it's projectile, in a trough under the machine. There should be no slack. One end of the sling is fastened to the lever, the other loops over a horn at the end of the lever. (opps that should be that the sling is fastened to one end of the lever, the other loops over a horn at the end of the lever). Note that the release point is now changed by 1/2 the angle between the fastining point and the horn. The simplest trigger (and its shortcomings not to mention its tendency to foul the frame and sling) has been mentioned. A second form of trigger is a wedged in bar across the lever. The wedge is knocked out with a sledge hammer. However, one can be seriously killed by flying crossbars the size of railroad ties. Another trigger consists of a hook and eye released when a lanyard is yanked by a whipped up group of draft animals (not squirrels.) Payne-Salwery and others have illustrated some very nice trigger mechanisms that could be made by any competent smith. As with most medieval siege engines, tecbuchets were transported, knocked down and erected on site. Philippe Contamine writes in Guerre dans le Moyens Ages amusingly of an English king who spent months transporting and erecting a monster trebuchet to besiege a castle in Scotland. When the enemy saw that itwas ready they marched out and tried to surrender. The king, understandably piqued, refused, sent them back in, fired demolished half the castle and its garrison and then honor being served accepted their surrender. It is possible to build a trebuchet but not really worth the bother when you can build a ballista or catapult equally portable, wit hvastly better performance. I have a ballista with a 1000 # prod that I can carry by myself. It will shoot a 2' 3/8" rebar bolt through a car door. Reference projectiles. I propose an SCA standard, the humble common brick. it's cheap, readily available and regular in siza and shape. It generally conforms to the size of a medieval brick although it is significantly heavier. It is self-replenishing - as you shoot down the wall, you get more ammo! -Pierre D'Ussf, Artificer aka Peter Maleady (413)549-0786 From: ddfr at quads.uchicago.edu (david director friedman) Date: 14 Nov 91 05:23:41 GMT Organization: University of Chicago Computing Organizations "It's vertical acceleration (ignoring friction) wil be 9.8m/sec. squared. Now it will take a while for the weight to reach it's terminal velocity." (Lord Pierre D'Ussf, discussing the physics of a trebuchet) The figure you give for acceleration would be appropriate for a mass falling free by itself. The counterweight of the trebuchet, however, is accelerating the throwing arm and the projectile as well--and their weight is pushing in the other direction, since they are on the other side of the pivot. Furthermore, the relation between vertical acceleration of the weight and angular acceleration of the arm etc. changes with the angle. When the arm reaches vertical, for example, a small rotation produces no vertical displacement, since at that point the velocity of the counterweight is horizontal. Since this is a rotational problem, it is much easier to solve it in terms of rotational dynamics. Angular acceleration is torque divided by moment of inertia. The torque is ((mass of the counterweight times its distance from the pivot) minus (mass of the rest of the system (the stuff on the other side of the pivot) times the distance of its center of mass from the pivot)) times sin of the angle of the arm from vertical. I do not see the relevance of terminal velocity. You reach terminal velocity when air resistance exactly balances torque. I doubt that is likely to happen at any plausible speed. "Needless to say the greater the mass (the more accelerated the counter-weight) the more convinient- try depleted urainium." (Lord Pierre) The acceleration of a falling body does not (air resistance aside) depend on its mass, as Galileo pointed out some years back. Increasing the ratio of the mass of the counterweight to the mass of the rest of the system will increase acceleration (see my verbal equation above)--but that would not be true if your original statement (quoted before this one) were correct. I think you may be confusing weight with density. You can get plenty of weight with a box full of dirt and stones, which I think is what they mostly used. "The theretical ballistically optimum turning point is 45 degrees. In practice however, this does not allow for sufficient fall of the counterweight, for friction etc. A practicle point is at about 30 degrees." (Lord Pierre) Forty-five degrees is the optimum angle if velocity does not depend on the angle. With a trebuchet velocity is increasing as the counterweight falls. The effect can be exactly calculated--that part is not a matter of "practical points." Patri, back when he was teaching physics classes, used to give it as a problem to his students. Friction is more complicated. With a sling, the velocity of the projectile when it is released is no longer at right angles to the arm, as it is with a rigid throwing arm. That means that it should be possible to combine the optimal angle for the projectile's velocity (45 degrees from vertical) with maximum velocity (throwing arm upright, counterweight all the way down), giving a longer range than would be possible for the same trebuchet without a sling. "It is possible to build a trebuchet but not really worth the bother when you can build a ballista or catapult equally portable, wit hvastly better performance." ((Lord Pierre) To build a ballista or catapult you need big twisted skeins of very strong cord--and there are, I believe, problems as you try to scale the beast up. All a trebuchet needs is wood, a little metal for release mechanism and such, and dirt (what they filled the counterweight with). David Friedman (Cariadoc has never heard of torque--he gets his physics from Aristotle) From: cctimar at athena.cas.vanderbilt.edu (Charles) Date: 18 Nov 91 05:51:21 GMT Organization: Vanderbilt University student of numerology His Grace, the Duke Cariadoc of the Bow writeth: > > "The theretical ballistically optimum turning point is 45 degrees. In > practice however, this does not allow for sufficient fall of the > counterweight, for friction etc. A practicle point is at about 30 > degrees." (Lord Pierre) > > Forty-five degrees is the optimum angle if velocity does not depend > on the angle. With a trebuchet velocity is increasing as the > counterweight falls. The effect can be exactly calculated--that part > is not a matter of "practical points." Patri, back when he was > teaching physics classes, used to give it as a problem to his > students. Friction is more complicated. Two points need to be considered, here. The first is that the optimum angle is the angle at which you are hitting your target, which is not necessarily the angle that throws the projectile the farthest. Of course, if you are overshooting, you will probably correct by removing a stone from the counterweight, rather than trying to adjust the stop. The second is that, because of air resistance, the longest range for a fixed firing velocity can usually be achieved by firing the projectile at 35-40 degrees above vertical. The best way to compute the actual angle is to do a computer simulation. The second best is just trial and error - I would start by subtracting 5 degrees from the angle that you compute the way Cariadoc suggests. Of course, there is also some friction involved in the arm spinning on its axis. I don't know how large an effect this will have. -- -- Charles, student, in Glaedenfeld, Meridies From: PAMCCOY at GALLUA.BITNET ("Pat McCoy a.k.a. Bones") Date: 26 Nov 91 22:49:00 GMT Organization: The Internet Greeting unto all on the Rialto from Padraigin nic'Aodha! I am enclosing a message from the physics teacher to all who responded to our inquiries concerning siege machines that chunk punkins, pianos and cars. :-) "I am the physics teacher (and non-SCA member) who has been asking questions (through a member on the Rialto) about trebuchets. I have taken great pleasure in the responses Pat McCoy had forwarded me from the Rialto and appreciate the resource you have been to me and my students. In early October, I assigned my introductory Physics students the following problem: "Design a machine which can throw an 8-10 pound pumpkin as far as possible, using the limited materials available." The students took sevel different approaches to the problem, from creating original designs to researching ancient siege machines. The trebuchet idea cropped up from a Wall Street Journal article on an Englishman's current project, (cited here incidentally). However, there was not enough information from that article to build a machine. The tips and suggestions (including excellent references) provided from several members on the Rialto set us off in a better direction. One team of students, (an all-girls team, by the way), constructed a small trebuchet, a simple counter lever device, (16-foot throwing arm, 225 lb. counterweight) and proceeded to tromp the other high school contenders. Our best throw was only about 37 yard with a 6-pound pumpkin, but the sight of that machine working was beautiful. The sling just sailed magnificently up and over, releasing the pumpkin at least a yard above the throwing arm. We adjusted parameters, (counterweight mass, length of sling lines, sling attachment, weight of the pumpkin, etc.) and collected data that is going to provide us with problems for much of the rest of the year. We have videos which will be analyzed in slow motion for other data. The class's three machines (the trebuchet, a catapult style and a centrifugal design) were carted to Delaware on November 2nd to participate in an annual pumpkin throw with adult teams from the local area. We were the only high school group to throw. Best throw of the day was 702.6 feet, somewhat short of the world record set last year at 776 feet. These throws were accomplished by an adult team with a centrifugal machine consisting of a 30-foot arm driven with a belt from the rear axle of a pick-up truck. (I apologize for this non-period stuff if it is not of interest. I didn't know how much to share about this rather extensive project, after getting such kind responses from the many of you who shared your knowledge.) There seems to be a clamor from physics-student-wannabe's for a repeat performance next year. Now that we know a little more about what we are doing and have some references in hand, I hope to throw in the 'several hundred feet' range mentioned graciously in several Rialto postings. The class and I thank all of you who responded to our queries and commended you on your preservation of the Middle Ages. May the Age of Chivalry live on forever. In debt to the Society, Mary S. Ellsworth Science Department Model Secondary School for the Deaf at Gallaudet University, Washington, DC" Thus ends the letter from MSSD and I also thank you for your help in this endeavor! Padraigin nic'Aodha - Barony of Storvik - Kingdom of Atlantia Pat McCoy - Washington, DC Trebuchet blues 15 May 92 From: rday at magnus.acs.ohio-state.edu (Robert E Day) Newsgroups: rec.org.sca Organization: The Ohio State University In article <01GK17U2M8B48WW44W at LEO.BSUVC.BSU.EDU> 00MJSTUM at leo.bsuvc.bsu.EDU wr ites: >Greetings unto all gentles who may read this! > >I have nearly finished a "quickie" prototype of a trebuchet. The arm >is merely 4 ft. in length. However, I have now come to that difficult >position of attaching a sling. My first attempts (with a hacked up >badmitton net) were, um, less than successful. I tied the ends of the >"sling" in such a manner that it would have a cupping effect... however >when the sling is released from its hook the projectile merely rolls >up the length of the sling and gets caught in the end. I've tried >remedying this in several ways with either no change or even worse side- >effects. > >Can anyone, who has made one, enlighten me with a description? I would >me _most_ grateful! > I have a friend who made one with an arm about 8 feet long. He used a small piece of leather(about 6" square) attached to rope as the sling. One end of the rope was attached to the arm only by a ring which hung on a hook and the other was securely attached to the arm. He used it to throw 8" warrer ballons. -- If the price that I must pay to obtain my * Robert E. Day/Syr Otto von * freedom, is to acknowledge that the Gov- * Schwartzkatz, Shire Mugmort * ernmet was granted the power to infringe * Barony Middle Marches, * on them, then I am not free. Paul Anderson* Middle Kingdom * 15 May 92 From: amlsmith at morgan.ucs.mun.ca (Andrew Smith 8848111) Newsgroups: rec.org.sca Organization: Memorial University of Newfoundland Greetings unto the Rialto from Sebastien. Located in far off Ar n-Eilean-ne, (Nfld., Canada). I have reason to believe that I am the last siege engineer before hitting Drachenwald. I too, am searching for information. The choice of the Trebuchet is a good one, less stesses are involved and therefore, safer. As far as readings go, DO start with Sir R.P. Galloway's book. For those who are interested, I understand that copies are available through : Albert Saifer Publisher BOX 7125 Watchung, NJ 07060 It can also be obtained (in Canada through U. of T. and Ottawa. My good lord with the sling problem: Try a simple sling of canvas or, failing that, burlap! My Trebuchet worked OK. It measures 6' at the base and 8' (ish) on the arm with a ratio of 6:1. Try that. To any and all mundane engineers and physics types... Can YOU work out the mathematical / mechanical formulae? For ballista type amusement, try to find _Harry and I Build a Catapult_ They used truck leaf springs and I beams. My final word is this: Any information, no matter how trivial about Seige weaponry would be greatly appreciated. This would include the Car and Driver issue and page number with the Trebuchet info , Please! Maybe we'll just e-chat. Sebastien Roland fils de MArek "Never challenge a guy who owns a catapult to a snowball fight" - Hagar OR A TREBUCHET!! Seb. amlsmith at morgan.ucs.mun.ca Trebuchet Blues (getting better) 18 May 92 From: 00MJSTUM at leo.bsuvc.bsu.EDU Newsgroups: rec.org.sca Organization: The Internet Unto the good gentles of the Rialto I send Greetings! I deeply thank each of you who responded so quickly to my request for help with trebuchet sling construction. As I posted previously, I attempted to use a "net" type sling as I had seen in almost all sketches of trebuchets. However, changing the sling to a "hand-held" design which involved a mere "patch" of leather or canvas attached with rope gave me the results I was looking for. Now, given that my prototype construction was very hastily done and a lot of power was lost due to movement, I was able to cast a tennis- ball a mere 24 yds with a 4ft/1ft throwing arm with approx. 40 lbs. of counterweight (the weight a _very_ loose guestimate... the structure could have held much more but I had no way of attaching any more weight). To those of you who have built or seen such engines, what are the vital statistics of your machines? (We can take this to E-mail and summarize later.) Missile Weight: Distance: Arm Length/Counter-Length: Counterweight: I'm curious if there's an optimum arm length/counter-length ratio as well as a maximum counterweight for a given arm length (for some reason I can envision _too_ fast of an arm movement). My objective is to construct an engine that will place a ~2lb object 100+ yds. What kind of scale are we talking about here? My first thought is to build an engine capable of holding ~6 cement blocks as counterweight with a 6' to 8' arm. However, my instinct tells me that this is still too small. Gratefully yours, Gwydion ap Myrddin --- 00MJSTUM at LEO.BSUVC.BSU.EDU Trebuchet Blues (getting better) 18 May 92 From: tip at lead.aichem.arizona.edu (Tom Perigrin) Newsgroups: rec.org.sca Organization: A.I. Chem Lab, University of Arizona Unto Gwydion ap Myrddin, doth Thomas Ignatius Perigrinus send his greetings, My Lord, My largest beast can send a grapefruit about 150 yards. The arm is a goodly 8' long, and is pivoted about 1 part towards the counterweight, and 6 parts towards the sling. This distance was decided after 5 trials with different arms. An the arm be to much one way, then the cast is too slow, an it be to much the other way, the weight be not ponderous enough to swing it well. The weight doth seem to be critical, for that I find two hundredweight is near unto being too little, whilst three hunderdredweight doth serve well. My counterweight is a mix of bronze and lead weights, suspended by chains and ropes, From julian at fgssu1.fgs.slb.com Fri May 29 00:52:28 1992 Date: Fri, 29 May 92 00:52:20 PDT From: julian at fgssu1.fgs.slb.com (Julian Carlisle) To: allaway, cat Subject: Seige Engine _A Scud It's Not, But the Trebuchet Hurls a Mean Piano_ Giant Medieval War Machine Is Wowing British Farmers And Scaring the Sheep By Glynn Mapes, Staff Reporter of the Wall Street Journal (25 Sept 91) ACTON ROUND, England--With surprising grace, the grand piano sails through the sky a hundred feet above a pasture here, finally returning to earth in a fortissimo explosion of wood chunks, ivory keys and piano wire. Nor is the piano the strangest thing to startle the grazing sheep this Sunday morning. A few minutes later, a car soars by - a 1975 blue two-door Hillman, to be exact - following the same flight path and meeting the same loud fate. Pigs fly here, too. In recent months, many dead 500-pound sows (two of them wearing parachutes) have passed overhead, as has the occasional dead horse. It's the work of Hew Kennedy's medieval siege engine, a four story tall, 30 ton behemoth that's the talk of bucolic Shropshire, 140 miles northwest of London. In ancient times, such war machines were dreaded instruments of destruction, flinging huge missiles, including plague-ridden horses, over the walls of besieged castles. Only one full-sized one exists today, designed and built by Mr. Kennedy, a wealthy landowner, inventor, military historian and - need it be said? - full-blown eccentric. A Pagoda, Too At Acton, Round Hall, Mr. Kennedy's handsome Georgian manor house here, one enters the bizarre world of a P. G. Wodehouse novel. A stuffed baboon hangs from the dining room chandelier (``Shot it in Africa. Nowhere else to put it,'' Mr. Kennedy explains). Lining the walls are dozens of halberds and suits of armor. A full suit of Indian elephant armor, rebuilt by Mr. Kennedy, shimmers resplendently on an elephant-sized frame. In the garden outside stands a 50-foot-high Chinese pagoda. Capping this scene, atop a hill on the other side of the 620-acre Kennedy estate, is the siege engine, punctuating the skyline like an oil derrick. Known by its 14th-century French name, trebuchet (pronounced tray-boo-shay), it's not to be confused with a catapult, a much smaller device that throws rocks with a spoon-like arm propelled by twisted ropes or animal gut. Mr. Kennedy, a burly, energetic 52-year-old, and Richard Barr, his 46-year-old neighbor and partner, have spent a year and #10,000 ($17,000) assembling the trebuchet. They have worked from ancient texts, some in Latin, and crude wood-block engravings of siege weaponry. The big question is why? Mr. Kennedy looks puzzled, as if the thought hadn't occurred to him before. ``Well why not? It's bloody good fun!'' he finally exclaims. When pressed, he adds that for several hundred years, military technicians have been trying fruitlessly to reconstruct a working trebuchet. Cortez built one for the siege of Mexico City. On its first shot, it flung a huge boulder straight up - and then straight down, demolishing the machine. In 1851, Napoleon III had a go at it, as an academic exercise. His trebuchet was poorly balanced and barely managed to hurl the missiles - backward. ``Ours works a hell of a lot better than the Frogs', which is a satisfaction,'' Mr. Kennedy says with relish. 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. When launch time comes, a farm tractor cocks the trebuchet, slowly hauling the slender end of the beam down and the weighted end up. Several dozen nervous sheep, hearing the tractor and knowing what comes next, make a break for the far side of the pasture. A crowd of 60 friends and neighbors buzzes with anticipation as a 30-foot, steel-cable sling is attached - one end to the slender end of the beam and the other to the projectile, in this case a grand piano (purchased by the truckload from a junk dealer). ``If you see the missile coming toward you, simply step aside,'' Mr. Kennedy shouts to the onlookers. Then, with a great groaning, the beam is let go. As the counterweight plummets, the piano in its sling whips through an enormous arc, up and over the top of the trebuchet and down the pasture, a flight of 125 yards. The record for pianos is 151 yards (an upright model, with less wind resistance). A 112 pound iron weight made it 235 yards. Dead hogs go for about 175 yards, and horses 100 yards; the field is cratered with the graves of the beasts, buried by a backhoe where they landed. Mr. Kennedy has been studying and writing about ancient engines of war since his days at Sandhurst, Britain's military academy, some 30 years ago. But what spurred him to build one was, as he puts it, ``my nutter cousin'' in Northumberland, who put together a pint-sized trebuchet for a county fair. The device hurled porcelain toilets soaked in gasoline and set afire. A local paper described the event under the headline ``Those Magnificent Men and Their Flaming Latrines.'' Building a full-sized siege engine is a more daunting task. Mr. Kennedy believes that dead horses are the key. That's because engravings usually depict the trebuchet hurling boulders, and there is no way to determine what the rocks weigh, or the counterweight necessary to fling them. But a few drawings show dead horses being loaded onto trebuchets, putrid animals being an early form of biological warfare. Since horses weigh now what they did in the 1300s, the engineering calculations followed easily. One thing has frustrated Mr. Kennedy and his partner: They haven't found any commercial value to the trebuchet. Says a neighbor helping to carry the piano to the trebuchet, ``Too bad Hew can't make the transition between building this marvelous machine and making any money out of it.'' It's not for lack of trying. 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.'' More recently, he has been approached by an entrepreneur who wants to bus tourists up from London to see cars and pigs fly through the air. So far, that's come to naught. Mr. Kennedy looks to the U.S. as his best chance of getting part of his investment back: A theme park could commission him to build an even bigger trebuchet that could throw U.S.-sized cars into the sky. ``Its an amusement in America to smash up motor cars, isn't it?'' he inquires hopefully. Finally, there's the prospect of flinging a man into space - a living man, that is. This isn't a new idea, Mr. Kennedy points out: Trebuchets were often used to fling ambassadors and prisoners of war back over castle walls, a sure way to demoralize the opposition. Some English sports parachutists think they can throw a man in the air *and* bring him down alive. In a series of experiments on Mr. Kennedy's machine, they've thrown several man-sized logs and two quarter-ton dead pigs into the air; one of the pigs parachuted gently back to earth, the other landed rather more forcefully. Trouble is, an accelerometer carried inside the logs recorded a centrifugal force during the launch of as much as 20 Gs (the actual acceleration was zero to 90 miles per hour in 1.5 seconds). Scientists are divided over whether a man can stand that many Gs for more that a second or two before his blood vessels burst. The parachutists are nonetheless enthusiastic. But Mr. Kennedy thinks the idea may only be pie in the sky. ``It would be splendid to throw a bloke, really splendid,'' he says wistfully. ``He'd float down fine. But he'd float down dead.'' From: haslock at rust.zso.dec.com (Nigel Haslock) Newsgroups: rec.org.sca Subject: Re: portable seige weapons: rope Date: 12 Mar 1993 19:14:11 GMT Organization: Digital Equipment Corporation - DECwest Engineering The twists in a rope can be measured in twists per inch. The twisting of a torsion spring bundle might amount to one twist per foot. Yes, there will be a slight difference in the energy stored on either side of the throwing arm. The questions are 1) does it affect the accuracy of the engine 2) is it a self correcting problem. I would suggest that it is self correcting and so does not affect the engine. It is self correcting because the throwing arm is free to center itself in the bundle. As the bundle is would up to tension, the throwing arm will move so as to equalize the tension on both sides. In an engine in which there are independent winding mechanisms for each half of the bundle, it is easy to create an unbalanced bundle. In such an engine, I would expect the shock or releaseing the arm to cause the bundle to equalise. In such an engine, I would expect uneven winding to far outweigh the effects of untwisting the ropes in the bundle. Fiacha Aquaterra, AnTir From: jlagrave at zeno.ss.uci.edu (John Lagrave) Subject: Our Seige Engine--A Trebuchet Organization: University of California, Irvine Date: Fri, 25 Jun 1993 07:14:29 GMT Greetings M'Lords and M'Ladies My college, the College of Fenwood Knoll, has completed the construction of a trebuchet. I wrote to this rialto sometime last year and asked for suggestions on where to go for sources and help. Lords Aryk Nusbacher, Tibor, Gille MacDomnuill, Jim Edwards-Hewitt, Hrothgar, Gwydion ap Myrddin Tarver (W. Ted Szwejkowski), and Sir Michael of York all get a most heart- felt thanks from myself. (If I have neglected anyone my humblest apologies, and of course my thanks). What follows is the story of the contruction of a working seige engine, from design to firing, with a couple of questions that I hope will be answered. I hope that you enjoy this story, and tolerate this bit of self aggrandizement. (Insert humble bow here.) The best source for the construction of a trebuchet is from a journal called the Viator, (VIATOR 4:99-114 (1973)) by Donald Hill title Trebuchets. The most entertaining source about trebuchet's is by Sir Paine-Gallwey titled The crossbow, mediaeval and modern, military and sporting; its construction, history & management. With a treatise on the balista and catapult of the ancients, and an appendix on the catapult, balista & the Turkish bow ( New York, Bramhall House [c1958]). Many a story might be spun by the clever bard upon reading this delightful, but innaccurate text. Without further ado, then, my story. Three intrepid lads, myself include, thinking themselves capable of putting saw to wood, discussed the possiblity of constructing a seige engine. After a bit of thought, no small feat for these lads, the possiblity of constructing a trebuchet reached critical mass and the lads were quite taken by the idea. Several obstacles lay in their path, however. One being the problem of transporting the bloody thing, for these lads planned to build something quite large, larger than, say, the cows they hoped to lauch from the thing, and not having large mechanisms with which to transport the device seemed a problem. Well they came upon the idea that no piece of wood would be larger than five feet. This, of course, led to a new problem, just how the hell were they going to join the pieces? None of their fathers having been carpenters, and none of the lads having had a useful education, such as taking a wood shop class, they created their own joint, which in hindsight could have been much better. The specifations of the trebuchet were worked out and the design of the machine was drawn oh so carefully. It was to measure a full ten feet in length, spanning some four feet in width, and projecting towards the heavens at the impressive height of seven and one half feet. This medium is hardly proper to convey its dimensions, but allow me a simple drawing, Side View Bird's E View +--+-----+-------+ /o| + + + + / | 7 1/2' 4' + + + + / | + + + + / | + + + + / | +--+-----+-------+ +--+------+-------+ 10' back front where the + are cross members. The throwing arm was to measure some twelve feet in length, but be capable of being extended to fifteen feet by some clever engineering. The counterweight arm was fixed at two feet. The ratio of throwing arm to counterweight arm was 6:1 (for those lacking the schooling in mathematics), but be capable of being increased. A sling was to fit onto this arm to even further increase the ratio--those of you who are wise already see the problem. The weight for hurtling the objects (we had rejected the notion of using a traction type trebuchet, do to the tremendous lack of ability to organize our college for any endeavor) was to be made from lead and steel encased in concrete. We proceeded to build our trebuchet, and in sporadic bursts the engine was completed. All uprights were split in two, along with the ten foot long base beams. All beams were four by four inches and all joints were joined by one by four inch boards with one half inch by ten inch bolts running through them. Corners of the base were joined together with metal braces after the original lag bolts were determined to be to weak. The pivot beam was joined to the upright by lag bolts and metal braces bolted to the sides of the beams to provided further support. The pivoting beam was constructed of a metal pipe and the throwing arm was made of some plumbing fittings. A four-way connector had two inch pipes which pivoted about the metal pipe which was in turn anchored to the uprights. (confused yet?) The throwing arm and counterweight arm were in turn connected to the four-way connector. The weight was connected to the counterweight arm by a t-type fitting with a rod placed though it and a series of links. When all this was finished a winch was fitted on the side to allow us to pull down the throwing arm. A sling trough consisting of a flat piece of board was placed between the uprights. The throwing arm consisted of a wooden dowel one and one half inches thick, twelve feet long. It fit inside a metal pipe fitted to the four-way connector, and was secured by bolts. We surveyed our work and felt satisfied. It seemed quite secure. Only one thing left to do, see if it worked. So on a fine day, the first of summer, the lads and I set out onto a field and set up our machine. The sun was hot and we worked up quite a sweat assembling our engine. We loaded a counterweight (some 150 pounds) thinking it best to try our engine with one weight lest we break the bloody thing and fall about in fits of crying. We rigged out sling, and fired the engine. WOOSH! The weight fell. Up went the throwing arm. Flop went the sling. Our stones (consisting of hard plastic balls covered with foam and then wrapped with duct tape) fell about us. DAMN! (Please excuse the language gentle folk but we were sorely mad.) Well we put our heads together and thought a good thought. Perhaps the sling was too long. We shortened it and fired again WOOSH! went the weight. CRACK! went the throwing arm. Wood fell about us as the arm broke into pieces. DOUBLE DAMN! (Again apologies to all.) Time to buy a new dowel, and, we reasoned, some reinforcement for said dowel. Off we trekked to the nearby supply store where we purchased some pvc pipe as a sleeve for the throwing arm. With a new throwing arm mounted on the trebuchet, we again tried the engine, but the sling did not open up completely. The sling is made of canvas and it is some two feet wide by three feet long. The sling ropes were shortened considerably and the sling began to extend more than before, until finally the sling was being fully extended in flight. But the bloody canvas was staying closed. We tried again and again to no avail, and we managed to break another wooden dowel in the process. We decide to go with a pvc pipe throwing arm with an inner wooden rod for support, with a reinforcing outer pvc sleeve. Well it weighed a lot, but we were darn confident that it would not break. Well, we decided to go with an earlier period trebuchet design and we placed a large basket at the end of our newly constructed arm. It worked splendidly. The foam balls flew out of the basket, arcing ever so gracefully toward the heavens, before being reminded that they were not birds. Ah, twas a glorious sight for these eyes. With one counterweight, the farthest a three-quarter kilogram ball went was 31 paces before striking the earth, and it was moving pretty fast went it hit the ground. With four balls placed in the basket, the range was about 22 paces with a grouping of four by four paces. We attempted to place a second counterweight on our engine, but the weight was too much. The release mechanism is also the mechanism we use to pull down the throwing arm and it bent straight from the weight. So, you see our predicament. We need to redesign our sling and our release mechanism. We already have an idea about separating the release mechanism from the spanning rope, but we need help with the sling design. Any suggestions? We suspect that the wind resistance of the sling is creating problems, but how do we overcome them without sacrificing delivery load? The lack of a sufficient counterweight may also be part of the problem, but that will (hopefully) be rectified by the modifications to the release mechanism, which will allow the second counterweight. I have taken enough, nay far too much of your time, but I thank you all for your patience. The seige engine will be on display and firing at the Gyldenholt anniversary this weekend. Those of you in Caid that can make it to Mile Square Park in Gyldenholt are invited to gaze upon its beauty. Yours in service, John (gotta quit working on the seige engines and work on that persona thing...:) -- jlagrave at aris.ss.uci.edu From: kuijt at umiacs.umd.edu (David Kuijt) Newsgroups: rec.org.sca Subject: Re: Trebuchet/China Date: 21 Jul 93 15:00:01 GMT Organization: UMIACS, University of Maryland, College Park, MD 20742 Regarding Trebuchets, Tadhg writes: >>[....] I know of no evidence that the >>trebuchet was invented by the Chinese. The earliest citation in the OED is >>from 1224 (in Latin), [....] to which Thorvald/James responds: >Perhaps the trebuchet was not invented by the Chinese, but they >appear to have used it at least as early as 759. Joseph Needham >in _Science and Civilisation in China_ quotes from a text of >that date. [...] > >"Tower-ships; these ships have three decks equipped with bulwarks >for the fighting-lines.... There are ports and openings for >crossbows and lances...while (on the topmost deck) there are >trebuchets for hurling stones...." Siege engine nomenclature was never standardized, and therein lies the problem. The word Trebuchet is commonly used by modern military historians to refer to the huge (HUGE) counterweighted arm design of siege engine developed around the time of the crusades, and used (for example) in the siege of Acre by Richard the Lionhearted and his buddies. This is likely the engine that Tadhg is referring to. This is also clearly NOT what Needham's quote refers to--the counterweight-arm design weighed much more than many ships, and could never have been placed, much less used, on the third deck of any medieval ship. It would have turned turtle immediately. Needham is also choosing an english word to translate a Chinese word. The fact that Needham called it a "Trebuchet" should not be used as evidence that this is the same engine as any other device called by that name unless Needham can provide a basis for his choice of that word over any of the other common words used for stone-hurling siege engines, such as Catapult, Onager, Scorpion, and even Ballista. All of these names have been used to denote a variety of dissimilar siege engines, and confused with each other. Some words (e.g. Arbalest) are used by one author to refer to a hand-held device (a big crossbow), and by another to refer to an immobile siege engine similar to a ballista. As for Needham's device, it may well have been similar to the Roman and Greek Ballista, or the Roman Onager. The first is a giant crossbow with twisted-skein arms, the second is a rigid arm throwing engine also powered by twisted-skein methods. Both the Romans and the Greeks used Ballistae on ships; there is some question as to whether the Onager was used that way, as the ships of the time were not heavily built, and the Onager "kicks" when it fires, which could quickly damage the warships of the time. Both the Ballista and the Onager were used to throw stones; the Ballista also shot large spears. Dafydd ap Gwystl David Kuijt Barony of Storvik kuijt at umiacs.umd.edu Kingdom of Atlantia (MD,DC,VA,NC,SC) From: doconnor at sedona.intel.com (Dennis O'Connor) Newsgroups: rec.org.sca Subject: Re: Trebuchet/China Date: 21 Jul 93 08:54:46 Organization: Intel i960(tm) Architecture kuijt at umiacs.umd.edu (David Kuijt) writes: ] >>[....] I know of no evidence that the ] >>trebuchet was invented by the Chinese. The earliest citation in the OED is ] >>from 1224 (in Latin), [....] ] ] to which Thorvald/James responds: ] ] >Perhaps the trebuchet was not invented by the Chinese, but they ] >appear to have used it at least as early as 759. Joseph Needham ] >in _Science and Civilisation in China_ quotes from a text of ] >that date. [...] ] > ] >"Tower-ships; these ships have three decks equipped with bulwarks ] >for the fighting-lines.... There are ports and openings for ] >crossbows and lances...while (on the topmost deck) there are ] >trebuchets for hurling stones...." ] ] The word Trebuchet is commonly used by modern military historians ] to refer to the huge (HUGE) counterweighted arm design [...] ] ] This is also clearly NOT what Needham's quote refers to--the ] counterweight-arm design weighed much more than many ships, and ] could never have been placed, much less used, on the third deck ] of any medieval ship. It would have turned turtle immediately. Though you may "commonly" think of a trebuchet as having a "massive" counter-weight (however much that weighs), this is not reason enough to dismiss Needham. Obviously you can build different size trebuchets, and if your intent is to smash wooden boats instead of fortifications, you probably build a smaller one that throws smaller rocks. Chinese trebuchets often used men as the counterweight (e.g. 20-30 guys holding ropes who sit/fall down on command ). This is about 3-4 thousand pounds of counterweight. Obviously you can put 20-30 men on the deck of a ship. Also obviously if you can put 3000 pounds of men on the deck you can put 3000 pounds of rock there instead. If you even need that much. So unless you have better reasons to fault Needham, I don't think you have presented enough evidence that he has made a mistake. Of course, if you are arguing that the Chinese didn't have trebuchets at all before 1200 ( I hope you are not ) then I definately don't accept it. There's a lot of pictorial evidence that they did ( tho I have to admit I'm unable to give exact references right now ). -- Dennis O'Connor doconnor at sedona.intel.com Intel i960(R) Microprocessor Division Solely responsible for what I do. From: Charly.The.Bastard at f1077.n147.z1.fidonet.org (Charly The Bastard) Newsgroups: rec.org.sca Subject: Shield Walls Date: Tue, 09 Nov 1993 18:29:12 -0500 WA>The question is how do you defeat a shield wall. The answer is a word, and the word is Catapults. Mobile siege engines that hurl huge rocks great distances. I designed one some time back that would throw a bowling ball 100 yards. It would fit in the back of a pickup, so it could be considered, with wheels and a team, towed artillary. From: johnric at saturn.wwc.edu (RICHARD ALLAN JOHNSON) Newsgroups: rec.org.sca Subject: Re: Trebuchets again! Date: Mon, 28 Mar 1994 17:06:27 GMT Organization: Walla Walla College In article <2n1uim$alb at portal.gmu.edu> tvalesky at mason1.gmu.edu (Tom Valesky) writes: >From: tvalesky at mason1.gmu.edu (Tom Valesky) >Subject: Trebuchets again! >Date: 26 Mar 1994 18:23:18 GMT >In this Sunday's column, Dave Berry describes a couple of guys who are >attempting to build a trebuchet sufficient to launch a Buick for a >distance of 200 yards. This made me curious as to what sort of >dimensions such a trebuchet would require -- the counterweight would >have to be enormous, and the strength of the arm prodigious to fling >such a missile. > >So... I was wondering about the mathematics of trebuchet design. Are >there any rules of thumb that are followed in building a trebuchet >(ratio of counterweight to missile weight, length of throwing arm) or >predicting the distance that the missile will be flung (a function, I >suppose, of missile weight, counterweight weight, throwing arm length, >and so forth)? > >Perhaps it would be fun to work up a computer simulation of a trebuchet >according to these design parameters and see what the effect of >modification of these parameters is. > >Tom Valesky > Already been done. Read a copy of Mechanical Engineer a couple of months back and you will see a mechanics class at some military school completely based around a trebuchet design. Rick From: Suze Hammond (6/28/94) To: markh at sphinx RE>BJECT:Re: Blackpowder, y >I'd love to see more seige engines, but a full-scale trebuchet is just as >likely to kill an inexperienced crew member as a target... Wonderful >engines, but very very nasty... As one of our local experimenters recently >said "Now we know why you never camp -behind- the trebuchet!" Uu> Hmm. I can imagine what happened, but before you mentioned it, it Uu> wouldn't have occured to me. So, what happened?? How big was the Uu> trebuchet and the projectile? Uu> Uu> Stefan li Rous Uu> Barony of Bryn Gwlad Uu> Ansteorra Unfortunately I wasn't there at the time, and they took it down, rather than leave it for the neighborhood kids to kill someone with. (Rural site.) As I understand, they were only throwing "SCA-legal rocks", ie huge lumps of closed-cell foam wrapped in duct tape. Quite a few it threw straight up, some it threw to either side, some went up and then somewhat to the rear, and some flew wonderfully, after they made adjustments to the sling part. Evidently the design and release of the sling element is quite critical! I understood that the fact they weren't using real rocks was something they were often quite thankful for. (And there are lots of largish rocks in easy "picking" range, which is why it had to be dismantled.) The descriptions I got made it sound like about 6 feet tall, with a ten foot arm (?) and I have no idea how heavy a duct-tape rock larger than your head might be. (I do know other An Tirians have built small ones to deliver water balloons in combat, but that was long ago... ): ... Moreach | Suze.Hammond at f56.n105.z1.fidonet.org -IGNORE OTHER ADDRESS! From: shininga at aol.com (ShiningA) Newsgroups: rec.org.sca Subject: Re: Cannon anyone? Date: 8 Jul 1995 17:14:06 -0400 Organization: America Online, Inc. (1-800-827-6364) If canon are not permissable in the SCA, consider the trebuchet, the successor to the catapult and used throughout the SCA timeframe. An excellent article on these siege devices is in the July 1995 issue of Scientific American. These things were quite advanced for their day, in terms of engineering, and could fling a load of rock or, occasionly, Plague ridden bodies, quite a distance. The reconstructed modern day trebuchet detailed in the Sc. Amer. article is some 60 feet high and tossed 1200 pound objects around the English countryside, including a small car sans engine block. Range for smaller recreated trebuchets is reported at some 550 feet. Will this device be demonstrated at the next Renaissance Festival? Sir Luke de Seubert Knight in Shining Armor From: morganh at teleport.com (Morgan Hall) Newsgroups: rec.org.sca Subject: Trebuchet Field Trials Date: 3 Oct 1995 10:37:10 -0700 Organization: Teleport - Portland's Public Access (503) 220-1016 Unto the good gentles assembled, Morgan de Comyn sends greetings. Upon the thirtyth day of September of this most memorable year we tested the concept of a traction trebuchet upon the field of combat during Acorn War here in sunny An Tir. For the furtherance of those who practice or study the arts of military engineering do I submit this report. Concept: An evening discussion of the principles of the trebuchet, fueled by the famous article about the gentleman in England who has thrown pianos, a video clip of one in action in Texas, the infamous Northern Exposure sequence, the July Scientific American article, and memory of wood cuts showing hand powered (traction) trebuchets deployed upon towers, culminated in the decision to build and test such an engine. The two main participants in this discussion, Edward of Left Field and myself, determined that such an engine must be small and light enough to be transported, and capable of throwing something usable in An Tir light combat. As we required the ammunition to be inexpensive, safe, and reliable we settled upon the ubiquitous tennis ball. Thus, with the basic parameters established, we began. Construction: As we would be limited in size and weight, we constructed a traction trebuchet, powered by the pull of two persons. Edward had recently constructed a forge that needed a test -- thus we combined the initial firing of his forge to heat the metal that would become the metal portions of our engine. For the basic construction we cut a number of hazel poles from the abundance that grow on my property. Lashed together, they formed a sort of truncated pyramid approximately 3 feet high as the base. The throwing arm was a (relatively) straight pole approximately 9 feet long, about 4 inches thick at the base and 3 inches thick at the business end. They were cut green and left to dry for about a week while other business was conducted. Motive power would be supplied by attaching two pulleys to a plank below the powered end of the arm, the pivot point being set at approximately 18 inches from the point where the ropes would attach. The traction crew would pull in opposite directions, equalizing side forces on the engine while the pulleys would change the horizontal forces into vertical forces pulling down on the short arm of the throwing beam. We decided that the actual bearings of this arm should be constructed from iron in order that we not break a wooden pivot by over-enthusiastic yanking on the ropes. Looking about my forge, we decided that 1/2 inch round mild steel would be of sufficient strength for the axle and the 1 3/4 inch bar would be excessive. Our first inclination was to mount a short axle to the working arm and let it ride on bearings on the support structure. A quick trial showed that our bracing was insufficient to allow free motion of the axle, side forces would distort the framework of light wood and cause the arm to bind. We re-thought the system and interchanged the pivot and bearing structures such that the arm carried the bearing and the axle could be bent in a "wishbone" shape to add rigidity to the frame while the bearing would travel with the working arm. We fabricated a bearing from a short length of flat iron approximately 1 inch wide by 3/8 inch thick. It was hot punched to allow attachment to the arm by screws, flattened on one end and spread out to nearly two inches, then formed over the 1/2 inch diameter axle rod. Spacers were then applied to keep the bearing centered on the axle portion of the wishbone. The whole assembly was screwed and lashed together, using screws to locate the various portions and tight lashings of cord to provide strength to the assembly. The release mechanism was provided by setting a short length of 3/8 inch iron rod into the long end of the throwing arm (the arm was tightly bound with cord to help prevent splitting). This was bent cold to what we assumed would be a useable angle. A sling pouch was fabricated from scrap leather, sling ropes from baler twine, pulleys and ropes attached, we worked it through by hand, found a tennis ball and were ready for the first test. Testing and Tuning the Trebuchet: The first test of the trebuchet was to pull it through without ammunition. The sling seemed to release properly so we inserted a tennis ball and pulled through with a rather easy motion. Our test site was in my back yard (rural area with neighbors about 1/2 mile away) with a 4 foot board fence about 35 feet from the assembly area. The tennis ball left the trebuchet with a downward motion, striking the fence with a sharp "crack" similar to a mild tennis serve. We considered the first "live firing" a sucess. Tuning was accomplished by altering the angle of the release pin. One of the old bearings (from the initial conception) was the right size and shape to be pressed into service as our "trebuchet wrench." We bent the release pin back to allow for earlier release and tried a second shot. The second shot sailed up at about a 20 degree angle and landed in my back field. A bit more tuning and we found that our maximum distance seemed to be approximately 200 feet at about 40 degrees. Wind resistance seemed to be the largest factor in the distance we could achieve -- a 45 degree angle seemed to slow down so fast it fell shorter than a lower angle. Fearing that continual cold bending of the release pin would eventually weaken it to the point of failure, we then fabricated two auxillary release pins and bent one to a low angle release and one to a very high angle release. Finally, to test the power of a heavier projectile, we placed a windfall apple in the sling and let 'er fly. The apple seemed to be still rising as it left my property, crossed a road behind it, and disappeared somewhere in my neighbor's alfafa field. No range for this shot was established. Field Trials: Intellectually we knew that there was a real difference from experimenting in the back yard and using an engine of this sort in armor. Knowing this, we began the great search for light armour to fabricate, borrow, or improvise. Our heartfelt thanks must go to all who helped in this endeavour, as only this made the field trials possible. As the morning of Acorn War dawned, we were making final adjustments, lashings, and fitting the collection of armour pieces to make ourselves field legal with a strange combination of light and heavy armor. At armor inspection, we passed. His excellency Baron Invari of Three Mountains asked us to support his forces, with Sir Blackhand commanding the other side supported by his infamous ballista mounted upon a machine gun tripod. We were ready for action! A few shots demonstrated -- we had the range on him! At this point, we made the error of moving the trebuchet back a bit. This put it on rougher ground which had the unfortunate effect of altering the sling travel and release point. We lost range. We moved again, near our original setup point, with shaken confidence. Ed and I lasted through the first battle scenario and halfway through the second when fatigue took its toll. We were too tired to continue after that point. Conclusions: The engine performed quite well. The effect of field conditions had unanticipated effects when grass clumps affected the swing of the sling and the release point and range of the engine. In no way could we have predicted the effects of adrenaline and fatigue upon our performance. Our judgement definitely was affected, and we didn't notice fatigue until it was quite severe. Mobility and dexterity became nearly non-existant. Attempts to power the trebuchet with untrained folks (building the thing seemed to train Ed and myself to work together) were less than sucessful. The triple release mechanism was VERY valuable! We have a number of changes to impliment on the next model. The Mark 1 trebuchet was a qualified success, but the Mark 2 will have some improvements. Mark 1 will probably take the field agin with some minor modifications, including a trained relief traction crew. I need to give some serious thought to improving light armor. In service, I remain Morgan de Comyn (Morgan Hall) Blacksmith and Piper to Clan Hubert, siege engineer in training -- morganh at teleport.COM From: david.razler at compudata.com (DAVID RAZLER) Newsgroups: rec.org.sca Subject: Re: Suburban Trebuchets? Date: Mon, 18 Mar 96 21:41:00 -0400 Organization: Compu-Data BBS -=- Turnersville, NJ -=- 609-232-1245 J>Might anyone out there know the title or author of a book that was J>published a year or two ago about a man and neighbour who built a J>trebuchet in suburban Anytown, USA? Thanks! They did NOT build a trebuchet, it was a leaf-spring siege engine: The book, short on plans is Catapult - Harry and I build a Siege Weapon, (c) 1981 by Jim Paul, no ISBN, Lib of Congress 623.4'41'097946-dc20 90-50664 Scientific American published a letter about and a picture of a backyard trebuchet earlier this year. Aleksandr the Traveller From: pat at lalaw.lib.CA.US (Pat Lammerts) Newsgroups: rec.org.sca Subject: siege weapons Date: 7 Aug 1996 21:27:47 -0400 I don't know of any comprehensive book on siege weapons, but I think you will find these two books very interesting. 1) Marsden, Eric William. Greek and Roman artillery; historical development [by] E. W. Marsden. Oxford, Clarendon Press, 1969. ix, 218 p. illus. (part col.) plates. 24 cm. 2) Marsden, Eric William. Greek and Roman artillery; technical treatises [by] E. W. Marsden. Oxford, Clarendon P., 1971. xviii, 278 p. 19 plates, illus. (some col.) 24 cm. ISBN 0198142692 #2 is the best, in that it gives the original text on one page and the English translation on the opposite page. It also gives very detailed plans that show how to make every ballista and catapault shown. For a light-hearted view of arms and armaments that touches on siege weapons, you should read: Halbritter, Kurt. Halbritter's Arms through the ages : an introduction to the secret weapons of history. New York : Viking Press, 1979, c1978. 158 p. : chiefly ill. ; 22 cm. ISBN 0670359084 It is a real hoot. Huette (pat at lalaw.lib.ca.us) Newsgroups: rec.org.sca From: Mark Schneider <mschneider at ctlnet.com> Subject: Re: Advice needed- Building a period catapult Organ