Tired of Politics & Religion: My Trebuchet Story

[Vanadorn]

CATAPULTS VS. TREBUCHETS – Part 1 – In the beginning. . .

(Any place that would appreciate this is here at CFC).

On an early summer day 3 years ago (2001), and I had a property clearing party with a bunch of friends. I have an acre of property, running 475 feet from front to back. At the end of the day, the conversation turned to catapults. There was a lot of conversation about building them and how it would work. Most everyone forgot that conversation the next day. I did not.

The following weekend, I began construction. I spent some time that week looking through books and reading a bit about the subject and decided that a trebuchet would be better, but was uncomfortable about building something that big. So I settled on a catapult.

It was to be the mule kick version, effectively a huge slingshot that kicked up when the throwing arm would hit the crossbeam. Started construction of the support box, made it 12’ x 8’. Throwing arm was to be 14’, with a platform as the throwing basket. Hurling material was to be bricks and rocks weighing between 5 and 9 lbs each. I am intelligent and capable with tools and carpentry.

The throwing axle started as a rounded 3” x 5” beam, with torsion ropes holding the throwing arm to the axle. The ropes tended to slip, constantly forcing us to readjust the arm after every test. Then we switched to a 2” diameter metal fence pole. We drilled a hole through the throwing arm (which we now had to double up around the base), as well as the sides of the support box (which also now needed doubling up). The throwing arm needed to be lighter at the end (entire arm weighed roughly 90 lbs at this point). Took the arm apart, and rebuilt it as a single board, 2”x6”x14’ with tripling up at the base.

With the arm now reworked and finished, we thought on new ways to get tension. We tried garage door springs (nor nearly strong enough). We also tried the roman version of wound ropes across the base of the throwing arm and the central axle. Unfortunately, although we had the rope wound very tight (4 men, combined weight almost 820 lbs, all dangling off the ground), we couldn’t garner enough energy to lift the throwing arm with any force. (To wind the ropes tight, we used huge 5’ diameter wheels mounted to the central axle)

So, I went back to the slingshot style idea. Something elastic to lift the throwing arm with enough force to hurl the missile. Scouring the local auto yard (re: junk), I settled on a pair of truck tire tubes. Each tube was thick, with an inside diameter of roughly 2 and ½’ plus. My friends suggested instead that we use a large leaf spring, effectively positioning this under the throwing arm vertically, and hurling the arm up. I said no. Can you imagine a 6’ shaft of spring metal compressed into a bent shape that could suddenly let go? It’d kill someone.

 

[Vanadorn]

CATAPULTS VS. TREBUCHETS – Part 2 – Catapult envy and disappointment.

We got the tires home, stretched them from across the stopper to behind the throwing arm, and back to the stopper. Once attached, the arm was forced into a vertical position. Using a multi pulley system, we were able to get the arm almost down to the base. So, with a little trepidation, we cocked the arm back as far as we could, and then let it go – effectively dry firing the machine, just to see if it would work.

The arm tore away from us, whistled through the air, and smashed with a resounding crack against the stopping beam. It was so powerful of a hit, that we snapped the throwing arm and I can safely say that the term MULE KICK is very very true. We thought, whoa, we are onto something great here!

We took the arm apart, replaced it with a new, undamaged beam, wrapped the throwing arm and the cross beam in ropes (now I know why some of the drawings showed ropes wrapped around the siege engines in some parts). By this time, it was early October. We were going to have a last barbecue and I wanted to show of the new, working catapult. Set up a trigger (3 eye hooks, 2 down, 1 up and attached to the throwing arm, with a pin running through all 3 attached to a rope), gave the whole machine a once over, and felt ready for the throwing on that Saturday.

So there I was, 30 odd friends and family in my back yard. 3 of us cocked the machine, set the pin, removed the guide ropes and pulleys, set the brick, and stepped back. I pulled the trigger and once again, the machine whooshed, kicked hard and high. . . and threw the brick 38 feet.

Oh the laughter. It was funny but grrrrr, all that work the tests, the designs, redesigns, and re-re-redesigns. We threw another couple of bricks that day with the catapult, everyone agreed is sounded scary, but then they took turns throwing the very same brick further than my machine could.

I spent the winter laughing about the experience with my wife, and she asked me many times what we did wrong. I explained about materials, ropes, tensions, parabolic formulas, force and applied levers, but what it came down to was the design didn’t work. In fact, catapults were never as effective a siege weapon as trebuchets. So my wife, who puts up with me and my idiosyncrasies, said (god bless her), “So build a trebuchet then.”

 

[Vanadorn]

CATAPULTS VS. TREBUCHETS – Part 3 – Trebuchets, A New Hope.

Next May (2002), I began dismanteling the catapult. During the prior year, my wife had painted the word “TONKA” on the side, effectively naming the catapult for me. Piece by piece, I separated the catapult into piles of garbage wood and useable materials. When I was done, I began the work on my trebuchet.

The throwing frame was 10’ 6” tall, with 13’ legs running down each side, making what appears to be a pair of A’s next to each other. At the base, I extended the machine’s foot print 8’ from the front, and both side, while going out 12’ across the back. The throwing arm was 18’ long, 14’ of which would be devoted to hurling the missiles. At the short end of the throwing arm, I fashioned a weight box big enough to hold 6-8 cinder blocks, and in deference to my catapult, I used the wood with Tonka written on it to make the box.

The box was attached to the throwing arm in such a way that it would pivot on a 1.25” solid threaded rod, with gravity always hanging in down. The arm itself was attached to the A Frames with another, longer threaded rod. Many of my neighbors who had seen and heard of my catapult the year before were watching me with bemused smiles and comments such as, “What is that, a swing?” and “It this one gonna work?”

I made a trough 10’ long and 1’ wide to hold the missiles in. My wife made a sling for me out of and old piece of leather, the sling was big enough to place the equivalent of a bowling ball into, and not have it fall out. A pair of 4’ ropes held it to the throwing arm, one side of which would let go at the top of the arc (29’ throwing potential, oh yeah!)The trigger was once again the 3 eye hooks with a metal dowel for a trigger.

Now I have to explain something. I live in a low ranch (single story). The trebuchet’s frame was 10’ 6”, and the throwing arm was 14’ on top of that, when the machine was in the after fired, or uncocked position. So from the road and down the block, you could see the top of this trebuchet. I was getting attention.

When it was finished, tightened up, and as ready as I could make it, I once again prepared to fire it. Except this time, it was only a handful of us, and we were not going to throw rocks at first, but something smaller and less likely to kill us. We settled on fruit. Using pumpkins (it was October again by this point) and grapefruits, I placed only 4 cinder blocks into the weight basket (roughly 230 lbs including the weight of the basket), brought the throwing arm down, loaded the sling with a pumpkin, and fired.

Oh it worked. Unfortunately, the pumpkin slipped out of the sling EARLY, sailed backwards from the trebuchet, went up really high, and smashed into my roof. When it was over, we checked for damage (none – thank god we did not use rocks), calmed my wife down, and reloaded again – using grapefruits this time. Fired – Eureka! The fruit went up, out and gone! It cleared all the land we had stripped of trees and landed in the woods – a good 180’ away. Firing it another dozen times, we achieved similar results and called it a winter. Success.

 

[Vanadorn]

CATAPULTS VS. TREBUCHETS – Part 4 – This time it’s personal.

Over the winter into the following spring, I worked on the weight box, the sling (extended the ropes to 5.5’), and tightening the entire machine up. So once again, in May (2003), we were ready to show off the war machine. We had another barbecue planned for Memorial Day (may 31st), and the invites went out. Oh, I heard a lot of jokes but inwardly I was smiling. For ammo, we made concrete balls roughly 6”-7” in diameter, and a couple of decent pounds each, painted yellow (so we could find them).

The day came, again 20-30 odd people in my back yard. This time, I fully loaded the box with 7 cinder blocks (about 400-450 lbs, twice as much as I had used before), cocked the machine back, loaded the yellow ball. . . and fired.

In the movies, you always hear the load whooshing whistling sound. I can say that it is true. The trebuchet lifted the ball in the sling, made a tearing sound through the air, lifted the payload up to 30’, and HURLED it. It looked like a major league pitched throwing a fast ball. The missile sliced through the air, rocketed into the woods, and everyone heard a very loud “crack” as it smashed into a tree trunk and knocked dead branches and leaves down everywhere.

While the machine was firing, everyone was quiet, spell bound. When the ball took off like a rocket, there were calls of “oh my god”, and “holy s**t!”. When it was over, there was applause and “wow! Can I fire it too?!”

In short, the machine functioned extremely well. We fired probably 40-50 missiles that day. One of the things about trebuchets is that when calibrated and fired, the shots always land in the same place. During that summer and fall, people would come over and talk about the trebuchet and want to fire it a few times.

After this winter, when my life fell apart (see different thread if interested), and now spring, I had to come to a decision in regards to my trebuchet. Originally I was going to move it further into my back yard as a conversation piece, but this weekend, I decided to take it apart (visitors from the county are supposed to show up this summer when my wife comes home (finally!)). So between Monday and Tuesday, after work, I went out side with my chainsaw and cut my trebuchet to pieces. A few friends came over to help and watch my child while I was doing this. We had a lot of laughs and stories about the trebuchet.

Once again the pieces were separated into garbage and useable wood (have to made some picnic tables this year), and everyone asked for one of the yellow balls, but I saved the piece of wood that said “Tonka” and placed it in my basement. This morning when I looked out back, it seemed so empty, and I wanted to share my story with you here.

Thanks for reading.

 

[betazed]

Great story. Thanks for sharing it.

 

[Enkidu Warrior]

Excellent story.

I'm going to have to add building a war machine to my list of things to do before I die.

 

[Serpico]

So cool. Thanks for sharing this story.

 

[Pirate]

Awesome. Good storytelling is always appreciated.

 

[Dann]

Great story. We should have more of these.

 

[yoshi74]

Great.
I'am very surprised about the precision of the trebuchet. It seems to be much better at hitting the same target again and again than any other artillery weapon.

 

[col]

Any pix? Ive watched a few programs about homemade trebs. Must have been awesome!

 

[Pointlessness]

What is the difference between a catapult and a trebuchet? For example, which one is my avatar?

 

[Vanadorn]

@ col: I have some pictures (of course!) but I need to scan them in. Give me a day or so and I'll post what I have (including the pumpkin on the roof!)

@ Pointlessness: It appears your avatar is a catapult. Not historically accurate or most likely really able to fire, but yes, a catapult.

Glad that everyone enjoyed the story! For 3 years I've looked out my back yard and have seen some sort of war machine dominating the landscape, and then yesterday morning. . .Nothing! It was bugging me sooooooo, I decided to share it. Sorry it was so long but it was a 3 year story in the making. I appreciate everyone who took the time to read the thread.

Too many threads lately have been about Iraq, Bush, God, and was getting tired of coming to see what was new on OT. So I hope this shook things up.

Reminder - pictures should be up tomorrow. Check back if you want!.

Vanadorn

 

[Gingerbread Man]

There is nothing quite like a homemade trebuchet

BTW, A trebuchet is a sling attached to a lopsided see-saw (or teeter-totter for you bizzare americans out there). Lots of weight on the shorter end, and a sling (which is usually rather long) attached to a longer end. At a certain angle, the sling slips off and the projectile flies. Immense fun.

Catapult is the same idea, but it is based on tension instead of weight. Not do easy to make, nor as exciting.

 

[thestonesfan]

What's next? A bombarde?

Seriously, it sounds like a cool project.

 

[Vanadorn]

A few pix.

1st is when tried to add the large wheels to the catapult to wind the ropes around the axles. Yes, that is me.

2nd is after we had abandoned the wheels and the ropes arounf the axle for tension and went with the truck tire.

 

[betazed]

Vanadorn, you look adequately bad-ass standing by your war machine, with a powerdriver in hand

Love those pics. Any pics of it in action?

 

[Vanadorn]

2nd set of picture

1st one is the completed product just before I added the pulleys and trigger. (Gosh - So proud)

2nd is the day that we tested the throwing arm and broke it (should have had my wife taken a picture 10 seconds later as well.

I'll add trebuchet pictures tonight.

Thanks again.

Vanadorn

 

[the mormegil]

Cool story.

Very effective for shutting up roudy neighbours I expect!

 

[Chieftess]

Reminds me of an episode of Junk Yard Wars years ago (trebuchet and catapult). BTW, You can make a small, and simple catapult out of a rubberband, long object (spoon, pen, pencil, etc), and your fingers.

Just hold the rubberband out, and keep twirling the pen/spoon/whatever around. Release, and watch it spin!