[Manuka Jock]

The largest functioning trebuchet that I know of is the replica of the "War Wolf," built and operated by Hugh Kennedy in England. He explained that he'd found an historical claim that the WW was capable to tossing a horse into a castle court yard from 300 yards away. He reasoned that if the account were true, it should be possible to replicate the feat. He did exactly that, using an assumption that the horse would have weight some 1,500lbs. Anybody who uses Hillman and Renault cars for ammo impresses me with their design skill.
Only from video that I've seen, the arm is jointed/assembled like a split cane fly fishing rod, possibly 4-5 feet in diameter over the counter weight and likely 50+ feet in length. That means that the tower must be 30-40 feet tall or more. Yes, it is almost indescribably immense.

Be that as it may, I enjoy the entertainment of any treb with payloads of 20 lbs or less. Designed at 200:1, 4,000lbs in the counterweight is not unreasonable.

If you haven't found them so far, I suggest you look at the results from the trebuchet section of the Punkin Chunkin Contest, an annual veggie tossing event in the United States. If memory serves me, the record for the air cannon section is 4,000+ feet/1,230m, across a freeway and into the filed on the other side. They have a contest site. That implies that all the siege engines have to be trucked to the site and assembled.

You misread the question .
I have viewed much of the published material in the past , Kennedy and the Danes included , and know that on average , the larger trebuchets were about 4 stories high , 40 - 60 feet.
Given that you have told us that you have built some , I'm asking you for your opinion , base on your personal the experience, of what might be theoretically possible

 

[Brian T.]

I haven't given any thought to treb design for more than a decade. Yes, I am an experienced trebuchet builder with published pictures of examples.

Period Machines: I think that we've seen the best of them come and go. Were I to mount a campaign of conquest using trebuchet, you can bet your last dollar that my engineers would have the design figured out. Logically, that means that there was a lot of military research and development that we will never read about. The plans didn't come to them in a dream. Even the angle of the sling finger for proper release. The size limit might be reached by several things: the modulus of elasticity of woods available for the arm. Laminations are certainly superior to a log. They would have known that from long bow construction, even the correct orientation of the growth rings. Friction on the slide with the sling basket. Grease can only do so much. For my part, a little 5W30 motor oil on axle parts has quite a dramatic effect. Inertia = how do you get the mass of the projectile to even begin to move? A rock would have fewer and more intensly confined pressure points on the slide, than a horse.

Modern Machines: I am not, nor ever was, a materials engineer. As parts of university dendrology courses, I did teach the fundamentals of mechanical and non mechanical properties as they apply to wood. Look for specifics on your own time.
What would I try, from the materials I'm aware of?
Arm: Boron-doped, carbon fiber lay up. The design might be eliptical in XS, the long/strong axis parallel to the plane of rotation. Roller bearings. ball bearings (which is best?) for the two axle points.
Swinging counterweight, made of and loaded with the densest element in the Periodic Table (can't find my reference book but I know for sure it isn't Uranium.)
Limits: Besides friction on the slide (travelling carriage?), overcoming the inertia of the projectile is not going to go away.
Risks: The counterweight is falling due to gravity as the arm begins its rotation. When the sling loop comes off the finger and the projectile is released, the arm does not come to a sudden freakin' halt.
The overtravel goes into quite violent recoil oscillations (very disconcerting if you aren't ready for it.)
As you know from reading, both the arm and the counterweight are flapping about. This is where I think that the failure will occur.
Desires: give me an automated disk brake damping system on the arm/counterweight pivot point. It's delayed beyond the release of the sling loop from the finger.

If it wasn't my money, I'd try an arm, 60' total. The tower and slide are not an issue. Loading would be least risky by lifting the counterweight, not pulling down on the arm. You've seen those people-powered wind-up mechanisms? Why do you suppose they went that way in the design? Huh? What did they break most easily? It is one big Hello of a surprise when the arm breaks. Cable trigger, not some box-latch screw-up. Can you imagine an iron counterweight and an electromagnetic latch?

Find a materials engineer, young person. Bring them up to speed and pitch the same question to them.

 

[Manuka Jock]

I haven't given any thought to treb design for more than a decade. Yes, I am an experienced trebuchet builder with published pictures of examples.

Period Machines: I think that we've seen the best of them come and go. Were I to mount a campaign of conquest using trebuchet, you can bet your last dollar that my engineers would have the design figured out. Logically, that means that there was a lot of military research and development that we will never read about. The plans didn't come to them in a dream. Even the angle of the sling finger for proper release. The size limit might be reached by several things: the modulus of elasticity of woods available for the arm. Laminations are certainly superior to a log. They would have known that from long bow construction, even the correct orientation of the growth rings. Friction on the slide with the sling basket. Grease can only do so much. For my part, a little 5W30 motor oil on axle parts has quite a dramatic effect. Inertia = how do you get the mass of the projectile to even begin to move? A rock would have fewer and more intensly confined pressure points on the slide, than a horse.

Modern Machines: I am not, nor ever was, a materials engineer. As parts of university dendrology courses, I did teach the fundamentals of mechanical and non mechanical properties as they apply to wood. Look for specifics on your own time.
What would I try, from the materials I'm aware of?
Arm: Boron-doped, carbon fiber lay up. The design might be eliptical in XS, the long/strong axis parallel to the plane of rotation. Roller bearings. ball bearings (which is best?) for the two axle points.
Swinging counterweight, made of and loaded with the densest element in the Periodic Table (can't find my reference book but I know for sure it isn't Uranium.)
Limits: Besides friction on the slide (travelling carriage?), overcoming the inertia of the projectile is not going to go away.
Risks: The counterweight is falling due to gravity as the arm begins its rotation. When the sling loop comes off the finger and the projectile is released, the arm does not come to a sudden freakin' halt.
The overtravel goes into quite violent recoil oscillations (very disconcerting if you aren't ready for it.)
As you know from reading, both the arm and the counterweight are flapping about. This is where I think that the failure will occur.
Desires: give me an automated disk brake damping system on the arm/counterweight pivot point. It's delayed beyond the release of the sling loop from the finger.

If it wasn't my money, I'd try an arm, 60' total. The tower and slide are not an issue. Loading would be least risky by lifting the counterweight, not pulling down on the arm. You've seen those people-powered wind-up mechanisms? Why do you suppose they went that way in the design? Huh? What did they break most easily? It is one big Hello of a surprise when the arm breaks. Cable trigger, not some box-latch screw-up. Can you imagine an iron counterweight and an electromagnetic latch?

Find a materials engineer, young person. Bring them up to speed and pitch the same question to them.

So , in answer to my original question you do not see any merit in building a wooden tree bucket any bigger , taller , longer , than those that have already been built , due to timber , iron and the technology of the medieval period not being fit for the task .

cheers

 

[Brian T.]

Possibly there would be merit in building bigger castle busters but I suspect that the medieval engineers knew what they faced (from R&D experience) in the form of materials failure. Plus, maybe his castle is nicer than mine and I'd like to live in it, not smashed up too badly.

Correct me if I'm wrong, but hand to hand combat was still popular.
A broken castle wall and a substantial invasion force often meant defeat for the current occupant. The tunnel guys did a fine job of collapsing castle walls until the innovation of a moat.

It has to be built in situ. If any of the King's scouts/patrols catch my stone masons quarrying and dressing 600+lb rocks, those guys are done for. Liberally applied receational torture and somebody is bound to give up my game. As an option, I'm not about to fling a 2,000lb ox into the castle couryard as a gift of food for the besieged inhabitants.

Best account (second or third hand) that I ever read was the story of the Spanish conquistadores vs the Aztec. The Aztec didn't want to give up his castle, gold and jewels. So the Spanish decided to build a big trebuchet and bomb the guy out of his house. So they built the treb. First shot, they got the trigger finger wrong. The sling released early. The rock went nearly straight up in a really tight arc and came down on the treb.

Size matters. My table top banquet-busters have just a 5lb ball off a trolling/fishing down-rigger. They go off like a gunshot, basically nothing to see unless you are focused on the head table. Big trebs go off creaking in a sweep of grandeur. The forces involved and the speed of the projectile still aren't readily appreciated until you hit something. Apples and oranges are good.

You know, one thing just occurred to me. If trebs were popular and effective, how come it is that there aren't more identified artifacts in the form of BIG round stones/projectiles? I know that lots of big stones from various stone circles were cut up and carted off for building material.

 

[Manuka Jock]

You know, one thing just occurred to me. If trebs were popular and effective, how come it is that there aren't more identified artifacts in the form of BIG round stones/projectiles? I know that lots of big stones from various stone circles were cut up and carted off for building material.

If out of balance ammo such as beehives, clay balls loaded with small stone shrapnel , casks of tar and oil on fire, dead animals , and prisoners of war and spies all manages to hit the targets , why would stone shot have to be manicured ?
Raw rock fired at stone walls , if they survived the impact , would not necessarily be distinguishable from the rubble .

I like the Monty Pythonesque conquistador anecdote :laughing: .
It would make a great scene in a film .

It may be that the great siege engines were fired more in the telling than in the doing , and that the threat of the Trebuchet was often more than enough to do the job .

The wolf that the vile longshanks built and used at Caerlaverock in 1300 against my Maxwell kin was only ever fired there once , and that was after the Garrison had already surrendered .
(Some say that theirs was a delaying tactic only , part of a greater strategy , and that a sustained defence would have only resulted in the unnecessary destruction of our Clan Seat )

 

[Brian T.]

You make excellent points. Thank you.
Old cordless telephones and oranges of the same mass have entirely different aerodynamic flights. I do not know if that would apply to siege loads.

With a basket in the sling, rock dressing might aid the release = it would be bad form indeed to have the rock stuck in the rope weave of the basket and not release.

I tried water balloons. They either rolled out the back or failed to release and smashed on the treb. Glad it was not solid.

I know that HK used a hook on the small cars.

Spies and traitirs? The King saw the treb. Sent an emmisary to negotiate a peace. The poor fellow was bundled up and tossed back into the castle as the reply. Regardless of his condition, he was certainly and suddenly dead upon arrival.

 

[Manuka Jock]

Re. stone ammo ,
I found this .

can't vouch for it tho

The Castilian camp fired trebuchets that discharged large quantities of spherical stone balls, or bolaños.[30] The trebuchets had a maximum range of 300 metres (980 ft), and were vulnerable to parties of besiegers that were able to cross the trenches.[35] So many stone balls were launched during the siege that in 1487 King Ferdinand II of Aragon sent an expedition to the ruins of Algeciras to retrieve them so they could be used again in the Siege of Málaga.[36][3
http://en.wikipedia.org/wiki/Siege_of_Algeciras_(1342–44)

And that practice may have carried on in conjunction with this

Mons Meg was a mammoth cannon from the 1450s that fired stone cannonballs. When it was brought into battle, stonemasons were brought along to make the balls.
http://bracl.smugmug.com/Europe/Europe08/4-Scotland-Edinburgh/i-DgDzK79

 

[Brian T.]

Ah! So it is possible that spherical stone garden ornaments in Europe
might have had a much darker origin.

 

[J Thomas]

This has been a very informative thread! I have never built a treb but have always been intrigued by them.
Here in eastern Maine we have what's known as the "Pirate Invasion" between the towns of Lubec and Eastport. Mostly a waterborne invasion.
This is a tourist attraction & bunches of locals get in on the game.
More than once it's been mentioned that we oughta build a couple small (trailer mounted) trebs to hurl water balloons so to repel the invaders.
I think it would be a great show and a heck of a surprise to the Eastport Clan if the Lubec Clan could pull off a "secret weapon"
I just need to find a few dedicated co-conspirators, who can keep a secret, to make this happen.
Too bad Robson Valley is on the west coast.. I'm sure he'd be involved.
Thanx for a great thread.
..Jon..

 

[Manuka Jock]

Ah! So it is possible that spherical stone garden ornaments in Europe
might have had a much darker origin.

Yep , looks that way :thumbsup:

The big stone balls, which were hurled against the town during the Count of Salisbury’s assult of 1425, still lie at the foot of the wall. In the small garden, don’t miss the strange looking Bollée sundial.

http://baguette.over-blog.net/article-cite-plantagenet-le-mans-75762012.html

 

[Darkmoor]

great thread guys, when do we get pic's of the freakin castle dark moor?

When it's done it will be on our website with a vid of my buddy who is a master bagpiper, playing the castle walls

No serious edifice in the old days was reduced with the tiny toy things jock promotes as effective siege weapons, or tunnelling/engineers, or starvation/thirst of the garrison

 

[Manuka Jock]

No serious edifice in the old days was reduced with the tiny toy things jock promotes as effective siege weapons .....

You are the only one who has promoted that claim .
If you cannot be honest , why are you here ?

 

[Darkmoor]

You are the only one who has promoted that claim .
If you cannot be honest , why are you here ?

How do you promote that tiny launchers that cannot breach massive defenses are effective?

It's a joke

 

[Manuka Jock]

How do you promote that tiny launchers that cannot breach massive defenses are effective?

It's a joke

What are you ranting on about ?

 

[Darkmoor]

What are you ranting on about ?

Wonderful, scientific answer, bro. BTW you never answered if we were rival clans..

 

[Manuka Jock]

Wonderful, scientific answer, bro. BTW you never answered if we were rival clans..

You have yet to state exactly what is it that you are trying to refute .
Also , you have yet to provide proof to your claim that trebuchet have been built and used that were 10 -20 times the size of the one that we all can see in the GalGael video .

You seem to be having difficulty with this topic , so I will give a conservative approximation of the measurements that you are required to front up with to avoid yourself being branded a purveyor of falsehoods .

The trebuchet that you are providing historical proof of are
between 80 - 160 feet for the height of the tower ,
and between 130 - 260 feet for the length of the arm .



If you cannot be honest , why are you here ?

 

[WoodSimply]

I believe its time to beat a dead horse. So let's assume that they did build one with 260 ft arm. And let's assume they some how where able to put the required counter weight on the end. At that size i t now has to add more weight to over cone the weight of the rest of the arm. Now let's say 1/3 more in the bucket. A) that's a big bucket. And b) its now been 8 months into your siege and the enemy has either died of illness and hunger or they rode out to burn your science project. It boils down to can it be useful. Yea many one was built, but you have to remember history is made by the victor not the loser. How else do you scare your enemy's but to send out messengers with false info on an alleged trebuchet that's bigger than the castle.

 

[Manuka Jock]

I believe its time to beat a dead horse. So let's assume that they did build one with 260 ft arm. And let's assume they some how where able to put the required counter weight on the end. At that size i t now has to add more weight to over cone the weight of the rest of the arm. Now let's say 1/3 more in the bucket. A) that's a big bucket. And b) its now been 8 months into your siege and the enemy has either died of illness and hunger or they rode out to burn your science project. It boils down to can it be useful. Yea many one was built, but you have to remember history is made by the victor not the loser. How else do you scare your enemy's but to send out messengers with false info on an alleged trebuchet that's bigger than the castle.

:thumbsup: Send out Darkmoor with false info on an alleged trebuchet that's bigger than the castle :yes:

:laughing:

 

[Brian T.]

MJ = post #70. Thank you so much! What a fantastic sight. Relief for my curiosity, at last.

It's one thing to have the treb set up correctly, it's another to have the projectile wheeling away to the right or left in the sky. Otherwise, we could use square bullets, yes? Ask a competition, big bore pistol shooter about "key-holing".
Believe me. Spherical projectiles are a joy to fling.

The rest of you: back off. This is a thread about the sheer enjoyment of mayhem and destruction.
You need to shed your parental inhibitions and just have a good time smashing things. I am so happy to know that I was brought up to appreciate these things.

As a short note added in proof. My reputation preceeds me. I can set up a "banquet-buster."
Positively ensures that after-dinner speeches are short and sweet, much to the disappointment of the general audience.