Introduction
The first encounter
I first encountered a trebuchet while watching a television program called NOVA in which they reconstructed two large trebuchets and hurled stones at a castle wall. I was very impressed with the show and my father and I were inspired to build one.
In the beginning
Our first trebuchet was about 2.5 feet tall and made out of a MECCANO. It could throw a marble about 30-35 feet. It was throwing too far to use in the house and fearing that we would lose the marbles in the grass if we took it outside; we had an excuse to build a bigger one. Unfortunately, this trebuchet no longer exists as its parts were dismantled for other projects.
We go one size bigger.
Next came Newton which is made out of wood scraps and is about six feet tall with the beam in the upright position. It has a three piece beam with a swinging basket and uses cement patio stones for the counter-weight. It throws golf balls 120 to 135 feet depending on the golf ball thrown. Well you might think us satisfied at that, but no, we had to go bigger.
They say bigger is better
Next came Thor, measuring in at 30 feet tall. The frame is made of wood from our woodlot, the axles are solid steel, and the counterweight is made up of 2300 lbs of reinforced concrete blocks. Its size was only limited by the materials available to us at the time to make the throwing arm (as it is the largest piece). Next, we gathered a number of bowling balls and started throwing them. At first, we were using a piece of rubber belting for a sling, and we were getting a 14 pound bowling ball to fly about 190 feet. We were unhappy with this, as from simulations and calculations we figured it would go a lot further. We wanted more, but could not figure out how to achieve it. We got lucky as one day as we were taking pictures of the trebuchet firing, we noticed that during the release, the ball would slide out the side of the sling before the sling unhooked. That meant that the ball was not getting all of the energy available to it. So we took off the sling. We drilled a hole though the bowling ball and attached it with a rope. Now instead of a sling we have a bowling ball on a string. The string flies along with it the bowling ball after it is launched. Attaching the ball in this manner has increased our range to just over 600 ft with the same counterweight and ball.
Future plans
We had had plans on extending the sides of Thor higher so we could have had a longer throwing arm and thus more leverage and thus farther distance. However, instead of rebuilding Thor, which has become unusable due to the deterioration of the wood structure, our current plans are to construct a larger steel one. Though, as with building any very large object there are more complications then we originally thought, so it may take a while before it actually comes to fruition. Stay tuned for updates on our progress on the steel trebuchet. In the meantime, we are building a replacement for Thor in its image as a hold over till the steel becomes a reality.
Jump to [Newton]-[Thor]-[Hawthorn]-[M1 Rolland Korg]
Newton
Newton's Specs
| Name: | Newton |
| Class: | Swinging bucket counter-weight Trebuchet |
| Beam type: | Three piece beam |
| Size: | Throwing arm length 3 ft. 2in. |
| Axle height (from ground): | 2 ft. 3 in. |
| Power unit: | 30-45 lbs. of cement patio stones in a wood basket |
| Projectiles: | Golf balls |
| Current range: | 100-110 ft |
| Based upon: | Paul Carlisle's trebuchet |
| Status: | Functional |
Notes on Newton
Newton was built as a machine to test out the mechanics and the functioning of a trebuchet. A lot of research and planning went in to this trebuchet before it was built and calculations were done to try to determine the best dimensions for everything.
Newton is made from scraps of ash with patio bricks as weights. We built it to throw golf balls and it works rather well in this capacity.
Thor
Thor's Specs
| Name: | Thor |
| Class: | Swinging counter-weight trebuchet |
| Beam type: | One piece, eight sided, tapered beam |
| Size: | Approximately 25 feet tall |
| Height to axle: | 11 ft. 6in |
| Power unit: | 2300 lbs of reinforced concrete |
| Projectiles: | Bowling balls 11-14 lbs |
| Current range: | Approximately 600 ft |
| Based upon: | Multiple trebuchets sources on the Internet and Newton |
| Status: | Retired due to deteriorating wood structure
|
| Special note: | Built using mortise and tenant joints. |
Modifications to Thor over time
We have made a number of modifications and repairs to Thor over its life. It is the culmination of all of our trebuchet knowledge rolled into one. We have added extra weight onto the basket, initially believing that we needed weight for the ball to go farther (it turned out to be the sling problem as mentioned above but having the extra weight doesn't hurt). We have also replaced parts in the priming and release mechanisms which have broke over time due to wear and improper design. We have also added extra bracing to the sides to add stability and extra supports to help out in bearing the weight of the main axle.
Thor pictures
Thor Videos
Montage of a couple of different shots of Thor. Sorry in advance for the green writing.
The cameraman decides to stand out in the field and get fired at.
Hawthorn
Hawthorn's Specs
| Name: | Hawthorn |
| Class: | Swinging counter-weight trebuchet |
| Beam type: | One piece tapered beam |
| Size: | Approximately 40 feet tall |
| Power unit: | ~2500 lbs of reinforced concrete |
| Projectiles: | Bowling balls 11-14 lbs or other roundish projectiles |
| Current range: | Untested |
| Based upon: | Thor |
| Status: | Under Construction
|
| Special note: | Built as a replacement for Thor with improvements built in. |
Notes on Hawthorn
Built as a replacement for Thor which was taken out of commission by age and deteriorating condition.
M1 Rolland Korg
M1 Rolland Korg's Specs
| Name: | M1 Rolland Korg |
| Class: | Swinging or fixed counter-weight trebuchet |
| Beam type: | Segmented beam |
| Size: | ~60 feet tall |
| Power unit: | Lots of concrete or steel |
| Projectiles: | Small vehicles |
| Estimated Range: | Unknown |
| Inspired by: | Yankee Siege, Warwick Castle trebuchet, Hew Kennedy's Trebuchet [1] [2], Own design. |
| Status: | Planned, initial drawings and some calculations completed.
|
| Special note: | Will be made of steel and will be completely dissembleable for transport. |
Notes on M1 Rolland Korg
Korg has been in the planning stages for a while now. The desire is there but currently the finances are not available. The currently plan is to get a CAD drawing completed of the entire machine and then look for some sponsors for the project. Then one summer, I hope to build it.
The name was inspired by the combination of the names on two electric keyboards at a friend's concert and that it is the first model.
Korg will be made out of steel with gusset plates at each joint and connected together with bolts to allow the complete disassembly of the machine. We found that one disadvantage of Thor is that it is very hard to move. With a much larger machine, the ability to move the machine will become even more important.
We are hoping to throw projectiles in the size range of small cars. This seems to be the golden standard for large trebuchets and I think that it would be jolly good fun. I am planning on using cars after they have been used in a demolition derby. Thus, they are no longer usable and are already smashed up a bit. I would have a hard time to throw a functional automobile as I think that would be very wasteful. I will investigate ways to reduce the environmental impact of throwing cars, by draining all fluids which may leak out after a throw, removing all glass from the car beforehand and recycling the wreck after all the fun is had.
M1 Rolland Korg's CAD drawing
This is the current state of the CAD drawing for Korg. Note that I am self taught in AutoCAD. My drawings may not inspire :)
The AutoCAD source file is available for download below. It was created with AutoCAD 2009, so earlier versions of AutoCad may not be able to open it properly.
Click to download Korg Drawing 1 - Updated June 31, 2009
Safety
Please understand that trebuchets are meant to be weapons. Thus, care must be used while around them.
Use your head at all times while building, operating and showing off your trebuchet, no matter the size.
I am not responsible for any injuries or damage that may result from you using the information I share on this website.
Last modified: April 27, 2010
© 2008, 2009 Joshua Kyle