Leonardo DaVinci's Self-Supporting Arch Bridge

Ancient Engineering SeriesCatapult Kits

Have you hurled today?

Leonardo DaVinci's Self-Supporting Arch Bridge

No Glue Required! No String, No Screws, and No Nails!

The unique structure of this bridge holds itself together without any fasteners or connectors. The parts are notched for easy assembly, just slip the notches together and build this sturdy bridge in a matter of minutes. Take it down and rebuild it again and again. The longest pieces are only ten inches long, but when assembled, this bridge spans more than three and a half times that distance. How can it do this without any glue, screws, string or nails?

Sometime around 1485-1487, Leonardo DaVinci devised a method for building a self-supporting arched bridge that doesn’t require any ropes or other fasteners. The bridge's own weight keeps it together; the more you stack on it, the more stable it gets. It was originally meant to be a quick bridge for military usage - just bring along the pre-cut pieces and slot them together.

Twenty one precision cut parts, guaranteed to fit together.
No metal, plastic or other parts - only wood!
All parts are precision cut by computer from high-quality hardwood
The finished model is 36” wide, 10” tall and 5-1/2” wide.

This kit is extensible! With two kits you can double the size of your arch and make a half-circle four feet long and two feet tall. The arch stands by itself without any fasteners or complicated joinery! It is also possible, although slightly challenging, to make a complete full circle by using four kits. (A circle constructed this way is not self supporting however. Can you figure out why?) By using rubber bands or glue to hold the joints together, it is possible to make a full circle.

This bridge kit is a fascinating example of early bridge building architecture. It's a combination of arch technology and a shallow-truss type technology - a truly ingenious system of interlocking forms. Each form supports the two segments adjacent to it in a daisy chain of mutual support, with only the two end segments touching the ground. It's no surprise that Leonardo DaVinci was the mastermind inventor who came up with it.

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Price: $21.95
Minimum age: 5
Availability: In stock.

Item code: 20101

Notes:
Why should a kid
build a catapult?

Because the world needs good engineers and scientists, and because the kids who will grow up to become engineers and scientists need a way to get hands-on experience with physics, math and engineering.

In this age of 200-plus channels of TV, the Internet and computer games, kids are also spending far less time building tree houses, tinkering with engines, or designing downhill racers. We believe those are important skills to have. They help form the basis for good problem solving skills and an innate understanding of the real, physical world that you just can't get from a computer game, no matter how good its physics simulation software is.

Ballistic motion was one of the key players in the development of the science of physics. The word "engineer" even originated as the builders and designer of Siege Engines

Why is a budding engineering student expected to take a year or two of calculus in high school, but she isn't expected to have any real-world experience in building or working with machines and materials? Pencil and paper (or computer screens) are only one part of the learning experience. Where will she apply all of the stuff she learned in geometry and trig? Without physical projects to touch, feel and see, the lessons become abstract, their utility questionable.

A catapult project gives students a chance to see that science and engineering really can be fun, and it's a lot more than just numbers on paper. The real payoff for an engineer is in the field, where she can see and enjoy the results of her ingenuity. And it may seem counterintuitive, but engineering projects not only help kids learn math and science, they are also great at getting kids back outdoors, away from the massive over-exposure to video games, TV and the Internet.

Why all this interest in getting kids to study science and engineering? Because it's important to our society, and it's great mental cross training regardless of what field of work the kids eventually go into. Most people develop a sense for what they want to do in life while they are still in high school or even earlier. A catapult project is fun and interesting enough to inspire some kids to study the science behind how they work, and then go on to become the engineers and scientists of tomorrow.

(Click images to enlarge)