History, Science, Technology:Ancient Engineering
Ingenious achievements of the ancients

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.

$21.95
Add to Cart

<< Previous Item | Next Item >>

[ Click here to see our complete line of models and kits. ]

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

    Add to Cart
    Item code: 20101


Links


Search for stuff
Search:
By Age
By Max Price
By Keyword
(help)

(Click images to enlarge)
(Click for larger Image)
(Click for larger Image)
(Click for larger Image)
(Click for larger Image)
(Click for larger Image)
Interesting Notes

The Roman Onager was the main artillery device of the Roman army. It was named after the Asian Wild Ass because they both have a tendancy to "kick" when they go off.

Oftentimes, an Onager would be fitted with a sling on the end of the arm instead of a cup or bucket. The sling will give greater range to a heavier projectile, but can only hurl one rock at a time. The bucket could be filled with lots of rocks at once - an effective anti-personnel device.

The kinds of things the Romans hurled includes heavy rocks and clay pots filled with pitch and tar- on fire.

Onagers are sometimes called a "Mangonel", but Mangonel literally translates as "War Machine" - a category that also includes ballistae and trebuchets.

The Onagers were used from early Roman times right up to the medieval period alongside the trebuchets. They lost their advantage to the cannons and gunpowder in the 13th century.