LIFE SIZE Leonardo's Arched Bridge (Leonardo's da Vinci Bridge)
Channel: Kids Fun Science
Date: 2020-03-29

LIFE SIZE Leonardo's Arched Bridge (Leonardo's da Vinci Bridge)

Last experiment I made a model size Leonardo's Arched Bridge with painters sticks. This time I'm going to make a LIFE-SIZE Arched bridge and cross my KOI pond. Remember this bridge has No Nails, Screws, glue or fasteners. Just friction and gravity. 

1 Inch x 48 Inch Wooden Dowel - https://amzn.to/2ScJ23B

Kids Fun Science On-line Store (All money goes back into the schools)
https://teespring.com/stores/kids-fun-science

Chapters
0:00 Kids Fun Science Intro
0:13 What you need
0:47 Set up
3:23 Test crossing and had to fix the 2x3's
4:16 First attempt to cross the pond
4:38 2nd attempt across the pond

Filming equipment 
Cell Phone Tripod 54 inch Travel Tripod with Bluetooth Remote - https://amzn.to/34REzbB
Blue Yeti USB Microphone - https://amzn.to/3ePJwGu
Green screen & lights - https://amzn.to/2XT9Yc1

What you need is:
(10) 2-inch by 3-inch (5.08cm by 7.62cm) boards and 
(5) 1 1/4 inch Dowel 48 inches long. (3.17cm = 1 1/4 inches and 121.92cm is 48 inches)
I only ended up using (8) 2x3's and (4) Dowels as my pond was not long enough to use all. 

Steps:
1)  start with (2) 2x3's and one dowel on top in the middle. Spaced about 3 feet (0.91m) apart. 
2) take (2) 2x3's and place on top of dowel, over lapping by 6 to 8 inches (15.24cm to 20.32cm)
3) One person picks up the (2) 2x3's on the ground high enough to put the dowel in between the 2x3's
making sure the 2x3's are 6 to 8 inches pass the dowel.
4) Repeat step 2 and place (2) 2x3's on the inside of other 2x3's on top of the dowel over lapping the dowel by 6 to 8 inches. 
5) Repeat step 3 by having one person grab the bottom (2) 2x3's that are on the ground and lift them high enough so the other person can put the dowel between them. Allowing the 2x3 to over lap by 6 to 8 inches.
You can continue adding on the same side, but my video my bocci ball court made me switch to the other side to continue. : )
6) Place (2) 2x3's on the inside on the dowel, over lapping the dowel by 6 to 8 inches. 
7) One person grab the bottom (2) 2x3's on the ground and lift them high enough for the second person to place a dowel in between, allowing the 2x3 to over lap by 6 to 8 inches. 
8) tighten up the 2x3's to be flush against each other and make sure the 2x3's that are on the ground are straight.

Now this is only using (8) 2x3's and (4) dowels, as my pond only needs this many. You can add more if required. 

LIFE-SIZED Leonardo's Arched Bridge 

What's cool about this experiment is doesn't use nails, screws, rope, glues, notches, or other fasteners are holding the bridge in place. Just friction and gravity. 

Leonardo da Vinci although he's best known for iconic works such as "Mona Lisa" and "Last Supper," in the early 16th century, da Vinci designed a lesser-known structure: a bridge for the Ottoman Empire that would have been the longest bridge of its time. Had it been built, the bridge would have been incredibly sturdy, according to a new study.

Interestingly, Norway's da Vinci Bridge—a pedestrian overpass opened in 2001—is loosely based on the 1502 sketch but uses steel and wood instead of masonry blocks. The prototype of the bridge is a walkway of 4 meters (13 feet) long and can hold a weight of up to 500 kilograms (1102 pounds)

SCIENCE BEHIND IT!
Modern bridges are built with high-strength materials and carefully selected fasteners. Designs considerations include the weight of the bridge and the load it carries as well as stresses caused by wind and earthquakes. Bridge components are subject to tension, compression, torsion, and shear 

Leonardo’s arched bridge is amazing in that the design is self-supporting, requiring no fasters. Leonardo envisioned using nothing but large logs to build his bridge. The bridge’s own weight holds it together. As weight is added to the bridge. Its structural elements are forced more tightly together, making it even stronger.