We built one, using maybe 140 sticks, give or take a few. Not expecting it to hold much weight, we were surprised by how strong it ended up being! (results in last step)

**Signing Up**

## Step 1: Design your bridge

A triangle spreads out weight and is much more stable than a simple rectangle or square support. Be sure to incorporate lots of triangles into your bridge design. More popsicle sticks doesn't necessarily mean a stronger bridge.

In fact, according to the internet, "If there is a single most important shape in engineering, it is the triangle. Unlike a rectangle, a triangle cannot be deformed without changing the length of one of its sides or breaking one of its joints. In fact, one of the simplest ways to strengthen a rectangle is to add supports that form triangles at the rectangle's corners or across its diagonal length. A single support between two diagonal corners greatly strengthens a rectangle by turning it into two triangles."[link]

My design consists of two main bottom supports, and two across the top, and then a lot of triangles across the sides, the top and bottom, and going from the bottom of one side to the top of the other. Very similar to the one in the diagram.

Draw your design on paper, and estimate the number of sticks you will need.

Be creative with your design!

I could be wrong, but that "silver thing" looks like a slotted aluminum extrusion. They can be found here: http://www.adafruit.com/products/1302, but I'm sure you could probably find them somewhere else with a quick Google search

Thanks for the steps! I won the competition and won a $150 Gift Card!!

i was in a class at school where we had to build a russ bridge that could hold as much as possible.

my design was something like the picture it was made out of toothpicks the trusses were three toothpicks in a triangular fashion and as long as they needed to be.

i made my bridge extremely sloppily and it still ended up being able to have me stand on it at the time i weighed somewhere in the range of 120-130 pounds

i suspect if one were to take the same design and make it extremely not messily it would do very well.

one thing i might try because of the materiels you have availible, make all the colomuns and trusses out of triangles of popsicle sticks. make the bottom have a open faced rectangle with the straws in that and have notches in the straws to hold the trusses in.

i would say make the base out of every other one a straw then a Popsicle stick

one thing i didnt draw is that you make an x with two more trusses between the bottom and top of each side

Judging Criteria:

The winner is determined by a point system as follows:

Complexity - 10 points : The number of purposeful members involved in the design.

Aesthetics - 5 points.

Engineering - 10 points : How much thought is placed into the design, where the connection points are and what member shapes are used in the design.

Workmanship - 5 points : A bridge that is "clean", such as nice glued edges, members matching at connections and nice sanded edges.

Efficiency - 30 points.

Rolling loads test- 20 points.

If anyone can help please mail me at pravinrox@gmail.com.

Heres the problem statement...

Construct a stable truss bridge of span 20 inches, height 5- 6 inches and internal width 4 inches with hollow and solid members (straws and Popsicle sticks) that sustains a minimum load of one kg.

The deck should be essentially made of straws. The loads will be uniformly/non-uniformly placed on the deck. The bridge will also be tested for its efficiency, rolling loads, complexity, aesthetics and workmanship. Paper (provided) can be used for joints consisting of three or more members.

The efficiency of the bridge will be calculated as follows-

Efficiency = Maximum load sustained by the bridge/Weight of the bridge.

Maximum use of straws is suggested as efficiency will be multiplied by the factor 'Number of straws/Number of Sticks used'.

But really, it's the triangles. Read the first couple steps.