2006 RHS Bridge Design Competition

RHS Annual Spaghetti Bridge Competition

Each group is to build a bridge made from spaghetti and hot glue. The object is to construct a bridge that will carry the heaviest load while still meeting specifications. Bridges will be loaded until they fail.

RULES:

1. The bridge is to be built from spaghetti and hot glue. Glue may only be applied at the nodes (joints). Nodes may be reinforced with 1 strand of string prior to applying not more than a Q-Tip head amount of hot glue. Spaghetti may not be bundled, and glue sticks are rationed to three per group.

2. The bridge shall be free-standing and must span two level surfaces which are 16” apart.

3. The support for the bridge shall be from the top of the level surfaces.

4. The bridge must include a decking of spaghetti to provide a suitable road surface at least 2” wide across the full span of the bridge. Three conditions must be met:

a) gaps in the bridge deck are not to exceed 1/8”,

b) a block of wood (2” x 2” x 4”) representing a car must be able to move along the length of the decking unobstructed from end to end,

c) the deck of the bridge must be at the same level as the supports.

5. You must incorporate a n open space at least ½” wide across the center of the bridge to attach the loading bar (popsicle stick). This popsicle stick is to be attached at the center of the bridge at the level of the bridge deck. All loads will be suspended from this popsicle stick, and there must be a clear space directly below it to allow loads to be attached. Loads will be attached using string down to a suspended bucket

6. The maximum vertical depth of the bridge, from the highest point in its structure to the lowest cannot exceed 9”. Bridge cannot exceed 18” in length.

7. Each group will be issued 7ounces (200 grams) of spaghetti, three glue sticks, and a spool of thread (for joints only, wrapped once).

When you design a bridge you should follow this process:

1. Identify the problem. Your project is to design a truss bridge across a river.

2. Define the problem. To fully define and understand the problem, you should carefully read the Design Specifications and familiarize with the characteristics of the project site.

3. Develop alternative solutions. To achieve a high-quality design, you will need to investigate several different site configurations and truss configurations.

4. Analyze and compare alternative solutions. Optimize each alternative configuration for minimum cost, then compare the results.

5. Select the best alternative. Select the alternative that costs the least, while still passing the load test.

6. Implement the solution. Finalize your design, and record it by saving it to disk, printing a drawing of it, and printing a copy of the load test results.

7. Evaluate the results. Think about what you learned about the design process and about structural behavior as you designed your bridge. Then apply these lessons to improve the efficiency and effectiveness of your next design.

(from: West Point Bridge Builder)

RUBRIC #7 – MR. JOHN RUF

Bridge Competition

Followed Instructions –

Bridge Complied with project requirements

for weight, height, length, width. 1 2 3 4 5

Complete – Included the required items –

Specs, Plans, Elevations, Perspective. 1 2 3 4 5

AutoCad Competence/Technical Drawing Skills –

Exhibited understanding of the elements required

for proper design presentation. 1 2 3 4 5

Design Performance –

Bridge performed below, at or above the average in load,

and load to mass ratio. 1 2 3 4 5

Conclusions-

Report reached valid and supported conclusions on the

performance of the bridge. 1 2 3 4 5

1. Did not attempt.

2. Attempted; met some but not all.

3. Met most minimum standards.

4. Met all minimum standards.

5. Met all, exceeded most standards.

Riverbend High School

12301 Spotswood Furnace Road

Fredericksburg, VA 22407

John Ruf

Phone: 540-548-4351 Ext. 2192

Email: jruf@hs.spotsylvania.k12.va.us