THE SPAGHETTI
BRIDGE
The goal of this competition is to develop a bridge that will carry as
much weight as possible, yet weigh as little as possible, while meeting
all of the requirements listed. The bridge design should achieve the
highest efficiency possible.
The material that is to be used is #9 spaghetti (thin), which is to be
supplied by the teacher. The structure must be three-dimensional and
capable of fitting in the testing jig provided. Maximum points for the
fabrication portion of the grade will be awarded for the lightest
structure that will support the load. Bridges failing will be graded
on the bridge’s structural efficiency (E). E=Max load supported/mass
of the bridge.
Students will work in groups of no more than three and all in the group
will receive the same grade (unless the group evaluates a member
differently.) It is expected that the work will be shared equally.
In addition to the fabrication of the structure, each person will
submit a one to two page report that will include all design drawings
and calculations.
Students will also research bridge designs on the Internet and find one
that fits their needs for the contest.
A bridge building program will also be used to construct and evaluate
compression and tension members of the bridge design. The bridge
building program will help students with efficiency evaluations.
Research:
Students can use books, magazines, and the library, to research bridge
designs. The Internet will be used to find a web site that explains
and demonstrates bridge styles and construction.
The students should include this information in printed form and attach
to their report.
West Point Bridge Building Program:
Student will make a drawing of the style of bridge they have selected.
The program will show compression and tension members and how strong
they are.
A cost analysis and efficiency rating will be used to help students
design and build their spaghetti bride.
Drawings:
A 2-D AutoCAD drawing and a 3-D inventor drawing, assembly, balloon
drawing and presentation file, of the whole bridge.
The front elevation and side elevation of the 3-D drawing will be
printed out and used as a pattern for the spaghetti bridge. The
spaghetti can be cut exactly to the right size by laying it down on the
drawing and cutting it.
Details about construction of the bridge:
Only spaghetti may be used for construction of the bridge. Any
adhesive may be used to join the ends of the spaghetti. Longitudinal
gluing may not be allowed. Hot Glue works very well. No part of the
bridge may extend more than ¾” below the support elevation.
The bridge length must be 15 long.
A hole must be provided in the center of the bridge to allow for the
threaded rod. It is suggested that this area be strengthened to
accommodate the point load. The roadway must have an opening in it to
allow a 1" thick by 2" wide x 6" long testing block to slide through.
The jig will be weighed and included in the weight on the bridge. The
bridge cannot weigh more that 100 grams.
Width of the bridge is 2.5 to 4.0 inches
No height requirement of total ht.
Testing Procedures:
The bridge will be centered on the supports.
A bucket will be attached to the center support and the load will be
applied. The student will add sand to the bucket until failure occurs.
Maximum time for loading will be 5 minutes.
The weight of the filled bucket will be massed and used in the
efficiency formula.
Failure of the bridge is defined as the inability of the bridge to
carry additional load without breakage or sagging more that 1 cm below
support elevation.
The Report:
PROPOSAL REQUIREMENTS
Format Requirements:
I. Typed
II. Double-spaced
III. 12-point font (Arial or Times New Roman)
IV. All pages on 8.5 by 11-inch paper
V. Information must be in the same order as shown below
VI. All pages numbered
Proposal Components:
I. Title Page. Include name of challenge, team name and logo, name of
school or organization, name of team captain and team members, and name
of teacher or advisor.
II. Table of Contents.
III. Introduction.
a. Describe what special skills were learned or demonstrated.
IV. Body. The main part of the report.
b. Explain the reasons behind the design of your bridge.
c. Explain the scientific principles supporting the design of your
bridge.
d. Include data tables and graphic representation of tests.
e. Include supporting calculations.
f. Include 8.5 x 11-inch scaled drawing of the bridge using AutoCAD
software and Inventor Do not crop or use the print screen option
when printing the drawing.
g. Explain how you tested your design, and the improvements you made as
h result of the testing.
i. Describe the problems you encountered in designing and building your
bridge and how you solved these problems.
j. List and describe any special tools or machines that were used to
design and/or build your bridge.
VI. Conclusions and Recommendations.
l. How successful is your project?
m. What did you learn by taking part in the bridge challenge?
n. Describe any recommendations you have to improve your bridge or the
bridge challenge competition.
IX. Bibliography.
o. List all references used, including internet, books and magazines.
X. Appendices.
aa. Working Drawings. Include working drawings not contained in the
design section.
bb. Additional Supporting Information.
Grading:
Research information
Accuracy Bridge/drawings
AutoCAD Drawings 2-D of Side View
3-D Drawing Inventor
West Point Bridge Program Drawing
Efficiency rating of Bridge
Report
Team Grades each persons work +Total points possible
Time line
(approx):
Research
West Point Building Program
3-D Drawing
Construction of Bridge
Report (on own time)
Graphs and other
Efficiency rating of Bridge
1st
2nd
3rd
4th
place
place
place
place
50
40
30
20
points
points
points
points
1
4
3
5
day
days
days
days
1 day
10 points
Individual
25 points
Individual
25 points
Individual
25 points
Individual
20 points
Individual
50 max See Schedule below
35 points
Individual
20 points
Individual
200 points