Loren C Memorial Bridge Project
Research Bridge Designs
Requirements
1. Research bridge design on the internet. You might check out West Point Bridge Building web pages. They also have a program you can download to test bridge designs.
2. Type a short essay (no less than ¾ page) based on what you’ve learned about the design of bridges and how you can incorporate those aspects into your bridge.
Design a Bridge
Requirements
1. Design and draw your bridge full size.
2. Drawn on paper to a 1:1 scale
a. 1 drawing of the side view
b. 1 drawing of the end view
c. 1 drawing for each of the top views or “levels”
3. Maximum length 14”
4. Maximum width 2.25”
5. Must fit on support platform without aid!
Instructor Approval
Requirements
1. Turn in your bridge design and your paper for approval.
Build a Toothpick bridge
Requirements
1. Use only flat toothpicks and white glue for the structure.
2. Must “only” use glue where you join toothpicks. Overuse of glue will result in 1000 kilograms being deducted from the weight the bridge holds.
Test
Requirements
1. Weigh and record that weight using the class scale.
2. Test the bridge using the classroom foundation.
3. Test the bridge to failure.
4. You can take pictures during the test and after the failure.
Evaluate
Requirements
1. Calculate the Performance Rating. Weight Held / Weight of the Bridge = Proficiency Rating
Example: 1870g/9.19g= PR of 203.48
2. Complete a typed evaluation.
The evaluation should include:
a. Your observations while it’s being tested
b. Your examination of the failed bridge
c. At least “4” concrete recommendations for the improvement of the bridge design.
d. A new sketch that includes your recommendations. Notes where necessary
Redesign
Requirements
1. Draw a new bridge based on the sketches in your previous evaluation and recommendations.
2. Draw it full scale.
Build a Toothpick bridge
Requirements Same as above
Test
Requirements Same as above
Evaluate
Requirements
1. Observations while it’s being tested.
2. Examination of the failure points.
3. Final evaluation of your changes.
Note: The final evaluations must be turned in no later than the Friday prior to finals week.
Hints
It’s important not to over glue the joints. I want you to test your design and not the strength of the glue. If your glue joints look like the sketch on the left, wipe off the excess before it has a chance to dry. I’ll be the “judge and jury” of over gluing your plan.
Tape your plan to a flat surface like a flat piece of cardboard. Then tape your wax paper over the top. You then build each side on top of the wax paper. It just sticks enough to hold things in place as you glue. You can use a flat tool like a putty knife to separate the bridge side from the wax paper after it dries. Two plans and two pieces of cardboard make the process go quicker because as one is drying you can work on the other. This cuts the project time almost in half!
Once the sides are complete you can use wood blocks to hold the sides up vertically and parallel with one another. Then it’s
a matter of gluing the cross pieces in to match the top view and end view levels.
Weighing the bridge is done with the scientific scale I have borrowed from the science department. Record the weight of your bridge in grams.
Finally, testing your bridge is done with the stand I’ve created. Place the given ¼” dowel in the center as shown in the diagram. Use the given wire to hang the bucket from the dowel. Then it’s a matter of adding weight to the bucket. The last weight held before breaking is the final weight to record.
Loren C Memorial Bridge Project
Start Date: Any Time…But don’t wait too long! This project is done almost completely from home. Weighing and Testing are done in class.
Final Day: Nothing will be accepted after the last Friday of the term before finals.
This is what I will expect for the completion of the project PLUS 2 broken bridges.
Page 1 Short Essay on truss bridges and your design concept
Page 2 1st Bridge Construction Drawing
Page 3 Evaluation of 1st Bridge and
Page 4 Recommendations for improvement
Page 5 2nd Bridge Construction Drawing
Page 6 Final Results & Evaluation
Research Bridge Designs
Requirements
1. Research bridge design on the internet. You might check out West Point Bridge Building web pages. They also have a program you can download to test bridge designs.
2. Type a short essay (no less than ¾ page) based on what you’ve learned about the design of bridges and how you can incorporate those aspects into your bridge.
Design a Bridge
Requirements
1. Design and draw your bridge full size.
2. Drawn on paper to a 1:1 scale
a. 1 drawing of the side view
b. 1 drawing of the end view
c. 1 drawing for each of the top views or “levels”
3. Maximum length 14”
4. Maximum width 2.25”
5. Must fit on support platform without aid!
Instructor Approval
Requirements
1. Turn in your bridge design and your paper for approval.
Build a Toothpick bridge
Requirements
1. Use only flat toothpicks and white glue for the structure.
2. Must “only” use glue where you join toothpicks. Overuse of glue will result in 1000 kilograms being deducted from the weight the bridge holds.
Test
Requirements
1. Weigh and record that weight using the class scale.
2. Test the bridge using the classroom foundation.
3. Test the bridge to failure.
4. You can take pictures during the test and after the failure.
Evaluate
Requirements
1. Calculate the Performance Rating. Weight Held / Weight of the Bridge = Proficiency Rating
Example: 1870g/9.19g= PR of 203.48
2. Complete a typed evaluation.
The evaluation should include:
a. Your observations while it’s being tested
b. Your examination of the failed bridge
c. At least “4” concrete recommendations for the improvement of the bridge design.
d. A new sketch that includes your recommendations. Notes where necessary
Redesign
Requirements
1. Draw a new bridge based on the sketches in your previous evaluation and recommendations.
2. Draw it full scale.
Build a Toothpick bridge
Requirements Same as above
Test
Requirements Same as above
Evaluate
Requirements
1. Observations while it’s being tested.
2. Examination of the failure points.
3. Final evaluation of your changes.
Note: The final evaluations must be turned in no later than the Friday prior to finals week.
Hints
It’s important not to over glue the joints. I want you to test your design and not the strength of the glue. If your glue joints look like the sketch on the left, wipe off the excess before it has a chance to dry. I’ll be the “judge and jury” of over gluing your plan.
Tape your plan to a flat surface like a flat piece of cardboard. Then tape your wax paper over the top. You then build each side on top of the wax paper. It just sticks enough to hold things in place as you glue. You can use a flat tool like a putty knife to separate the bridge side from the wax paper after it dries. Two plans and two pieces of cardboard make the process go quicker because as one is drying you can work on the other. This cuts the project time almost in half!
Once the sides are complete you can use wood blocks to hold the sides up vertically and parallel with one another. Then it’s
a matter of gluing the cross pieces in to match the top view and end view levels.
Weighing the bridge is done with the scientific scale I have borrowed from the science department. Record the weight of your bridge in grams.
Finally, testing your bridge is done with the stand I’ve created. Place the given ¼” dowel in the center as shown in the diagram. Use the given wire to hang the bucket from the dowel. Then it’s a matter of adding weight to the bucket. The last weight held before breaking is the final weight to record.
Loren C Memorial Bridge Project
Start Date: Any Time…But don’t wait too long! This project is done almost completely from home. Weighing and Testing are done in class.
Final Day: Nothing will be accepted after the last Friday of the term before finals.
This is what I will expect for the completion of the project PLUS 2 broken bridges.
Page 1 Short Essay on truss bridges and your design concept
Page 2 1st Bridge Construction Drawing
Page 3 Evaluation of 1st Bridge and
Page 4 Recommendations for improvement
Page 5 2nd Bridge Construction Drawing
Page 6 Final Results & Evaluation