Build a Bridge

Time required

50 minutes

Objective

Allows students to experience what it is like to participate as a member of an engineering design team to complete an engineering project within a specified budget and schedule.

Required materials

• bridge specification, material list, and schedule
• building materials: straws, paper cups, scotch tape, etc.
• play money for each team
• 16oz soda bottle filled with water

Divide the class into engineering teams of 4-8 students each.

Procedure

You will be given a specification for a bridge, a budget, and a schedule. Your task will be to complete the design and construction of the bridge within the allotted budget and schedule.

Bridge Specifications

Bridge must span a distance of 12″ between two desks and must be capable of supporting a 16oz soda bottle filled with water. The bridge must be constructed exclusively with materials purchased for this project.

Schedule

• Design phase: plan bridge construction and material procurement – 10 min
• Implementation phase: construction – 15 min
• Testing – 5 min

Budget

Total budget: $20,000

(provide each team with 20 each $1000 bills)

Available materials

• 5 straws cost = $1000
• 1 paper cup cost = $1000
• 12″ scotch tape cost = $1000
• etc.

Hand out specification, budget, and schedule. Briefly go over schedule, e.g. all materials must be purchased during design phase, no additional material can be purchased after entering implementation phase. Allow about 5 min for any questions to clarify objective.

Note that specification is left intentionally vague to allow individual interpretation. Once you start, write the times when each phase will be completed on the board. I placed all the materials on a table and allowed the students to get their own materials on the honor system. This allowed me to circulate through the class and answer any questions. During the test phase, take a 16oz soda bottle filled with water and test each bridge in turn to see if it supports weight.

Wrap-up

At the completion of this exercise you can discuss issues and challenges the students encountered and relate these to challenges you face at work. Some examples are the following:

• Do any two bridges look alike? What are some of the differences in designs?
• What makes one design better than another? Strength, Cost (Anyone design a bridge under budget?), Time (Did anyone finish before allotted time was up?)
• Did the final design end up anything like what you planned? Did you have enough time to plan your bridge?
• Was the design specification clear?
• Did everyone feel that they participated equally on their team? Why not? Discuss challenges of working on design teams. How were decisions reached?

Thanks to Steve Delach in Oregon for providing this activity idea.