Tacoma Narrows Bridge lesson plans - Science lab

Science lab activity

Construction of 1940 and Reconstruction in 1950

The purpose of this lab activity is to introduce the challenges of building a suspension bridge. Students will explore the engineering challenges of building the new Tacoma Narrows Bridge in 1950.

Lesson objectives

As a result of this lesson, students will be able to:

  1. Develop an understanding of the design constraints engineers encounter when building a bridge
  2. Begin to understand the important of planning before building their bridge especially when supplies are limited.

Materials needed:

8 feet of string per group, a roll of masking tape, a cardboard box, pencil, scissors, pop-sickle sticks, sand or clay, books, and a piece of paper.

Lesson steps

1. Students will break up into groups of four.

2. Each group will obtain their materials.

3. The group must construct a suspension bridge across two stacks of books with the materials listed above.

4. The group must sketch the bridge they built.

5. After the sketch is complete, the group will use the Narrows Bridge web site illustration of basic suspension bridge parts to label their drawing with the different parts of a typical suspension bridge.

6. The group will measure the following in inches:


  1. You may not talk to the group across from you.
  2. You cannot use any more material than what was given to you.
  3. Record any design changes you make when building your bridge and explain why this was necessary.

Post-lab activity:

The students should describe what they observed during this activity as well as some principles of physics. The similarities between engineering a bridge and building their model bridge will be noted.

Relating Mathematics:

Use the following measurements of the current Tacoma Narrows Bridge to have the students compare the measurements of their bridge to the real bridge. Incorporate scale factor. The bridge machine since 1950 has "Span Statistics" that could be used in the classroom for fun facts:

Related links on this site:

Suspension bridge basics: The parts


Evaluate each attribute on an appropriate scale based on your own school's grading system, for example giving points or letter grades, or ask students to evaluate the projects that they observe.