Skip to content

Session 3: Bridge Engineering 🌉

Overview

Grades: 3-4 | Duration: 40 minutes | Session: 3 of 17

Students explore bridge engineering principles and build bridges using KEVA planks, testing their structures for strength.

Session 3: Bridge Engineering

Learning Objectives

By the end of this session, students will:

  • Identify different bridge types and their features

  • Understand how triangles add strength

  • Build and test a bridge structure

  • Apply the engineering design process

Session 3: Bridge Engineering

Materials Needed

  • 📦 KEVA Planks (from CSCOE library)

  • 📸 Bridge type pictures

  • 🪙 Weights for testing (coins, washers)

  • 📏 Rulers for measuring span

  • 📓 Engineering journals

Catholic Integration

Saint Connection

St. Patrick — Built "bridges" between people and faith in Ireland. He connected communities!

Scripture

"How beautiful are the feet of those who bring good news!" — Romans 10:15 (Bridges help spread good news!)

Opening Prayer

Dear God, you connect heaven and earth. Like St. Patrick who built bridges of faith, help us build structures that connect and serve others. Amen.

Lesson Procedure

Opening Circle (6 minutes)

  1. Bridge Purpose — "Bridges connect people and places!"
  2. Bridge Types:
  3. Beam — Simple, flat across supports
  4. Arch — Curved, pushes weight outward
  5. Truss — Uses triangles for strength
  6. Suspension — Hangs from cables
  7. Triangles = Strength — Demonstrate with hands
  8. St. Patrick — Connected communities through faith

Main Activity: Bridge Building Challenge (26 minutes)

Part 1: The Challenge (3 minutes)

  • Build a bridge that:
  • Spans at least 8 inches (between two books)
  • Can hold weight

  • Uses only KEVA planks

  • Success = Most weight held without collapse!

Part 2: Design & Build (18 minutes)

IMAGINE (3 min):

  • Sketch your bridge design

  • Label: supports, deck, special features

  • Which bridge type will you use?

PLAN (2 min):

  • Estimate planks needed

  • Decide where to start building

CREATE (11 min):

  • Build your bridge!

  • Remember: Triangles add strength

  • Test balance before adding weight

TEST (2 min):

  • Add weights one at a time

  • Count how many before collapse

  • Record your results

Part 3: Analysis (5 minutes)

  • Which bridges held the most weight?

  • What designs worked best? Why?

  • How could you improve?

  • Class discussion of findings

Engineering Journal (5 minutes)

  1. Sketch your bridge design (before and after building)
  2. Record: "My bridge held ___ weights"
  3. Write: "Triangles help bridges by..."
  4. Write: "Next time I would..."

Closing Circle (3 minutes)

  1. Celebrate Successes — Recognize strong bridges
  2. Real Bridges — Where do you see bridges in our community?
  3. Closing Prayer — "God, help us be bridge builders—connecting people with love and service. Amen."

Assessment

Observation Checklist:

  • Identified bridge types

  • Created design before building

  • Built stable bridge structure

  • Tested and recorded results

Differentiation

For Students Who Need Support

  • Provide starter bridge base

  • Work with partner

  • Simplified span requirement

For Advanced Students

  • Longer span requirement

  • Design constraints (limited planks)

  • Research famous bridges

Wonder at Home 🏠

Family Activity: Find bridges in your community! What type are they? Why were they designed that way? Build a bridge at home using blocks, straws, or popsicle sticks. Test with toy cars!

Teacher Notes

  • Reserve KEVA planks from CSCOE library

  • Clear large floor/table space

  • Use books for stable supports

  • Take photos for portfolio

  • Connect to local bridge examples

Previous: Session 2 — Dash & Code
Next: Session 4 — Animal Habitats