Informal Learning Activity Build a Tower with an Egg on Top (en español)

Quick Look

Grade Level: Middle school

Time Required: 1 hour

Expendable Cost: US $1.00

Group Size: 3

Subject Areas: Science and Technology

Bolded words are vocabulary and concepts to highlight with students during the activity.

Towers have been created in human societies for centuries, serving a variety of purposes, from watch towers to modern cell towers. Engineering designs are subject to requirements and constraints, often including limitations on time, materials and budget, as well as specifications such as size, strength, materials and capacity. Engineers design different types of towers to best suit different purposes: guyed or cable-supported, free-standing or self-standing, and monopole (refer to Figure 1).

A photograph shows the "twin towers" of Bologna, Italy—two side-by-side masonry towers, ~150 feet high and ~300-feet high, both with bases wider than their tops. The shorter one in the foreground leans a little.
Self-supporting towers built in the 1100s in Italy.
Copyright © 2005 Patrick Clenet, Wikimedia Commons


Each group needs:

  • 1 sheet of paper
  • 3 x 5-inch notecard
  • 30 craft sticks
  • 12 inches (30 cm) of masking tape
  • 20 inches (50 cm) of string
  • ruler

To share with the entire class:

  • 1 weighted plastic egg, filled with marbles or pennies
  • hot glue and hot glue guns; alternative: masking tape
  • (optional) four or five wooden dowels, ~3/16 x 12 inches; hand out if groups ask for them


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Students design and build towers that use the provided supplies and can hold a weight 12 inches above the ground for 20 seconds. They may use any of the common tower designs shown in Figure 1 or their own designs, as long as the footprint, excluding any cable supports, fits within the notecard area.


  1. Present and discuss the introduction content.
  2. Explain the engineering challenge: To design and build a tower that can hold the weighted egg 12 inches above the ground for 20 seconds.
  3. Show students some sketches of common tower designs (Figure 1).
  4. Explain some requirements:
  • The base of the towers must fit within the area of the notecard, excluding any cable (string) supports that might be part of the design.
  • They may not use the egg to test their designs, but they may measure it to make sure it fits on/in their towers.
  1. Organize the students into groups of three.
  2. Distribute the supplies to each group.
  3. Give groups time to draw their design plans. Have them get instructor approval of their designs before they begin construction.
  4. Give groups a set amount of time to build.
  5. At the end of the time, have each group test its tower in front of the class, using the weighted egg.
  6. If time and supplies permit, let groups redesign to improve their designs.
    Line drawings illustrate three tower types. A monopole is a tall narrow tower, slightly wider at its base, with a short horizontal beam across the top. A self-supporting tower is composed of crisscrossed bars that form a tower structure that gets narrower as it goes up (similar to an electrical power tower), with a short horizontal grid across the top. A guyed tower is a tall pole with a short horizontal beam across the top and three cables from three locations on the top half of the pole secured to the ground (similar to a telephone pole).
    Figure 1. Common tower designs.
    Copyright © 1998 OSHA via Electronic Library of Construction Occupational Safety & Health (eLCOSH)

Wrap Up - Thought Questions

  • What worked well about your design? Why?
  • What did not work well? Why not?
  • How would you improve your design if you had more time?

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Last modified: May 11, 2022

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