Life Vest Challenge

This lesson explores the engineering behind life vests or personal flotation devices and the challenges met by these devices. Students work in teams to design and build a flotation device out of everyday materials that can keep an unopened can of soup or vegetables afloat in a bucket of water or sink for a minute.

Learn about engineering design and redesign.
Learn about personal flotation devices (PFDs).
Learn how engineering can help solve society’s challenges.
Learn about teamwork and problem solving.

Age Levels: 8-14

Lesson Plan Presentation

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Materials & Preparation

Build Materials (For each team)

Required Materials (Trading/Table of Possibilities)

Soup or vegetable cans (must be identical for each team)
Paper cups
Straws
Paper towels
Rubber bands
Paper clips
Balloons
Plastic bags or lunch bags
Corks
Foam pieces
String
Aluminum foil
Hose or tubes
Small containers
Paper towels

Testing Materials

Water source
Bucket or sink area

Testing Materials & Process

Materials

Water source
Bucket or sink area

Process

Test each team’s flotation device by placing it in a tub or sink with water. The can must be attached to or placed on/in the device in no more than 20 seconds. Score the team’s results based on the following and compare each team’s total scores.

PFD attached to can within 20 seconds?
- Yes – 30 points
- No – 0 points
Float time:
- 1 minute: 70 points
- 45 seconds: 45 points
- 30 seconds: 30 points
- 15 seconds: 15 points

Engineering Design Challenge

Design Challenge

You are part of a team of engineers given the challenge of developing a personal flotation device (PFD) or life vest out of everyday materials that can provide enough support to float an unopened can of soup or vegetables for at least one minute.

Criteria

Device must be one attached piece
Device is able to be attached to a can or the can placed on/in it within a 20 second period
Some part of the can itself must be touching the water and get wet

Constraints

Use only the materials provided
Teams may trade unlimited materials

Activity Instructions & Procedures

Break class into teams of 2-4.
Hand out the Life Vest Challenge worksheet, as well as some sheets of paper for sketching designs.
Discuss the topics in the Background Concepts Section. Consider asking the students whether they have ever worn a life vest and if they have heard of anyone whose life was saved by using one.
Review the Engineering Design Process, Design Challenge, Criteria, Constraints and Materials.
Instruct students to start brainstorming and sketching their designs.
Provide each team with their materials.
Explain that students must design and build a personal flotation device (PFD) or life vest out of everyday materials that can provide enough support to float an unopened can of soup or vegetables for at least one minute.
Announce the amount of time they have to design and build (1 hour recommended).
Use a timer or an on-line stopwatch (count down feature) to ensure you keep on time. (www.online-stopwatch.com/full-screen-stopwatch). Give students regular “time checks” so they stay on task. If they are struggling, ask questions that will lead them to a solution quicker.
Students meet and develop a plan for their flotation device. They agree on materials they will need, write/draw their plan, and present their plan to the class. Teams may trade unlimited materials with other teams to develop their ideal parts list.
Teams build their designs. They can practice attaching the can to the device but only have one chance to test it.
Test each team’s flotation device by placing it in a tub or sink with water. The can must be attached to or placed on/in the device in no more than 20 seconds. Score the team’s results based on the following and compare each team’s total scores.
- PFD attached to can within 20 seconds?
  - Yes – 30 points
  - No – 0 points
- Float time:
  - 1 minute: 70 points
  - 45 seconds: 45 points
  - 30 seconds: 30 points
  - 15 seconds: 15 points
  - Never floats: 0 points
Teams should document whether they could attach the can to their design within 20 seconds. They should also document the amount of time the can could float.
As a class, discuss the student reflection questions.
For more content on the topic, see the “Digging Deeper” section.

Extension Activity

Have students develop a system to keep a brick afloat in water. Have students consider how new materials might improve how life vests are used and how well they save people.

Student Reflection (engineering notebook)

Were you able to design a PFD for the can that you could put on the can in 45 seconds? Was this part of the challenge harder than you thought? Why or why not?
Did you redesign your PFD after presenting your drawing to the class? Why or why not?
How similar was your final drawing to the actual PFD your team built to support the can?
If your team found it needed to make changes during the construction phase, describe why the group decided to make revisions.
Which PFD in your class worked best? What was it about that design that made it superior?
Do you think that this activity was more rewarding to do as a team, or would you have preferred to work alone on it? Why?
If you could have used one additional material (tape, glue, wood sticks, foil — as examples) which would you choose and why?
Do you think your design is scalable? Would it work efficiently if it had to float a brick or a bicycle? Why or why not?

Time Modification

The lesson can be done in as little as 1 class period for older students. However, to help students from feeling rushed and to ensure student success (especially for younger students), split the lesson into two periods giving students more time to brainstorm, test ideas and finalize their design. Conduct the testing and debrief in the next class period.

Engineering Design Process

Background Concepts

What is a Life Vest or PFD?

A personal flotation device (abbreviated as PFD; also referred to as, lifejacket, life preserver, life vest, life saver, cork jacket, buoyancy aid, flotation suit, etc.) is a device designed to help keep a person or animal afloat — whether they are conscious or not. In most of the world, lifejackets or life vests are now mandatory on airplanes that travel over water. These usually consist of a pair of air cells or bladders that can be inflated by triggering the release of carbon dioxide gas from a canister — or can be inflated by blowing into a tube with a one-way valve to seal in the air. Lifejackets are also provided on both recreational and commercial seafaring vessels — so all crew and passengers can wear one in an emergency. Not only people wear personal flotation devices; some are available for dogs and other animals to wear. Most people are familiar with the story of the Titanic, which struck an iceberg a century ago — many know there were not enough lifeboats on board to rescue all the people, but interestingly, there were enough life-jackets (see example on the right) for all the people aboard, and most everyone was wearing one. Of course, in the frigid water of the North Atlantic, the life vests alone were not enough to save many people. Simple flotation devices are used by many children learning to swim, and can be a vest or arm “bubbles.”

History and Inventors

The most ancient examples of “primitive life jackets” can be traced back to inflated bladders of animal skins or hollow, sealed gourds, for support when crossing deeper streams and rivers. Personal flotation devices were not part of the equipment issued to naval sailors up to the early 19th century, for example at the Napoleonic Battle of Trafalgar. Seamen who were press-ganged into naval service might have used such devices to jump ship and swim to freedom. It wasn’t until lifesaving services were formed that personal safety of boat crews heading out in pulling boats generally in horrific sea conditions was addressed.

Purpose-designed buoyant safety devices consisting of simple blocks of wood or cork were used by Norwegian seamen. The modern lifejacket is generally credited to one Captain Ward, a Royal National Lifeboat Institution inspector in the United Kingdom, who, in 1854, created a cork vest to be worn by lifeboat crews for both weather protection and buoyancy. The rigid cork material eventually came to be supplanted by pouches containing watertight cells filled with kapok, a vegetable material. These soft cells were much more flexible and more comfortable to wear compared with devices utilizing hard cork pieces. Kapok buoyancy was used in many navies fighting in the Second World War. Foam eventually supplanted kapok for “inherently buoyant” (vs. inflated and therefore not inherently buoyant) flotation.

The Goldfish Club

In November, 1942, During World War II, C. A. Robertson was the Chief Draftsman at the United Kingdom’s PB Cow & Co., one of the world’s largest manufacturers of air-sea rescue equipment. He formed “The Goldfish Club” after hearing of the experiences of airmen who had survived a “ditching” at sea. The club was reserved for airmen who owed their lives to their life jacket, or flotation device! By the end of World War II, the club had 9,000 members from all branches of the Allied Forces. Find out more at www.thegoldfishclub.co.uk.

Innovation in Life Jacket Design Competition

Each year, the U.S. Boat Association sponsors the “Innovation in Life Jacket Design Competition” to encourage and solicit innovative ideas to revolutionize the design of life jackets that the majority of average boaters might wear. In one of the challenges, the first place winner was the “See-Tee,” a design from Jeff Betz of the Troy, NY based FloatTech Inc. This isn’t Betz’s first life jacket innovation – his company started as the result of a graduate school project that designed the firm’s first non-traditional inflatable life jacket based on a foul weather coat. The Sea-Tee is a standard shirt that many water sports enthusiasts are used to wearing – but with a twist. It has a built-in inflatable bladder similar to most inflatable life jackets. Find out more at https://www.boatus.org/design/.

Vocabulary

Buoyant: Able to rise and float on top of a liquid
Constraints: Limitations with material, time, size of team, etc.
Criteria: Conditions that the design must satisfy like its overall size, etc.
Engineers: Inventors and problem-solvers of the world. Twenty-five major specialties are recognized in engineering (see infographic).
Engineering Design Process: Process engineers use to solve problems.
Engineering Habits of Mind (EHM): Six unique ways that engineers think.
Float: To rest on the surface of a liquid
Iteration: Test & redesign is one iteration. Repeat (multiple iterations).
PFD: Personal flotation device (i.e. life jacket) is a device designed to help keep a person or animal afloat – whether they are conscious or not
Prototype: A working model of the solution to be tested.

Dig Deeper

Internet Connections

Personal Flotation Device Manufacturers Association (www.pfdma.org)
BoatUS Foundation Life Jacket Design Competition

Recommended Reading

What Floats? What Sinks?: A Look at Density (ISBN: 978-0761360551)
Experiments with Water: Water and Buoyancy (ISBN: 978-1432923204)

Writing Activity

Write an essay or a paragraph describing how life vests have changed over the past 50 years as new technologies and materials have become available.

Curriculum Alignment

Alignment to Curriculum Frameworks

Note: Lesson plans in this series are aligned to one or more of the following sets of standards:

U.S. Science Education Standards (http://www.nap.edu/catalog.php?record_id=4962)
U.S. Next Generation Science Standards (http://www.nextgenscience.org/)
International Technology Education Association’s Standards for Technological Literacy (http://www.iteea.org/TAA/PDFs/xstnd.pdf)
U.S. National Council of Teachers of Mathematics’ Principles and Standards for School Mathematics (http://www.nctm.org/standards/content.aspx?id=16909)
U.S. Common Core State Standards for Mathematics (http://www.corestandards.org/Math)
Computer Science Teachers Association K-12 Computer Science Standards (http://csta.acm.org/Curriculum/sub/K12Standards.html)

National Science Education Standards Grades K-4 (ages 4-9)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

Abilities necessary to do scientific inquiry

CONTENT STANDARD B: Physical Science

As a result of the activities, all students should develop an understanding of

Properties of objects and materials
Position and motion of objects

CONTENT STANDARD E: Science and Technology

As a result of activities, all students should develop

Abilities of technological design
Understanding about science and technology

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

Personal health
Types of resources
Science and technology in local challenges

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

Science as a human endeavor

National Science Education Standards Grades 5-8 (ages 10-14)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

Abilities necessary to do scientific inquiry

CONTENT STANDARD B: Physical Science

As a result of their activities, all students should develop an understanding of

Properties and changes of properties in matter
Motions and forces

CONTENT STANDARD E: Science and Technology

As a result of activities in grades 5-8, all students should develop

Abilities of technological design
Understandings about science and technology

National Science Education Standards Grades 5-8 (ages 10-14)

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

Risks and benefits
Science and technology in society

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

Science as a human endeavor
History of science

National Science Education Standards Grades 9-12 (ages 14-18)

CONTENT STANDARD A: Science as Inquiry

As a result of activities, all students should develop

Abilities necessary to do scientific inquiry

CONTENT STANDARD B: Physical Science

As a result of their activities, all students should develop understanding of

Motions and forces
Interactions of energy and matter

CONTENT STANDARD E: Science and Technology

As a result of activities, all students should develop

Abilities of technological design
Understandings about science and technology

CONTENT STANDARD F: Science in Personal and Social Perspectives

As a result of activities, all students should develop understanding of

Personal and community health
Natural and human-induced hazards
Science and technology in local, national, and global challenges

CONTENT STANDARD G: History and Nature of Science

As a result of activities, all students should develop understanding of

Science as a human endeavor
Historical perspectives

Next Generation Science Standards Grades 2-5 (Ages 7-11)

Matter and its Interactions

2-PS1-2. Analyze data obtained from testing different materials to determine which materials have the properties that are best suited for an intended purpose.

Motion and Stability: Forces and Interactions

Students who demonstrate understanding can:

3-PS2-1. Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.

Next Generation Science Standards Grades 2-5 (Ages 7-11)

Engineering Design

Students who demonstrate understanding can:

3-5-ETS1-1.Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
3-5-ETS1-2.Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
3-5-ETS1-3.Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.

Next Generation Science Standards Grades 6-8 (Ages 11-14)

Engineering Design

Students who demonstrate understanding can:

MS-ETS1-1 Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
MS-ETS1-2 Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

Next Generation Science Standards Grades 9-12 (Ages 14-18)

Engineering Design

Students who demonstrate understanding can:

HS-ETS1-2.Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.

Standards for Technological Literacy – All Ages

The Nature of Technology

Standard 1: Students will develop an understanding of the characteristics and scope of technology.
Standard 3: Students will develop an understanding of the relationships among technologies and the connections between technology and other fields of study.

Technology and Society

Standard 4: Students will develop an understanding of the cultural, social, economic, and political effects of technology.
Standard 6: Students will develop an understanding of the role of society in the development and use of technology.
Standard 6: Students will develop an understanding of the role of society in the development and use of technology.

Standards for Technological Literacy – All Ages

Design

Standard 8: Students will develop an understanding of the attributes of design.
Standard 9: Students will develop an understanding of engineering design.
Standard 10: Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving.

Abilities for a Technological World

Standard 11: Students will develop abilities to apply the design process.
Standard 13: Students will develop abilities to assess the impact of products and systems

Student Worksheet

Engineering Teamwork and Planning

You are part of a team of engineers given the challenge of developing a personal floatation device (PFD) or life vest out of everyday materials that can provide enough support to float an unopened can of soup or vegetables for at least one minute. There are some rules:

The device must be in one attached piece and able to be affixed to the can within a 20 second period
Some part of the can itself must be touching the water.

Research Phase

Read the materials provided to you by your teacher. If you have a life jacket or vest at home take a look at the design and consider the materials used in manufacture. Also consider all the materials provided by your teacher and how they might be used to create a system that can be quickly attached to the can — in 20 seconds.

Planning and Design Phase

Draw a diagram of the PFD you will build for the can…be sure to make a list of all the materials you will need for the construction phase.

Materials you will need:

Presentation Phase

Present your plan and drawing to the class, and consider the plans of other teams. You may wish to fine tune your own design.

Build it!
Next build your PFD. You can practice putting it on and taking it off the can so you are within the 20 second limit, but you’ll only have one chance to test it — under the supervision of your teacher. During the building phase, you may share unused building materials with other teams — and trade materials too. Be sure to watch what other teams are doing and consider the aspects of different designs that might be an improvement on your team’s plan.

Test it!
You’ll test your PFD along with other student teams and earn points in the grid below.

PFD on can within 20 seconds?
Yes 30 points
No 0 points

Float time:

1 minute: 70 points
45 seconds: 45 points
30 seconds: 30 points
15 seconds: 15 points
Never floats: 0 points

Total Score?

Reflection

Complete the reflection questions below:

Were you able to design a PFD for the can that you could put on the can in 45 seconds? Was this part of the challenge harder than you thought? Why or why not?