Lesson overview

The submarines used for the XL Catlin Deep Ocean Survey were in the strictest sense submersibles. A distinction is made between true submarines that operate independently and submersibles which require the support of a surface vessel. In this lesson, students develop an understanding of structural strength and stability. They will then design and build a model crane suitable for lifting and moving a weight. This activity replicates the science involved in launching and recovering a submersible using a surface vessel.

Learning outcomes

• Describe how to produce a strong and stable structure (foundation)
• Describe the purpose of each part of a crane’s structure (developing)
• Construct a working model of a crane (competent)
• Calculate the moments of some given examples (expert)
• Explain the importance of launching and raising the submarine from the back of a ship, rather than the side (advanced)

Lesson steps

1. Brief (5 mins)
   Students are introduced to the concept of structures, and how structures are designed and built for strength by looking at the similarities between various structures. The context of designing and building a crane to launch and recover a submersible vehicle at sea is introduced. Students set themselves targets based on the learning criteria of the lesson.
2. Cranes (40 mins)
   Students follow the investigation brief to try to design and build a crane suitable for lifting and placing a mass. Students are encouraged to adapt their designs, and make changes as they go.
3. Calculate moments (10 mins)
   Using the slides, students learn how to calculate moments, and the safety considerations when launching and recovering a submersible vehicle. Students calculate various moments due to lifting a submersible vehicle at sea, and determine if they will result in a surface vessel tipping. Teacher may well wish to dedicate more time to the design and build task.
4. Self-reflection (5 mins)
   Students decide if they have met their targets set at the beginning of the lesson, and reflect on the lesson’s importance in the context of the Scheme of Work to design a submarine.

England

Key Stage 3 Physics

• Energy: energy changes and transfers, changes in systems
• Forces: as pushes or pulls
• Forces: using force arrows in diagrams, adding forces in one dimension, balanced and unbalanced forces
• Forces: gravity
• Forces: measured in newtons
• Forces: moment as the turning effect of a force
• Forces and motion: cause objects to stop or start moving, or to change their speed or direction

Key Stage 3 Working scientifically

• Scientific attitudes
• Experimental skills and investigations
• Analysis and evaluation

USA

NGSS Grades 5-8

• Motion and Stability: Forces and Interactions
  5-PS2-1. Support an argument that the gravitational force exerted by Earth on objects is directed down.
  MS-PS2-2. Plan an investigation to provide evidence that the change in an object’s motion depends on the sum of the forces on the object and the mass of the object.
• Engineering Design
  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.
  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.
  MS-ETS1-3. Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
• Science and Engineering Practices
  Asking questions
  Developing and using models
  Planning and carrying out investigations
  Analyzing and interpreting data
  Using mathematics
  Constructing explanations
  Engaging in argument from evidence
  Obtaining, evaluating and communicating information