Submarine pressure investigation

Lesson overview

The operating depth limit for the submersibles used on the XL Catlin Deep Ocean Survey was 1,000 feet. To put this in context, recreational scuba diving has a limit of 130 feet, but the deepest point in the ocean is an astounding 36,070 feet down.

In this lesson, students investigate the effects of pressure increasing with depth, and the implications that this has for submarine design. Get the design wrong and the submarine will implode.

Learning outcomes

  • Describe the dangers of exploring a depth (foundation)
  • Explain why pressure increases with depth (developing)
  • Design and carry out a fair test to investigate the effects of increasing depth (competent)
  • Calculate the amount of pressure caused at different depths (experts) Explain, in terms of forces, why submarines have a safe limit to which they can dive (advanced)

Lesson steps

  1. Brief (15 mins)
    Students are introduced to the concept of pressure at depth through a demonstration. The context of designing an investigation into the effects of pressure on submersibles is introduced. Students set themselves targets based on the learning criteria of the lesson.

  2. Investigation (30 mins)
    Students follow the investigation brief to try to design and carry out an investigation into the effects of pressure at depth on a submarine’s hull. Students are encouraged to adapt and design their plan through practical trials.

  3. Pressure calculations (15 mins)
    Using the slides, students learn how to calculate pressure at depth, and the importance of the submersible’s structure supporting the forces of the water. Students calculate pressure at depth for various contexts, and predict if a submersible will be able to safely dive to a given depth.

  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 to the context of the Scheme of Work.