How Seawater Sabotages Ships: Crash Course Engineering #43

TL;DR

Marine engineering involves designing and building ships and structures that can withstand the challenges of the ocean, including waves, corrosion, and marine life.

Transcript

If you’ve ever bought a new phone, a t-shirt or, well, basically anything, it’s probably come a long way – maybe even from a different continent! That’s possible almost entirely because of shipping – as in the kind with actual ships. Shipping is responsible for supporting 90% of global trade, from the latest toys to life-saving medicine. As the wo... Read More

Key Insights

• 📦 Shipping plays a vital role in global trade, supporting 90% of it, and marine engineering is essential for designing ships capable of safely transporting goods.
• 🧡 Marine engineers work on various structures, including ships, offshore oil rigs, and wind farms, requiring a broad range of engineering knowledge.
• 🤬 Challenges in marine engineering include designing watertight structures, creating efficient propellers that avoid cavitation, combating corrosion caused by contact with water, and addressing fouling from marine life.
• 💦 Solutions to these challenges include conducting tests and using ultrasound detection to locate and fix water leakage, designing propellers to reduce cavitation, using sacrificial anodes and weak currents to prevent corrosion, and implementing coatings to prevent fouling.
• 🚀 Construction of ships often requires innovative methods such as using dry docks or shipways to build and launch ships into the water.
• 📦 The field of marine engineering will continue to grow as the demand for shipping increases, necessitating the construction of more ships and structures.

Questions & Answers

Q: What are some of the challenges faced by marine engineers in designing and building ships?

Marine engineers have to tackle issues such as water leakage, creating watertight structures, designing efficient propellers that avoid cavitation, preventing corrosion, and dealing with fouling caused by marine life.

Q: How do marine engineers address water leakage in submarines?

Marine engineers subject submarine hatches to tests, such as high-pressure spraying and ultrasound detection, to locate and fix any small gaps that might allow water to enter the submarine.

Q: What is cavitation, and how does it affect ship propellers?

Cavitation occurs when the pressure difference on either side of rotating ship propeller blades creates tiny steam bubbles. When these bubbles collapse, they create a shockwave that can seriously damage and warp the blades, reducing their efficiency.

Q: How do marine engineers prevent corrosion on ships?

Marine engineers use sacrificial anodes, typically made of zinc, to divert corrosion away from the structural hull. They may also apply a weak current through the hull to cancel out the corrosion caused by saltwater.

Summary & Key Takeaways

• Shipping supports 90% of global trade, and marine engineering plays a crucial role in designing vessels capable of safely navigating the ocean.

• Marine engineers need a broad knowledge of mechanical, electrical, and civil engineering to work on ships, offshore oil rigs, wind farms, and other structures.

• Challenges in marine engineering include dealing with water leakage, designing efficient propellers, preventing corrosion, and combating fouling caused by marine life.