The GPO Amethyst Cargo Ship (Full Episode) | Superstructures: Engineering Marvels | Nat Geo

The GPO Amethyst Cargo Ship (Full Episode) | Superstructures: Engineering Marvels | Nat Geo

GPO Amethyst: A Semi-Submersible Heavy Lifter

The GPO Amethyst is one of the largest ships in the world, capable of carrying enormous sea cargos by partially submerging itself in water. With a deck spanning 600 feet long and 158 feet wide, the ship can accommodate massive oil rigs, solving the problem of transporting heavy and unwieldy cargo across the globe.

Design and Engineering

The Amethyst’s exceptional design and engineering allow it to lift and transport weights of up to 50,000 tons. The deck is only an inch thick but features a lattice structure underneath, comprised of I-beam-shaped steel beams that provide stiffness and prevent distortion. This design allows the ship to maintain its buoyancy while supporting immense loads.

Propulsion System

The Amethyst is equipped with four massive diesel engines, each producing 9,600 horsepower, which is equivalent to 12 Ferrari V12 engines. The engines drive electric generators that power electric motors at the stern, which directly drive the 18-foot-tall propellers. The propellers have a unique mechanism that allows the blades to swivel and change pitch, enabling the ship to move efficiently in various conditions.

Operation and Challenges

The crew of the Amethyst faces challenges from both the massive cargo and harsh weather conditions. The ship’s high-tech propellers can switch to reverse thrust, using 8,000 kilowatts to force water backwards and stop the ship in 500 yards. However, stopping the ship is a challenging task due to its huge momentum, and it requires a significant force in the opposite direction to bring it to a stop.

Loading Oil Rigs

The crew prepares to load two massive oil rigs onto the ship’s deck, but they face a crisis when they discover the rigs are sitting lower in the water than expected. The Amethyst is a semi-submersible ship that will load the rigs by deliberately submerging its deck beneath them and then refloating to lift them out of the water.

Submerging and Lifting

The crew begins the complex process of submerging the ship to load a massive 13,500-ton oil rig. As the ship’s hull sinks 30 feet into the water, it becomes vulnerable to instability and the risk of sinking. The crew must carefully calculate the ballast tanks to maintain positive stability, and the ship’s water plane area is crucial in preventing it from plunging further into the ocean.

Conclusion

The Amethyst successfully loads two massive oil rigs and sets sail on its long journey to Oman, showcasing its capabilities as one of the world’s most advanced heavy-lift ships. With its powerful engine system, advanced maneuvering systems, and sophisticated computer system, the Amethyst is a vital solution for industries like oil and gas, capable of transporting heavy and unwieldy cargo across the globe.



Term Definition Example Usage
Semi-Submersible A type of ship that can partially submerge itself in water to load or unload cargo. The GPO Amethyst is a semi-submersible heavy lifter, capable of carrying enormous sea cargos by partially submerging itself in water.
Buoyancy The ability of an object to float or rise in a fluid, such as water or air. The Amethyst’s design allows it to maintain its buoyancy while supporting immense loads, thanks to its lattice structure underneath the deck.
Lattice Structure A type of structure composed of intersecting beams or bars, often used to provide strength and stability. The Amethyst’s deck features a lattice structure underneath, comprised of I-beam-shaped steel beams that provide stiffness and prevent distortion.
Ballast Tanks Compartments on a ship that can be filled with water or air to control its stability and buoyancy. The crew must carefully calculate the ballast tanks to maintain positive stability as the ship submerges to load the oil rig.
Propulsion System A system used to generate power and propel a ship through the water. The Amethyst is equipped with a propulsion system that includes four massive diesel engines, electric generators, and electric motors that drive the propellers.
Stability The ability of a ship to resist capsizing or sinking, often affected by its design, cargo, and environmental conditions. The Amethyst’s stability is crucial as it submerges to load the oil rig, and the crew must carefully calculate the ballast tanks to maintain positive stability.
Maneuvering Systems Systems used to control the movement and direction of a ship, including propulsion, steering, and braking. The Amethyst’s maneuvering systems, including its propellers and propulsion system, allow it to move efficiently in various conditions and stop quickly when needed.
Submergence The act of sinking or diving below the surface of the water. The Amethyst submerges its deck 30 feet into the water to load the massive oil rig, becoming vulnerable to instability and the risk of sinking.
Heavy-Lift Ship A type of ship designed to carry extremely heavy or large cargo, often used in industries such as oil and gas. The GPO Amethyst is one of the world’s most advanced heavy-lift ships, capable of transporting heavy and unwieldy cargo across the globe.
Positive Stability A condition in which a ship is stable and resistant to capsizing, often achieved through careful design and operation. The crew must maintain positive stability as the Amethyst submerges to load the oil rig, to prevent the ship from sinking or becoming unstable.




GPO Amethyst Vocabulary Quiz

Test your knowledge of the GPO Amethyst with this 5-question multiple-choice quiz.

Question 1: What does “buoyancy” mean in the context of the GPO Amethyst?

A) The ability of the ship to change direction quickly B) The ability of the ship to float in the water C) The ability of the ship to carry heavy loads D) The ability of the ship to move at high speeds

Question 2: What is the term for the process of deliberately submerging the ship’s deck to load cargo?

A) Ballasting B) Submerging C) Refloating D) Semi-submersing

Question 3: What is the purpose of the “lattice structure” underneath the ship’s deck?

A) To provide additional storage space B) To reduce the weight of the ship C) To increase the ship’s speed D) To provide stiffness and prevent distortion

Question 4: What is the term for the amount of energy required to stop the ship?

A) Momentum B) Thrust C) Horsepower D) Kilowatts

Question 5: What is the term for the ship’s ability to maintain its stability while carrying heavy loads?

A) Positive stability B) Negative stability C) Neutral stability D) Dynamic stability

Answer Key:

1. B) The ability of the ship to float in the water 2. D) Semi-submersing 3. D) To provide stiffness and prevent distortion 4. A) Momentum 5. A) Positive stability



Modal Verbs for Ability and Capacity


Modal verbs such as “can”, “could”, and “be able to” are used to express ability and capacity. In the context of the GPO Amethyst, we see examples of these verbs being used to describe the ship’s capabilities, such as “capable of carrying enormous sea cargos” and “allow it to lift and transport weights of up to 50,000 tons”. The verb “can” is used to describe the ship’s ability to accommodate massive oil rigs, while “be able to” is used to describe its ability to maintain its buoyancy while supporting immense loads.
Now, let’s test your understanding of modal verbs for ability and capacity with the following quiz: 1. The GPO Amethyst ____________________ carry enormous sea cargos by partially submerging itself in water. A) can B) may C) could D) shall 2. The Amethyst’s exceptional design and engineering ____________________ it to lift and transport weights of up to 50,000 tons. A) allows B) enable C) can D) be able to 3. The ship’s high-tech propellers ____________________ switch to reverse thrust, using 8,000 kilowatts to force water backwards and stop the ship. A) can B) may C) could D) might 4. The crew of the Amethyst ____________________ load two massive oil rigs onto the ship’s deck, but they face a crisis when they discover the rigs are sitting lower in the water than expected. A) is able to B) can C) could D) may 5. The Amethyst ____________________ maintain its buoyancy while supporting immense loads due to its lattice structure underneath the deck. A) can B) is able to C) could D) may Answer Key: 1. A) can 2. A) allows 3. A) can 4. A) is able to 5. B) is able to