LNG Carrier Tank Types Quiz

LNG carriers can be categorized based on the technology used to contain the liquefied natural gas.

Moss and Membrane are two primary types of LNG containment systems.

Type A tanks are modified LPG (Liquefied Petroleum Gas) containment systems adapted for LNG. They are independent, self-supporting, prismatic tanks made of aluminum.

The self-supporting design of Type A tanks allows for flexibility in filling levels, eliminating sloshing issues and optimizing volume utilization.

Type A tanks use low-density foam insulation for better thermal performance, minimizing boil-off rates.

Moss tanks are spherical, self-supporting tanks typically made of 9% Nickel steel. They are known for their high capacity and low boil-off rates.

Membrane tanks utilize flexible membranes to contain the LNG. They are lighter and offer better volume utilization compared to Moss tanks, but require more maintenance.

Membrane tanks are known for their flexibility and versatility in tank design, allowing for customization to meet specific cargo requirements.

A type of LNG tank system where the membrane is not self-supporting and relies on insulation layers for support.

An alloy with a very low thermal expansion coefficient and low thermal conductivity, making it suitable for LNG tank membranes.

The thin, flexible material that directly contains the LNG in a membrane-type LNG tank.

The layer of material that surrounds the membrane in an LNG tank, providing insulation and support.

A type of LNG tank system with a primary panel made of stainless steel membrane with grooved ribs and a secondary panel composed of composite material.

A restriction for LNG loading in membrane tanks, limiting the liquid level to between 10% and 70% to prevent sloshing and ensure ship stability.

The movement of liquid cargo within a tank due to the ship's motion.

The ability of a ship to maintain equilibrium and avoid capsizing.

A type of LNG containment system that is pressure-resistant, self-supported, and made of low-temperature resistant materials. It is commonly used on smaller and medium-sized LNG carriers.

C-type tanks are widely used on smaller and medium-sized LNG carriers because they are less expensive to build than other containment systems.

C-type tanks are designed to meet pressure vessel standards and are built with low-temperature resistant materials.

C-type tanks can be either cylindrical or spherical and have limited internal structure. They are generally covered with insulating materials to minimize heat transfer and reduce boil-off.

The largest C-type LNG carrier in the world was built in China and has a capacity of 30,000 cubic meters.

LNG carriers use their cargo as fuel, which is referred to as Boil Off Gas (BOG).

LNG propulsion technology has evolved with the development of the LNG carrier fleet and trade routes.

Low-pressure, two-stroke, dual-fuel engines are the preferred choice for both LNG carriers and LNG-fueled vessels.

MAN Energy Solutions (ME-GI/ME-GA) and WinGD (owned by Wärtsilä) (X-DF) are the dominant manufacturers of dual-fuel engines in the LNG propulsion market.

The use of Boil Off Gas (BOG) for fuel in LNG carriers is an example of how the industry is striving for sustainability and reducing emissions.

Membrane tanks can be shaped to perfectly fit the hull of the ship, maximizing the amount of cargo they can carry.

Membrane tanks utilize the space within the ship's hull more effectively, unlike spherical tanks that take up more room.

Membrane tanks have a thin layer of material and insulation, making them lightweight compared to other tank options, potentially improving fuel efficiency.

The membrane can withstand significant thermal contractions (shrinking) when the LNG is cooled to cryogenic temperatures.

Designs like the TGZ MARK III have a 'waffle pattern' to absorb thermal contractions, preventing damage to the tank.

The ability of the membrane to absorb thermal contractions safely and efficiently is crucial for the longevity of the tank.

Continuous leak detection is essential for membrane tanks. The GT96 design has a double membrane with nitrogen flushing to detect leaks between them.

Regular inspection and maintenance are essential to ensure the integrity and safety of the membrane tank system.

A brief amount of LNG remaining in the tanks after a voyage. It acts as fuel and keeps the tanks cold for the next load.

A term used to describe the process of preparing LNG tanks for dry dock or initial loading. This involves cleaning, purging, and pressurizing the tanks.

A measurement of the actual cargo volume that can be carried by an LNG carrier, often expressed as cubic meters (CBM) or tonnes (T).

A key factor in LNG carrier performance, referring to the rate at which LNG evaporates during storage and transportation. A lower boil-off rate is more efficient.

A type of LNG carrier that is optimized for fuel efficiency. This refers to the engine type used, usually a slow-speed, two-stroke engine.

The process of loading LNG into the carrier's tanks. This is a specialized operation requiring careful procedures to ensure safe and efficient loading.

A voyage where an LNG carrier travels with its cargo tanks fully loaded.

A voyage where an LNG carrier travels with its cargo tanks mostly empty, with a small quantity of LNG remaining for fuel and tank conditioning.