What is the IGC Code? Role, Key Aspects, and Compliance

The International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) establishes an international standard for the safe carriage of liquefied gases. IGC Code ensures that the transport of hazardous gases like LNG and LPG follows strict safety guidelines.

The Role of the IGC Code

The IGC Code governs the design and construction of gas carriers to minimize risks from flammable, toxic, or reactive substances. It helps safeguard ships, crews, and the environment. Gas carriers, such as those used by the top LNG shipping companies, adhere to the IGC Code to ensure safe and compliant operations.

Gas carriers are specialized tankers designed to transport liquefied gases in bulk. According to the International Maritime Organization (IMO), liquefied gases are defined as products with a vapor pressure exceeding 2.8 bar absolute at 37.80°C. Gas carriers are built and maintained following the IMO’s Gas Codes, including the IGC Code, and the American Bureau of Shipping (ABS) Rules incorporate this code.

Key Objectives of the IGC Code

The IGC Code aims to:

1. Ensure Safety: It defines safety requirements for the transport of hazardous liquefied gases.
2. Protect the Environment: It reduces risks related to the accidental release of dangerous gases.
3. Establish International Standards: It ensures consistent design and equipment standards for gas carriers across the maritime industry.

IGC Code Content and Application

The IGC Code became mandatory under the SOLAS Convention on 1 July 1986. The maritime industry acknowledged the rapid advancements in gas carrier design technology and recognized that the code should evolve alongside these changes. As a result, the IGC Code has undergone several updates, including:

1. Major Update on 1 January 2016: Under IMO Resolution MSC.370(93), the code was extensively revised to reflect new safety and design standards.
2. Fire Integrity Arrangements: Adopted in November 2016 and effective as of 1 January 2020, these updates introduced new fire-rating requirements for windows on gas carriers.
3. Certificate of Fitness: A revised model form of certification, known as the Certificate of Fitness, was adopted in May 2018 and entered into force on 1 January 2020.
4. Upcoming Amendments (1 July 2024): New requirements for watertight doors on gas carriers are expected to come into force.

Ships Required to Comply with the IGC Code

All gas carriers built after 1 July 1986 must comply with the IGC Code. Older vessels must be retrofitted to meet the requirements. This includes LNG carriers, LPG carriers, and ethylene/ammonia carriers.

For more information on the differences between these gases, check out the article on LNG vs. LPG: A Comprehensive Guide.

Key Aspects Covered by the IGC Code

1. Ship Design and Structure:
   • The code outlines the structural requirements for gas carriers, ensuring the hull and tanks can withstand the high pressures and low temperatures associated with liquefied gases.
2. Cargo Containment Systems:
   • The IGC Code categorizes tanks into Type A, Type B, and Type C, depending on their insulation and design capabilities, to ensure proper containment of different gas types.
3. Equipment and Safety Systems:
   • Ships must be equipped with specialized ventilation, gas detection systems, and firefighting equipment. These systems ensure that any leaks or fires are quickly detected and managed.
4. Operational Procedures:
   • The code defines strict operational safety procedures for loading, unloading, and emergency situations, along with mandatory crew training to minimize risk.

Liquefied Gases Governed by the IGC Code

The IGC Code governs the transport of various liquefied gases that are potentially hazardous. These gases include:

• Liquefied Natural Gas (LNG):
  • Liquefaction Temperature: −162°C
  • Transport Method: Refrigerated
  • Description: Methane, transported in bulk at cryogenic temperatures.
• Liquefied Petroleum Gas (LPG):
  • Liquefaction Temperature: -42°C
  • Transport Method: Refrigerated, pressurized, or semi-pressurized
  • Description: Includes propane and butane, commonly used as fuel.
• Propane:
  • Liquefaction Temperature: −42°C
  • Transport Method: Pressurized or semi-pressurized
  • Description: Widely used in heating, cooking, and industrial processes.
• Butane:
  • Liquefaction Temperature: −0.5°C
  • Transport Method: Pressurized or semi-pressurized
  • Description: Utilized in fuel and as a feedstock in the petrochemical industry.
• Normal Butane (n-Butane):
  • Liquefaction Temperature: −0.5°C
  • Transport Method: Semi-pressurized or pressurized
  • Description: A form of butane used as a fuel and refrigerant.
• Isobutane:
  • Liquefaction Temperature: −12°C
  • Transport Method: Pressurized or semi-pressurized
  • Description: Used in refrigeration and fuel applications.
• Ethylene:
  • Liquefaction Temperature: −104°C
  • Transport Method: Refrigerated
  • Description: A flammable gas used in the production of plastics and chemicals.
• Ethane:
  • Liquefaction Temperature: −89°C
  • Transport Method: Refrigerated or semi-pressurized
  • Description: Often used as a petrochemical feedstock for ethylene production.
• Ammonia:
  • Liquefaction Temperature: −33°C
  • Transport Method: Pressurized or semi-pressurized
  • Description: A toxic gas mainly used in fertilizers and industrial processes.

These gases are transported in bulk using specially designed gas carriers that comply with the IGC Code, ensuring safety through methods such as refrigeration, pressurization, or semi-pressurization depending on the specific gas.

How Classification Societies Implement the Rules and Requirements of the IGC Code

Classification societies play a crucial role in ensuring that the design, construction, and operation of ships comply with the International Gas Carrier (IGC) Code. These societies develop and implement safety standards and conduct inspections, surveys, and certifications to ensure ships adhere to the IGC Code.

Here are the key ways classification societies implement the IGC Code:

1. Design Approval

Classification societies review and approve the ship’s design to ensure it meets the structural and equipment requirements of the IGC Code. This process includes evaluating:

• Hull strength: Ensuring the ship’s hull can withstand the stresses of carrying liquefied gases.
• Containment systems: Verifying that tanks (Type A, B, or C) are suitable for the specific gas types being transported.
• Ventilation, gas detection, and firefighting systems: Ensuring proper safety systems are in place.

2. Construction Supervision

During the shipbuilding process, classification societies monitor the construction to ensure it complies with the approved design and the IGC Code requirements. This includes:

• Supervising the construction of cargo tanks.
• Ensuring the installation of safety and monitoring equipment.
• Overseeing material selection for components exposed to low temperatures or high pressure.

3. Certification

Once the construction is complete, classification societies issue a Certificate of Fitness under the IGC Code. This certificate confirms that the vessel complies with all the IGC Code’s rules. It is mandatory for a gas carrier to hold this certification before it can operate.

The certification includes:

• Initial inspection: A comprehensive survey of the ship’s systems, safety measures, and equipment.
• Issuance of the Certificate of Fitness: This document certifies that the ship meets all IGC Code requirements.

4. Ongoing Surveys and Inspections

Classification societies perform regular surveys and inspections to ensure continued compliance with the IGC Code throughout the ship’s operational life. These surveys are categorized as:

• Annual surveys: Checking critical systems and safety equipment.
• Intermediate surveys: More detailed inspections of the ship’s structural integrity and safety measures.
• Renewal surveys: Conducted every five years, assessing the ship’s overall condition and revalidating its Certificate of Fitness.

5. Amendment Compliance

When the IGC Code is updated or amended, classification societies ensure ships comply with the new requirements. This includes:

• Modifying existing ships to meet updated structural or safety requirements.
• Issuing new certificates reflecting compliance with the latest standards.

6. Crew Training and Operational Procedures

Classification societies verify that gas carriers have trained crews who are knowledgeable about the IGC Code’s safety protocols. They also ensure the ship has proper operational procedures for loading, unloading, and emergency situations.

Through these processes, classification societies ensure that gas carriers maintain high safety standards in line with the IGC Code.

Class Rules, Regulations, and Notations for Implementing the IGC Code

Classification societies play a vital role in ensuring that gas carriers meet the safety and operational requirements of the International Gas Carrier (IGC) Code. They establish and enforce rules, regulations, and notations to guarantee that ships carrying liquefied gases in bulk adhere to the highest safety standards.

Class Rules and Regulations

Classification societies incorporate the IGC Code into their rules for the design, construction, and operation of gas carriers. They provide guidance on the structural integrity, containment systems, and safety equipment required for transporting hazardous gases like LNG, LPG, ethylene, and ammonia. The rules also cover the ongoing maintenance and inspection of gas carriers.

• Lloyd’s Register (LR): LR’s Rules and Regulations for the Classification of Ships include specific requirements for liquefied gas carriers under Part 4, Chapter 5. This section ensures compliance with the IGC Code for structural safety, containment systems, and firefighting measures.
• American Bureau of Shipping (ABS): ABS integrates the IGC Code into its Rules for Building and Classing Marine Vessels, particularly in Part 5C, Chapter 8. These rules govern the design, safety systems, and operational procedures of gas carriers.
• DNV (Det Norske Veritas): DNV’s Rules for Classification of Ships under Part 5, Chapter 7 apply to liquefied gas tankers and ensure compliance with the IGC Code’s structural and safety regulations.

Certification and Surveys

Once gas carriers are constructed, classification societies perform initial inspections to verify compliance with the IGC Code and issue a Certificate of Fitness. This certificate confirms that the vessel is equipped to safely transport liquefied gases in bulk.

Classification societies also conduct annual, intermediate, and renewal surveys to ensure ongoing compliance with the IGC Code and to inspect the condition of safety systems, containment tanks, and firefighting equipment.

Class Notations

Class notations are designations provided by classification societies that confirm a vessel complies with specific rules, including the IGC Code. These notations indicate that the ship meets all safety, design, and operational requirements for carrying liquefied gases.

• Lloyd’s Register (LR):
  • GAS CHEM: For ships constructed to carry liquefied gases or chemicals in bulk.
  • GAS CARRIER: The main notation for vessels transporting liquefied gases, ensuring IGC compliance.
  • IGC: Denotes full compliance with the IGC Code.
• American Bureau of Shipping (ABS):
  • ✠A1 Liquefied Gas Carrier: Indicates that the vessel meets ABS’s construction and safety standards in line with the IGC Code.
  • IGC: Confirms compliance with the IGC Code for liquefied gas transport.
  • SH-DLA: Signifies that the ship meets special design standards for transporting liquid ammonia under the IGC Code.
• DNV (Det Norske Veritas):
  • GAS READY: For ships designed or prepared to operate as gas carriers or to use gas as fuel, complying with IGC Code standards.
  • GAS CARRIER – IGC: Denotes that the ship is certified to carry liquefied gases in bulk and meets all IGC Code requirements.
  • Tanker for Liquefied Gas: Confirms compliance with the gas carrier standards, including the IGC Code.

By adhering to these rules, regulations, and notations, classification societies ensure that gas carriers operate safely, are properly equipped, and meet international safety standards for transporting liquefied gases in bulk.

IGC Code in The Ships Library

All gas carriers transporting liquefied gases in bulk must have the IGC Code available in their onboard library. This includes ships that handle products with flammable, toxic, or reactive properties, as defined by the International Maritime Organization (IMO). The IGC Code applies to ships constructed after 1 July 1986 and any gas carrier modified to comply with these safety standards.

Types of Ships Required to Have the IGC Code

1. Liquefied Natural Gas (LNG) Carriers

• Trade: LNG carriers transport liquefied natural gas, which is primarily used for energy generation and industrial applications. These vessels often engage in long-haul international routes between major LNG export hubs (e.g., Qatar, Australia, the United States) and import terminals in regions like Europe and Asia.
• Typical Sizes: LNG carriers range from 125,000 m³ to 266,000 m³ in capacity. The Q-Max vessels, the largest LNG carriers, have capacities up to 266,000 m³.
• Tank Construction: LNG is transported at cryogenic temperatures of -162°C, and tanks are typically built using materials like nickel steel to withstand extremely low temperatures. LNG tanks are often membrane-type or Moss-type spherical tanks, designed for efficient storage and insulation to maintain the low temperature during transit.

2. Liquefied Petroleum Gas (LPG) Carriers

• Trade: LPG carriers transport propane, butane, and other hydrocarbons. They are often used in energy trading, as well as in the petrochemical industry. These vessels operate on both long-haul routes, such as from the Middle East to Asia and Europe, and shorter regional routes.
• Typical Sizes: LPG carriers come in a variety of sizes:
  • Very Large Gas Carriers (VLGCs): >80,000 m³
  • Large Gas Carriers (LGCs): 40,000–80,000 m³
  • Medium Gas Carriers (MGCs): 20,000–40,000 m³
  • Small Gas Carriers: up to 20,000 m³.
• Tank Construction: LPG tanks are either fully pressurized or semi-pressurized and typically constructed using steel capable of withstanding high pressures. Most LPG ships use Type C tanks, which are self-supporting, insulated tanks designed for pressurized transport at around -42°C.

3. Ethylene and Ammonia Carriers

• Trade: Ethylene and ammonia carriers specialize in transporting highly reactive and hazardous gases like ethylene, used in the plastics industry, and ammonia, primarily used in fertilizers and industrial processes. These ships often serve specific niche trades between chemical hubs in Europe, the Gulf of Mexico, and Asia.
• Typical Sizes: Ethylene and ammonia carriers typically have capacities ranging from 5,000 to 15,000 m³, with some larger vessels capable of transporting up to 25,000 m³.
• Tank Construction: These vessels use fully refrigerated tanks to maintain cargo at low temperatures (ethylene: -104°C, ammonia: -33°C). The tanks are often Type C pressurized tanks, made from materials that resist the corrosive nature of ammonia and maintain the low temperatures required for ethylene.

4. Ships with Mixed Cargo

• Trade: These vessels are designed to carry a combination of different liquefied gases, such as LPG, ethylene, and ammonia, allowing for flexible operations across different trades. They serve routes where multiple types of cargo are shipped together, often transporting various products from chemical hubs to regional distribution centers.
• Typical Sizes: Mixed cargo carriers range from 10,000 to 40,000 m³ in capacity, allowing them to accommodate different products in separate tanks on the same voyage.
• Tank Construction: The tanks in these vessels are usually segregated, with each tank designed to meet the specific containment requirements of the gas it carries. Depending on the cargo, tanks may be semi-pressurized or fully pressurized, and are typically made from nickel steel or other corrosion-resistant materials to handle the wide variety of chemicals being transported.

How to Obtain the IGC Code?

There are several ways to acquire the IGC Code:

1. IMO Publications Website:
   • The International Maritime Organization (IMO) sells official publications, including the IGC Code. It can be purchased directly from the IMO Bookshop or authorized distributors.
2. Maritime Bookstores:
   • Many specialized maritime bookstores and online retailers offer the IGC Code, both in printed and digital formats. You can also try to get a good deal on Amazon.
3. Subscription Services:
   • Some maritime safety organizations provide access to IMO codes, including the IGC Code, through subscription-based platforms. These platforms often include the latest amendments and updates.

By ensuring access to the IGC Code, gas carriers can stay compliant with the safety regulations and operational standards required for transporting hazardous liquefied gases.