MARPOL 73/78 CONVENTION: LATEST UPDATES

The International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978, more commonly referred to as MARPOL 73/78, is the primary international agreement developed by the International Maritime Organization to prevent pollution of the marine environment from ships. Adopted in response to growing concern over oil spills and vessel discharges in the 1970s, it has since evolved into a comprehensive framework that addresses multiple forms of ship-source pollution. Together with SOLAS, MARPOL is regarded as one of the twin pillars of international maritime law, protecting both human life and the natural environment. MARPOL applies to all ships, though its requirements vary depending on size, type, and operation. Compliance is ensured through certification by flag states, enforcement by port state control, and the application of special provisions for designated “special areas” and “emission control areas” where stricter rules apply. Over the years, the Convention has grown through six technical annexes, each dedicated to a specific category of pollution. These annexes are the foundation of MARPOL and remain central to its implementation. Annex I addresses the prevention of pollution by oil. It includes requirements for double-hulled oil tankers, oil discharge monitoring and control systems, oily water separators, and record books. It is one of the most detailed annexes, reflecting the seriousness of oil pollution incidents. Annex II concerns the control of pollution by noxious liquid substances carried in bulk. It establishes categories for chemicals, prewash procedures, and restrictions on discharges, requiring chemical tankers to operate under strict safety and environmental standards. Annex III regulates the prevention of pollution by harmful substances carried by sea in packaged form. It is closely linked to the International Maritime Dangerous Goods (IMDG) Code, ensuring labeling, packaging, and documentation are standardized. Annex IV covers the prevention of pollution by sewage from ships. It requires ships to install approved sewage treatment plants or holding systems and regulates discharges into the sea, particularly in designated sensitive areas. Annex V deals with the prevention of pollution by garbage from ships. It prohibits the discharge of plastics, restricts the disposal of other wastes, and requires vessels to maintain garbage management plans and record books. This annex has been strengthened repeatedly to reflect the global urgency of reducing marine litter. Annex VI addresses the prevention of air pollution from ships. It limits emissions of sulfur oxides (SOx) and nitrogen oxides (NOx), regulates fuel oil quality, prohibits ozone-depleting substances, and introduces greenhouse gas reduction measures such as the Energy Efficiency Design Index (EEDI), Ship Energy Efficiency Management Plan (SEEMP), and the Carbon Intensity Indicator (CII). It also establishes Emission Control Areas where more stringent standards apply. Recent amendments highlight MARPOL’s responsiveness to modern environmental challenges. In 2024, Annex I was updated to require improved oil discharge monitoring equipment, while Annex II introduced expanded prewash obligations in the Baltic and North Sea to reduce chemical residues. Annex IV tightened sewage effluent standards, and Annex V expanded garbage management requirements to smaller ships and reinforced prohibitions on plastics. Annex VI amendments in 2024 introduced stricter nitrogen oxide limits for new engines and strengthened rules for ships using alternative fuels, ensuring adequate fire protection and fuel distribution systems in parallel with the IGF Code. By 2025, MARPOL continues to advance global decarbonization and environmental protection objectives. Annex VI now mandates enhanced monitoring and verification of the Carbon Intensity Indicator, requiring ships to achieve satisfactory efficiency ratings or adopt corrective action plans. This step places greater responsibility on shipping companies to reduce operational emissions. Electronic record books for oil, garbage, and cargo handling operations are increasingly being accepted in place of paper logs, reflecting the shift toward digital compliance and reducing administrative burdens. New reporting obligations for lost containers at sea, coordinated with parallel SOLAS amendments, will also apply from 2026, ensuring faster notification to authorities and minimizing environmental and navigational hazards. Annex III, through updates aligned with the IMDG Code, further enhances labeling and documentation for harmful substances in packaged form. These updates underline MARPOL’s role as a living instrument that evolves in response to both long-standing pollution risks and emerging challenges such as climate change, marine litter, and the transition to alternative fuels. The integration of greenhouse gas measures under Annex VI,

EMERGENCY GENERATOR

Ship Emergency Generator: Essential Safety Power at Sea On board a ship, electricity powers almost every operation from navigation and communication systems to lighting, pumps, and emergency alarms. When the main power supply fails, the safety of the vessel, its crew, and cargo relies on a reliable backup source. This is where the ship’s emergency generator becomes indispensable. Mandated by the International Convention for the Safety of Life at Sea (SOLAS), the emergency generator is a critical piece of equipment designed to supply electrical power to essential systems during emergencies. Background and Purpose The emergency generator serves as the ship’s lifeline during power loss or blackout. It automatically starts and transfers load to an emergency switchboard to ensure that key systems remain operational. Its purpose is not to run the entire ship but to sustain safety and emergency functions until the main power supply can be restored or the ship is brought to safety. The generator powers essential equipment such as emergency lighting in accommodation spaces, machinery areas, lifeboat embarkation points, and escape routes. It also supplies energy to fire detection and alarm systems, communication equipment, navigation instruments like radar and GPS, and in some cases, the steering gear. Pumps for fire-fighting and bilge operations, as well as emergency batteries and chargers, also depend on this backup system. Location and Construction To maximize reliability, the emergency generator is installed in a separate compartment from the main engine room—typically on an upper deck with its own ventilation, fire protection, and access. This arrangement prevents the generator from being compromised by incidents in the engine room. Most are diesel-driven alternators chosen for their rapid start-up capability and rugged design. They have independent fuel tanks, cooling systems, and starting mechanisms to ensure operation even if the main systems fail.

Central Cooling System

Central Cooling System (CCS) on Ships The Central Cooling System (CCS) is the primary method used on modern vessels to maintain safe operating temperatures for engines and auxiliary machinery. Instead of relying on multiple separate cooling circuits, a CCS uses a single freshwater loop to cool major equipment. This freshwater absorbs heat from engines and machinery and then transfers that heat to seawater through a central cooler. By using freshwater internally and seawater externally, the system offers both efficiency and protection for vital components. Purpose of the Central Cooling System The CCS is designed to provide a stable and controlled cooling environment for the ship’s mechanical systems. Its main purposes include: •Preventing Overheating: Engines, compressors, generators, and pumps produce significant heat during operation. The CCS ensures they remain within safe temperature ranges. •Reducing Corrosion: Freshwater circulates inside machinery rather than corrosive seawater, greatly extending equipment lifespan. •Improving Efficiency: Consistent cooling improves fuel efficiency, power output, and overall engine performance •Simplifying Maintenance: A centralized system requires fewer individual coolers, making inspection and repairs easier and more cost-effective. •Environmental and Safety Protection: Proper cooling prevents machinery failures that could lead to pollution, downtime, or emergency situations. A Brief History of Marine Cooling Systems Early ships relied on direct seawater cooling, where seawater passed directly through engines. While simple, this system caused rapid corrosion, fouling, and frequent breakdowns. As engine outputs increased with advancements in marine propulsion, a more reliable and controlled method became necessary. By the mid- 20th century, ships shifted toward a jacket-water (freshwater) cooling system, where freshwater circulated around the engine block. However, many small coolers were still used for individual machinery, creating complexity. The modern Central Cooling System emerged as a solution: •One freshwater loop for all machinery •One central cooler to transfer heat to seawater •Better temperature control and lower maintenance Today, the CCS is standard on most commercial vessels due to its efficiency and durability.

Marine Boiler

WHAT IS A MARINE BOILER? A marine boiler is a high-pressure vessel installed on ships to heat water and convert it into steam, which is then used for propulsion, power generation, or operating essential auxiliary systems. Unlike land-based boilers, marine boilers must be compact, durable, and capable of functioning reliably under constant motion, vibration, and varying sea conditions. Their design emphasizes strength, efficiency, and safety to ensure consistent steam production throughout a ship’s voyage. A BRIEF HISTORICAL BACKGROUND The origins of marine boilers trace back to the early 1800s, when steam engines dramatically changed maritime transportation. Early boilers were basic fire-tube types that burned coal to heat tubes carrying hot gases through water. As technology progressed into the late 19th and early 20th centuries, water-tube boilers became more common due to their ability to handle higher pressures and improved operational safety. Over time, advancements in materials, combustion systems, and automation led to compact, highly efficient boilers suited for modern vessels. These innovations not only boosted performance but also significantly enhanced reliability and crew safety. HOW A MARINE BOILER WORKS A marine boiler functions by burning fuel traditionally marine fuel oil, though alternative fuels are becoming more common inside a furnace. The heat produced travels through tubes (in fire-tube designs) or across external surfaces of water-filled tubes (in water-tube designs). As the water absorbs heat, it converts into steam under controlled pressure. The resulting steam is collected in a steam drum or header and distributed to various systems onboard. Depending on the vessel type, this steam may drive turbines, support heating systems, operate fuel or cargo-handling equipment, or power steam-driven generators. PURPOSE AND IMPORTANCE IN MARINE ENGINEERING The primary purpose of a marine boiler is to supply steam for essential shipboard operations. On older or steam-powered ships, boilers serve as the heart of propulsion systems. On most modern vessels powered by diesel or gas engines, boilers fulfill auxiliary functions—heating heavy fuel oil for proper viscosity, producing hot water, powering cargo pumps (especially on tankers), generating inert gas for safety, or driving equipment requiring steam. Without a dependable boiler, many critical tasks on board would be impossible to perform effectively.