Maritime Glossary

Administration

Maritime administrations, also known as flag state administrations, are the executive arms of each government responsible for carrying out shipping responsibilities within their territorial waters and for vessels flagged in their country. These administrations administer national shipping and boating laws, ensuring safety, compliance, and efficient maritime operations

ACV

Air-cushion vehicle (ACV), also known as a hovercraft, is an amphibious craft capable of traveling over land, water, mud, ice, and various other surfaces. Hovercraft use blowers to produce a large volume of air below the hull, creating an air cushion that is slightly above atmospheric pressure. The pressure difference between the higher-pressure air below the hull and the lower-pressure ambient air above it produces lift, causing the hull to float above the running surface.

100 A1

Marine classification societies issue the category symbol 100 A1, which indicates that a vessel was built under their survey and satisfies strict requirements for structural integrity and maritime safety. This designation certifies that the ship’s hull was constructed in compliance with the strict requirements of the society and is in excellent shape. For a variety of marine operations, vessels classified as 100 A1 are regarded as dependable and secure, guaranteeing adherence to global safety standards. This certification is indicative of a dedication to upholding the highest standards of quality and safety in maritime engineering.

ABS

The American Bureau of Shipping (ABS) is a leading international classification organization, specializing in maritime safety and regulatory compliance. Founded in 1862, ABS ensures the structural integrity and operational safety of ships and offshore structures. It provides services including certification, engineering, and risk assessment to the global marine and offshore industries. ABS is recognized for its commitment to innovation and sustainability in advancing the marine sector.

Aft

In maritime terminology, “aft” refers to the rear section of a ship or vessel. It is the area located towards the stern, opposite the bow. The aft section typically houses essential components like the engine room, steering gear, and accommodations. Navigating and managing the aft section is crucial for maintaining the ship’s balance and propulsion.

Aft peak tank

The aft peak tank is a compartment located at the rear (aft) end of a ship, below the waterline. It is primarily used for storing ballast water to maintain the vessel’s stability and trim. This tank helps in balancing the ship during loading and unloading operations. Additionally, it can provide some level of protection to the rudder and propeller shafts from damage due to impacts.

Alleyway

An alleyway on a ship is a narrow passageway that runs along the length of the vessel, typically connecting various compartments and cabins. It provides a route for crew members to move between different areas of the ship safely and efficiently. Alleyways are essential for ensuring quick access during emergencies. They are designed to optimize space and often contain safety features like handrails and emergency lighting.

Alongside

Amidships”Alongside amidships” refers to the area adjacent to the central section of a ship’s hull, extending along its length from the port or starboard side. This location is crucial for docking and mooring operations, allowing for the transfer of cargo, passengers, or provisions. Being amidships, this area experiences minimal motion, making it ideal for safe and stable operations. It is also a key point for boarding and disembarking during port calls.

AMSA

The Australian Maritime Safety Authority (AMSA) is a government agency responsible for ensuring the safety and environmental protection of Australia’s maritime activities. AMSA oversees maritime safety regulations, conducts inspections, and responds to marine emergencies, including search and rescue operations. It also manages marine pollution prevention and response initiatives. Through its comprehensive oversight, AMSA plays a crucial role in maintaining safe and sustainable maritime operations in Australian waters.

Anchor

An anchor is a vital piece of maritime equipment used to secure a vessel to the seabed. Typically made of heavy metal and featuring flukes or arms that grip the seabed, anchors provide stability and prevent drifting while ships are stationary. Anchors are deployed using chains or ropes called anchor cables, which connect them to the ship’s hull.

Anchor cable

Anchor cable, also known as anchor chain, is a heavy-duty chain specifically designed to connect the ship’s anchor to the vessel itself. It plays a crucial role in anchoring operations by providing a secure link between the anchor and the ship’s hull. Anchor cables are constructed from high-strength steel to withstand the stresses and forces encountered during anchoring and mooring. They are typically marked with intervals to measure the amount of chain deployed, aiding in determining the depth at which the anchor lies.

Anode

An anode in marine contexts is a sacrificial metal component attached to a ship’s hull or submerged structures. Its purpose is to protect the hull from corrosion by attracting corrosive elements away from the main structure. Made typically of zinc or aluminum alloys, anodes gradually corrode over time, requiring periodic replacement to maintain effective protection. Anodes are crucial in ensuring the longevity and structural integrity of marine vessels and equipment.

Antifouling (paint)

Antifouling paint is specially formulated marine paint applied to the hulls of ships and boats to prevent the accumulation of marine organisms such as barnacles, algae, and mollusks. It contains biocides that deter marine growth and help maintain vessel performance and fuel efficiency by reducing drag. Regular application and maintenance of antifouling paint are essential for preserving the hull’s smoothness and integrity, thereby optimizing the vessel’s speed and maneuverability.

Appendage(s)

Appendages in marine terminology refer to additional structures attached to a ship’s hull, such as rudders, propellers, stabilizers, and thrusters. These components play crucial roles in maneuverability, propulsion efficiency, and stability of the vessel. Appendages are designed and positioned strategically to optimize performance and minimize drag, ensuring safe and efficient navigation at sea.

Astern

Astern refers to the direction opposite to the vessel’s forward motion, where the ship moves backward or in reverse. This maneuver is typically controlled by reversing the thrust of the propulsion system, such as engines or propellers. Going astern is essential for docking, maneuvering in tight spaces, or reversing course safely in maritime operations.

Auxiliary (machinery)

Auxiliary machinery in marine contexts refers to additional mechanical equipment aboard a vessel that supports its primary operations. This includes generators, pumps, compressors, and refrigeration units, among others, essential for power generation, fluid transfer, and climate control. Auxiliary machinery ensures the functionality and comfort of crew and passengers while complementing the main propulsion systems of the ship.

Azimuth thruster

An azimuth thruster is a versatile propulsion system used in marine vessels, capable of rotating 360 degrees around a vertical axis to provide thrust in any direction. It enhances maneuverability and precision during docking, dynamic positioning, and tight navigation in confined waters. Azimuth thrusters are commonly mounted on the ship’s hull, often retractable, and used in combination with traditional propulsion systems for efficient control and enhanced operational flexibility at sea.

Ballast

Ballast in marine contexts refers to heavy material, such as water, sand, or gravel, loaded into a vessel’s ballast tanks to ensure stability and proper trim. It helps maintain the ship’s balance, prevents excessive rolling, and improves handling, especially in rough seas or when the ship is not carrying cargo. Proper ballast management is crucial for the vessel’s safety, operational efficiency, and compliance with environmental regulations.

Barge

A barge is a flat-bottomed, non-self-propelled vessel primarily used for transporting cargo, often on inland waterways or sheltered coastal areas. It relies on tugboats or towboats for movement and is ideal for carrying heavy or bulk goods such as coal, grain, and construction materials. Barges play a crucial role in efficient and cost-effective transportation within the shipping and logistics industry.

Baseline

In marine terminology, the baseline refers to an imaginary horizontal line drawn at the lowest point of a ship’s hull, typically at the keel. It serves as a reference point for measuring vertical distances, such as draft and freeboard, ensuring accurate and consistent ship design and construction. The baseline is essential for naval architects and marine engineers when calculating stability, buoyancy, and overall vessel performance.

Beam

The beam of a ship refers to its widest point, measured horizontally across the vessel’s hull from side to side. It is a critical dimension that influences the ship’s stability, cargo capacity, and handling characteristics. A wider beam generally provides greater stability and deck space, enhancing the vessel’s overall performance and safety at sea.

Bed plate

A bed plate in marine engineering is a robust, machined surface foundation to which a ship’s engine and other major machinery are securely mounted. It ensures precise alignment, stability, and vibration dampening, critical for the reliable operation of the engine and mechanical systems. The bed plate is typically made of cast iron or steel and is bolted to the ship’s hull, forming the structural backbone for the machinery installation.

Berth

A berth in maritime contexts refers to a designated location where a ship is moored or anchored in a port or harbor. It provides a safe and secure spot for loading and unloading cargo or passengers and performing maintenance or repairs. Berths are equipped with necessary facilities, such as mooring lines and fenders, to accommodate vessels of various sizes and types.

Bilge

The bilge is the lowest part of a ship’s hull, where water and other liquids collect. It serves as a drainage area, and bilge pumps are used to remove this accumulated water to prevent flooding and maintain the vessel’s stability. Proper bilge maintenance is essential for the ship’s safety and operational efficiency.

Bilge bracket

A bilge bracket is a structural component in a ship’s hull, providing reinforcement where the bottom shell plating meets the transverse frames. It enhances the vessel’s structural integrity, distributing stresses and preventing deformation in the bilge area. Bilge brackets are crucial for maintaining the strength and durability of the ship’s hull, especially in rough sea conditions.

Bilge keel

A bilge keel is a longitudinal fin-like structure attached to the bottom sides of a ship’s hull to reduce rolling motion. It enhances stability by increasing hydrodynamic resistance when the vessel rolls, thereby improving passenger comfort and operational safety. Bilge keels are particularly effective in minimizing the side-to-side motion in rough seas.

Bilge strake

A bilge strake is a specific row of hull plating located along the bilge area of a ship, where the bottom and sides of the hull meet. It is crucial for the vessel’s structural integrity, providing additional strength and durability to withstand stresses and impacts. The bilge strake plays a key role in ensuring the overall stability and seaworthiness of the ship.

Bitts

Bitts are sturdy posts or fixtures on a ship’s deck used for securing mooring lines or cables. They provide a strong point of attachment for ropes, preventing the vessel from drifting when docked or anchored. Bitts are strategically placed around the ship to accommodate various mooring configurations and ensure safe and efficient berthing operations.

Body plan

A body plan in marine architecture is a graphical representation showing the cross-sectional shapes of a ship at various points along its length. It provides detailed profiles of the vessel’s hull design, including contours, curves, and dimensions. Naval architects use body plans to visualize and refine the ship’s hydrodynamic characteristics, stability, and performance in different sea conditions.

Bollard

A bollard is a sturdy, vertical post on a dock or quay used for securing mooring lines of ships. It provides a fixed point of attachment to prevent vessels from drifting away while loading, unloading, or during docking maneuvers. Bollards are typically made of metal or concrete and are strategically placed along the waterfront to accommodate various sizes and types of vessels.

Boot-topping

Boot-topping refers to a distinct painted stripe or band along the waterline of a ship’s hull, typically applied just above the anti-fouling paint. It serves both functional and aesthetic purposes, such as providing a visual indication of the ship’s load line or draft when fully loaded. Boot-topping also helps in keeping the hull clean and free from marine growth near the waterline, enhancing the vessel’s overall efficiency and appearance.

Bossing

Bossing in marine engineering refers to the process of shaping or reinforcing metal plates, typically in the construction of ship hulls. This technique involves forming raised or recessed areas on the plate surface to enhance structural integrity and accommodate fittings or connections. Bossing is crucial for ensuring the strength and durability of the hull, particularly in areas subjected to high stress and pressure.

Bow

The bow of a ship is the forward-most part of its hull, designed to cut through water efficiently and reduce resistance. It influences the vessel’s maneuverability, stability, and hydrodynamic performance. The shape and construction of the bow vary based on the ship’s purpose, optimizing its ability to navigate various sea conditions and maintain speed.

Bow door

A bow door on a vessel is a large, hinged opening located at the forward end of the ship’s hull, designed for efficient loading and unloading of cargo or vehicles directly onto docks or ramps. It facilitates quick deployment and retrieval of goods or equipment during maritime operations, especially in roll-on/roll-off (Ro-Ro) ferries and cargo ships. Bow doors are crucial for enhancing efficiency and reducing turnaround times in port operations.

Bow thruster

A bow thruster is a maneuvering device mounted in the forward section (bow) of a ship’s hull, typically at the sides near the waterline. It provides lateral thrust to aid in maneuvering the vessel sideways, enhancing its agility and reducing reliance on tugs in tight spaces or adverse weather conditions. Bow thrusters improve safety during docking and berthing operations, allowing for precise movements without the need for significant forward or reverse propulsion.

Bracket

In maritime terminology, a bracket refers to a structural component used to support or attach various equipment, fixtures, or fittings on a ship’s deck or hull. It provides stability and reinforcement, ensuring secure mounting of items such as navigation lights, antennas, or safety equipment. Brackets are designed to withstand marine environments and the stresses encountered during vessel operations, contributing to the overall functionality and safety of the ship.

Breadth

Breadth in marine terms refers to the width of a ship at its widest point, measured horizontally across the hull. It is a critical dimension that influences the vessel’s stability, cargo capacity, and maneuverability. Breadth plays a significant role in determining the ship’s overall dimensions and its ability to navigate through narrow passages or dock in ports with restricted space.

Breasthook

A breasthook is a structural component in a ship’s bow that reinforces and connects the forward ends of the hull planking or frames. It provides additional strength and support to the bow structure, helping to withstand the forces encountered at sea. Breasthooks are essential for maintaining the overall integrity and shape of the vessel’s bow, contributing to its stability and seaworthiness.

Bridge

The bridge on a ship is the command center and navigation hub, typically located above the main deck and forward part of the vessel. It houses the wheelhouse, where the ship’s steering controls and navigational equipment are located. The bridge allows the crew to oversee and control the ship’s operations, ensuring safe navigation and communication with other vessels and shore facilities.

Bridge wing(s)

Bridge wings are extensions of the ship’s bridge structure, located on either side of the main navigation area. They provide additional vantage points for the officers to oversee ship operations, especially during docking, maneuvering, and navigating in narrow channels. Bridge wings enhance visibility and communication with the crew stationed on deck, ensuring safe and precise ship handling in various maritime conditions.

Bulk cargo

Bulk cargo refers to loose, unpackaged commodities or materials that are transported in large quantities, typically loaded directly into a ship’s hold without individual packaging. Examples include coal, grain, ore, and petroleum products. Handling bulk cargo efficiently involves specialized equipment and procedures to ensure safe loading, transportation, and unloading at ports or terminals worldwide.

Bulk carrier

A bulk carrier is a specialized merchant vessel designed for transporting bulk cargo such as grain, coal, ore, and cement in large quantities. It features a spacious cargo hold without internal divisions, optimized for efficient loading and unloading through hatches on deck. Bulk carriers vary in size and configuration to accommodate different types of bulk cargo, playing a crucial role in global trade and logistics by transporting commodities between ports worldwide.

Bulkhead

A bulkhead in marine engineering refers to a vertical partition or wall within a ship’s hull, designed to separate compartments and provide structural support. It enhances the vessel’s strength, stability, and safety by preventing the spread of water in case of leaks or collisions. Bulkheads also contribute to the ship’s buoyancy and help maintain its trim and stability during loading and unloading operations.

Bulkhead deck

A bulkhead deck on a ship is a horizontal partition or platform that serves as a structural division between different compartments or levels within the vessel’s superstructure. It reinforces the ship’s hull integrity, providing support and stability while also compartmentalizing the internal space. Bulkhead decks contribute to the vessel’s safety by containing potential hazards and preventing the spread of fire or flooding in case of emergencies at sea.

Bulwark

A bulwark on a ship is a raised protective wall or structure along the sides of the main deck, extending above the ship’s hull. It shields the deck and crew from waves, wind, and spray, enhancing safety and comfort during navigation. Bulwarks also serve as a barrier to prevent cargo and equipment from falling overboard, contributing to the overall security of the vessel.

Bureau Veritas

Bureau Veritas is a global leader in testing, inspection, and certification services, specializing in ensuring safety, quality, and sustainability across various industries, including maritime. It provides classification and certification services to ships and offshore structures, verifying compliance with international regulations and standards. Bureau Veritas plays a critical role in enhancing operational efficiency and safety for marine operators worldwide.

Buttock line

In naval architecture, a buttock line is a theoretical line running vertically through a ship’s hull, representing the intersection of a vertical plane with the hull surface. It helps designers and engineers visualize the shape and curvature of the ship’s hull in side view. Buttock lines are essential for assessing hydrodynamic performance, stability, and overall hull shape during the ship design and construction phases.

Butt weld

A butt weld is a type of weld used in shipbuilding and marine engineering where two pieces of metal are joined together end-to-end along a single plane. It provides a strong and smooth connection, essential for maintaining the structural integrity and watertightness of the vessel’s hull and components. Butt welding is widely used in constructing ship hulls, tanks, and pipelines to ensure reliability and durability in marine environments.

Cabin

A cabin on a ship refers to a private room or living space allocated for passengers or crew members. It provides accommodations, including sleeping quarters and personal storage, designed for comfort during voyages. Cabins vary in size and amenities, ranging from basic berths to luxurious suites, depending on the type of vessel and passenger requirements.

Cable layer

A cable layer is a specialized vessel designed for laying underwater cables, such as telecommunications and power cables, on the seabed. Equipped with advanced machinery and technology for precision placement, these ships play a crucial role in establishing and maintaining global communication networks and power distribution systems. Cable layers are essential for connecting continents, islands, and offshore installations, ensuring reliable and efficient data and power transmission.

Cable locker

A cable locker on a ship is a compartment used to store the anchor chain or cable when it is not in use. Located near the bow, this area ensures the anchor chain is neatly coiled and readily accessible for deployment and retrieval. The cable locker helps maintain order and safety on deck by preventing the chain from becoming tangled or causing obstructions.

CAD/CAM

CAD/CAM in marine engineering stands for Computer-Aided Design and Computer-Aided Manufacturing. CAD involves using software to create precise 2D and 3D models of ship components and structures, enhancing design accuracy and efficiency. CAM translates these designs into manufacturing instructions, guiding automated machinery to produce parts with high precision. Together, CAD/CAM streamline the design and construction processes, reducing errors and improving the quality and performance of marine vessels.

Camber

Camber in marine design refers to the slight upward curvature of a ship’s deck from the centerline towards the sides. This design feature allows water to drain off the deck more efficiently, enhancing safety and preventing water accumulation. Camber contributes to the structural strength of the deck and improves the overall seaworthiness of the vessel.

Cant frame

A cant frame is a structural component in a ship’s hull, positioned at an angle to the keel near the bow or stern. Unlike regular transverse frames, cant frames are inclined to follow the curved contours of these areas, providing additional support and shaping. They are essential for maintaining the structural integrity and hydrodynamic efficiency of the vessel in these complex, curved sections.

Capstan

A capstan is a vertical, spool-shaped mechanical device on a ship used for handling heavy ropes, cables, and chains. It is primarily utilized for tasks such as raising anchors, hoisting sails, and mooring. Operated manually or powered by an engine, the capstan provides the necessary leverage to manage heavy loads efficiently and safely on deck.

Car carrier Cargo door

A car carrier cargo door is a large, hinged or sliding door on a specialized vessel designed for transporting vehicles. Located at the stern or side of the ship, this door provides access to ramps and decks, facilitating the efficient loading and unloading of cars and other vehicles. It is engineered to handle the weight and dimensions of vehicles, ensuring safe and secure transfer during port operations.

Casing

A casing on a ship refers to an enclosed structure that surrounds and protects machinery, equipment, or structural elements. Commonly found around engine rooms, exhaust stacks, or ventilation systems, casings provide protection from the elements and reduce noise levels. They also contribute to the vessel’s overall safety by containing potential hazards and facilitating maintenance access.

Cathodic protection

Cathodic protection is a corrosion prevention technique used on ships and marine structures to protect metal surfaces submerged in water. It works by making the metal surface the cathode of an electrochemical cell, typically through the use of sacrificial anodes or impressed current systems. This method effectively prevents rust and deterioration, extending the lifespan of the ship’s hull and underwater components.

CCS

CCS, or China Classification Society, is a non-profit organization dedicated to providing classification and certification services to ships and offshore installations. It ensures compliance with international maritime safety and environmental standards, supporting safe and sustainable maritime operations. CCS plays a vital role in promoting maritime safety and contributing to the development of China’s shipping industry.

Cellular container ship

A cellular container ship is a specialized vessel designed with a series of vertical cells or slots to efficiently transport standard shipping containers. These containers fit precisely into the ship’s cargo holds, stacked in rows and columns. Cellular container ships are integral to global trade, facilitating the transport of goods in a standardized and secure manner across international waters. Their design maximizes cargo capacity and allows for efficient loading, unloading, and transportation of containers between ports worldwide.

Centreline

The centreline of a ship refers to an imaginary line running longitudinally along its keel, dividing the vessel into port (left) and starboard (right) halves. It serves as a crucial reference point for structural alignment, stability calculations, and symmetrical placement of equipment and compartments. The centreline is fundamental in ship design and navigation, ensuring balanced weight distribution and optimal performance at sea.

Chain locker

A chain locker on a ship is a compartment or storage area located near the bow where the anchor chain is stowed when not in use. It ensures the anchor chain is neatly stored and ready for deployment and retrieval during anchoring operations. The chain locker also helps prevent the chain from causing clutter or hazards on deck, maintaining safety and efficiency aboard the vessel.

Chemical carrier (Tanker)

A chemical carrier, also known as a chemical tanker, is a specialized vessel designed for transporting liquid chemicals in bulk. These tankers are equipped with segregated tanks and advanced cargo handling systems to ensure safe and efficient transportation of various chemical cargoes. They adhere to strict safety and environmental regulations, including measures to prevent contamination and leakage, making them essential for the global chemical industry and maintaining maritime safety standards.

Classification societies

Classification societies are independent organizations that establish and apply technical standards for the design, construction, and maintenance of ships and offshore structures. They conduct inspections, surveys, and certification to verify compliance with international regulations and industry standards, ensuring safety, reliability, and environmental protection. Classification societies play a critical role in enhancing maritime safety, facilitating global trade, and promoting sustainable practices in the shipping industry.

Coaming

A coaming on a ship refers to a raised edge or border around a hatch, opening, or compartment on the deck. It helps contain water and prevent it from entering the enclosed area during rough seas or inclement weather. Coamings also provide structural support and serve as a barrier to protect cargo, equipment, and personnel from exposure to elements such as waves, spray, and rain.

Cofferdam

A cofferdam on a ship is a watertight enclosure or compartment used to isolate and contain liquids or gases, providing protection and safety for onboard operations. It serves as a barrier between different areas of the vessel, preventing leaks or spills from spreading to other compartments. Cofferdams are crucial in maintaining the structural integrity of the ship and ensuring environmental safety by minimizing the risk of pollution or contamination at sea.

Collision bulkhead

A collision bulkhead is a reinforced partition located at the forward end of a ship’s hull, designed to absorb and minimize the impact of collisions or accidents. It enhances the vessel’s safety by preventing the penetration of water into other compartments during emergencies. Collision bulkheads are strategically positioned to protect critical areas and ensure the ship remains seaworthy and operational in adverse conditions.

Compartment

A compartment on a ship refers to a separate section or room enclosed by bulkheads, typically serving specific purposes such as accommodation, machinery housing, or storage. It helps organize and compartmentalize the ship’s interior for efficient use of space and facilitates maintenance and safety management. Compartments are essential for ensuring the functionality, safety, and operational readiness of the vessel during maritime operations.

Complement

The complement of a ship refers to the total number of crew members required to operate the vessel effectively during normal operations. It includes officers, engineers, deck crew, and other personnel essential for navigation, maintenance, and cargo handling. The complement size varies depending on the ship’s size, type, and operational requirements, ensuring all tasks and responsibilities aboard the ship are adequately managed and performed.

Container vessel

A container vessel is a specialized ship designed for efficiently transporting standard shipping containers between ports worldwide. These vessels feature large cargo holds and a series of vertical cells or slots to accommodate containers of various sizes stacked securely on deck. Container vessels play a pivotal role in global trade, facilitating the transportation of goods in a standardized and efficient manner. They are equipped with advanced cargo handling systems and adhere to strict safety and operational standards to ensure reliable and timely delivery of cargo.

Continuous welding

Continuous welding in marine engineering refers to a welding technique where the welding process is uninterrupted along the entire length of the joint. This method ensures a continuous and strong bond between metal components, enhancing structural integrity and durability. Continuous welding is commonly used in constructing ship hulls, pipelines, and other critical components to achieve uniformity and reliability in strength and performance.

Counter

In naval architecture, the counter refers to the aft, or rear, part of a ship’s hull above the waterline. It typically extends beyond the waterline and contributes to the vessel’s overall aesthetics and hydrodynamic performance. The counter may feature decorative elements or serve functional purposes such as housing rudders, stern gear, or accommodating crew spaces.

Crew boat

A crew boat is a small, fast vessel designed to transport personnel and light cargo to and from offshore platforms, ships, or installations. These boats are equipped with seating and safety features to accommodate crew members, ensuring efficient crew transfer and support during offshore operations. Crew boats play a vital role in the oil and gas industry and maritime logistics, providing essential transportation services in offshore environments.

Davit(s)

Davits are mechanical devices installed on a ship’s deck used for raising, lowering, and storing lifeboats, tenders, or other small vessels. They consist of a pair of pivoting arms equipped with winches and cables, enabling safe and efficient launching and recovery of boats. Davits are crucial for emergency preparedness and routine operations, ensuring quick deployment and secure handling of lifeboats and other auxiliary craft.

Deadlight

A deadlight is a strong, fixed cover or shutter fitted over a porthole or window on a ship. It is used to provide extra protection against heavy seas, preventing water from entering the vessel during rough weather conditions. Deadlights are typically made of metal and are secured in place to enhance the ship’s safety and watertight integrity.

Deadrise

Deadrise in marine terminology refers to the angle between the horizontal plane of a boat’s hull and the surface of its bottom, measured at the centerline or keel. It indicates how much the hull slopes upwards from the keel towards the sides. A higher deadrise angle typically results in a deeper V-shaped hull, which can improve performance in rough seas by providing a smoother ride. Conversely, a lower deadrise angle results in a flatter bottom, which can enhance stability and speed in calm waters.

Deck height

Deck height refers to the vertical distance between the bottom of a ship’s hull (the keel) and the deck, or the height of a specific deck above the base line or another reference point on the vessel. It is a critical measurement in ship design and construction, influencing the ship’s overall stability, cargo capacity, and structural integrity. Proper deck height ensures adequate headroom and accessibility for crew and passengers, as well as efficient space utilization for cargo and equipment.

Deck stringer

A deck stringer is a longitudinal structural member running along the outer edge of a ship’s deck, providing support and reinforcement. It connects the deck plating to the hull structure, enhancing the deck’s strength and rigidity. Deck stringers are crucial for maintaining the structural integrity of the ship, distributing loads, and ensuring the durability of the deck under various operational conditions.

Deep tank

A deep tank on a ship is a large, enclosed tank that extends from the bottom of the vessel up to the main deck, used for storing ballast water, fuel, or liquid cargo. These tanks are integral to the ship’s stability and trim, allowing for adjustments in weight distribution as needed. Deep tanks enhance the vessel’s operational flexibility by providing additional storage capacity for essential liquids during voyages.

Derrick

A derrick is a lifting device on a ship, typically consisting of a mast, boom, and associated rigging, used for loading and unloading cargo. It provides a mechanical advantage for hoisting heavy loads onto or off the vessel, particularly in locations where shore-based cranes are unavailable. Derricks are essential for handling cargo efficiently and safely, contributing to the overall productivity of maritime operations.

Design draft

The design draft of a ship refers to the vertical distance between the waterline and the lowest point of the hull (keel) when the ship is fully loaded to its designed capacity. This measurement is crucial for determining the vessel’s buoyancy, stability, and safe navigation in various water depths. The design draft ensures the ship operates efficiently and safely within its intended load and operational parameters.

Det norske Veritas

Det Norske Veritas (DNV) is an international classification society headquartered in Norway, providing services for risk management and quality assurance to the maritime, oil and gas, and renewable energy industries. DNV establishes technical standards for the design, construction, and operation of ships and offshore structures, ensuring safety, reliability, and environmental sustainability. It conducts inspections, certifications, and research to promote best practices and innovation in maritime operations globally.

Diesel generator

A diesel generator on a ship is a crucial piece of machinery that converts diesel fuel into electrical power, ensuring a reliable energy supply for various onboard systems and equipment. It provides electricity for propulsion, lighting, navigation, communication, and other essential operations, particularly when the ship is not connected to shore power. Diesel generators are designed for efficiency, durability, and safety, supporting the continuous and smooth functioning of maritime vessels.

Displacement

Displacement in maritime terms refers to the weight of water displaced by a ship’s hull when it is floating or submerged in water. It is a fundamental measurement used to determine the ship’s buoyancy and load-carrying capacity. Displacement includes the weight of the ship, cargo, fuel, crew, and any other onboard items. This measurement is critical for assessing the vessel’s stability, performance, and operational characteristics.

Docking plan

A docking plan in maritime operations is a detailed strategy outlining procedures and preparations for safely docking a ship at a pier, wharf, or dockyard. It includes factors such as approach angle, speed adjustments, mooring arrangements, and communication protocols with port authorities and tugboats. The docking plan ensures efficient and safe maneuvering of the vessel during arrival and departure from ports, minimizing risks and optimizing turnaround times for maritime operations.

Double bottom

A double bottom in maritime engineering refers to a structural feature of a ship’s hull where there are two layers of watertight compartments or spaces between the bottom of the hull and the innermost surface of the ship’s bottom plating. This design provides additional protection against water ingress and enhances the vessel’s structural integrity and buoyancy. Double bottoms are commonly used to store ballast water, fuel, or fresh water, and they serve as a safety measure to mitigate the risk of hull damage from grounding or collisions.

Double skin

Double skin in marine terminology refers to a hull construction design where there are two layers of hull plating separated by a space or void. This configuration enhances the ship’s structural strength and provides additional protection against hull damage from external impacts or corrosion. Double skin hulls are commonly found in modern ships, especially oil tankers and chemical carriers, to meet stringent safety and environmental regulations governing the transportation of hazardous cargoes.

Draft (or draught)

Draft (or draught) in maritime terms refers to the vertical distance between the waterline and the deepest part of a ship’s hull, typically measured from the keel to the waterline when the ship is fully loaded. It is a crucial measurement for determining the ship’s buoyancy, stability, and ability to navigate safely in various water depths. Draft affects the ship’s maneuverability, cargo capacity, and overall performance, making it an essential consideration in ship design, operation, and navigation planning.

Draft marks

Draft marks on a ship are numerical markings or lines painted on the bow (forward) and stern (aft) of the hull to indicate the ship’s draft or depth in the water. These marks help determine the vessel’s loaded condition and ensure it maintains proper trim and stability. Draft marks are essential for monitoring and recording changes in draft due to loading, fuel consumption, or water density variations during voyages.

Dredger

A dredger is a specialized vessel or equipment used for excavating and removing sediment or debris from the bottom of rivers, harbors, and other water bodies. It is equipped with powerful pumps, suction devices, or mechanical tools to loosen and extract materials, facilitating deepening of channels, harbor maintenance, and land reclamation projects. Dredgers play a crucial role in maintaining navigable waterways, improving water quality, and supporting infrastructure development in coastal and inland regions.

Drill ship

A drill ship is a specialized vessel equipped with drilling equipment and facilities for offshore exploration and production of oil and gas. It typically features a derrick or drilling rig capable of drilling deep into the seabed to extract oil or gas deposits. Drill ships are mobile platforms capable of operating in deep waters, providing flexibility for exploration and development activities in remote offshore locations. They play a pivotal role in offshore drilling operations, contributing to the global energy industry’s exploration and production efforts.

Dry bulk

Dry bulk refers to commodities or materials that are transported in large quantities without packaging, typically loaded directly into a ship’s hold. Examples include grains, coal, iron ore, and cement. Ships designed for transporting dry bulk cargo are called dry bulk carriers, which feature large, open holds to accommodate bulk commodities. Dry bulk shipping plays a vital role in global trade, facilitating the efficient transport of essential raw materials between producers and consumers worldwide.

Dry dock

A dry dock is a large structure, typically made of concrete or steel, used for docking, maintaining, and repairing ships. It is designed to be flooded and then drained to allow ships to be floated in and out, exposing their hulls for inspection, maintenance, and repair work. Dry docks provide a controlled environment for ship maintenance, ensuring efficient and safe servicing of vessels without the need for them to remain in the water.

Duct

In maritime terms, a duct refers to a channel or conduit on a ship used for directing air, fluids, or electrical cables between different compartments or areas. Ducts are essential for ventilation systems, cooling mechanisms, and ensuring the efficient flow of essential services throughout the vessel. They contribute to maintaining optimal operating conditions and safety aboard ships by regulating air circulation and preventing overheating of equipment.

Duct keel

A duct keel in ship construction refers to a longitudinal structure or channel integrated into the bottom of the ship’s hull. It serves multiple purposes such as providing a pathway for cables, pipes, and other systems running along the length of the vessel. Additionally, the duct keel reinforces the ship’s structure and enhances its overall stiffness and strength, contributing to its seaworthiness and structural integrity.

Electro-hydraulic

Electro-hydraulic systems in marine applications utilize electricity to control hydraulic machinery and equipment aboard ships. These systems efficiently convert electrical energy into hydraulic power, enabling precise and reliable operation of functions such as steering mechanisms, stabilizers, and cargo handling equipment. Electro-hydraulic systems enhance operational efficiency and safety by providing responsive control over critical shipboard functions, contributing to overall maritime performance and reliability.

Endurance

Endurance in marine terminology refers to the maximum duration or distance a ship can travel on a single supply of fuel and provisions without refueling or resupplying. It is a measure of the ship’s capability to sustain operations at sea, indicating its range and self-sufficiency. Endurance is influenced by factors such as fuel capacity, engine efficiency, and the crew’s provisions, essential for prolonged voyages and maritime missions.

Engine control room

The engine control room on a ship is a dedicated space where engineers monitor and manage the operation of the vessel’s propulsion system and auxiliary machinery. It houses control panels, monitoring displays, and communication equipment essential for overseeing engine performance, fuel consumption, and power distribution. The engine control room ensures efficient and safe operation of the ship’s engines, contributing to optimal performance, reliability, and safety during maritime operations.

Engine room

The engine room on a ship is a vital compartment where the main propulsion engines and auxiliary machinery are housed and operated. It contains engines, generators, pumps, and other essential equipment necessary for power generation, propulsion, and various onboard systems. The engine room is carefully designed to optimize space, ensure efficient operation, and maintain safety standards, playing a critical role in the vessel’s overall performance and reliability at sea.

Ergonomic

In a maritime context, ergonomic principles focus on designing shipboard environments and equipment to optimize safety, efficiency, and comfort for crew members. This includes the layout of workspaces, seating arrangements, and the design of controls and interfaces to minimize physical strain and fatigue. Ergonomic considerations are crucial for enhancing crew performance, reducing the risk of injury, and promoting overall well-being during maritime operations.

Even keel

“Even keel” refers to the state of a ship when it is floating levelly in the water without any significant list or trim. It indicates that the vessel is properly balanced, with the bow and stern at equal heights above the waterline. Maintaining an even keel is essential for stability and efficiency during navigation, ensuring optimal performance and comfort for crew and passengers alike.

Factory ship

A factory ship is a large vessel equipped with extensive facilities for processing and preserving fish or other marine resources directly on board. These ships can catch, process, package, and freeze seafood, allowing them to stay at sea for extended periods. Factory ships enhance efficiency in the fishing industry by combining harvesting and processing operations, enabling immediate preservation of the catch and reducing the need for shore-based processing facilities.

Fender

A fender is a protective device used on ships and boats to absorb impact and prevent damage when mooring, docking, or coming alongside another vessel. Made from materials such as rubber, foam, or plastic, fenders are placed between the ship’s hull and the dock or another vessel to cushion the contact. They play a crucial role in maintaining the structural integrity of the vessel and ensuring safe and secure mooring operations.

Ferry

A ferry is a vessel designed to transport passengers, vehicles, and goods across bodies of water, typically between fixed points on a regular schedule. Ferries vary in size and capacity, ranging from small boats for short crossings to large ships capable of carrying hundreds of passengers and vehicles over longer distances. They play a vital role in public transportation, providing essential links in coastal, island, and riverine areas where bridges or tunnels are impractical.

Flag State

A Flag State refers to the country under whose laws a ship is registered and whose flag the ship is entitled to fly. The Flag State has jurisdiction over the vessel and is responsible for enforcing regulations concerning safety, crew welfare, and environmental standards. This includes conducting inspections, certifying vessels, and ensuring compliance with international maritime conventions and laws.

Flange

A flange in maritime engineering is a projecting rim or edge, typically used to strengthen or attach one component to another. Commonly found in piping systems, flanges connect pipes, valves, pumps, and other equipment, ensuring a secure and leak-proof joint. They are essential for maintaining the integrity and efficiency of onboard systems, facilitating maintenance and assembly by allowing easy disconnection and reconnection of components.

Flare

In maritime terminology, a flare refers to the outward curvature or widening of a ship’s hull towards the upper sections, typically found in the bow or stern areas. This design feature helps improve the vessel’s stability and performance in rough seas by reducing pitching and enhancing wave deflection. Flares also contribute to the ship’s aesthetic appearance and can serve practical purposes such as providing additional buoyancy and reducing spray on deck.

Floor

In maritime construction, a floor refers to a transverse structural member that supports the bottom of a ship’s hull frames. Floors are essential for distributing loads and reinforcing the hull’s structural integrity against bending and twisting forces encountered at sea. They span between the keel and the frames, contributing to the overall strength and stability of the vessel’s hull structure.

Flush deck hatch

A flush deck hatch on a ship is a watertight opening in the deck that lies flush with the surrounding surface when closed. It provides access to compartments below deck for cargo handling, equipment maintenance, or storage. Flush deck hatches are designed to maintain the integrity of the deck structure while allowing easy and secure access when needed, contributing to efficient operations and safety aboard the vessel.

Flush deck ship

A flush deck ship is a vessel with a continuous, unbroken main deck that extends from bow to stern without any raised structures or superstructures above it. This design provides a flat and open deck space, which can be advantageous for certain types of cargo handling and operations. Flush deck ships are typically seen in smaller vessels or historical designs where simplicity and practicality in deck usage are prioritized.

Focsle

The forecastle (fo’c’sle) on a ship is the forward part of the main deck, located near the bow, and often includes crew accommodations and storage spaces. It serves as a working area for handling anchors and mooring lines, as well as providing essential housing for crew members. Additionally, it helps to improve the ship’s buoyancy by adding a volume to the front of the ship

Forebody

The forebody of a ship refers to the front section of its hull, extending from the bow to amidships. It includes the forwardmost part of the vessel’s structure and is critical for shaping its hydrodynamic performance, stability, and maneuverability. The forebody typically houses compartments such as crew accommodations, storage areas, and sometimes specialized equipment or machinery essential for the ship’s operations.

Forecastle

The forecastle (often abbreviated as fo’c’sle) on a ship is the forward part of the main deck, situated near the bow. Historically, it served as a raised platform for observation and defense in sailing vessels. In modern ships, the forecastle may house crew accommodations, storage areas, and sometimes machinery or equipment essential for ship operations. It also serves as a working area for handling anchors, mooring lines, and other deck operations.

Foredeck

The foredeck on a ship is the forward part of the main deck, extending from the bow towards amidships. It is typically a flat or slightly raised platform used for various operations, including handling anchors, mooring lines, and cargo. The foredeck provides essential workspace for crew members during docking, anchoring, and other deck activities, contributing to the efficient and safe operation of the vessel.

Forefoot

The forefoot of a ship refers to the forward-most part of the hull where the keel and the stem intersect. It plays a critical role in cutting through the water and influencing the ship’s hydrodynamic performance, stability, and maneuverability. The design and shape of the forefoot impact the vessel’s ability to navigate efficiently and maintain directional stability, making it an essential feature in ship construction and naval architecture.

Fore peak tank

The fore peak tank on a ship is a compartment located at the forward-most part of the vessel’s hull, near the bow. It is used primarily for storing ballast water, which helps adjust the ship’s trim and stability. Additionally, the fore peak tank serves as a safety measure to prevent water ingress into other compartments in case of damage to the bow. It is an integral part of the ship’s hull structure, contributing to its overall buoyancy and seaworthiness.

Forest product carrier

A forest product carrier is a specialized vessel designed for transporting various forestry-related products such as logs, lumber, wood chips, and pulp. These ships are equipped with specific cargo handling facilities and storage areas tailored to handle different types of timber and wood products. Forest product carriers play a crucial role in the global timber trade, facilitating the efficient transportation of raw materials and finished wood products between production areas and consumer markets worldwide.

Forward

“Forward” in maritime terminology refers to the direction or area towards the bow (front) of the ship. It is used to describe the location of objects, compartments, or movements relative to the vessel’s front end. For example, “forward deck” indicates the deck area near the bow, and “move forward” means to proceed towards the bow. This term helps in navigation, communication, and operational activities aboard a ship.

FPSO

FPSO stands for Floating Production Storage and Offloading. It is a type of floating vessel used in offshore oil and gas production. FPSOs are equipped with processing facilities to extract, process, store, and offload oil and gas extracted from subsea wells. They serve as mobile production units, capable of operating in remote offshore locations where fixed platforms are not feasible. FPSOs play a crucial role in the offshore oil industry by facilitating efficient and cost-effective production and transportation of hydrocarbons to shore facilities.

Frame

In maritime construction, a frame refers to a transverse structural member that runs perpendicular to the ship’s longitudinal axis, providing support and strength to the hull. Frames are spaced along the length of the vessel and help to maintain the shape and integrity of the hull structure. They play a critical role in distributing loads and stresses evenly throughout the ship, enhancing its stability, rigidity, and overall seaworthiness. Frames are typically spaced at regular intervals and are connected to the keel, hull plating, and other structural components to form the skeletal framework of the ship.

Frame station(s)

Frame stations on a ship refer to specific points along the hull’s longitudinal axis where frames or structural members are located and numbered for reference. These stations are marked at regular intervals along the length of the vessel, typically from the forward (bow) to the aft (stern). Frame stations are essential for shipbuilding and maintenance, providing standardized locations for measuring hull dimensions, assessing structural integrity, and conducting inspections or repairs. They serve as crucial reference points for ship designers, builders, and engineers throughout the lifecycle of the vessel.

Freeboard

Freeboard on a ship is the vertical distance between the waterline and the main deck level, measured amidships (at the midpoint of the ship’s length). It represents the margin of safety and buoyancy above the waterline, helping to prevent water from entering the ship’s hull during normal operating conditions and ensuring adequate stability and seaworthiness. Freeboard is a critical design consideration in shipbuilding, influenced by factors such as vessel type, cargo load, and international regulations governing safety at sea.

Freeboard deck

The freeboard deck on a ship is the uppermost continuous deck that provides a margin of safety above the waterline, ensuring adequate buoyancy and stability. It serves as a working platform for crew activities, cargo handling, and navigation equipment. The height of the freeboard deck above the waterline is determined by the ship’s design, intended load conditions, and regulatory requirements to maintain safety and seaworthiness at sea.

FRP

FRP stands for Fiber Reinforced Plastic, commonly known as fiberglass. In marine applications, FRP refers to composite materials made of a polymer matrix reinforced with fibers, typically glass fibers. These materials are lightweight, strong, and resistant to corrosion, making them ideal for constructing boat hulls, decks, and other marine structures. FRP is valued for its durability, versatility, and ease of maintenance, offering advantages such as reduced weight, improved fuel efficiency, and extended service life in marine environments.

Funnel

A funnel on a ship is a vertical structure used to expel exhaust gases from the ship’s engines and provide ventilation for the engine room and other compartments. It is typically located on the upper deck or superstructure and can vary in size and design depending on the ship’s propulsion system and operational requirements. The funnel also serves as a distinctive feature of the ship’s profile, often adorned with the vessel’s insignia or colors, and is a recognizable element in maritime aesthetics.