Different Parts of a Ship Explained with Functions

With over 109,000 vessels in the global commercial fleet, each weighing at least 100 gross tons, knowing your way around a ship is essential for professionals working at sea.

Hull and Main Structure

The hull is the watertight body of the ship that keeps the vessel afloat. Every other structural component connects to or sits within the hull. Modern hulls are typically constructed from steel, designed to withstand constant exposure to seawater and varying weather conditions.

Key structural components include:

Keel: The backbone of the ship running along the bottom centerline from bow to stern. The keel provides structural integrity, supports the entire ship structure, and prevents the vessel from drifting sideways in strong currents. The keel also helps distribute loads along the ship's length and is critical for vessel stability.

Bulkheads: Vertical watertight walls inside the hull that divide the ship into separate compartments. Bulkheads enhance structural strength and contain flooding to isolated sections during emergencies, preventing total loss of buoyancy. Ships are designed with multiple bulkheads as required by international maritime regulations.

Double Bottom: A safety feature on modern vessels that creates an additional protective layer at the lowest part of the hull. The double bottom compartment serves dual purposes, providing structural support and creating a safety barrier against grounding or collision damage.

Bilge: The lowest internal point of the hull where water and residual liquids collect during normal operations. Regular bilge management is essential for vessel maintenance and environmental compliance, with water pumped overboard through designated systems.

Bow and Stern: Front and Back of the Ship

Bow

The bow is the forward section of the ship that cuts through water as the vessel moves. A well-designed bow minimizes drag and prevents waves from splashing excessively onto the deck. Many commercial vessels feature a bulbous bow, a rounded projection below the waterline that improves fuel efficiency by 10-15% through wave modification.

Understanding the load lines convention for ships is essential for grasping how the bow's draft and freeboard relate to the vessel's safe carrying capacity and stability characteristics.

Stern

What is the back of a ship called? The rear section is known as the stern. The stern houses critical components, including the rudder, propellers, and steering gear system. A properly designed stern reduces resistance and improves propulsion efficiency while minimizing vibrations during operation. The transom is the flat vertical surface at the very back of the stern, often used as a mounting point for equipment and through-hull fittings.

Deck Structures for the Ship

The deck is the horizontal surface covering the hull, creating both working platforms and structural support. Ships typically have multiple deck levels, each serving different purposes:

Common deck areas include:

• Main Deck (Weather Deck): The uppermost deck exposed to weather conditions, serving as the primary working surface

• Forecastle (Foc'sle): The raised forward section of the upper deck containing anchoring equipment and ground tackle. The forecastle typically does not extend beyond 7% of the total deck length and houses the windlass and anchor chain systems.

• Poop Deck: The raised deck at the stern, providing the captain and crew with an elevated position to supervise vessel operations

• Freeboard: The vertical distance between the waterline and the main deck edge, critical for stability calculations and regulatory compliance

A proper understanding of 10 important ship construction regulations ensures that deck structures meet international safety and design standards for structural integrity and crew safety.

Navigation and Control Areas

Bridge

The bridge serves as the command center of the ship. All navigation and control functions occur here, including:

• Controlling ship speed and direction through the engine order telegraph and steering wheel

• Monitoring weather and sea conditions through radar, electronic instruments, and visual lookout

• Determining and fixing the vessel's position using GPS, electronic charts, and celestial navigation

• Managing internal communications with the engine room and external communications with other vessels and shore authorities

Modern bridges integrate electronic navigation equipment mandatory under international maritime regulations. Understanding navigation equipment used on modern ships is essential for mariners to operate vessels safely and maintain compliance with SOLAS requirements.

Monkey Island

Located directly above the navigation bridge, the monkey island provides the highest accessible platform on the ship. Also called the flying bridge, this area often houses additional navigation equipment, magnetic compasses, and signal flags. The monkey island provides an unobstructed observation point for maneuvering the vessel in confined waters.

Propulsion and Steering Systems

Engine Room

The engine room is the powerhouse of the vessel, typically positioned on the lowest deck toward the stern. Major equipment housed here includes:

• Main propulsion diesel engine

• Auxiliary generators for electrical power

• Boilers for steam generation

• Fuel purifiers and oil treatment systems

• Fresh water generators

• Pumps, compressors, and heat exchangers

The engine room operates at temperatures exceeding 45°C and requires continuous monitoring to ensure safe and efficient vessel operation.

Propeller

Propellers generate thrust to move the ship forward. Made from corrosion-resistant alloys like bronze or manganese, propellers convert engine power into movement through the water by creating pressure differences across the blade surfaces. Commercial vessels may have one, two, or three propellers depending on size and design requirements. Propellers work on Newton's Third Law of Motion, pushing water backward createsan equal and opposite force moving the ship forward.

Rudder

Attached to the stern, the rudder controls the ship's direction. When the helmsman turns the wheel on the bridge, the rudder pivots to change the vessel's heading. The main rudder must be capable of moving from 35 degrees port to 35 degrees starboard within 28 seconds under international safety regulations. Backup steering systems (auxiliary rudders) ensure continued directional control if the main rudder fails.

Bow and Stern Thrusters

Side-mounted propellers at the bow and stern allow for lateral movement without forward motion. Bow thrusters are particularly valuable when maneuvering in ports, canals, or crowded waterways at slow speeds where the main rudder is ineffective. These tunnel thrusters significantly reduce reliance on tugboat assistance during docking operations.

Cargo and Storage Areas for Your Ship

Cargo Hold

The hold is where cargo is stored during transport. A vessel may have multiple holds, each accessible through hatch openings on deck. The cargo hold is completely enclosed to protect cargo from weather exposure during the voyage. Hold capacity ranges from 20 tons to 200,000 tons, depending on vessel size and type. Liquid cargo vessels, known as tankers, use specialized tanks instead of traditional holds.

Hatch Covers

Hatch covers seal cargo storage areas, keeping them watertight and protecting goods from weather exposure and seawater spray during the voyage. Hatch covers are hydraulically driven on modern vessels, allowing rapid opening and closing to optimize cargo handling efficiency.

Ballast Tanks

Compartments that hold water to maintain vessel stability and proper trim. Proper ballast management is essential for safe ship operation, fuel efficiency, and environmental compliance. Ballast water is regulated internationally to prevent the spread of invasive marine species between ocean regions.

Additional Critical Components for Your Ship

Mast

A vertical steel structure mounted on the bridge or near the bow. Masts support radar antennas, navigation lights, communication equipment, signal flags, and various sensing devices. The mast provides the elevated platform necessary for radar signals to transmit effectively and for navigation lights to be visible across the required range.

Funnel (Stack)

The chimney that discharges exhaust gases from the engine and boiler systems. Modern funnels are angled toward the stern to direct smoke away from the bridge and deck areas. Funnel design must account for air pollution regulations, requiring scrubbers or other emissions control equipment on many vessels.

Accommodation

Living quarters for the crew, including cabins, galley (kitchen), mess rooms, recreation areas, and medical facilities. Larger vessels may include gymnasiums, laundry facilities, and prayer rooms to support crew welfare during extended voyages. Under maritime labor conventions, all vessels must provide adequate accommodation meeting minimum space, lighting, ventilation, and safety standards.

Anchor

A heavy metal device attached to chain cables, stored in the hawse pipe when not in use. The anchor secures the ship in position when waiting for a berth or in holding areas. Modern ship anchors typically weigh 15-20 tons and are connected to hundreds of meters of chain cable stored in dedicated chain lockers.

Conclusion

Understanding ship parts and their functions is essential for anyone working in the maritime industry. From the keel providing structural support to the rudder controlling direction, each component plays a critical role in safe and efficient vessel operation. Maritime professionals must be familiar with these terms and understand how each part contributes to overall vessel performance and safety.

For comprehensive navigation publications, maritime regulations, and compliance resources needed to operate safely and efficiently, American Nautical Services provides essential tools for maritime professionals worldwide.

FAQs

Q1. What is the back of a ship called?

The back of a ship is called the stern. The area inside the ship toward the rear is referred to as aft, while the outside rear portion is the stern itself. The flat vertical surface at the very back is the transom.

Q2. What are the left and right sides of a ship called?

When facing the bow, the left side is called port (traditionally marked with red lights), and the right side is called starboard (marked with green lights). This standardized terminology prevents confusion regarding ship orientation.

Q3. What is the main body of a vessel?

The main body of a vessel is the hull, the watertight structure that provides buoyancy and structural support for all other ship components. The hull extends both above and below the waterline.

Q4. What is the difference between a deck and a hull?

The hull is the main watertight body of the ship that provides buoyancy and structural integrity. The deck is a horizontal surface that covers the hull, providing a platform for crew activities, equipment placement, and cargo storage.

Q5. Why do ships have bulbous bows?

Bulbous bows create a wave that partially cancels the bow wave created by the hull moving through water. Reducing wave resistance improves fuel efficiency, typically achieving 10-15% better fuel economy compared to conventional bow designs. This makes bulbous bows standard on most large commercial vessels.

Q6. What is the function of the keel?

The keel serves as the backbone of the ship, providing structural support, distributing loads along the ship's length, and preventing lateral drift. The keel also contributes to vessel stability and is essential for safe ship operation in varying sea conditions.