Parts of a Merchant Ship & Their Functions Best Explained

by | Last updated May 9, 2024 | Career Guide, Ship Parts, Vessel Information | 0 comments

Merchant ships are the workhorse of the global economy. We build them in different types and sizes to accomplish specific tasks. But, despite their diversity, merchant ships share common parts and functions. 

If you are a seaman, you may be familiar with the terms bow, bridge, rudder, thrusters, accommodation, and many others.

All types of merchant ships share these most basic parts.

There are hundreds of thousands of components that make up a merchant vessel. Building them is like a huge jigsaw puzzle. Many of them are so specific. Even so, professionals know exactly how to assemble them.

But let’s not dive into that since we won’t be building one. Let’s focus on the most common parts of a merchant ship that you can find on any vessel. 

If you become fully familiar with them, you can readily identify these components in the blink of an eye.

Parts of a Merchant Ship

Vessels look different from one another. There are those carrying boxes like container ships and those transporting oil like tankers of varying sizes.

The most striking difference readily visible to anyone is their deck area. That’s discounting their paint job, of course.

But even if they look different, their similarities dwarf these variations. So here are the most common parts of a merchant ship found on any vessel.


For a vessel to float, it needs a hull.

A hull is a part of a ship that carries the whole vessel. It runs from forward to aft and is basically where we build everything on the vessel.

The hull has various parts as well and one of them is the keel which is the backbone of the ship. Other parts include the girders and the frames.

Aft Section of the vessel showing the accommodation, rudder, funnel, mast, bridge, and the ship's hull.
Aft Section of a vessel.


The bow of a vessel is the forward-most part of the ship. It is the section where it crashes into the waves when sailing.

The most notable component of the bow is the bulbous bow. 

A bulbous bow is a bulb-shaped sticking out on the forward part of the vessel. It is mostly submerged to reduce the ship’s resistance against the flow of water.

Other parts of the bow include the forecastle, chain locker, and anchors.


This is the middle part of the vessel between the bow and the stern.

Specifically, we can measure the midship as the distance between the forward and aft perpendiculars.


This is the opposite of the bow. The stern is the aft-most part of a merchant ship. This is where they install the propeller, rudder, and towing pendants.

Engine Room

The engine room is the place where we can find most of the ship’s machinery. It is located in the stern part of the vessel but is not readily seen since it is under the accommodation block.

The engine room is the “playground” of the engineers. We can find here the main engine that runs the ship, the boiler, generators, various pumps, and many more.

Accommodation Block

Also known as the Accommodation, this part of any merchant vessel is the living space. In short, it accommodates the crew and visitors, if any.

This is where we can find the cabins including galleys, messrooms, day rooms, gym, and the Bridge.

The accommodation has many “floors” called decks. For directional purposes, we name them first deck, upper deck, second deck, bridge deck, etc.

The Bridge

The bridge is the command and control center of a vessel. It sits on top of the accommodation block. You can find many communications equipment and navigational devices inside the bridge.

It is called a Bridge because, in ancient ship designs, it connects the port and starboard side of the vessel.

You can find a fun and informative article about nautical terms and their origins on that hyperlink.

The extension of the bridge on the port or starboard side which is exposed to the weather is called the bridge wings.

Two crew walking past by the forward part of the vessel where we can see the bow thrusters and bulbous bow as the ship rests on drydock.
The Bow Thrusters with its markings embossed above the waterline indicate its presence.

Port Side

Now that we cover the forward, middle, and aft parts of the vessel, another term you can hear on board is the port side and starboard side.

The port side is the left side of the ship when you are standing inside the bridge and facing the bow.

Starboard Side

The right side of the vessel when you are facing the bow is the starboard side. Always!

Whichever direction you face on board, the port side and starboard side stay the same.


A ship is not complete without a mast.

There is a part of a merchant ship where you can find a tall structure. Specifically, you can find it forward.

A mast is a pole or a similar tall structure built so we can install other components. These components are usually small and must be as high as possible according to SOLAS. The mast fulfills that.

Normally, there are three masts on board- forward, aft, and on the top of Monkey Island.

Navigational lights, fog horns, floodlights, antennas, and radar are among the instruments installed on masts.

Monkey Island

We know that animals are not allowed on board but we do have a place called Monkey Island.

A Monkey Island is a place on the vessel located just above the bridge deck where we can find the magnetic compass

Aside from the compass, we can also find other equipment such as radio antennas, VDR, searchlight, and radar mast.

We call it Monkey Island because, during the age of sails, this place is usually the highest part of the vessel built for lookout purposes.


Decks are similar to floors in buildings.

If you are on a vessel right now, you are most probably standing on the deck.

A deck is a surface that occupies one side of the ship to the other. Like a building, a ship also has levels or floors called decks.

Propeller, Rudder, and the Engine Room
Propeller, Rudder, and the Engine Room.


Now we go to the submerged parts.

This time is the propeller. A propeller is a mechanical device that propels the ship. It is a fan-like structure that rotates and gives thrust to the vessel.


A rudder usually goes with a propeller.

A rudder is a piece of blade installed behind the propeller that gives directional control to the vessel.

We can see the rudder and propeller when the ship’s draft is low.


Thrusters are like mini propellers but installed facing the port and starboard sides of the vessel.

While propellers move the ship forward and backward, thrusters enable it to move laterally or rotationally.

Some ships have bow thrusters. Others both have the bow and stern thrusters. Still, some have none at all.


Since vessels transform fuel into propulsion, they also produce smoke or gasses.

They release these gasses through the funnel which is located behind the accommodation block.

A ship’s funnel is one of the most obvious parts of a merchant ship. It is painted with colors that signify the company running them.

Many ships may share the same orange hull, green decks, or white accommodation blocks. But one way to differentiate them is through the color and design of their funnels.

Ship’s Crane

A ship’s crane is a crew-operated machine that lifts heavy objects on or off the vessel.

Most of the time, they are of fixed installation while other rare types are movable or traveling.

Some ships have cranes built on the cargo deck while others have none. Most vessels have cranes on the aft part. It is used during provision and taking in stores or spare parts.

Ballast Tanks

Ballast tanks are compartments around the vessel where we pump seawater in or out during ballasting and deballasting for stability purposes.

Although not entirely visible, you can easily identify them. They are built on the ship’s side as a way to balance the ship.

Their purpose is also to protect the cargo spaces in case there is a breach in the hull.

Top view of a bulk carrier performing cargo operations with its parts labeled.
Bulk carrier performing cargo operation.

Cargo Space

A vessel’s purpose is to transport cargo from one place to another using the seas, oceans, or any waterways.

The cargo space is where we stow or lash these goods. These spaces can be huge tanks for tankers or holds located below deck.

Meanwhile, some of them are stowed in bays like containers.

Cargo spaces are parts of a merchant ship which are also called earning spaces.

These are but a few of the parts of a merchant vessel. There are even more and many of them are very technical.

One reason why they have commonalities with other ships is because of SOLAS Regulations. SOLAS is about ship construction requirements so vessels should follow the same standards.

We will have a look at them sometime in the future.

Hope you learn something today.

May the winds be in your favor.



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