Skip to main content

Part Four - Types of Maritime Vessels

There are many different types of ships, and the differences are mostly based upon the type of cargo the ship transports. Most all ships have some basic things in common. Generally the deck from which the gangway comes off is the maindeck. The forward most compartment below the maindeck is the forepeak tank used for ballast. Also forward will be found the chain locker for the anchor chain which protrudes down into the forepeak tank. If you spot the main stack and go directly down below the maindeck you will find the engineroom. Going aft from the engineroom at the center of the ship, if it only has one engine, or on both sides if it has two engines, will be the shaft alley. On both sides of the shaft alley you will generally find tanks. What type of tanks those are will depend on the ship. They could be fuel oil, lube oil, fresh water and so on.

On most all general cargo ships, and on any number of other ships, going forward from the engineroom to the end of number two hold will be a pipe tunnel. In the pipe tunnel you will find steam pipes going to fuel oil tanks. Most ships use bunker oil for fuel. Bunker oil is almost as thick as tar and needs steam to heat it in order for it to be able to be pumped. Some will burn the fuel directly in the engines, while others will burn it in large boilers, and the steam created runs the engines, these are called steamships.

Upon the stern of the ship you will find written the ship's homeport, and the flag of the country in which the ship is registered. Upon the stack you will find, in most cases, a design that identifies the shipping line that owns the ship, If you see a red flag flying off the mast that means that the ship is taking on fuel. The following is a rundown of the major types of commercial ships:


1). General cargo ships (sometimes called Breakbulk Carriers).

These ships will mostly have four or five holds (a hold is the cargo space in a ship), with one or, in a few cases, two holds aft of the engineroom, and four to five holds generally forward of the engineroom. They have long protruding rigging for winches by each hold. These winches are used to load and unload the cargo. The cargo is usually packaged and moved as single parcels, or assembled together on pallet boards. Longshoremen go down into the holds to hook up the cargo to be lifted out. Some general cargo ships may also have refrigerated spaces for perishable cargo. The average general cargo ship is about 500 feet long.


2). Bulk carriers.

Like general cargo ships bulk carriers will have large hydraulic hatches covering the holds, but will not have any overhead rigging. Bulk carriers are used for things such as grain, ore, wood chips, etc, that can be poured down into a hold. They will load and off-load at special port terminals for whatever cargo they may carry. Sometimes the holds must be steamed cleaned by laborers when the ship is set to carry a different cargo than the one that it unloaded. The average bulk carrier ship is around 800 feet long.


3). Container ships.

These ships are designed to carry large steel containers that are usually 20 feet or 40 feet long, eight feet wide and eight feet tall. These ships are loaded and off loaded by large cranes to and from trucks. There are some that are also designed where the bow opens up and barges are pulled in that have containers on them. Container ships are limited to ports that have container terminals.

The advantage of using containers is that all the cargo in each container will be destine for some location away from the port taken there by either truck or rail. This does away with the warehouses that are needed for general cargo ships where the cargo is divided up and loaded into truck trailers or railcars. Container ships come in many different sizes; some now are incredibly huge.


4). Auto carriers.

These are huge ships that are nothing more than floating parking garages. They can hold between 2,000 and 4,000 vehicles. Ramps are lowered out of the side of the ship and the vehicles are driven off. The average auto carrier is about 600 feet long, 100 feet wide, and over 100 feet tall.


5). Tankers.

These are little more than oil drums with an engine. Though the most common tanker hauls oil, there are other tankers that haul many different types of liquids and gases. You can spot a tanker by the large amount of piping forward of the bridge on the main deck. The piping is for loading and off loading the cargo. There will be no large hatch covers like there is on general cargo ships and bulk carries, but there will be much smaller manholes at each tank for workers who need to climb down into the holds to work.

Just forward of the bridge is the pumproom, where the pumps for the ballast system will be found. Tankers come in all sizes, with the largest ones being supertankers that are nearly a quarter of a mile long and wider than a football field. There are few ports that supertankers can enter and thus they are mostly loaded and off-loaded from pumping stations off shore.


6). Fishing vessels.

Most people think of fishing vessels as being just boats, but in today's industrial world many of these vessels are as large as some ships and, in some cases, they are converted general cargo ships. The following are different types of fishing vessels:

  • A. Fishing boats - These may be as long as 90 feet and will have refrigerated holds.
  • B. Processors - These ships not only catch fish, but also within them there is a factory to completely process the fish. The factory deck will be right under the main deck and the fish come in and they are cleaned, filleted and packaged.
  • C. Non-fishing processors - These are a rather new type of ship that a few multinational corporations use. All that I have seen have been converted general cargo ships that have huge factory decks and refrigerated holds.

7). Oil industry vessels.

These are the vessels that are used by the oil industry in offshore drilling. These include work and living barges, supply boats, and pipeline vessels. The pipeline vessels will have huge rolls of pipe that they roll out into the water to connect the offshore oil well with an onshore facility.


8.) Passenger ships.

Today passenger ships are mostly used as cruise ships, but there are still a few passenger ships that transport people from port to port for the purpose of transportation, rather than sightseeing. I have worked on only one such ship that took people from New Orleans to the Panama Canal.

Some cargo ships will also include rooms for passengers, because if a ship has passengers, in many ports, it is allowed to dock before other ships. I have known a few people who have used this as a cheap means to travel to different parts of the world.


9). Ferryboats.

These are still in use in places where bridges cannot be built or are not constructed, for one reason or another. Some cross short bodies of water, while some sail long distances, like the Alaskan ferry. Ferries come in all sizes; from small passenger only ferries to the huge ferries the size of container ships that are used in northern Europe.


10). Tow and tug boats.

These are small vessels that generally have two powerful engines. Towboats are used for moving barges while tugboats are used to move ships, in most cases to dock them.


11). Barges.

These are unpowered vessels that require a towboat to move. Barges are used to transport different cargoes of which there are three basic types: there is the sunken hold type for such things as grain and ore, the flat top type for such things as containers and the tanker barges for liquids and gases. There are also barges for many other purposes; living barges, work barges, crane barges to name a few.


12). Specialized ships.

There are many ships that are constructed or converted for specialized purposes, like dredging, exploration, offshore construction, work gang ships (these are for housing workers in areas where there is no onshore living quarters), or for specialized cargo. For example, banana boats that are not much more than small general cargo ships. Banana boats are nasty damn ships, for down in their holds one may come across very large spiders.

As a pipefitter, there are few, if any, compartments, tanks, voids, tunnels and holds that we do not, at some time, have to work in. Along with shipfitters, marine pipefitters will have more direct experience in all the parts of a ship than even the seamen who sail the ship.