Types of Ships. Part19

Types of Ships

Cargo ships are classified into various types on the basis of purpose, size, type of cargo etc.

The economic factor is of prime importance in designing a merchant ship. Every owner wants maximum return on their investment which means a ships construction not only depends on the current economic necessities but the factor of future adaptability also plays a part.

From the preliminary design of a vessel due for construction, the following information can be obtained:

1.      Dimensions

2.      Displacement

3.      Stability

4.      Propulsive characteristics and hull form

5.      Preliminary general arrangement

6.      Principal structural details

A layout of the various ship types and their subdivisions will be listed out, covering a wide range of all vessels in operation. 

The type of ship plays an important role in deciding the above mentioned parameters.

Types of Ships

Ships are mainly classified into the following types:

1. Container Ships

2. Bulk Carrier

3. Tanker Ships

4. Passenger Ships

5. Naval Ships

6. Offshore Ships

7. Special Purpose Ships

1. Container Ships

As the name suggests, a vessel structured specifically to hold huge quantities of cargo compacted in different types of containers is referred to as a container vessel (ship).

Types of Container Ships On Basis Of Sizes:

1. Panamax
2.  Suezmax
3. Post-Panamax
4. Post-Suezmax
5. Post-Malaccamax

2. Bulk Carrier Ships

Bulk carriers are a type of ship which transports cargoes (generally dry cargo) in bulk quantities. The cargo transported in such ships is loose cargo i.e. without any specific packaging to it and generally contains items like food grains, ores and coals and even cement.

1.          Conventional bulkers
2.          Geared bulker
3.          Gearless bulker
4.          Self-discharging bulker
5.          Lakers
6.          BIBO

Some other forms of dry cargo are:

         Tramps: A boat or ship engaged in the tramp trade is one which does not have a fixed schedule or published ports of call.

         Cargo Liners: An ocean liner is a ship designed to transport passengers from point A to point B. The classic example of such a voyage would be a transatlantic crossing from Europe to America.

3. Tanker Ships

Tanker ships are specialised vessels for carrying a large amount of liquid cargo. Tankers are further sub-divided into different types on the basis of the cargo they carry.

The main types of tankers are:

Oil Tankers: Oil tankers mainly carry crude oil and its by-products.

Liquefied Gas Carriers: A gas carrier (or gas tanker) is a ship designed to transport LPG, LNG or liquefied chemical gases in bulk.

Chemical and Product Carriers: A chemical tanker is a type of tanker ship designed to transport chemicals and different liquid products in bulk

Other types of tankers: Some other types of tankers are juice tankers, wine tankers, integrated tug barges etc.

On the basis of their size, tankers are further divided into varies types such as:

1.  VLC
2. ULCC
3. Panamax
4. Aframax
5. Suezmax
6. Capesize
7. Handymax
8. Lighters
9. Handy

4. Roll-on Roll-Off Ships

Ro-Ro is an acronym for Roll-on/roll-off. Roll-on/roll-off ships are vessels that are used to carry wheeled cargo.

Pure Car Carrier (PCC) and Pure Car and Truck Carrier (PCTC) RoRo Ships

1. Container Vessel + Ro-Ro (ConRo) Ship
2. General Cargo + Ro-Ro Ship (GenRo) Ships
3. RoPax
4. Complete RoRo Ships

5. Passenger Ships

Passenger ships, as the name suggests, are mainly used for transiting passengers.

They are mainly classified into:

Ferries  Vessels used for transiting passengers (and vehicles) on short-distance routes are called ferries.

Cruise Ships  Mainly used for recreational activities, cruise ships are like luxurious floating hotels with state-of-the-art facilities.

They are further classified as:

1.  Liners, Cruise Ships, Pilgrimage Ships
2. CrossChannel Ferries, Coastal Ferries, Harbour Ferrie
3. Arctic and Antarctic Cruises

6. Offshore Vessels

Offshore vessels mainly help in oil exploration and construction jobs at sea. Offshore vessels are of several types.

Some of the main ones are:

1. Supply Ship: Vessels that supply to offshore rigs
2. Pipe Layers: Vessels engages in laying pipes and cables
3. Crane Barges or floating cranes: A crane vessel, crane ship or floating crane is a ship with a crane specialized in lifting heavy loads
4. Semi-submersible Drill Rigs: These are Mobile Offshore Drilling Units to make stable platforms for drilling oil and gas
5. Drill Ships: A drillship is a merchant vessel designed for use in exploratory offshore drilling of new oil and gas wells or for scientific drilling purposes
6.          Accommodation Barges: Could be a stand-alone floating hotel or can include accommodation as well as space for Cargo.
7. Production Platforms: To extract and process oil and natural gas, or to temporarily store product until it can be brought to shore for refining and marketing
8. Floating Storage Unit (FSU)  Floating vessel mainly used for storage of oil and by-product.
9. Floating Production and Storage Unit (FPSO): A floating production storage and the offloading unit is a floating vessel used by the offshore oil and gas industry for the production and processing of hydrocarbons, and for the storage of oil
10. Anchor handling vessels  These are used for offshore construction and installation operations.
11. Diving vessels  Are vessels used by divers for diving in the ocean for underwater jobs.

7. Fishing Vessels

Ships or boats used for recreational or commercial fishing at sea are called fishing vessels.

Fishing vessels are mainly classified into two types  trawlers and non-trawling vessels.

Trawlers, Purse Seiners: A fishing trawler, also known as a dragger, is a commercial fishing vessel designed to operate fishing trawls. Trawling is a method of fishing that involves actively dragging or pulling a trawl through the water behind one or more trawlers. A purse seine is a large wall of netting deployed around an entire area or school of fish. The seine has floats along the top line with a lead line threaded through rings along the bottom. Once a school of fish is located, a skiff encircles the school with the net.

Factory Ships: A factory ship, also known as a fish processing vessel, is a large ocean-going vessel with extensive on-board facilities for processing and freezing caught fish or whales

8. Speciality Vessels

Speciality vessels are constructed and used for specific purposes.

1. Tugs: A tug (tugboat) is a boat or ship that manoeuvres vessels by pushing or towing them.
2. Tenders  A boat or a larger ship used to service or support other boats or ships, generally by transporting people and/or supplies is called a tender vessel.
3. Pilot Crafts  Pilot crafts are used for the transportation of harbour pilots.
4. Cable Layers  Cable laying vessels help in laying cables on to the sea bed. 
5. Research Vessels  They are special types of vessels used for carrying out a variety of researches at sea. Some of the most common types of research vessels are  seismic vessels, hydrographic vessels, oceanographic vessels, polar vessels etc.
6. Salvage Vessels  Salvage vessels are vessels engaged in salvage operation; recovery of lost property at sea.
7. Lightships: A lightvessel, or lightship, is a ship which acts as a lighthouse. They are used in waters that are too deep or otherwise unsuitable for lighthouse construction.
8. Barge Carriers: A barge is a flat-bottomed boat, built mainly for river and canal transport of heavy goods.
9. Timber Carriers: Vessels that carry timber
10. Livestock Carriers: Vessels that carry livestock/animals
11. Ice breaker ships: They are used for cutting ice deposits in extremely cold climate conditions to make waters possible to navigate

9. High-Speed Craft

High-speed crafts are a special type of technologically advanced high-performance (typically high speed) marine vehicles. Though most of these technologies are not used in commercial vessels, a few have been successfully implemented and tested in conventional merchant vessels of small scale.

Some of the main types of high-speed crafts are:

1.          Multihulls including wave piercers
2.          Small waterplane area, twin-hull (SWATH)
3.          Surface effect ship (SES) and Hovercraft
4.          Hydrofoil
5.          Wing in Ground Craft (WIG)

10. Dredgers 

Dredging is an excavation activity usually carried out underwater, in shallow seas or freshwater areas with the purpose of gathering up bottom sediments and widening

Dredgers are vessels with excavation tools used for removing sand and other types of deposits from the seabed. Dredgers are used for several purposes such as making shallow coastal areas navigational, deep-sea mining etc.

Dredgers are mainly classified into two types:

1.      Mechanical dredgers

2.      Hydraulic dredgers