What are Cargo Ships?

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What are Cargo Ships?

Any ship or vessel that transports heavy goods and materials from one port to another is called a cargo ship. These are also known as freighters, and thousands of them swarm the seas of the earth at any given time because they handle the major bulk of international trade services.

Even today, shipping is considered the best mode of transportation and transfer of trade goods and any business item. This is because it is very safe handling delicate materials and is relatively cheap.

Present-day cargo ships are being revolutionised as shipping companies become more carbon neutral and reduce emissions from terminals’ operations, warehousing and logistics etc.

There are four different kinds of cargo ships, and they are classified based on the cargo they carry, namely, general cargo vessels, multi-purpose vessels, dry-bulk carriers and, last but not least, tankers. General cargo vessels mostly carry packaged goods like foods, footwear, garments, chemicals, machinery, furniture, motor vehicles, etc.

 

Types of Cargo Ships

A different kind of specification further segregates the cargo ships into two distinct categories: the liners and the tramp ships. The ships that travel on a fixed pre-scheduled route and have charged tariffs are called liners or cargo liners. On the other hand, the vessels that do not follow any pre-determined schedule or route and are chartered by various users to transport their goods at a fixed contractual price are called tramp ships.

The smaller shipping companies generally opt for tramp ships as they do not have enough fleet to run liner voyages. In some cases, the cargo ships also carry few passengers along. So any ship that can hold 12 or more passengers along with the loads is called a passenger-cum-cargo liner.

General cargo or multi-purpose vessels are designed for flexibility and carry a huge variety of cargo. To get the most from a general cargo ship, it is important to minimise any time spent in port and optimise the efficient use of the vessel’s cargo carrying space. Get these elements right and your vessel will achieve its maximum earning capabilities.

Even though the general cargo ships had the flexibility of carrying different types of packaged items, the long time that they used to take for loading and discharging, led to the advent of Container ship[s.

What are Container Ships?

As the name suggests, a vessel structured specifically to hold vast quantities of cargo compacted in different containers is called a container vessel (ship). The process of sending shipments in special containers is known as containerisation.

 

One of the most powerful methods of hauling goods is done by Container Ships. These ships have made it feasible to transfer high quantities of cargo at a time and have changed global trade effectively.

Container ships are the cargo ships that carry most seagoing non-bulk cargoes. In today’s world, container vessels have around 90% of the world’s non-bulk cargo. One of the main ways of carrying ready goods worldwide is through Container Vessels. These containers are of a standardised size so that they can be easily transferred to various modes of transport. Anything can be carried on a Containership.

Because of the increasing demand in the market, increasing cargo-carrying capacity, increasing operating efficiency and improvement in environmental processes and operation of a container vessel in liner service, the container vessels have continuously become bigger.

The container carrying capacity of container ships today has increased more than 1200% compared to 1968. They have become more technologically advanced and fuel-efficient over time.

History of Container Ships

The initiation of container shipping forms one of the most remarkable developments in the maritime cargo industry. Container ships, a type of cargo ship, have revolutionised how cargo supplies are ferried and transported across the world by assuring the safety and security of the thus transported cargo supplies. Today, some of the biggest shipping companies deal mainly with the containerised form of cargo.

The first models of container ships were launched in the early 1950s and were mainly designed to ferry goods trains’ freight cars. Using crane and ramp systems, these freight cars could be loaded and unloaded from the vessels.

Over the years, technological advancement has made it possible for comparatively far more feasible methodologies. However, crane systems still play a significant role in the loading and unloading operations of the containers to and from the vessels’ holds. Specialised lashing and cargo handling systems are used to secure the containers in their places.

Container vessels are typical in that they are constructed to accommodate immense possible cargo loads. The load holding capacitance of container vessels is measured in terms of Twentyfoot Equivalent Units or TEUs, with the giant container ships carrying as much as over 15,000 20,000 TEUs.

Types of Container Ships

Container vessels can be classified in many ways:

Development Generations

Containers vessels have been through various phases. These phases have been classified as generations.

  1. First Generation – 1956 TO 1970
  2. Second Generation – 1970 TO 1980
  3. Third Generation – 1980 TO 1988
  4. Fourth Generation – 1988 TO 2000
  5. Fifth Generation – 2000 TO 2005
  6. Sixth Generation – 2006 TO TILL DATE

Handling Modes

LoLo Container Ships

Lift-on/Load-off vessels are Geared container vessels which can load and discharge the cargo using the ship’s crane.

ROCON Container Ships 

ROCONs are ro-ro vessels that also carry containers. The arrangements are such that the containers may be loaded on the deck, or there is a separate hold specifically for loading containers.

Container Ship Sizes

 Some of the main types of container ships based on size are:

  • Panamax
  • Suezmax
  • Post-Panamax
  • Post-Suezmax
  • Post-Malaccamax

Panamax

  • Panamax size vessels were first introduced in 1980.
  • These vessels were of around 4000-5000 TEUs.
  • Their dimension was such that they could pass the Panama canal. They were limited to the max length of 294.1m, Breadth of 32.3m and max draught of 12m, which was par compared to the canal’s dimensions.

Post- Panamax

  • APL introduced a new transportation net without using the Panama Canal. This created the ‘Post-Panamax’ type. The Introduction of Regina Mærsk in 1996 started a new development in the container ship market with an official capacity of 6400 TEU.
  • Post-Panamax’s development was climactic. In the present world, they occupy nearly 30% of the world’s fleet.
  • These sizes of vessels were subversive, introducing new ideas and methods in the container shipping market.
  • The concept of cellular container vessels was introduced. The cell guides ran from the bottom of the hold to some tiers above the deck. This reduced the running cost of ship owners as no lashing materials were used to secure the containers but also improved the speed of loading and discharging and reduced container shifting.

Suezmax

  • Suezmax max-size vessels were introduced about the Suez Canal. These vessels have nearly the same size as that of the Suez Canal.
  • Suezmax vessels have a carrying capacity of around 12000 TEUs, with a Breadth of about 50-57 m and draught between 14.4m-16.4m.

Post-Suezmax

  • These are Ultra-large container vessels with a carrying capacity of 18000 TEU with a breadth of 60m 21m max draught.
  • These vessels are known as Post Suezmax as their dimensions are too big for the vessel to pass the Suez Canal.

Post – Malacamax

  • This size emulates the maximum permissible draught of 21m of Malacca Strait.
  • The port authorities must be ready for this vessel to enter the Ports. Presently only two ports in the world are prepared to accept this size of ship, i.e., Singapore & Rotterdam.

Container Ships Service Range

Feeder Ship

  • These ships are used for short routes. The voyages are no longer than 500nm and only trade in the coastal areas.
  • The Capacity of such vessels does not exceed 1500TEU.

Mother Ship

  • These are the vessels that are in international trade.
  • The size of these vessels is much bigger than feeders.

Basic Design of Container Vessels

The design of the accompanying container vessel is decisive. The hull is akin to the conventional Bulk Carriers and General cargo ships built around a firm keel. The lower part of the vessel has a significant effect on the construction of the ship. There are lower decks, an Engine room, great ballast, and Fuel Tanks. The Cargo holds are the places where the under deck Containers are loaded.

Inside the hold, cell guide arrangements guide the container to slot well. This helps the crane operator safely slide the container inside the handles and acts as a guide. It is imperative to maintain this cell guide well. Any damage to the cell guides may lead to critical consequences. These holds are topped by hatch covers, above which the containers are stacked.

Most modern container vessels do not have cranes, but some have cargo cranes installed on them, especially in vessels of smaller sizes. Vessels with cranes are called geared container vessels, whereas vessels without cranes are called Gearless container vessels.

These geared container vessels use them for self-loading and discharging at ports where the cargo volume is low. There are also some specialised systems for securing the containers onboard.

In most container vessels, lift-away types of Hatch covers are used. Hatch covers to increase the ship’s carrying capacity and prevent water ingress inside the hold & fissure, the containers underdeck and on deck both. These hatch covers have cleats that must be closed after every cargo operation & before the vessel departs from any port. The lift on lift off type of hatch pontoons also assists in planning the loading, as container vessels are the only type of vessels which load in 4-5 ports and discharges also in 4-5 ports.

Also, within a container ship, well-demarcated holds separate each container from the other, simplifying the entirety of the filing of the containers.

  • In essence, container ships are regarded to be a generic reference. Within their ambit, there are several different types of container ships. Each container vessel is unique and different, with an undiminished operational singularity.
  • Container ships explicitly built to fit into the Panama Canal channels are called the Panamax container vessels. These ships can be loaded with a maximum TEU of about 5,000 and measure slightly over 290 metres lengthwise.
  • The slightest variance of container vessels is the Small Feeder type. These container vessels can carry loads up to 1000 TEUs. Several developments made to the Feeder categorisation have resulted in the development of the categories of ‘Feedermax’ and ‘Feeder.’ The former can carry a maximum of about 3,000 TEUs, while the latter can carry around 2,000 TEUs.

Container shipping vessels represent a majority in terms of the packaged cargo ferried across the world. On account of the relevance and the ever-increasing demand for better maritime cargo transportation channels, there have been considerable strides in the container ships’ domain. Such advancements are expected to grow even more in the days to come.

 

 

 

 

 

Capt TV Raghuraman,, Faculty,

       Sri Chakra Maritime College, Puducherry