TLDR: Cargo ships are big boats that carry stuff from one place to another. They come in different sizes and types, like container ships, tankers, and bulk carriers. They have been around for a long time and play a major role in international trade. Some famous cargo ships include the Liberty ships and the Ever Given.

Cargo ships, also known as freighters, are merchant ships that transport cargo, goods, and materials between ports around the world. They are specially designed for this task and come in all sizes. They are usually made of welded steel and have a lifespan of about 25 to 30 years.

There are different types of cargo ships based on the kind of cargo they carry. Some examples include feeder ships, general cargo vessels, container ships, tankers, dry bulk carriers, multi-purpose vessels, reefer ships, and roll-on/roll-off vessels. Each type is designed to carry specific types of cargo, such as packaged items, liquid cargo, dry bulk cargo, or vehicles.

Cargo ships have a long history, dating back to ancient times when waterborne trade was already in practice. Over the centuries, improvements in ship design and the need for longer trade routes led to the development of larger and more efficient cargo ships. In the past, cargo ships were often armed to protect against piracy, and they were sometimes escorted by warships.

Piracy is still a concern in some waters, particularly in the Malacca Straits and off the coasts of Somalia and Nigeria. Governments and international organizations have taken measures to improve the security of cargo ships in these areas.

Cargo ships are categorized based on their cargo capacity, weight, and dimensions. There are different size categories, such as small handy size, Seawaymax, Handymax, Panamax, Neopanamax, Capesize, Chinamax, and Baltimax. Each category has specific limitations, such as the maximum length, width, draft, and height of the ship.

One of the challenges associated with cargo ships is pollution. Most large cargo vessels are powered by bunker fuel, which contains high levels of sulfur. This contributes to air pollution and has a negative impact on the environment. Efforts are being made to reduce sulfur emissions and improve the environmental performance of cargo ships.

In conclusion, cargo ships are essential for international trade, transporting goods and materials across the world's seas and oceans. They come in different sizes and types, each designed for specific types of cargo. While they have a long history, they continue to evolve to meet the demands of global trade.