Transport systems: Sea

For thousands of years, people have used boats and ships to transport goods over the water. The earliest boats rely on people rowing, and the first ships rely on the power of the wind to sail. But humans can only row so far, so fast, and the wind comes and goes. People want a way to carry more goods over longer distances, so they can trade with more people. Over time, ships grow larger and engines powered by gas and diesel are used to move them.

Today, the largest modern ships are about 80 times bigger than ships that sailed in the 1800s! These ships are the main mode of transportation for carrying goods around the world. It is estimated that today, over 80% of all goods are transported by ships. There are many different types of ships... Ships that transport oil across oceans in storage tanks are called tankers.

Each year, tankers transport nearly two billion tons of crude oil. Ships that carry loose cargo like iron ore, grains, cement, or coal are called bulk carriers. Most cargo, however, is packed into large, stackable metal boxes called shipping containers. The biggest container ships can carry close to 24,000 standardized containers at a time. Loading and unloading is fast and easy when containers are the same size.

And it also means that they can be used across different modes of transport – from ship to rail to truck – without needing to be unpacked. The time it takes to move cargo has gone down since the container shipping industry began in the late 1950s. Ships are important not just for transporting goods... but people, too. For those who live on small islands and need to access the mainland frequently, for example, passenger ships are an essential part of everyday life.

Passenger ships that move people across short-distances are called ferries. There are also ships used mainly for vacationing: cruise ships. Cruise ships are like floating hotels! They can carry anywhere from 100 to over 6000 passengers, and sail long distances. Whether on short journeys or round-the-world trips, transporting goods and people across the sea requires many systems working together.

We need reliable ways to communicate weather data so that ships can avoid storms. We need GPS so that navigators can accurately measure their speed and determine their location. There are also important waterways built by engineers that have shortened shipping times. The Suez Canal connects the Mediterranean Sea to the Red Sea, allowing ships to carry cargo between Europe and Asia. The Panama Canal connects the Atlantic and Pacific oceans.

These are just some subsystems that come together to make the marine transportation system work well. It is estimated that the volume of goods being shipped by sea will nearly triple by 2050. As demand grows, so too will the importance of innovation. New technologies, more efficient ship designs, low-carbon fuels, and improved route planning are just some ways that marine transport systems will likely develop going forward. Sea transport has been important for thousands of years and will certainly continue to be important in the future.