The three-masted carrack Santa Maria, onboard which Christopher Columbus discovered America, was 26 meters long, with a crew of up to forty people. The container ship Evergiven, which blocked the Suez Canal in March 2021, is one and a half times as wide as the length of the Columbian carrack, and its length is 400 meters: more than three Bolshoi Theaters. The size and weight of ships increased tenfold require new approaches to propulsion systems, and new environmental requirements leave their mark on the shipbuilding industry.
The first rafts that the tribes knitted turned into boats hollowed out of wood: this technology is still used, including in remote corners of Russia. Then there were rowing galleys and Viking ships, on which, after the invention of the sail, it was first used as an auxiliary control tool to the oars, and later as the main one.
Trade between peoples on different continents became the main incentive for the development of shipbuilding. Ships that used only a sail, without oars, appeared in the 10-11th centuries. And the era of Great Geographical Discoveries became the peak of the heyday of the shipbuilding industry. The number of masts and sails on them increased, with different purposes, multi-deck vessels appeared, ships began to be divided into military and commercial.
The first steam-powered vessel with a paddle wheel was built in 1807 by Robert Fulton. On September 25, 1838, the first electric ship was tested on the Neva. The Vandal river tanker, built in 1903, became the first diesel-powered motor ship. In 1954, the American submarine Nautilus became the first nuclear-powered vessel.
Read about the engine ideas offered on the shipbuilding market today in this Scientific Russia article.
Gas engines
The industry strives for environmental friendliness – new developments reduce the amount of greenhouse gas emissions into the atmosphere from cars, factories, energy. The shipbuilding industry is also approaching low-carbon development.
One of the solutions is vessels that use liquefied natural gas as the main fuel source. According to various sources, from 175 to 250 vessels around the world operate on gas – this is not much compared to the total number of civilian vessels, but the number of orders for them is growing. The engines of ships that run on natural gas emit 20-25% less carbon dioxide than diesel engines, and the emission of nitrogen oxides is reduced by more than 90%. In addition, the gas allows you to completely eliminate the release of sulfur oxides and solid particles. At the same time, natural gas is much cheaper than diesel fuel.
Gas is transported on ships in compressed and liquefied forms. Compressed gas does not require the operation of gas liquefaction plants, but the capacities that are needed to store compressed gas on a ship are at least two and a half times larger than for liquefied gas. To increase the period of autonomous navigation of the vessel and reduce the volume and weight of fuel, liquefied gas is mainly used.
Gas piston engines are more complex than diesel engines: this is due to the control and management of systems, fuel supply, and ignition. In a diesel engine, the ignition of the mixture occurs due to compression in the combustion chamber. A spark is needed in a gas engine, while natural gas is less stable than diesel fuel – fuel detonation may occur. To prevent a possible explosion, sensors and a detonation controller are installed on the engine, which collects information and, if necessary, changes the parameters of the ignition system.
Engines using solar and wind energy
Solar energy is one of the most popular types of alternative energy. Solar panels are also used as energy in shipbuilding.
The largest vessel that uses solar energy is the thirty-meter MS Tûranor PlanetSolar catamaran, launched in 2010. To get the necessary level of energy, 537 square meters of solar panels are installed on the catamaran, which charge the batteries. The solar cells installed on the catamaran were used in the construction of residential buildings with solar systems in the US, and the vessel can accelerate up to fourteen knots – this is almost 26 kilometers per hour. In 2011, the catamaran with a team of four people made a trip around the world.
The manufacturers of the French catamaran Energy Observer went a step even further in the field of alternative energy use. It combines solar panels, wind turbines, and hydrogen, which is converted into electricity. Interchangeable sources allow the ship to move even if one of the energy sources disappears, or two at once, for example, on a cloudy windless day.
For now, the use of only solar or wind energy on ships is an exception to the general rule: it is not possible to provide a large vessel with sufficient energy. But panels and wind turbines are used as additional sources for the operation of auxiliary systems.
Integrated electric motor systems
One of the new solutions in shipbuilding is a combination of gas turbines, diesel generators, and electric motors. Integrated electric motor systems use gas fuel and diesel fuel to generate a three-phase current, which ensures the operation of the engine rotating the propeller wheels or screws.
Electrical rather than mechanical power transmission allows for freer placement of engines, makes ships less noisy, and reduces weight. Integrated electric motor systems can use both a combination of gas-diesel and one of the types of fuel. On large military ships and cruise liners, both types are more often used. On smaller ships, preference is given to either a diesel generator or gas turbines. Diesel generators are characterized by increased efficiency, but the use of gas reduces the amount of harmful emissions into the atmosphere – for example, in Norway, ferries with gas-electric installations are used to cross fjords. They can accelerate to 18 knots and reduce carbon dioxide emissions by 300,000 tons per year.
Photo: kolashtov / ru.123rf.com
Based on open sources
