Developing Greener Ships

Kirsten Long

The oceans play a vital role in the life of our planet, producing oxygen, absorbing carbon and forming clouds that bring us fresh water. We are constantly trying to find new ways in which we can save our oceans.

Ships travel the oceans everyday in order to transport people, goods and services, catch fish and more. The engine systems used in the vessels can be harmful to the environment, which is why Zuomin Dong and his research team, from the University of Victoria, are working on engineering solutions to make environment-friendly ships. The mechanical engineer is focusing on hybrid electric propulsion systems, not only for ships but heavy-duty mining trucks as well as trains. BC Ferries is among the several industry partners interested in fleet conversion that are working with Dong.

Unlike cars, ships cannot be mass-produced, as the design of each system is unique and cannot be used as a template for all other ships. The conditions of the water, being open or protected waters, the cargo its carrying, currents and winds are all factors that need to be considered when designing the system. The challenge BC ferries is facing is grasping the amount of electrical energy needed for a ferry to complete its route. They also want to explore how that energy can be replenished into the onboard batteries while the ferry is picking up new passengers.

University of Victoria News reports that Dong’s team uses a computer design model to give a profile that is unique to each ship, as an integrated system. This helps them to predict energy requirements, which they are successful at 90 percent of the time. The system also incorporates ship-induced noise into the model in order to guide the design of propulsion systems and the operating procedures that cause cavitation. Cavitation’s are the loud, persistent sound made underwater caused by air bubbles from the propeller that are known to interfere with marine animal communications.

Dong has stated that greener ships can be made possible through the amalgamation of natural gas engines and hybrid electric propulsion systems. Natural gas may be cleaner than diesel but it does not completely combust at certain loads, which limits the reduction in greenhouse has (GHG) emissions and results in an increase in hydrocarbon discharges. When the propulsion systems are combined with a hybrid electric system, they can be programmed to steer clear of these conditions, switching to electric power. After tests were conducted using Dong’s model, the team was able to reduce GHG by 19 percent and cut fuel costs by 39 percent, proving that there are ways in which we can create environmentally friendly ships, thus helping to preserve oceans.