What type of propulsion is most commonly used for cargo carriers?

The most commonly used propulsion type for cargo carriers is a single or twin screw system. This method involves using one or two propellers, referred to as screws, that extend from the ship to convert rotational power from the engine into thrust, propelling the vessel forward.

Single or twin screw systems are favored for their efficiency, simplicity in design, and high power-to-weight ratio. They provide good maneuverability and are well suited for the typical operating conditions of cargo vessels, which often operate in a variety of sea states and port conditions. Furthermore, maintaining and repairing this type of propulsion system tends to be easier and more cost-effective, which is crucial for the commercial shipping industry.

Other propulsion systems like jet propulsion, solar-powered, and magnetic propulsion are less common in cargo shipping due to various factors such as cost, efficiency, and current technological limitations for large-scale applications. Jet propulsion is primarily used in aircraft and certain fast ferries, while solar power and magnetic propulsion are still largely experimental or niche technologies that have not yet been widely adopted in the maritime cargo sector.