Great Lakes bulk carrier features Berg direct drive electric technology

The Nukumi features the first Direct Drive Electric solution from Berg Propulsion to be installed on a bulk carrier. (Photo: Berg Propulsion)

The Chinese-built Nukumi single-point self-unloader represents the first lake-going vessel to feature a diesel-electric drivetrain, according to Berg Propulsion, a global supplier of custom propulsion solutions. The 26000 metric tons deadweight vessel built by China’s Chengxi Shipyard was commissioned by Canada Steamship Lines (CSL) and developed in collaboration with Windsor Salt to deliver de-icing salt from Mines Seleine on Magdalens Islands for use on roads across Quebec and Newfoundland. It arrived in Halifax just in time to take up duties for the 2022 Great Lakes season.

The vessel features Berg’s Direct Drive Electric technology, an integrated solution developed “to make high-efficiency electric propulsion easier to adopt,” Berg states. The installation in the Nukumi marks its debut in the bulk carrier market.

In announcing the application, Berg noted that while the performance and sustainability gains of electric propulsion are widely recognized, particularly when ships demand variable load capabilities, the simplicity of direct drive solutions could prove a game changer for the marine industry.

“Conventional electric propulsion systems feed power from the generator to the power distribution system, then on to the frequency controller and the electric motor before they reach the main propeller shaft via the reduction gear,” Jonas Nyberg, Managing Director West, Berg Propulsion, explains. “This can be overly complex and hard to maintain, while energy is lost at every step.”

The Direct Drive Electric solution instead utilizes electric motors integrated to directly drive the propeller shaft. The higher torque generated means the same power is available to drive larger propellers, while the removal of gears allows for shorter shaft lines, fewer bearings and a smaller engine room footprint.

Configuration for the Direct Drive Electric system supplied by Berg for CSL’s new self-unloader Nukumi. (Photo: Berg Propulsion)

According to Berg, the energy savings from this solution compared to other electrical options can be more than 5%, with equivalent fuel savings. It adds that the technology is “future proofed” to accommodate alternative energy sources, using a dc hub (“superdrive”) to draw on main engines or stored energy from zero-emissions batteries and fuel cells, as required.

“For Nukumi, the use of Direct Drive Electric propulsion shows the value available when a shipowner, an equipment maker and a system integrator work together in the early ship design phase on prioritizing performance and sustainability,” Nyberg commented. “This is a key reference for Direct Drive Electric as a fuel-efficient and easy to install technology, which broadens the appeal of greener electric propulsion.”

The vessel’s combination of optimized hull form, electric propulsion technology and Tier 3 diesel-electric engines will enable it to cut greenhouse gases by 25% and other pollutants by 80% compared to its predecessor, stated Frederic Jauvin, vice president, Global Technical Services, CSL. In addition, the propulsion solution will enhance maneuverability when navigating the shallow Magdalen Island channel.

“Nukumi charts new waters when it comes to safe, sustainable and efficient shipping in the Gulf of St. Lawrence and Great Lakes region,” said Jauvin. “Its efficiency and sustainability are truly exciting and Berg Propulsion’s integrated solution and its engineering partnership with Chengxi Shipyard has been key to securing all of the available performance enhancements.”