DNV grants first RoPax Silent(E) notation

Wärtsilä has designed and delivered controllable pitch propellers for Ala’suinu, Stena’s new RoPax vessel. Following these trials, it became the first such vessel to fulfil the DNV Silent(E) notation, satisfying the criteria at 11 and 18 knots.

The Ala’suinu, which was built at CMJL Shipyard (Weihai) in China, is under a five-year lease to Marine Atlantic, a Canadian operator based in province of Newfoundland & Labrador.

“The Ala’suinu is a specially designed vessel for Marine Atlantic,” said Captain Anderson Noel, Marine Atlantic’s Director of Fleet Operations.

“The dedicated Wärtsilä propeller design enables us to minimise underwater noise for the benefit of marine life off Canada’s coasts.”

The Silent(E) notation was introduced to protect sensitive marine ecosystems, and assesses a vessel’s ability to reduce emissions of underwater radiated noise.

“With this notation, Stena and Wärtsilä are showcasing their commitment to taking proactive steps to reduce shipping’s environmental footprint,” said Øystein Solheim Pettersen, Head of Section, Noise and Vibration – DNV.

“Despite RoPax being a challenging ship type from an underwater noise perspective, this innovative machinery configuration has enabled a propulsion plant with sufficiently low noise emissions to satisfy the notation.”

In addition to the propeller, Wärtsilä has also supplied an integrated hybrid propulsion system comprising Wärtsilä 46DF main engines, Wärtsilä 20DF auxiliary engines, both of which are complimented with Wärtsilä NOx Exhaust gas cleaning system and Wärtsilä LNGPa, as well as the reduction gear boxes and bow thrusters with motors.

Also included in the scope are the hybrid DC-link shaft generator system, batteries and energy & power management system, integrated automation system and navigation & external communication system.