Rolls Supplying Ro-Pax Propulsion Systems
By Jack Burke26 October 2018
Rolls-Royce Commercial Marine will provide power and propulsion systems for four newbuild Ro-Pax vessels of Havyard 923 design ordered by Havila Kystruten AS.
Beginning in January 2021, Havila Kystruten will operate four ships on the coastal route between the cities of Bergen in southwestern, and Kirkenes in northern Norway. The company has contracted Spain’s Astillero Hijos de J. Barreras shipyard to build two of the cruise ferries and Turkey’s Tersan yard to construct the remaining two.
Rolls-Royce will provide a fully integrated liquefied natural gas (LNG) power and propulsion solution to all four ships. This includes two LNG fuel tanks with process system, and control and safety systems, four Bergen gas engines, main propulsion thrusters of type Azipull with Permanent Magnet (PM) drive motor, PM tunnel thrusters, and stabilizers of type Neptune 200.
The main propulsion thrusters with integrated PM motors are developed in close cooperation with ship designers, to ensure optimal integration with the hull. The energy efficient tunnel thrusters allow for a slimmer hull shape due to their narrow design, which fits well with the project’s overarching goal of energy efficiency and low emissions. The low noise and vibration levels of the PM tunnel thrusters combined with the roll damping effect of the stabilizers will benefit the comfort of both passengers and crew.
The LNG Fuel System from Rolls-Royce will supply Bergen gas generator sets. Each vessel will have two engines with nine in-line cylinders, and two with six cylinders. The engines can operate on variable speed to reduce both fuel consumption and emissions. The Bergen engines series is in operation across a range of vessel types today, including cargo vessels, PSVs and tugs as well as passenger vessels. Two separate LNG fuel systems are designed in cooperation with the shipowner and include flexibility to bunker both tanks from the same side of the ship, as well as the option to supply the front and aft machine rooms from both tanks. This ensures high redundancy and flexibility during operation.
“Havila Kystruten has chosen an LNG fuel system that builds on our long experience with these type of systems, designed to be robust and reliable in rough weather conditions,” said Steinar Oppedal, Technical Product Manager for LNG Fuel Systems, Rolls-Royce – Commercial Marine. “No less important is the fact that the system and its engines will provide a significant reduction in emissions compared to conventional diesel engines.”
The chosen Bergen engines series reduces total greenhouse gas (GHG) emissions by about 20% compared to a similar diesel engine and is IMO Tier 3 compliant. The whole LNG System is designed for safety with double walled stainless steel containment.
In May 2018 the Norwegian government awarded 11 new licenses for the renowned passenger and cargo route from Bergen in the southwest to Kirkenes in the north. For the first time, the licenses have been split between two operators, and new entrant, Havila won four of the 11 licenses. The route has, since its beginning in 1884, kept coastal Norway connected, with 34 ports seeing daily ship calls. The new agreement starts in January 2021, and a key requirement from the Ministry of Transportation has been to reduce CO2 emissions.