Wärtsilä manufactured the LNG engines for the Megastar

The Megastar will have a total of five Wärtsilä 50DF engines, of which three will be V12 engines, and two will be 6-cylinder engines. The engines are manufactured at Wärtsilä’s factory in Trieste, Italy. The engine capacity is influenced by wind direction, schedules, and ice conditions, for example.

With the help of different types of engines, the capacity can be optimised as required. The small engines function as a type of adjustment units alongside the big ones. The task of the engineer officer is to assess which engines should be used at any given moment,” said Mika Ojutkangas, Wärtsilä Marine Solutions GM.

With the use of LNG, the ship’s emissions that strain the environment will be considerably reduced. Exhaust fumes from Wärtsilä’s 50DF engine contain hardly any nitric oxides, which are particularly harmful regarding the eutrophication of the Baltic Sea, for example.

According to calculations done in Norway, the nitric oxide emissions of a 95-metre diesel vessel, compared to the emissions of a LNG vessel, correspond to removing 20 000 passenger cars from traffic.

Carbon dioxide emissions will also be reduced by about 25-30%. The nuisance of port towns, sulphur and small particles, will also be absent,” said Ojutkangas.

Familiar technology

There is a lot of familiar technology in LNG engines. The main components of the engines, such as the blocks and connecting rods, are the same in LNG and diesel engines. The difference is in the fuel injection equipment, as well as the optimisation of the combustion chamber, because the operating mechanisms of the diesel and the LNG ignition engine technology are different. The Megastar’s engines are Dual Fuel engines, so marine diesel can also be used if the gas system has malfunctioned.

The Megastar’s LNG system represents the newest technology in this industry. The control systems and the sensors of the new engines in particular will give more specific information about the performance of the engines.

With these, the engines will be operating more optimally than previous models. Nature will be happy when the combustion process is optimised even more precisely than before.

Safety first

LNG is liquefied natural gas, with a refuelling temperature of about -150 degrees. Gas often has dangerous associations in people’s minds. Ojutkangas has a reassuring response to this discussion.

The LNG mixture that goes into the engine does not catch fire under normal air pressure. To ignite, it would need considerable heat and pressure. Cargo ships have been using LNG for about 50 years, and even passenger ships for about 15 years. The LNG systems have been designed to be at least as safe as the current diesel fuel systems, in every way.