Serenity on the Sea

Amaneku. An old word from the native Japanese lexicon, it means to reach far and wide, to spread to every corner.

A new vessel entering service in Tokyo Bay in 2027 — an intimate dining cruise ship — has been named Amane, with the wish that the ship, and the feeling behind it, will reach people far and wide — amaneku.

The name has a second meaning as well. Written in kanji as 海音, Amane is the sound (音) of the sea (海).

Tokyo is surrounded by wide stretches of water. Go out onto the water and listen closely, and you encounter a presence of the sea that you rarely notice while in the city: waves, wind, sounds crossing the surface of the water. Amane was envisaged to be quiet enough for you to notice those sounds.

A ship, though, is also a vehicle that comes with sensations of its own: the sound of the engine, vibration through the floor, the smell of fuel. Quieting them as far as possible, so that the sound of the sea comes through. That aim drove the many ideas and technical challenges layered into Amane's design.

"A lot of people around me actually say they like that smell of fuel you get when you board a ship." So says Junpei Hotta, who led the basic planning for Amane.

Hearing this, Yuki Isomura, chiefly responsible for installing the hydrogen fuel cell system, laughs and answers: "The only people who say an engine's vibration feels nice, or that they like the smell of fuel, are the engineers."

Haruka Yamazaki, the on-site supervisor stationed at the shipyard in Sasebo, Nagasaki Prefecture, picks it up from there: "What makes Amane different, I think, is that the standard for every decision isn't the technology. It's the guest experience."

The three of them, all from NYK Line, are deeply involved in Amane's technical development, and on behalf of the many people working on the ship, they explained the workings behind the quiet that Amane takes its name from. Knowing how it works may change, a little, how the vessel feels once you are aboard.

Junpei Hotta, Planning Team, Technical Group, NYK Line

Leads Amane's technical team. In the department responsible for the basic planning of ship procurement, he has spent about a year since the contract working out the vessel's interior specifications together with the designers and the shipyard.

Yuki Isomura, Green Technology Team, Engineering Development Group, NYK Line

Works in the technical development of ships. Involved in a next-generation fuel vessel project, and on Amane chiefly responsible for installing the hydrogen fuel cell system.

Haruka Yamazaki, Shipbuilding Team, Technical Group, NYK Line

Handled specifications from the basic planning stage on the Planning Team. Now stationed at the shipyard in Sasebo, where the vessel is under construction, as the on-site supervisor managing the work through to delivery.

A Quiet Ship, Running on Electricity

Why is Amane so quiet? To put it in automotive terms: if a conventional ship is a gasoline car, Amane is closer to a hybrid vehicle. On a typical ship, the rotation of the engine is carried directly to the propeller. Amane, by contrast, is an electric-propulsion vessel. Electricity drawn from shore power, batteries, diesel generators, hydrogen fuel cells, and other sources drives a motor, and the motor turns the propeller. A motor produces less vibration and noise than an engine, and running on batteries deepens the quiet in the cabins further still.

The early planning team put every option on the table. The first candidate was to run on batteries alone, charged from shore power. "But once you account for the space constraints, the weight of the batteries, and the cost, covering a full day of cruising on batteries alone wasn't realistic for a vessel this size," Yamazaki recalls. The area the batteries take up grows until "you end up with no room for people, and no way to serve them a meal." In the end, the plan switched to a hybrid: batteries, diesel generators, and hydrogen fuel cells combined.

The three power sources come from three different makers. "We compared everything — cost, warranties, track record — to arrive at the combination we have now. Bringing the makers we chose together at the shipyard and building a single system out of it was the toughest technical challenge of all." What Yamazaki pointed to was not some striking new technology. It was the unglamorous, painstaking work of integration.

Bringing Hydrogen Aboard

The use of hydrogen fuel cells is another of Amane's defining features. Hydrogen is a clean fuel: used in a fuel cell, it emits no CO2 or NOx. Its weakness is that it holds far less energy per unit of volume than heavy fuel oil. Carrying enough of it to sail on means tanks many times larger than those for heavy fuel oil. And there was little precedent for putting hydrogen aboard a ship at all, along with strict regulations governing where and how it could be placed.

Run on hydrogen alone, and it becomes a ship for carrying hydrogen rather than people. With the guest's experience as the priority, going without hydrogen was also an option. Even so, there was surely historical meaning in putting a next-generation fuel aboard now. After long discussion, hydrogen was brought aboard to supply part of the ship's power.

"Ships have run on oil for about 100 years. Now, with the move toward decarbonization, that is changing to new fuels. I think of it as a historical turning point," Isomura says. Around 80% of the world's trade in goods, by volume, still moves by ship. And a ship, once built, stays in service for a long time — 20 years, 30 years. That is why the choice of technology going into Amane now mattered so much.

Few vessels currently being designed match this level of complexity — a reality that has surfaced repeatedly throughout the project. From the first studies to the shipbuilding contract, the process took two years. "Typically, a contract takes about a year — six months when it's quick. Two years happens only when a ship is genuinely made to order," Hotta says. Then another two and a half years from contract signing to completion. Four to five years in all, and Amane is still under construction in Sasebo today.

And yet those aboard will hardly ever be aware of this turning point. About the only technology they can notice is the hydrogen tanks, visible on the right as you board. "Not letting the technology make itself felt too much, even though it's all really there — carrying on as if it weren't. I think that's the point." So says Isomura himself, the person chiefly responsible for putting the hydrogen aboard. They want people to feel that this is a vessel made with care all the way into the places no one sees. That was the thought shared by everyone who spoke with us.

A Sound No One Has Heard Yet

On a conventional ship, the engine starts up at departure, conversation breaks off for a moment, and the passengers realize the ship has begun to move.

Amane has none of that. Hotta puts it this way: "I think the feeling will be that you look up and it's already moving. Moving, and yet as though you were still on land." Conversation carries on, and the vessel alone leaves the shore. Whether that turns out to be true, we will know on the day it enters service.