PHILOSOPHY VOICE Vol.04

Mr. Tamashima has led the industry through his ship design and development work based on fluid dynamics. After starting his career at a shipbuilding company, he built a path at a research firm specializing in fluid studies. In 2000, he established his own design support company. Today, he collaborates with Nakashima Propeller in joint efforts aimed at improving the overall propulsion performance of ships. What drives his enduring passion for "the flow around ships"? We spoke to him to find out.

What is your current work focus?

My main task is designing the hull—the shape of the ship below the waterline—from the perspective of energy efficiency. This theme has remained consistent since our founding. In addition, I’m involved in developing and designing devices that are mounted on the stern to improve fuel efficiency. We also manufacture testing equipment and model ships used in towing tank tests to evaluate ship performance. Moreover, we conduct performance assessments by measuring the operational condition of ships after they enter service. While our work spans a broad range, it is all fundamentally based on the philosophy of “hull form development.”

What kind of work did you do in your previous position?

Together with seven colleagues from a shipyard hull development team, we established a company focused on hull shape research and design consulting. We also built circulating water tanks and supported towing tank tests at shipyards both in Japan and abroad. When reviewing hull designs submitted by shipbuilders, we often provided feedback on areas for improvement. Gradually, I developed the desire to engage in hull design from earlier stages of planning—incorporating fluid dynamics from the outset—which led me to launch my current company.

How did your collaboration with Nakashima begin?

Even before founding Fluid Techno, I already had connections with Nakashima. I once joined a team with Nakashima executives and other maritime companies from the Chugoku region to conduct a site visit to Southeast Asia. After establishing my company, I began attending technical meetings as an advisor. While I provided input from the hull design side and Nakashima offered expertise from the propeller side, our conversations increasingly shifted toward integrated hull-propeller design. This eventually led to a full-scale collaboration.

What do you hope to achieve in your collaboration with Nakashima?

Rather than treating each underwater component of a ship separately, I believe it’s essential to consider how to optimize the ship as a whole. The hull, propeller, and rudder do not exist in isolation; only by considering their interrelationships can we achieve optimal performance. This is the essence of “integrated optimization.” I hope to combine Nakashima’s propulsion expertise with our hull development know-how to jointly propose world-class, highly competitive designs. For that, we aim to deepen the exchange of technical knowledge and collaboration between engineers on both sides.

What first sparked your interest in ships?

I grew up on an island in Hiroshima and commuted by boat to high school in Kure. One day, our commuter ferry was overtaken by one of the largest tankers at the time, heading into dry dock. It was so massive that it blocked the entire view of Kure city. I was captivated by the sight of such a huge ship moving across the water. That curiosity—"How can something so large move?"—led me to develop an interest in the maritime industry. At university, I chose to study marine propulsion performance.

Do you have a personal motto?

Yes, I value the principle of “Chūjo” (忠恕), which emphasizes sincerity and compassion—being honest and considerate of others’ perspectives. I always keep this in mind in my work, striving to earn the trust and satisfaction of our clients.

Do you have any advice for young engineers?

I would encourage them to “observe phenomena using all five senses.” For example, in hull design: observe water flow around the ship with your eyes, analyze wave patterns, listen for any abnormal sounds, touch the model ship and feel the subtle contours. Of course, computer simulations and CFD results are critical, but it’s equally important to check whether those numerical outputs align with your own physical intuition. By sharpening your senses, you open yourself to new insights.

Do you have any hobbies?

Recently, I have been enjoying walking. It refreshes my mind and allows me to perceive changes in my environment, which helps me think from new perspectives. Along the way, I often take photos of trees. The way their branches stretch toward the sky and their roots grow downward seems symbolic of “flow” to me. In Adrian Bejan’s book “Flow and Form,”there’s a line that resonates with me: “What moves the world is neither love nor money—it is flow and design.” I’ve written this on the first page of the notebook I always carry. Whether it’s trees, water, people, or information—nothing stays in place. Everything moves as part of a flow, and that flow is the driving force that moves the world. I believe it is continuously evolving.