On December 2nd, Kuribayashi Steamship Co., Ltd. announced that it will establish a joint venture in April 2025 with Nisshin Kaiun, Daiichi Chuo Kisen, and Kamome Propeller as joint investors to support the basic design work of the new rudder, "Gate Rudder," and that it has recently signed a basic design contract with a major domestic shipbuilding company.
<New Steering Wheel "Gate Ladder">
The gate ladder is an energy-saving technology invented by the late Sadatomo Kuribayashi, former chairman of Kuribayashi Steamship Co., Ltd., together with Professor Emeritus Noriyuki Sasaki of the University of Strathclyde, and the Kuribayashi Steamship Group and Kamome Propeller Co., Ltd. jointly hold the patent.
A key feature of this design is that it reduces drag by equipping rudder blades on both sides of the propeller, and improves fuel efficiency and propulsion performance through the thrust generated by the asymmetrical airfoil shape of the rudder blades.
Because it is expected to contribute to environmental improvement through the reduction of GHG (greenhouse gas) emissions, the company has received orders for a total of more than 20 vessels domestically and internationally across a wide range of ship types, including container ships, tankers, cargo ships, bulk carriers, car carriers, refrigerated carriers, cement carriers, training ships, and fishing vessels. In the past year, inquiries for the introduction of its systems into large vessels from both domestic and international sources have increased sharply.
<Image of the new company's development>
The new company will undertake basic design work from shipyards, such as proposing optimal stern shapes and propeller diameters for each ship type and model, and will deliver packaged deliverables, including gate rudders, to the shipyards.
The shipyard will then consider the ship's shape and layout based on the deliverables, and procure a complete set of components, such as gate rudders, from the manufacturer.
Currently, we are working on the basic design for implementing gate rudders on approximately 60 vessels, and our future plans include working to promote the widespread adoption of gate rudders on ships worldwide.
■ Overview of the new company
Company Name: Gate Ladder Design Center
Date of establishment: September 2025, 4
Shareholders: Kuribayashi Shipping Co., Ltd., Nisshin Shipping Co., Ltd., Daiichi Chuo Kisen Co., Ltd., Kamome Propeller Co., Ltd.
Head office location: Chiyoda-ku, Tokyo
Job Description: Basic design and design support services for gate rudders, and sales of these services (energy saving effect estimation, main rudder component analysis, layout analysis, propeller design for gate rudders, advice on tank testing methods, etc.)
