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A New Energy Saving System, Confirming 14% Energy Saving On Actual Ship

The Gate Rudder® consists of two uniquely shaped rudder placed in parallel both sides of the propeller instead of placing behind the propeller, which reduces resistance of rudder and create thrust to save the fuel consumption of 14% . It is a new type of steering system designed based on a completely new idea.

*We received support from The Nippon Foundation for the development of the Gate Rudder.

Three property was confirmed by comparing with the sister ship

    By comparing the data of MV SHIGENOBU equipped with the Gate Rudder System and its sister ship equipped with a flap ladder, several excellent performances were confirmed.


  1. Comparatively high energy saving
    Comparing the results of sea trials of two sister ships equipped with the Gate Rudder and a flap rudder resectively, the high energy-saving of MV SHIGENOBU with the Gate Rudder was shown.

    Even fuel consumption for one year, you can see that the Gate Rudder can achieve overwhelmingly low fuel consumption per ton mile regardless of the season.

  2. Excellent course keeping and turning performance
    In the Gate Rudder, by operating the two asymmetrical rudders at appropriate rudder angles, the turning circle at low speed of the ship is significantly smaller than that of the flap ladder, and extremely high turning performance at slow speed is realized.

    The turning performance at maximum speed has also cleared the IMO standard.

  3. High noise reduction
    Since the rudder plates are placed on both sides of the propeller, the stern wake flowing into the propeller is made uniform and a quiet effect is also produced. Compared with the sister ship equipped with a flap ladder, it was confirmed that the Gate Rudder was 5 dB quieter at the same ship speed. (With the same output, the noise level will be 3 dB)

Principle: Duct effect used in the "duct propeller"

The fluid force acting on the conventional rudder creates resistance, but the main feature of the Gate Rudder is that it uses the "duct effect" to convert the fluid force into thrust. “Duct effect” is a phenomenon in which a fluid enters a duct with a special cross-sectional shape that surrounds a propeller to create a velocity difference, and as the result, the forward component of the lifting power contributes to thrust.

For the Gate Rudder, by studying the blade shape of the duct and applying the effective blade shape to the shape of the rudder, the thrust that cannot be generated by a conventional rudder leads to a large energy saving effect.


The Gate Rudder integrated with the auto-pilot with optimization algorithm, steering gear, shafting system and propeller as a system could only achieve high performance of the ship. We will be responsible for planning the system according to the kind and type of the ship.


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