Lepke
Guru
- Joined
- Jun 19, 2016
- Messages
- 3,035
- Location
- US
- Vessel Name
- Charlie Harper
- Vessel Make
- Wheeler Shipyard 83'
A read about gate rudders awhile ago, and now there's a couple Youtube videos. Two single screw ships were built in Japan to the same size, design and machinery except for the rudder. One has a single conventional rudder and the other with twin rudders alongside the prop with expanded movement ability. Besides enhanced rudder effects, they claim a 14% energy savings with the gate rudders in an early trial and now claim 20-30%.
I've used Kort nozzles and they give a lot more thrust with the same engine. The twin rudders confine the thrust and probably duct it like a Kort. I don't know what the rudder machinery looks like, complicated I'm sure. But if used with simple twin rudder machinery and just for the added thrust and energy savings it looks worth the effort for a 20% savings over the life of the vessel. You could run at the same cruising speed with lower rpm or cruise faster at the current rpm. On new builds, a smaller engine.
I've used Kort nozzles and they give a lot more thrust with the same engine. The twin rudders confine the thrust and probably duct it like a Kort. I don't know what the rudder machinery looks like, complicated I'm sure. But if used with simple twin rudder machinery and just for the added thrust and energy savings it looks worth the effort for a 20% savings over the life of the vessel. You could run at the same cruising speed with lower rpm or cruise faster at the current rpm. On new builds, a smaller engine.