[Shayne Young]

So the question is what are canted hulls and what do they look like. Hopefully this will help answer the questions if I can figure out how to use this forum thing Anna made.

Hopefully this will help explain with some simple pictures.

A canted hull is simply a standard hull tipped over. The way it is tipped over in the configuration of a catamaran is that the top of the hull leans in to the middle of the boat and the bottom leans out. The amount that the hull leans over is called the cant angle.

Here we can see that the hulls on the water are wider in the canted configuration with out increasing the overall beam. The increase of beam on the water also increases the righting moment (power) of the boat. An increase of 587kg/m in the righting moment. This is done with no weight penalty.

A smaller but desirable effect on a catamaran is having the leeward hull being upright while in the normal sailing condition. The picture shown here shows ideal situation if the catamaran is intended to be hull flying mode.

The extra beam from the centre of buoyancy (centre of hull) to the Centre of Gravity (CG) can again be seen. It should be noted that most larger catamarans do not spend much time in the hull flying mode, even racing ones! Smaller trailerable catamarans however spend a large amount of their time flying a hull, so having the hull upright in addition to the increase in righting moment is desirable.

So for catamarans it is a design choice that is not always a clear option. On a trimaran it is a totally different story. The Amas (floats) are nearly always better being canted due to the large beams dimensions of a trimaran. Also a trimaran is designed to have a desired heel to keep the windward hull clear of the water as much as possible.

Trimarans are cool because the give the designer a lot of options on how to set up the cant of the Ama depending on the intended use for sailing.

• This topic was modified 1 year, 8 months ago by Shayne Young.
• This topic was modified 1 year, 8 months ago by Shayne Young.

[youngbarnacles]

THIS COMMENT IS FROM GEOFF
I Tried to do my own web “research” re the difference between canted and asymmetric bows but found Nada on canted, is the term “tulip” bows at all similar to canted ?
I’m assuming/postulating that the term ” canted ” refers to the twisting of the vertical plane of the hull rsulting in an increase of the resistance of the hull to vertical movement ( by displacing separate masses of water on either side of the bow when moving up and down) – while retaining the same horizontal width at the waterline / water surface.
Anywhere close ?

[Geoff]

Got it, thanks 🙂

 

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