Low-wash hull

[Slipy]

Hello

I look for some information about low-wash hulls. Generally I have to know what conditions have to be granted that hull can be called as “low-wash”

Best regards
Ślipy

[Leo Lazauskas]

Originally Posted by Slipy

Hello

I look for some information about low-wash hulls. Generally I have to know what conditions have to be granted that hull can be called as “low-wash”

Best regards
Ślipy

"Low Wash" is not a very well-defined term. One measure that has been used is the "Washington State Ferry Limit" or a name similar to that.

If you do find out more I would love to hear about it.

Good luck!
Leo.

[gerard baladi]

look for the "stolkraft" hull form

[tspeer]

The Washington State Ferry criteria for the wake wash are an energy of 2,450 joules per meter for the highest wave in the wave train, and a maximum wave height of 28 centimeters.

[tspeer]

BTW, in the case of the MV Chinook, there was a paper a couple of years ago in Marine Technology, I think, that showed the wake wash as a function of speed. At 34 kt (the ferry's maximum speed was 35 kt), the curve was below the WSF criteria. However, at speeds below that it was WAY higher until the speed dropped to quite low value - I don't know recall if it was below the 11 kt specified by the court injunction that was subsequently overturned by the WA State Supreme Court. So making the vessel slow down, they may have been making the problem worse. I thought it was a classic case of meeting the letter of the spec but not really producing a design that was operationally acceptable.

The problem is, it's not just the height of the waves that matters. High speed craft can produce long wavelength waves that have a lot of energy in them even if the wave height is modest. The problem is greatest where the water is shallow, so the operating area has to be taken into account, too.

[Slipy]

I found same values (2450 J/m and 28cm) but in my opinion it is not general rule of WFS. As I uderstood it for particular vessel.
Am I right?