hello，we have a problem in stepped planning craft

Third or forth word messaging is at best, a useless way to convey information about a set of problems. Coupled with no accurate or descriptive commentary, from an NA or designer, that's intimate with the design and no video to examine, makes anything but shear guesses at the possibilities the only offering available here.

Step placement, arrangement, size, ventilation tactics, etc. are quite critical and must be matched with the expected performance envelop and at that, the "window" of effective operation tends to be rather small. There's absolutely no reason to develop a stepped hull, on a craft running in the 20 to 30 knot range. This S/L range would be best suited for a more conventional set of shapes. Lastly, anyone placing steps on a modest deadrise, warped bottom hasn't studied the lessons of the '63 series tests and follow up, now archival data, pertaining to high speed hull forms and their design approaches. Given this information, you might be best advised to "take your lumps" and leave this hull as a "learning tool", eventually developing another, possibly designed by someone with considerably more understanding, of high speed, stepped configurations.

Simply put, provide access to someone with much more understanding of the hull form, that's experiencing the problem and of course, some video of the hull form, as it's displaying it's handling characteristics. Other wise, it's just gibberish that will lead to nothing more than a debate on the usefulness of less than fully understood design concepts.

 

From the description, chine walking is seems to fit and usually worse in calm/smooth water. I am away until June 26 so can't off much more right now.
Do tests and make up a log book describing all the 'traits' in various loads, speeds, trim, etc.
Who is the designer... he should have a cure.

 

thanks very much,can you give the book's name?

 

I'm a chinese ,this QQ is yours?

 

By a "log" book, I meant a book or notepad describing all the behavior etc. of what the boat does. Like a doctor: we need symptoms before we can diagnose & cure. I still think you should get an expert to help: if you don't know the probelm, you can't cure it.
The first step would be a Lines Plan of the hull together with hydrostatics and draft readings.

I am away until June 28 so this may be my last response.

 

Yes is mine and I am here all day every day !! call and lets chat !!