Stiffener calculation based on ISO 12215

Wow thank you, This picture makes it clearer.

 

No , that 5 mtr boat was simply a parable. so that it is easier for me to explain.

 

Dear everyone, I have a question, again, that is very basic in designing boat I think. And I should have asked this before I asked about construction calculations. Suppose I am stupid but don't judge me because I am in the process of learning now.
the question is, where do we get the particulars such as the main dimension, speed, draft, weight of the boat and so on. Is it purely from our desire or is there a certain calculation and consideration to get it? In fact, these particulars are the basic data that will be used to calculate the construction. One that confuses me the most is mLDC, where do we get it from? even though we're just going to calculate the construction. Is there a book or something else that can help me to study? So far I have used existing boat data and tried to calculate its strength from that data. I'm talking about small boats, 6 mtr up to 24 mtr regulated by ISO 12215

 

That depends upon your perspective.
If you are the naval arch, then you get these via a list of requirements (from the client) that the vessel must satisfy. This is called the SOR - statement of requirements.
If you are the client, then this comes form what you may wish to have, to beat a competitor, for example, or simply to get the "WOW" factor...

No, the SOR forms the basis for the whole design.

That is your job as the naval arch, you create a design that satisfies the SOR, and when it does it has a lightship. The mLDC. The design will have a breakdown of all the weights onboard that makes THE design.

Kind of yes, there are some books that are written to assist in such matters, or just look at other 'designs' in the same size/speed/capacity that your SOR satisfies.
Then you could simply use that data, from each 'similar' design as a start.

However, to really answer you questions, you need to graduate and then work for a company and be trained by the chief designer (or other) of the hows and whys of design, and all the disciplines that are required to be a naval arch.
It take years of experience to be able to get this right.. it is not done at the click of a button.

 

Ad Hoc nailed it totally above - boat design is not (just) about being proficient at using a fancy CAD program.
There is a LOT more to it than drawing pictures on a computer.
In fact the drawing aspect is in many ways the nicest part - you also have to do lots of tedious (and not at all romantic) stuff like weight estimates.
But computers can again help enormously with this, re their spreadsheets.