the boat draft

[darlian]

hi, there...
i am a beginner in boat design, and i am trying to design a wooden fishing boat
in delftship software.
its a Longliner for my local community in Indonesia.
the Loa is 17m, Beam 3.7m
height 1.52,
my questions are:
1. how can we determine the boat draft?
2. is there any formula to calculate the construction weight?
many thanks

[Guest625101138]

If you are using Delftship you can use the Hydrostatics function to determine the draft for a range of displacemenst.

The layer properties provide a means to determine the hull weight. You need to know the thickness of the building material and the density of the material. It will give both surface area of the layer and the total weight of the layer. If you have different materials then you need to average the density or make different layers for each material.

Rick W.

[darlian]

Thanks Rick,
in Delftship, i can calculate the boat Disp. and....

Disp. = DWT + LWT, in order to get DWT i have to calculate the fish hold, tanks, men etc....

for LWT, i have to calculate the construction weight, engine, equipments etc...
its that right?

[Guest625101138]

Yes. You need to know all the things that are fixed to the boat and all the things that you intend to transport in the vessel to get the displacement.

You can use DelftShip layers to allow for all the components of the displacement. For example you can position people around the hull as a layer and give them a thickness and density to correspond with 80kg each say. There are Delftship .part files for people and other parts posted on the forum.

If you take the time to model everything in Delftship you can get a printout for all hydrostatic information giving the coordinates of the CoG. You can then adjust weight distribution or trim to get the CoG to align vertically with CoB. Also helps in determining stability.

I have sometimes just used simple cyclinders in Delftship to place objects around the hull so I can determine total displacement and CoG. You need to be mindful of either ticking or unticking the symmetry box in the layer control.

Rick W.

[darlian]

thanks Rick
i am working on it....