# what is a station

DELFTship forum Hull modeling what is a station

• Author
Posts
• #34297
Dennis Bekkering
Participant

Hello, I dont really get the concept of a station. What exactly does it mean and what is the purpose.

thnx

• #34298
S . Warr
Participant

A station defines vertical points (Z axis) measured along the keel line (X axis), with transverse measurements defining the beam (Y axis).

I’m interested though B) . If this basic nomenclature confuses you, what is your interest in using this program or participating in this forum ðŸ˜‰ ?

All sincere & honest enquiries responded to… ðŸ™‚

• #34299
Dennis Bekkering
Participant

Thnx for taking time to answer me Phillip. My interest is in designing a boat and learning the basic nomenclature ðŸ˜‰ I now understand what a station is. I still dont really understand the purpose though. How do you know where the stations should be, since the amount and position can be changed. By default there seems to be a lot of them. Do I need them anyway if I use plate development?

• #34300
MICHAEL KERR
Participant

Hi,
a station is a bit like a slice of bread of a loaf
it defines the cross sectional shape of the hull. The major cross sectional shape is near the middle of your hull which helps to define the overall shape of your vessel fore and aft and altimately
its displacement, bouyance and prismatic coefficient. In metal boat construction you have to build up a skeletal shape by using longitudinal stringers and the stringers are attached to the cross sectional stations and then you can attach the metal plate to it. How many, well as less as you can get away with but usually in small boats they are evenly spaced every 600mm or 2.5 feet is about normal but dont hold me to that one.
Mike

• #34301
MICHAEL KERR
Participant

as usual dennisb I have forgotten the most important part.
If we want to define a point in space that has no length breath or depth its position relative to the zero point can be defined my its x,y.z coordinates.
But a boat has length breath and depth so we need many coordinates to define its shape, to do this we need a grid. The grid is made up of the Stations (X coordinate), Buttocks (Y coordinate) and Water lines (Z coordinate). Where these planes intersect gives us its XYZ position on the surface of our hull. These positions are listed in what is called a Table of Off-Sets. Because our hull is symetrical we only need the off sets from one side of our hull. With out the off-set table the hull can’t be built.

Mike

• #34302
Dennis Bekkering
Participant

thnx Mike for clearing that up. For my complete understanding, do the buttock lines always corresponds with the actual stringers and the station lines with the actual ribs (right nomenclature ?) construction wise? Cause I also read something about lofting but that seems to be replaced by cadcam and cnc cutting. Bit confused still ðŸ˜‰

• #34303
MICHAEL KERR
Participant

dennisb,
no the buttock lines cant be used for stringers because the curature at the bow is to servere. You can add your own, in programs like Rhino or AutoCad and other such 3D programs. Delftship is used to create hull and superstructure but its not a construction program for internals, although I have managed to make it do a lot of things that it was never intended to do.
Your second question about stations is yes, although you might have to move them this way or that to line up with internal bulkheads but I do try to keep them reasonally evenly spaced apart. And because your building in steel you wont have to reduce the ribs by the hull thickness.
Question 3, if your doing a one off build the off-set table for lofting is a lot simpler than designing for CNC construction. All the major parts have to be designed then nested onto the steel plate then there is tool path generation an code checking, its an area full of witch craft and other such hocus pocus, only for horses and fools like me.

• #34304
Dennis Bekkering
Participant

thnx Mike for taking time to make me understand it all, most appreciated