Re:hull thickness deduction

[otaku]

Hi Mike,

I noticed that when a layer is created there is the option to set the density and the thickness of steel on that layer.

In recollection of being able to create waterlines (and nicely having them naturally follow the hull at a given waterline) but lamenting an inability to have a planar 90-degree shift for transverse bulkheads or longitudinal bulkheads that self-trim against intervening bhds, i though i’d try this:

— create stations of some convenient spacing according to hull length — in my case about 45′ – 55′ and mind start on what is my main deck — some 46′ above waterline (but consider that i may be necessary keep them reasonably short to avoid unintended straighter edges)

— extrude the boundary edge to some distance and then re-set the inboard points’ longitudinaly Y coordinate points to 0 (do this one bulkhead spacing at a time to avoid dealing with coincident/overlapping points/nodes)

— extrude downward a transverse edge of a previously extruded boundary edge then reset the points to 0′ (the keel, for me; go higher if you for some reason don’t want the IB subdivided with the OB)

— insert points onto the (boundary?) edge that runs vertical to and is outboard of the hull. In my case, since my hull has waterlines at 6, 16, 26, 36, and 46 foot levels (convenient for creating the decks’ bottom surfaces based on these waterlines, throwing thickness skyward)

— move each point to the location coincident to a point on the station, attempting to introduce the least curvature in the transverse bulkhead as possible.

Admittedly, it is easier for me to use the surface creation tools in ViaCAD. I found that if i do this extrusion in DELFTship, then the sideshell and extruded surface i intended to use as “deck surface” geometry, then ViaCAD sees this as one line. It becomes troublesome creating surfaces between the starboard and port stations/extrusions if there is skeg-like turning in the lines. The ACIS kernel cannot cope with the change in direction.

But, in DELFTship, this could help further refine the weight estimate of shell, deck, and bulkhead and house plating. With details of equipment and their centers, it might become possible to insert into DELFTship rudimentary squares or blocks to represent the motors and any vitals you want to account for while creating reports in D/S. I imagine it would be good to put those loose/non-hull items on a separate layer. It might be a good idea to export them as parts if you want to reuse them in another model.