The empty shell expansion drawing

The empty shell expansion drawing gives an overview of the hull, laid out as an expanded view of the outer shell before the construction is filled in. An empty shell expansion is an intermediate drawing generated directly from the lines plan (3D the hull shape model). It only shows the geometric profile of the hull surface.

When the 3D hull outer surface is developed into a 2D plane, the drawing contains only:

1. Base line and frame positions (or ordinates).
2. Outer shell contour boundaries.
3. Any other geometrical reference.

It does not include: basic construction, plate thickness notation, individual plate numbers, butt seams, shell openings, stiffeners on shell plating, section cutting lines or bevel information. Essentially, it acts as a geometric canvas for defining those in later design stages.

An example of an empty shell expansion drawing, made in MasterShip, is presented below.

Which SHIP-commands apply?

The following applies to this deliverable:

• Exporting this drawing: for example to PDF-format. Using the steps in this article: Making paper-space views using MasterShip's templates.
• Include it in the assembly (the 3D construction model): By including the shell expansion drawing in your assembly file (assembly.dwg), you will get one comprehensive overview of both the shell expansion and the 3D construction model in one file. If you run the AutoCAD-command XREF, whilst having the file assembly.dwg active on your screen, you can add the shell expansion drawing to this view.

How can the empty shell expansion be used?

Once the empty shell expansion drawing is set up, it can be used for defining basic construction elements in the shell expansion. And next to that, the empty shell expansion can be used for:

• Preliminary layout of shell strakes: Determine the arrangement of keel plate, bottom strakes, side strakes and sheer strakes in advance. Check fairness of strake layout and avoid regions of high curvature. Evaluate whether strake width matches commercially available steel plate sizes to prevent unreasonable seam arrangements in later stages. As design is an iterative process, those preliminary strakes can be used for defining the basic construction in the next process step. An example is shown below.