Why Ship Shell Expansion Drawing is used

In a short, shell expansion plan means plan showing the seams and butts, thickness and associated welding of all plates comprising the shell plating, framing, etc. By doing these we can approximately calculate the required amount of plates and can estimate the hull weight.

Ship Shell Expansion Drawing Considerations

During shell expansion drawing we considered the following points –
o Welding seam shouldn’t coincide with any frame.
o Welding seam can’t coincide with any structural member (Longitudinal, Girder, keelson etc)
o We have to organize the plate such a way so that minimum number of plates is used and wastage of plate is minimized.
o Plates of dimension 6m 2m is used.
o Plate with dimension less than 300mm 300mm can’t be used.
o The plates were numbered from one according to type of plate.