Boundary distance, the dimension from the perimeter of the
hatchway to the boundary of the compartment, is used to calculate
the average depth (Vd) of the void in a “filled" compartment.
Although it is a specific dimension when measured perpendicularly
to the periphery of the hatchway, it is not explicitly defined as
to how it should be measured in the corners of the compartment. Refer
to figure 3, which shows the
forward end of a `tween-deck compartment in a general cargo ship.
Figure Forward end of a tween deck compartment
Dimension x is clearly the boundary distance in area (A).
Dimension y is the boundary distance in area (B). The question is-what
is the boundary distance in area (C), i.e. in the corners, and which
girder depth (d) is to be applied in the calculation of (Vd), the
depth of the hatch end beam or the hatch side girder. The following
guideline addresses this question.