5.1.2
The Rule length, L, for ship units and other surface type units is
the distance, in metres, on the maximum design operating summer load waterline from
the forward side of the stem to the after side of the rudder post or to the centre
of the rudder stock if there is no rudder post. L is to be not less than 96
per cent, and need not be greater than 97 per cent, of the extreme length on the
maximum design operating summer load waterline. For nonpropelled Units, L is
to be 97 per cent of the extreme length on the maximum design operating summer load
waterline.
5.1.3 In units with unconventional form or unusual stem or stern arrangements,
the Rule length, L, will be specially considered in relation to the transit
or operating waterlines.
5.1.4
Breadth, B, is the greatest moulded breadth, in metres.
5.1.5
Depth, D, is measured, in metres, at the middle of the length,
L, from the top of keel to top of the deck beam at side on the uppermost
continuous deck.
5.1.6
Draught,
, is the maximum design operating summer draught, in metres,
measured from top of keel.
5.1.7
Draught,
, is the maximum design transit summer draught, in metres,
measured from top of keel.
5.1.8 The block coefficient, 
, is the moulded block coefficient corresponding to the maximum
design draught T based on the Rule length L and moulded breadth
B as follows:
where
|
T |
= |
 for ship units and other surface type units |
|
T |
= |
 for self-elevating and semi-submersible units. |
5.1.9 In general, the forward perpendicular, F.P., is the perpendicular at the
intersection of the waterline at the draught T with the fore end of the hull.
The aft perpendicular, A.P., is the perpendicular at the intersection of the
waterline at the draught T with the aft end of the hull, see also
Pt 4, Ch 1, 5.1 General 5.1.2.
5.1.10 Amidships is to be taken as the middle of the Rule length, L,
measured from the forward side of the stem or hull.
5.1.11
Lightweight is defined as the weight of the complete unit with all its
permanently installed machinery, equipment and outfit, including permanent ballast,
spare parts normally retained on board, and liquids in machinery and piping to their
normal working levels, but does not include liquids in storage or reserve supply
tanks, items of consumable or variable loads, stores or crew and their effects.