(1) The bow height (F
b),
defined as the vertical distance at the forward perpendicular between
the waterline corresponding to the assigned summer freeboard and the
designed trim and the top of the exposed deck at side, shall be not
less than:
where:
|
F
b
|
= |
is the
calculated minimum bow height, in mm; |
|
L
|
= |
is the length, as defined
in regulation 3, in m;
|
|
B |
= |
is the moulded breadth, as defined
in regulation 3, in m;
|
|
d
1
|
= |
is the
draught at 85% of the least moulded depth, in metres; |
|
C
b
|
= |
is the
block coefficient, as defined in regulation 3;
|
|
C
wf
|
= |
is the
waterplane area coefficient forward of L/2: C
wf = A
wf/ {(L/2) x B};
|
|
A
wf
|
= |
is the
waterplane area forward of L/2 at draught d1, in m2.
|
For ships to which timber freeboards are assigned, the summer
freeboard (and not the timber summer freeboard) is to be assumed when
applying paragraph (1).
(2) Where the bow height required in paragraph
(1) is obtained by sheer, the sheer shall extend for at least 15%
of the length of the ship measured from the forward perpendicular.
Where it is obtained by fitting a superstructure, such superstructure
shall extend from the stem to a point at least 0.07L abaft the forward
perpendicular, and shall be enclosed as defined in regulation
3(10).
(3) Ships which, to suit exceptional operational
requirements, cannot meet the requirements of paragraphs (1) and (2)
of this regulation may be given special consideration by the Administration.
(4)
-
(a) The sheer of the forecastle deck may be taken
into account, even if the length of the forecastle is less than 0.15L,
but greater than 0.07L, provided that the forecastle height is not
less than one half of standard height of superstructure as defined
in regulation 33 between 0.07L and the
forward perpendicular.
-
(b) Where the forecastle height is less than one
half of the standard height of superstructure, as defined in regulation 33, the credited bow height may be
determined as follows:
-
(i) Where the freeboard deck has sheer extending
from abaft 0.15L, by a parabolic curve having its origin at 0.15L
abaft the forward perpendicular at a height equal to the midship depth
of the ship, extended through the point of intersection of forecastle
bulkhead and deck, and up to a point at the forward perpendicular
not higher than the level of the forecastle deck (as illustrated in figure 39.1). However, if the value of the
height denoted ht in figure 39.1 is
smaller than the value of the height denoted hb then ht may
be replaced by hb in the available bow height.
-
(ii) Where the freeboard deck has sheer extending
for less than 0.15L or has no sheer, by a line from the forecastle
deck at side at 0.07L extended parallel to the base line to the forward
perpendicular (as illustrated in figure 39.2).
Figure 39.1
|
hf
|
= |
Half
standard height of superstructure as defined in regulation
33.
|
(5) All ships assigned a type 'B' freeboard, other
than oil tankersfootnote, chemical tankersfootnote and gas carriersfootnote, shall
have additional reserve buoyancy in the fore end. Within the range
of 0.15L abaft of the forward perpendicular, the sum of the projected
area between the summer load waterline and the deck at side (A1 and
A2 in figure 39.3) and the projected
area of an enclosed superstructure, if fitted, (A3) shall not be less
than:
where:
|
Fmin
|
= |
is calculated by:
Fmin = (F0 × f1) + f2;
|
|
F0
|
= |
is the tabular freeboard,
in mm, taken from table 28.2, corrected
for regulation 27(9) or 27(10), as applicable;
|
|
f1
|
= |
is the correction for
block coefficient given in regulation 30;
and
|
|
f2
|
= |
is the correction for
depth, in mm, given in regulation 31.
|
Figure 39.3