Hull and Stability

SECTION 1 SUBDIVISION ARRANGEMENT
1 Number and arrangement of transverse
watertight bulkheads
1.1 Number of watertight bulkheads
1.1.1 General
All ships, in addition to complying with the requirements of
[1.1.2], are to have at least the following transverse watertight
bulkheads:
one collision bulkhead
one after peak bulkhead
two bulkheads forming the boundaries of the machinery
space in ships with machinery amidships, and a bulkhead
forward of the machinery space in ships with
machinery aft. In the case of ships with an electrical
propulsion plant, both the generator room and the
engine room are to be enclosed by watertight bulkheads.
1.1.2 Additional bulkheads
For ships not required to comply with subdivision regulations,
transverse bulkheads adequately spaced and in general
not less in number than indicated in Tab 1 are to be
fitted.
Additional bulkheads may be required for ships having to
comply with subdivision or damage stability criteria (see
Part E for the different types of ships).
Length (m)
Table 1 : Number of bulkheads
Number of bulkheads
for ships with aft
machinery (1)
Number of
bulkheads for
other ships
L < 65 3 4
65 ≤ L < 85 4 5
85 ≤ L < 105 4 5
105 ≤ L < 120 5 6
120 ≤ L < 145 6 7
145 ≤ L < 165 7 8
165 ≤ L < 190 8 9
L ≥ 190 to be defined on a case by case basis
(1) After peak bulkhead and aft machinery bulkhead are
the same.
2 Collision bulkhead
Pt B, Ch 2, Sec 1
2.1 Arrangement of collision bulkhead
2.1.1 (1/7/2011)
A collision bulkhead is to be fitted which is to be watertight
up to the freeboard deck. This bulkhead is to be located at a
distance from the forward perpendicular FPLL of not less
than 0,05 LLL or 10 m, whichever is the less, and not more
than 0,08 or 0,05 LLL + 3 m, whichever is the greater.
2.1.2 (1/7/2011)
Where any part of the ship below the waterline extends forward
of the forward perpendicular, e.g. a bulbous bow, the
distances, in metres, stipulated in [2.1.1] are to be measured
from a point either:
at the midlength of such extension, or
at a distance 0,015 LLL forward of the forward perpendicular,
or
at a distance 3 metres forward of the forward perpendicular;
whichever gives the smallest measurement.
2.1.3 (1/7/2011)
The bulkhead may have steps or recesses provided they are
within the limits prescribed in [2.1.1] or [2.1.2].
No door, manhole, ventilation duct or any other opening is
to be fitted in the collision bulkhead below the freeboard
deck.
2.1.4 The Society may, on a case by case basis, accept a
distance from the collision bulkhead to the forward perpendicular
FPLL greater than the maximum specified in [2.1.1]
and [2.1.2], provided that subdivision and stability calculations
show that, when the ship is in upright condition on full
load summer waterline, flooding of the space forward of the
collision bulkhead will not result in any part of the freeboard
deck becoming submerged, or in any unacceptable
loss of stability.
2.1.5 (1/7/2011)
Where a long forward superstructure is fitted, the collision
bulkhead is to be extended weathertight to the next deck
above the freeboard deck. The extension need not be fitted
directly above the bulkhead below provided it is located
within the limits prescribed in [2.1.1] or [2.1.2] with the
exemption permitted by [2.1.6] and that the part of the deck
which forms the step is made effectively weathertight.The
extension is to be so arranged as to preclude the possibility
of the bow door causing damage to it in the case of damage
to, or detachment of, a bow door.
2.1.6 (1/7/2011)
Where bow doors are fitted and a sloping loading ramp
forms part of the extension of the collision bulkhead above
the freeboard deck, the part of the ramp which is more than
2,3 m above the freeboard deck may extend forward of the
limit specified in [2.1.1] or [2.1.2]. The ramp is to be weath-
RINA Rules 2012 31