NR 546, Sec 3
24 Bureau Veritas Draft July 2019
10.4.5 Stiffener scantling
In addition to the analysis of stiffeners carried out in accord-
ance with Sec 7, [4], the stiffeners within the ice belt and
subject to ice loads are to be checked according to Sec 7,
[4.1.3] taking into account the following values of bending
moment, in kN.m, and shear force, in kN:
a) For transverse stiffener:
Note 1: Where less than 15% of the span of the stiffener is located
within the ice strengthening hull area as defined in [10.4.3],
the present check is not required.
b) For longitudinal stiffener:
where:
p : Design ice pressure, in N/mm
2
, as defined in
[10.4.4].
10.4.6 General structure arrangement
As a general rule, the local reinforcement of the side shell
panel in the area of the ice belt and subject to ice loads is to
be examined on a case-by-case basis.
In particular, when sandwich panels are used for side shell,
designer is to submit the mechanical characteristics and is
to justify the scantling of the sandwich to avoid excessive
indentation of the sandwich and deterioration of strength
and stiffness properties by collapse with the core crushing
beneath the ice belt area due to local instability of the com-
pressive face sheets.
Local monolithic side shell panels may be required in the
ice belt area.
11 Special features
11.1 Bow doors, bow visors and inner doors
11.1.1 Application and general arrangement
The requirements application and the general arrangement
of bow doors, bow visors and inner doors are to be in
accordance with the Rules for the classification and/or certi-
fication of ships (see Sec 1, [1.1.2]).
11.1.2 Plate and secondary stiffeners
Scantlings of the plates and secondary stiffeners of bow
doors and bow visors are to be not less than scantlings of
the plates and secondary stiffeners of hull fore part obtained
according to the Society Rules for the classification of ships
(see Sec 1, [1.1.2]) and to the general requirements defined
in the present Rule Note.
11.1.3 Primary supporting members
Primary supporting member scantlings are to be determined
by direct calculation in accordance with the Rules for the
classification of ships (see Sec 1, [1.1.2]).
11.1.4 Securing and supporting devices
Securing and supporting devices are to be examined on a
case by case by the Society and on the bases defined in
[11.1.3]. A particular attention is to be drawn to the con-
nection between metal devices and composite structure.
11.2 Side doors and stern doors
11.2.1 Application and general arrangement
The requirements application and the general arrangement
of side doors and stern inner doors are to be in accordance
with the Rules for the classification and/or certification of
ships (see Sec 1, [1.1.2]).
11.2.2 Plate and secondary stiffeners
Scantling of the plates and stiffeners of side doors and bow
doors are to be not less than scantlings of the adjacent side
shell obtained according to the Society Rules for the classi-
fication and/or certification of ships (see Sec 1, [1.1.2]).
11.2.3 Primary supporting members
Primary supporting member scantlings are to be determined
by direct calculation in accordance with the Rules for the
classification of ships (see Sec 1, [1.1.2]).
11.2.4 Securing and supporting devices
Securing and supporting devices are to be examined on a
case by case by the Society and on the bases defined in
[11.2.3]. A particular attention is to be drawn to the con-
nection between metal devices and composite structure.
11.3 Hatch covers
11.3.1 General
General arrangement, securing devices, height of coamings
and weathertightness where applicable and structure scant-
ling for hatch covers located on exposed or non exposed
decks are to be as defined by the Society Rules for the clas-
sification and/or certification of ships (see Sec 1, [1.1.2].
11.4 Rudders
11.4.1 Rudder stock and rudder blade scantlings
Rudder stock and rudder blade scantlings are to be checked
by direct calculations, taking into account the forces and
torque acting on rudder as defined in the applicable
requirements of the Society Rules for the classification
and/or certification of ships (see Sec 1, [1.1.2]).
Where it is not specified otherwise, the safety factors to take
into account to check the rudder blade and the rudder stock
scantlings are those defined in Sec 2, [1.3], increased by a
coefficient to be taken at least equal to 1,3.
M
phs 2 h–()
8
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10
3
=