SC161 (May 2000) Timber deck cargo in the context of damage stability requirements
(Chapter II-1, Regulation 25-8.1)
SOLAS Regulation II-1/25-8.1
reads:
Stability information
1 The master of the ship
shall be supplied with such reliable information as is necessary to
enable him by rapid and simple means to obtain accurate guidance as to
the stability of the ship under varying conditions of service. The
information shall include: .1 a curve of minimum operational
metacentric height (GM) versus draught which assures compliance with the
relevant intact stability requirements and the requirements of
regulations 25-1 to 25-6, alternatively a corresponding curve of the
maximum allowable vertical centre of gravity (KG)versus draught, or with
the equivalents of either of these curves;
.2 instructions concerning the operation of
cross-flooding arrangements; and
.3 all other data and aids which might be necessary to
maintain stability after damage.
Scope
The provisions given hereunder apply
to ships that are subject to SOLAS, Chapter II-1, Part B-1 subdivision
and damage stability calculations and engaged in carrying timber deck
cargoes. The buoyancy of the timber deck cargo can optionally be taken
into account in the damage stability calculations, subject to the
provisions that have been set forth in this document.
They shall comply with the requirements of the
CODE OF SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES, 1991, and
Ships that are provided with and make use of their timber load line
shall also comply with the requirements of regulations 41 to 45 of the
LOAD LINE CONVENTION, 1966.
Definitions
The following definitions apply for
the purposes of this interpretation: timber means sawn wood or lumber,
cants, logs, poles, pulpwood and all other types of timber in loose or
packaged forms. The term does not include wood pulp or similar cargo;
timber deck cargo means a cargo of timber carried on an uncovered part
of a freeboard or superstructure deck. The term does not include wood
pulp or similar cargo; timber load line means a special load line
assigned to ships complying with certain conditions related to their
construction set out in the LOAD LINE CONVENTION 1966 and used when the
cargo complies with the stowage and securing conditions of the CODE OF
SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES, 1991 (Resolution
A.715(17)); deepest timber subdivision load line is the subdivision load
line which corresponds to the timber summer draught to be assigned to
the ship;
respective partial load
line is the light ship draught plus 60% of the difference between the
light ship draught and the deepest timber subdivision load line.
Interpretation
1. The stowage
of timber deck cargoes shall comply with the provisions of Chapter 3 of
the CODE OF SAFE PRACTICE FOR SHIPS CARRYING TIMBER DECK CARGOES, 1991
(resolution A.715(17)).
2.
The ship shall be supplied with comprehensive stability information
which takes into account timber deck cargo. Such information shall
enable the master, rapidly and simply, to obtain accurate guidance as to
the stability of the ship under varying conditions of service, and as
required in SOLAS Regulation II-1,25-8 it shall include, among other
damage stability related issues, a curve of minimum operating
metacentric height (GM)versus draught which covers the requirements of
SOLAS Regulation II-1/25-8.1.1.
3. The height and extent of the timber deck cargo shall be
in accordance with Chapter 3.2 of the CODE OF SAFE PRACTICE FOR SHIPS
CARRYING TIMBER DECK CARGOES, 1991, and shall be at least stowed to the
standard height of one superstructure, if considered buoyant in the
context of the subdivision and damage stability calculations.
4. Account may be taken of
the buoyancy of the timber deck cargo, assuming that such cargo has a
permeability of 25% of the volume occupied by the cargo, however, the
buoyancy of only one standard superstructure height of timber deck cargo
may be considered.
5. Unless
instructed otherwise by the Administration, the stability information
for ships with timber deck cargoes may be supplemented by a second curve
of limiting GM (or KG)covering the then permissible draught range as
specified below. Thus when accepting two stability limiting curves one
curve shall be applicable when carrying timber deck cargo and a second
curve for any other loading condition.
6. The above described provision of two curves
are to be developed as described in SOLAS Regulation II-1/25-8.3, if
they have been determined from considerations related to the subdivision
index, based on the following:
6.1. for any loading condition other than timber deck cargo
the limiting GM with the draughts as described in SOLAS Regulation
II-1/25-8.3, and
6.2. for
timber deck cargo the limiting GM shall be varied linearly between that
the deepest timber subdivision load line and the respective timber
partial load line. Where timber freeboards are not assigned the deepest
and partial draughts shall relate to the summer load line.
7. For the purpose of the
subdivision and damage stability calculations, the permeabilities of
each space or part of space shall be as described in SOLAS Regulation
II-1/25-7, however supplemented by the following for the undamaged
timber deck cargo:
Spaces
Timber cargo on deck for both
draughts.
Permeability
0.25
8. When considering the vertical extent of
damage, the upper deck may be regarded as a horizontal subdivision (in
accordance with SOLAS Regulation II-1/25-6.3).Thus when calculating
damage cases limited vertically to the upper deck with the corresponding
v-factor, the timber deck cargo may be considered to remain buoyant with
an assumed permeability of 0.25. For damage extending above the upper
deck the timber deck cargo buoyancy in way of the damage zone is to be
ignored.
Footnote: Implementation date 1 January
2001