1. ------IND- 2007 0031 S-- EN- 20070124
- PROJET
The
Swedish
Maritime
Administration’s Collection of
Statutes
SJÖFS 2007:XX
Published on dd mm 2007
Regulations amending the Swedish Maritime
Administration's regulations and general advice
(SJÖFS 2003:4) concerning Finnish-Swedish ice
classes;
adopted xx xxxx 2006.
The Swedish Maritime Administration lays down 1 the following by virtue
of Chapter 2 (1) of the Ship Safety Order (2003:438) and section 5 of the
Icebreaker Order (2000:1149) in relation to the Swedish Maritime
Administration’s regulations and general advice (SJÖFS 2003:4) concerning
Finnish-Swedish ice classes:
- that the phrase “BWL” is to be replaced with “LIWL” and that the
phrase “LWL” is to be replaced with “UIWL”,
- that the present Annex is to be designated Annex 1,
- that Chapter 2 (1–3), (7), Chapter 3 (3), Chapter 4 (7) and the headings
immediately before Chapter 2 (1) and (2) are to be worded as follows,
- that a new section, 3 a, and a new Annex 2 worded as follows are to be
inserted in Chapter 2.
Chapter 2
Upper and Lower Ice Waterline
Section 1
The Upper Ice Waterline (UIWL) shall consist of the
waterline corresponding to the greatest draught in which the vessel can
operate when sailing in ice. The waterline may be broken.
1
The regulations have been drawn up in collaboration between the Swedish Maritime
Administration and the Finnish Maritime Administration.
Notification has been carried out in accordance with Directive 98/34/EC of the
European Parliament and of the Council of 22 June 1998 laying down a procedure for the
provision of information in the field of technical standards and regulations and of rules on
Information Society services (OJ L 204, 21/7/1998, p. 37, Celex 398L0034), amended by
Directive 98/48/EC of the European Parliament and of the Council (OJ L 217, 5/8/1998, p.
18, Celex 398L0048).
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SJÖFS 2007:XX
The Lower Ice Waterline (LIWL) shall consist of the waterline
corresponding to the minimum draught in which the vessel can operate
when sailing in ice.
Maximum and minimum ice class draught ahead and aft
Section 2
The maximum and minimum ice class draught ahead and
aft shall be determined in accordance with the Upper and Lower Ice
Waterlines.
Section 3
Draught restrictions for sailing in ice shall be documented
and be readily available to the ship’s captain. The maximum and minimum
draught ahead, amidships and aft when sailing in ice shall be specified in the
classification certificate.
Section 3 a
In the case of vessels in which the keel has been laid, or in
which construction had started on 1 July 2007 or later, the vessel shall be
provided with a freeboard mark amidships for the ice class if the freshwater
load line in the summer is higher than the UIWL. A mark and warning
triangle shall be positioned on each side of the vessel in accordance with
Annex 2 at the draught corresponding to the greatest ice class draught. In
the case of vessels built before 1 July 2007, a corresponding freeboard mark
for ice classes shall be applied if the UIWL is lower than the summer
freeboard. This shall take place by the time of the first drying of the vessel
that takes place after 1 July 2007.
Section 4
The draught and trim limited by the UIWL shall not be
exceeded when the vessel is sailing in ice. The salt content of the water
along the intended route shall be taken into account when the vessel is
loaded.
Section 5
The vessel shall always be loaded down to at least the LIWL
when sailing in ice. Each ballast tank located above the LIWL and needed to
load the vessel down to this waterline shall have devices to prevent the water
from freezing.
Section 6
When laying down the LIWL, account shall be taken of the
need to guarantee a reasonable capacity to sail in ice with ballast. The
propeller shall be completely under water and, if possible, completely under
the ice.
Section 7
The draught ahead shall be at least:
(2 + 0.00025 Δ) ho [m], but need not be greater than 4 ho, where
Δ
ho
2
= the displacement [t] of the vessel on the Upper Ice Waterline in
accordance with Chapter 2 (1).
= ice thickness in accordance with Chapter 4 (6).
SJÖFS 2007:XX
Chapter 3
Section 2
The engine power shall be calculated on the basis of the
draughts corresponding to the UIWL and the LIWL. The engine power
shall be not less than either of these, as given by the formula below, and in
any event no lower than 1000 kW for ice classes IA, IB and IC and no lower
than 2800 kW for ice class IA Super.
Section 3
The vessel dimensions defined below shall be measured on
the basis of the maximum ice class draught and ballast draught.
L
LBOW
L PAR
B
T
A wf
length of the vessel between perpendiculars [m]
length of the bow [m]
length of the parallel midship part [m]
maximum width of the vessel [m]
maximum ice class draught (UIWL) or ballast draught
(LIWL) [m] in accordance with Chapter 2 (2)
= waterline area of the bow [m2 ]

= opening angle of the waterline at B/4 [degrees]
1
= stem angle at the centreline [degrees]
2
= gradient of the vertical against the waterline at B/4
[degrees]
= propeller diameter [m]
= thickness of crushed ice in the middle of the channel [m]
= thickness of the belt of crushed ice broken by the bow [m]
DP
HM
HF
=
=
=
=
=
If the vessel has a bulb, 1 = 90
Figure 1
Translation of diagram caption
Vertikal vid B/4 = Vertical at B/4
3
SJÖFS 2007:XX
When determining a vessel’s parameters concerning draught, the draught
in question shall be used. T in the parameter DP /T concerns the draught at
the UIWL. L and B are, on the other hand, always determined by the
draught UIWL.
Section 6
To achieve ice class IA Super or IA, existing vessels shall
meet the requirements in Chapter 3 (5).
If the hull parameters cannot be determined in accordance with Chapter 3
(5), the formula below shall be applied.
3
 LT  B
2
N
R CH  C1  C 2  C3 H F  H M  B  0.658H F   C 4 LH 2F  C5  2 
B  4
In the case of ice class IA, C1 and C2 may be assumed to be equal to 0. In
the case of ice class IA Super, vessels without a bulb, the following applies:
BL
 1.84f 2 B  f 3 L  f 4 BL 
T
2 1
B
T  B2

C 2  3.52g1  g 2 B  g 3 1  1.2 
B L

C1  f1
In the case of ice class IA Super, vessels with a bulb, C1 and C2 are
calculated in accordance with the following:
C1  f1
BL
 289f 2 B  f 3L  f 4 BL 
2 T 1
B
T  B2

C2  6.67g1  g 2B  g3 1  1.2 
B L

f1 = 10.3 N/m2
g1 = 1530 N
f2 = 45.8 N/m
g2 = 170
N/m
f3 = 2.94 N/m
g3 = 400
N/m1.5
f4 = 5.8
C3 =
C4 =
C5 =
N/m2
460 kg/(m2s2)
18.7 kg/(m2s2)
825 kg/s2
3
 LT 
The following conditions shall apply: 20   2   5
B 
The basis for performing a control calculation of power requirements is
set out in Annex 1.
4
SJÖFS 2007:XX
Section 8
The engine power shall be not less than what is indicated in
the formula below and in any event no lower than 740 kW for ice classes IB
and IC.
P
= f1  f2  f3  (f4 ·Δ + Po) [kW], where
f1
= 1.0 for a propeller with a fixed blade
= 0.9 for a propeller with a swivelling blade
f2
= 1 /200 + 0.675 but no more than 1.1.
The product f1  f2 shall not be assumed to be less than 0.85.
1
= the forward-facing angle between the stem and the UIWL. If the
stem forms a uniform curve within the ice belt, as defined in
Chapter 4 (8), it may be represented as a straight line between the
points of intersection of the stem with the upper and lower limits
of the ice belt. If the stem forms a broken line, the greatest value
for 1 shall be used.
f2
= 1.1 for a bulb stem
f3
= 1.2 B/1/3 but not less than 1.0
f4 and Po shall be assumed to be as follows:
f4
Po

IB
IC
 < 30000
0.22
0.18
370
0
IB
IC
  30000
0.13
0.11
3070
2100
= the displacement [t] of the vessel at the maximum ice class draught
in accordance with Chapter 2 (1). The displacement need not be
assumed to be greater than 80000 t.
Chapter 4
Ice pressure
Section 7
formula
The design pressure shall be calculated with the following
p = cd  cl  ca  po [MPa], where
cd = factor that takes account of the influence of the vessel’s size and
engine power.
The factor is calculated with the following formula:
cd 
ak  b
1000
k
ΔP
1000
a and b are given in the following table:
5
SJÖFS 2007:XX
a
b
Fore
k  12 k > 12
30
6
230
518
Area
Amidships & aft
k  12
k > 12
8
2
214
286

= the displacement of the vessel on the upper icewater line in
accordance with Chapter 2 (1) [t]
P = actual continuous engine power of the vessel [kW]
cl = factor catering for the probability of the design pressure arising in
a certain area of the hull for the ice class in question.
The value of cl is given in the following table:
Ice class
IA Super
IA
IB
IC
Fore
1.0
1.0
1.0
1.0
Area
Amidships
1.0
0.85
0.70
0.50
Aft
0.75
0.65
0.45
0.25
ca = factor catering for the probability of the entire length of the area in
question being subjected to pressure at the same time. The factor is
calculated with the following formula:
ca =
6
47 - 5 l a
; maximum 1.0 ; minimum 0.6
44
SJÖFS 2007:XX
la shall be assumed to be as follows:
Structure
planking
rib
Ribbing type
athwartships
fore-and-aft
athwartships
fore-and-aft
ice weigher
frame rib
la [m]
the rib distance
2  the rib distance
the rib distance
span of the rib
span of the weigher
2  the distance between the frame
ribs
po = the nominal ice pressure; the value 5.6 MPa is to be used.
Section 8
The vertical extent of the ice belt shall be in accordance
with Figure 2 and have a vertical extent in accordance with the following:
Ice class
IA Super
IA
IB
IC
Over UIWL
[m]
0.6
0.5
0.4
0.4
Below LIWL
[m]
0.75
0.6
0.5
0.5
In addition, the following areas shall be reinforced:
Lower prow: In the case of ice class IA Super, the boarding below the ice
belt, between the stem and a position equal to five main ribs aft of the point at
which the stem profile deviates from the keel line, shall have at least the
thickness required in the ice belt in the midship area.
Upper front ice belt: In the case of ice classes IA Super and IA on vessels
with a service speed in open water of 18 knots or more, the boarding from the
upper edge of the ice belt to 2 metres above it and from the stem to a position
at least 0.2 L aft of the leading perpendicular shall in any event be not less
than the thickness required in the ice belt in the midship area.
7
SJÖFS 2007:XX
Ribs
Section 11
The vertical extent of the ribbing shall meet at least the
following requirements:
Ice class
Area
from the stem to
0.3 L aft of it
Above
UIWL
[m]
1.2
IA Super
aft of 0.3 L
from the stem
midships
aft
IA, IB, IC
from the stem to
0.3 L aft of it
aft of
0.3 L
from the stem
midships
aft
Below LIWL
[m]
to tank top or below
upper edge of bottom
stocks
1.2
1.6
1.2
1.2
1.6
1.2
1.0
1.6
1.0
1.3
1.0
1.0
1.3
1.0
Where an upper, front ice belt is required in accordance with Chapter 4 (8),
the ice reinforcement of the ribbing shall extend to at least the height of this
ice belt.
Where the ice reinforcement must be extended past a deck or a tank top by
no more than 250 mm, it may be terminated at this deck or tank top.
Section 23
In the case of a stem made of bent sheet metal, the sheet
thickness shall be calculated in accordance with the formulae in Chapter 4
(10) assuming that:
s
= the distance between the elements that support the sheet metal [m]
pPL = p in accordance with Chapter 4 (7) [MPa]
la = the distance between vertical supporting elements [m]
The same applies to all parts of the boarding that form an angle of 30° or
more with the centreline in the horizontal plane in connection with an obtuse
stem.
The stem and the part of an obtuse stem described in the first paragraph
shall be supported by bottom stocks or elbow tabs spaced at intervals of no
more than 0.6 m and whose thickness is at least half the thickness of the
boarding. The reinforcement of the stem shall extend from the keel to a point
0.75 m above the UIWL or, where a front ice belt is required in accordance
with Chapter 4 (8), to the upper limit of the ice belt.
8
SJÖFS 2007:XX
Section 25
On vessels whose displacement does not exceed 30 000
tonnes, the part of the bow that extends to a height of at least 5 metres above
the UIWL and at least 3 metes aft from the stem shall be reinforced to
withstand the loads caused by pin towing. For this purpose, intermediate
ribs shall be installed and the ribs shall be supported by weighers or the
deck.
Section 28
An aft mirror shall, where possible, not be extended below
the UIWL. If this is unavoidable, the part of the aft mirror located below
the UIWL shall be kept as narrow as possible. The part of an aft mirror that
is located within the ice belt shall be reinforced in the same was as the
midship area.
Entry into force and transitional provisions
This statute shall come into force four weeks after the date on which the
statute according to information on it was published in the Swedish
Maritime Administration’s collection of statutes.
On behalf of the Marine Surveying Department
JOHAN FRANSON
Göran Liljeström
(The Marine Surveying Department)
Publisher:
Jan-Olof Selén, the Swedish Maritime Administration,
Norrköping, Sweden
ISSN 0347-531X
9
SJÖFS 2007:XX
Annex 1
Annex 1
Basis for control calculation of power requirements
To allow control calculation of the power requirements, Table 2 shows input
data for a number of type vessels.
Table 2
Example no.
Ice class
#1
#2
#3
#4
#5
#6
#7
#8
#9
IAS
IA
IB
IC
IAS
IAS
IA
IA
IB

°
24
24
24
24
24
24
36
20
24
1
°
90
90
90
90
30
90
30
30
90
2
°
30
30
30
30
30
30
30
30
30
L
m
150
150
150
150
150
150
150
150
150
B
m
25
25
25
25
25
22
25
25
25
T
m
9
9
9
9
9
9
9
9
9
LBOW
m
45
45
45
45
45
45
45
45
45
LPAR
m
70
70
70
70
70
70
70
70
70
Awf
m 
500
500
500
500
500
500
500
500
500
DP
m
5
5
5
5
5
5
5
5
5
1/CP
1/CP
1/CP
1/CP
1/CP
1/CP
1/CP
1/CP
1/FP
3477
2252
6797
6404
5342
5017
3870
8469
7645
6614
6614
2
No. of propellers/type
New vessel
kW
7838
4939
Existing vessel
kW
9198
6614
(calc. pursuant to Chap 3 (6))
11
SJÖFS 2007:XX
Annex 2
Annex 2
Freeboard mark for ice class
If, under the terms of Chapter 2 (3 a), each side of a vessel must be
provided with a freeboard mark and associated warning triangle for the ice
class, this shall be designed in accordance with Figure 1 below.
The warning triangle is to show that the vessel has a draught restriction
when sailing in ice. This information is important for icebreaker captains
and port inspectors.
Figure 1
Comments on Figure 1
1.
2.
3.
4.
The upper edge of the warning triangle is placed vertically above the
‘ICE’ mark, 1000 mm above the summer freeboard in fresh water.
The warning triangle needs, however, to be placed above the deck
line. The sides of the triangle measure 300 mm.
The freeboard mark for the ice class must be placed 540 mm aft of
the centre of the freeboard mark. If the vessel is provided with a
freeboard mark for the timber load, the ‘ICE’ mark must be placed
540 mm aft of the vertical marking of the timber load line.
Markings shall be made in sheet metal of 5–8 mm thickness and
welded on the side of the vessel. The markings shall be painted red
or yellow in reflective colours to make the marks readily visible even
under conditions of ice.
The dimensions of all marks are the same as for the freeboard mark.
13
Impact assessment of draft regulations for the
Finnish-Swedish ice classes and ice classes for
traffic on Lake Vänern
General
The regulations that currently govern ice classes are SJÖFS
2003:4 concerning Finnish-Swedish ice classes and SJÖFS
2003:16 concerning ice classes for Lake Vänern. These
regulations stipulate that the ice class draught LWL must
correspond to the draught of the summer freeboard in fresh
water. It has emerged that there is sometimes a need to
restrict the draught in relation to the summer load waterline
in fresh water when sailing in ice.
Finland and Sweden have jointly decided that this should be
possible and it is therefore proposed that the draughts that
determine the ice belt should be renamed so as to distinguish
them from the draughts in previous rules. A draught
restriction must be marked on the vessel, and a marking of
this kind is proposed in connection with the freeboard mark.
The proposed changes have been approved by IACS, which
means that they are also introduced internationally.
In practice, this means that the LWL in the regulations must
be replaced with UIWL (Upper Ice Waterline) and the BWL
with LIWL (Lower Ice Waterline). In addition, an annex
showing the freeboard mark for ice classes is added.
The rules are intended to come into force on 1 July 2007 and
are to apply to all new vessels with a Finnish-Swedish ice
class.
In the case of vessels built before 1 July 2007, a draught
restriction for ice classes need be carried out only if the
vessel’s LWL = UIWL is less than the draught
corresponding to the summer freeboard in salt water. Such
14
a marking of reduced ice class draught must be carried out
by the first drying of the vessel after 1 July 2007.
In purely practical terms, the proposed rules mean that
vessels that have their ice belt positioned relative to the
summer freeboard in salt water are allowed to retain their
ice class.
Parties concerned
The proposed rules mainly concern shipowners with vessels
classified for ice and also shipyards and consultants who
plan and build vessels with Finnish-Swedish ice classes.
Resource requirements
The amendments do not result in any resource requirements
for the Swedish Maritime Administration, shipping
companies, shipyards, classification societies and other
parties concerned.
Training/Information
The proposed amendment will not affect the need for
training within the Maritime Safety Inspectorate.
Inspectors, etc. are to be informed of what the new
regulations entail via a notice in the Inspectorate’s
newsletter. The information is also to be disseminated via
the channels that the Icebreaking Department has for winter
shipping.
Content and disposal
Amendment of affected text and figures and a new annex
concerning marking of the ice freeboard.
Description of
consequences
The proposed amendment of the regulations gives all
shipowners greater flexibility in being able to design their
vessels without unnecessary reinforcements of the full being
required to be able to sail in ice in a restricted draught.
15
There should be no Swedish vessels that require marking of
reduced ice class draught. Any vessels that have their ice
belt relative to the summer freeboard in salt water will, as a
result of the new regulations, meet the Swedish ice class
rules.
The change in the rules does not entail any environmental
consequences.
Costs
The costs are assessed as being SEK 0.
16