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1. Objective The objective
of this chapter is to describe the underlying principles of the rules, and to
define some concepts used throughout the rules. Page index
2. References
Reference is made to the following documents:
- ISO 8666:2002 Principal dimensions
- ISO 6185:2001 Inflatable boats
- ISO 12217-1:2002 Stability and buoyancy assessment and categorization
- SOLAS
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3. Background
These rules are developed originally from Nordic Boat Standard (NBS-Y). New
rules has been modernised and the scope of the rule has been extended using ISO
standards developed during last decade. Main improvements are: - Scope
of the rule has been widened to cover boats up to 24 m long;
- Design categories as defined by Recreational Craft Directive has been
added;
- Vessel types has been specified by the primary use of the boat, some
requirements are based on those types;
- Catamarans and rigid inflatable boats (RIBs) have been added;
- ISO standards are referred often.
Boats with hull length from 15 to 24 metres: rules use requirements from ship
standards, if relevant.
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4. Principles of using ISO-standards
The international (ISO) standards referred to were mainly developed for
certification of boats according to the directive 94/25/EC and 2003/44/EC (the
Recreational Craft Directive). The scope of these standards is "small craft"
under 24 m hull length and as such not only restricted to recreational craft.
The principles used in these standards are often relevant to commercial craft as
well, even though the level of safety required in the standards in some
instances may be argued to be too low.
The ISO standards are implemented as follows:
In the rule text the ISO standard text is only quoted to an extent that makes
the rules usable for the most typical cases. The original standard text must be
consulted for accurate definitions and special cases. It is thus necessary for
the serious user of the rules to possess a set of the referenced standards.
Higher requirements than those in the ISO standard may be given in these rules.
The intention is that a boat that fulfils the requirements of these rules also
complies with the referenced ISO standard. It is the intention that these rules
will be updated to be in line with the newest version of the referenced ISO
standard as they may appear.
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5. The rules vs international conventions
Of the four design categories that are referred to in these rules (see 7.1),
the most severe, Category A, is intended for extended voyages, but shall not be
regarded as unrestricted service in the same sense as in the international
conventions. Therefore, the requirements for category A craft are in many cases
lower than those given in the conventions.
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6. Validity of rules
6.1 Length
The rules apply to naval craft with a length of hull up to 24 metres long
measured according to ILCC. This is the the length greater of following:
- 96% from the length of the hull measured at the 85% height of the freeboard
amidships or - length between forward perpendicular and rudder axis at the
same height (85% of the freeboard amidships).
6.2 Type of hull
The rules apply to monohull crafts, catamarans and inflatable boats (including
RIBs). 6.3 Material of hull
Fibre-reinforced plastics, aluminium and steel construction are covered in the
rules.
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7. Operating conditions
7.1 Design categories A boat given design category A is
considered to be designed to operate in winds up to Beaufort force 10 and
associated wave heights, and to survive in more severe conditions. Such
conditions may be encountered on extended voyages, for example across oceans, or
inshore when unsheltered from the wind and waves for several hundred nautical
miles. Winds are assumed to gust to 28 m/s.
A boat given design category B is considered to be designed
for waves up to 4 m significant height and winds up to Beaufort force 8. Such
conditions may be encountered on offshore voyages of sufficient length or on
coasts where shelter may not always be immediately available. These conditions
may also be experienced on inland seas of sufficient size for the wave height to
be generated. Winds are assumed to gust to 21 m/s.
A boat given design category C is considered to be designed
for waves up to 2 m significant height and and winds up to Beaufort force 6.
Such conditions may be encountered on exposed inland waters, in estuaries and in
coastal waters in moderate weather conditions. Winds are assumed to gust to 17
m/s.
A boat given design category D is considered to be designed
for occasional waves of 0.5 m height and typical steady winds up to Beaufort
force 4. Such conditions may be encountered on sheltered inland waters and in
coastal waters in fine weather. Winds are assumed to gust to 13 m/s.
Table 1. Summary of design category definitions.
|
Design category |
A |
B |
C |
D |
|
Wave height up to |
approx.
7 m significant |
4 m significant |
2 m significant |
0.5 m maximum |
|
Typical Beaufort wind force
|
£
10 |
£
8 |
£
6 |
£
4 |
The significant wave height is the mean height of the highest one-third of
the waves, which approximately corresponds to the wave height estimated by an
experienced observer. Some waves will be double this height.
7.2. Temperature and salinity All materials used in the craft as well as
the assembled craft including its systems shall be capable of being stored in
temperatures in the range -40 - +60 °C. The craft including its essential
systems shall be capable of operating in the temperature range 0 - 50 °C. All
materials that may be in contact with sea water shall be capable to sustain
salinity of 5%. Page index
8. Type of boat
Depending on its missions, the craft is assumed to fit into one or several of
the Craft Types described below..
8.1 General workboat
A boat that fulfils all relevant requirement based on the length, design
category and deck arrangement, but which is not assigned any special mission.
The greatest amount of cargo in addition to persons and bunker must not exceed
1000 kg. 8.2 Cargo vessel
Primary mission, transport of cargo. Special attention is paid to the handling,
distribution and lashing of cargo. The stability is to be sufficient for the
type and amount of cargo.
8.3 Fast rescue/patrol boat
Primary mission is to transport persons. Amount of persons onboard other than
rescue mission is 12. Typically fast rescue boats are seaworthy to their design
category, good redundancy of installed equipment and ergonomity of steering
point.
8.4 Tugboat
Primary mission is towing of floating materials and other crafts. Stability,
prevention of water ingress and safety of working deck, especially at the
proximity of towing hook are especially paid attention.
8.5 Pollution responsevessels
Mission of responsevessel is to transport oil recovery equitment or to collect
oil or transporting recovered oil to other ships or to shore. Special attention
is paid to safety for operating outside shipping lanes (shallow water),
workingdeck safety and fire safety.
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9. Additional notations
A boat can be assessed as having items in addition the basic rule
requirements. If the item in question is found to comply with the rules for the
item in question, an additional notation is given on the certificate. The
following Additional Notations are presently included:
9.1 Ice strenghtened
To a craft that fullfills all relevant requirements at chapter 40 is assigned
the additional notation "Ice strengthened."
9.2 Damage stability
A craft that meets the requirements in chapter 6 is assigned the additional
notation "One compartment damage stability."
9.3 Additional equipment
Requirements for some essential special equipment are given in Chapter 41. These
special equipment include Deck cranes. Additional notation "Deck crane.".
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10. Approvals
10.1 Product verification
Normally, boats are individually surveyed as new boat types or
sister boats. A new boat type is surveyed according to all
relevant parts of the rules. The survey of a sister boat is limited to
parts that are dependable on workmanship and production, and, in addition,
possible modifications of the design compared to the (previously approved)
parent boat.
10.2 Type approval with production control
Type approval is possible for series-built boats. If applied, the documentation
and production control are to be sufficiently comprehensive to facilitate the
manufacturing of identical products.
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11. Documentation and verification
The required documentation to be submitted depends on the type of craft in
question. For all craft, the following documentation shall be submitted:
Application with general information of the craft including intended type of
boat, Design Category and possible Additional Notations;
General arrangement drawing;
The required additional topic-specific documentation is listed in each
chapter.
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12. Symbols and units udes throughout the rules
12.1. Mass and size of persons
When determining the loading cases and for various other purposes in the Rules,
the weight, centre of gravity and size of a person seat shall be taken as
following: (use of greater values might be required when persons have special
gear, for eg. diving equipment)
- Mass: 85 kg
- Seat width: 0,4 m
- Height above seat: 0,9 m
- Horizontal distance from backrest to feet: 0,75 m
- Vertical centre of gravity above seat or deck 0,1 m
12.2. Symbols and units used throughout the rules
Table 2. Symbols
|
Symbols |
Unit |
Meaning |
Standard reference |
|
LH |
m |
Length of hull |
ISO 8666 |
|
LWL |
m |
Length of waterline in the appropriate loading condition |
ISO 8666 |
|
BH |
m |
Beam of hull |
ISO 8666 |
|
BWL |
m |
Beam waterline in the appropriate loading condition. In multihull crafts, beam waterline is sum of beams of waterlines |
ISO 8666 |
|
BC |
m |
Beam of chines |
|
|
FM |
m |
Freeboard amidships in the appropriate loading condition. |
ISO 8666 |
|
TC |
m |
Draught of the canoe body in the appropriate loading condition. |
ISO 8666 |
|
m3 |
Displacement volume |
ISO 12217 |
|
f |
degree (o) |
Angle of heel |
ISO 12217 |
|
CL |
|
Crew limit = maximum number of persons on board |
ISO 12217 |
|
GM |
m |
Transverse metacentric height |
ISO 12217 |
|
GZ |
m |
Righting lever = righting moment (Nm)/(mass (kg) x 9.806) |
ISO 12217 |
|
LCG |
m |
Longitudinal position of the centre of gravity from a chosen datum |
ISO 12217 |
|
mLDC |
kg |
Loaded displacement mass |
ISO 12217 |
|
m MOC |
kg |
Mass of the boat in minimum operating condition |
ISO 12217 |
|
mMTL |
kg |
Mass of the maximum total load |
ISO 12217 |
|
RM |
Nm |
Righting moment |
ISO 12217 |
|
VCG |
m |
Vertical position of the centre of gravity from a chosen datum |
ISO 12217 |
|
V |
knots |
Speed |
|
|
VMAX |
knots |
Greatest speed |
|
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