Iranian Classification Society Rules
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Section 1 General
101. General
1. The requirements in this chapter apply to ships with ice breaking capability and Icebreakers in- tended for navigation in the arctic seas.
2. For those not defined in this Chapter, the requirements of the Rules for the Classification of Steel Ships are to be applied.
102.
Class of a ship and Class notation
1. Class notations are assigned to Icebreakers and Arc class ships in compliance with the requirements of Par 2 to 4. At the owner's discretion, class notations of Ch 1, Ch 2 and of this chapter may be assigned simultaneously, provided such ships comply with the requirements for both.
2. If an Icebreaker complies with the requirements of this chapter, one of the class notations
Icebreaker3 ∼ Icebreaker6 described
teristics as Table 3.1.
below can be assigned. Icebreaker have the following charac-
Table 3.1 Characteristics of Icebreakers
Icebreaker3 | - Intended for ice breaking operation in harbour and roadstead water areas as well as in non-arctic freezing seas where the ice is up to 1.5m thick. - Ice breaking capability in ice up to 1 m thick. |
Icebreaker4 | - Intended for ice breaking operation in the arctic seas on coastal routes during winter/spring navigation in ice up to 2.0 m thick and summer/autumn navigation in ice up to 2.5 m thick; in non-artic freezing seas and mouths of rivers flowing into arctic seas in ice up to 2.0 m thick. - Ice breaking capability in ice up to 1.5 m thick. - The total shaft power not less than 11 MW. |
Icebreaker5 | - Intended for ice breaking operations in the arctic seas on coastal routes during winter/spring navigation in ice up to 3.0m thick and summer/autumn navigation without restrictions. - Ice breaking capability in ice up to 2.0m thick. - The total shaft power not less than 22 MW. |
Icebreaker3 | - Intended for ice breaking operation on coastal routes in arctic seas during winter/spring navigation in ice up to 4.0 m thick and summer/autumn navigation without restrictions. - Ice breaking capability in ice over 2.0 m thick. - The total shaft power not less than 48 MW. |
3. If a ship complies with the relevant arctic seas, one of the Arc1 ∼ Arc3
requirements of this Chapter and intended for navigation in class notations shall be assigned. At the owner's discretions,
a ship which perform icebreaking operations periodically and complies with the relevant require- ments of Icebreaker, one of Icebreaker3 or Icebreaker4 class notations may be assigned.
4. Table 3.2 shows, for Arc class ships, limiting type and thickness of ice enabling a ship to navi- gate in a channel following an Icebreaker at a low speed(3 to 5 knots) without running a height- ened risk of damage through contact of hull with ice. Table 3.3 shows, Arc class ships operating independently, permissible speeds which a ship under the ice conditions set out in the table may reach when navigating in fractures between floes or surmounting ice isthmuses without running a heightened risk of damage through contact of hull with ice.
Table 3.2 Permitted type and thickness of ice(Icebreaker escorted navigation)
Arc class | Permitted type and thickness of ice | |
Winter/spring navigation | Summer/autumn navigation | |
Arc1 | First-year | Medium first-year up to 0.9 m |
Arc2 | Medium first-year up to 0.8 m thick | Medium first-year |
Arc3 | Medium first-year | Thick first-year up to 1.5 m |
Arc4 | Thick first-year up to 1.8 m | Second-year |
Arc5 | Multi-year up to 3.4 m | Multi-year |
Arc6 | Multi-year | Multi-year |
Note : The classification of ice adopted according to the "Sea Ice Nomenclature: of the World Meteorological Organization (WMO)" Ice type Ice thickness Multi-year > 3.0 m Second-year > 2.0 m Thick first-year > 1.2 m Medium first-year 0.7 - 1.2 m Thin first-year < 0.7 m | ||
Table 3.3 Permitted type and thickness of ice(Independent navigation)
Arc class | Permitted speed, in knots | Ice concentration and type | Ice thickness, in m | Methods of surmounting ice ridges | |
Winter/ spring navigation | Summer/ autumn navigation | ||||
Arc1 | 6-8 | open floating first-year ice | 0.6 | 0.8 | Continuous motion |
Arc2 | open floating first-year ice | 0.8 | 1.0 | ||
Arc3 | open floating first-year ice | 1.1 | 1.3 | ||
Arc4 | close floating first-year ice | 1.4 | 1.7 | Episodic ramming | |
Arc5 | 10 | close floating second-year ice | 2.1 | 3.0 | Regular ramming |
Arc6 | 12 | very close floating and compact multi-year ice | 3.5 | 4.0 | Surmount of ice ridges and episodic ramming of compact ice fields |
103. Documentation
1. Forward region, forward intermediate region, midship region, aft region and defined in 203. are to be indicated in the Shell Expansion.
2. UIWL and LIWL
UIWL, LIWL of Par 3
(1) The upper ice waterline (UIWL) shall be the envelop of the highest points of the waterline at which the ship is intended to operate in ice.
(2) The lower ice waterline (LIWL) shall be the envelop of the lowest points of the waterline at which the ship is intended to operate in ice.
(3) The maximum and minimum ice draughts at fore and aft perpendiculars shall be determined in accordance with the upper and lower ice waterlines.
(4) An ice loadline shall be
navigation.
3. Restrictions on draughts when
disregarded heel and mass of ice in case of icing during ice
operating in ice shall be documented and kept on board readily
available to the master. The maximum and minimum ice draughts fore, amidships and aft shall be indicated in the classification certificate.