Arctic Shipping Pollution Prevention Regulations (C.R.C., c. 353)

Regulations are current to 2016-11-21

SCHEDULE VI(ss. 2 and 6)Hull Design for Arctic Class Ships

Interpretation

  • 1 In this Schedule,

    aft perpendicular

    aft perpendicular means a perpendicular that coincides with the after side of the rudder post, or where no rudder post is fitted, with the centreline of the rudder stock; (perpendiculaire arrière)

    amidships

    amidships means the middle of length (L); (milieu du navire)

    bilge boundary line

    bilge boundary line means a line that in elevation is parallel to the line of the keel and coincident amidships with the boundary between the side of the hull and the upper turn of bilge; (ligne de démarcation du bouchain)

    breadth (B)

    breadth (B) means the greatest moulded breadth in metres; (largeur (B))

    forward perpendicular

    forward perpendicular means a perpendicular erected at the intersection of the fore side of the stem and the deepest operating load waterline; (perpendiculaire avant)

    length (L)

    length (L) means the distance in metres on the summer load waterline from the fore-side of the stem to

    • (a) the after side of the rudder post, or

    • (b) to the centre of the rudder stock, if there is no rudder post,

    which distance shall not be less than 96 per cent and need not be greater than 97 per cent of the extreme length on the summer load waterline; (longueur (L))

    ice breaker

    ice breaker means a ship specially designed and constructed for the purpose of assisting the passage of other ships through ice. (brise-glace)

Definitions

    • 2 (1) Subject to subsection (2), in every Arctic class ship, other than a Class 1 ship,

      • (a) the bow, forefoot, mid-body and stern are the parts of the ship, and

      • (b) the bow area, lower bow area, mid-body area, stern area, upper transition area and lower transition area are the areas of the shell

      shown in the figure to this section.

    • (2) In every Arctic class ship, other than a Class 1 ship,

      • (a) the forward extremity of the upper transition area is the forward extremity of the bow;

      • (b) the aft extremity of the upper transition area is the aft extremity of the stern;

      • (c) the forward extremity of the forefoot is the point at which the line of the keel is tangent to the stem contour;

      • (d) the bow area includes the bottom of the hull over the length of the forefoot;

      • (e) the lower bow area includes the bottom of the hull between the aft end of the forefoot and the aft end of the bow; and

      • (f) the lower boundary of that part of the lower transition area that is forward of amidships is the shortest line on the outside of the hull between

        • (i) the intersection of the bilge boundary line with the aft boundary of the lower bow area, and

        • (ii) the forward end of that part of the lower boundary of the lower transition area that is aft of amidships.

    • (3) In every Arctic class 1 ship the ice belt is that part of the shell that lies between

      • (a) a line that is 760 mm above and parallel to the deepest operating load waterline; and

      • (b) a line that is 610 mm below and parallel to the lightest operating waterline.

      Illustration and specifications for bow area, lower bow area, mid-body area, stern area, lower transition area and upper transition area in every Arctic class ship, other than a Class 1 ship

Dimensions

    • 3 (1) For an Arctic class ship set out in Column I of an item of Table I,

      • (a) the vertical height (D) of the forward extremity of the bow area above the deepest operating load waterline is set out in Column II of that item;

      • (b) the vertical height (AW) of the upper boundary of the mid-body area above the deepest operating load waterline is set out in Column III of that item;

      • (c) the vertical depth (BW) of the lower boundary of the mid-body area below the lightest operating waterline is set out in Column IV of that item;

      • (d) the vertical height (UT) of the upper boundary of the upper transition area above the upper boundaries of the bow area, mid-body area and the stern area is set out in Column V of that item;

      • (e) the vertical depth (BW + LT) of the lower boundary of

        • (i) the stern area, and

        • (ii) that part of the lower transition area that is aft of amidships,

        below the lightest operating waterline, is the value set out in Column VI of that item added to the value set out in Column IV of that item;

      • (f) the vertical height (C) of the aft extremity of the stern area above the deepest operating load waterline is set out in Column VII of that item;

      • (g) the length of the forefoot (E) is set out in Column VIII of that item;

      • (h) the horizontal distance (F) between the forward perpendicular and the aft end of the bow is set out in Column IX of that item; and

      • (i) the horizontal distance (S) between the aft perpendicular and the forward end of the stern is set out in Column X of that item.

    • (2) Notwithstanding paragraph (1)(h), the distance referred to in that paragraph need not be greater than the distance between the forward perpendicular and the point on the centreline that is 0.04L aft of the point at which, when proceeding aft from the stem, the breadth (B) is first reached.

    • 4 (1) The bow of every Arctic class ship shall be shaped so that it can break ice effectively.

    • (2) The stern of every Arctic class ship shall be shaped so that it can displace broken ice effectively.

Shell Plating and Framing

    • 5 (1) Subject to subsections (2) and (3), for each Arctic class ship set out in Column I of an item of Table II the shell plating and main framing in each area specified in the heading to each of Columns II to VII shall, without exceeding the yield stress of the materials from which they are made, be capable of withstanding the ice pressure shown in that Column of that item.

    • (2) Where waste is stowed in direct contact with the shell plating in the bow of a ship, other than an Arctic class 8 or 10 ship,

      • (a) the values shown in Columns II and III of an item of Table II, and

      • (b) with respect to the bow, the values shown in Column VI of an item of Table II

      do not apply and the values shown in those Columns of the next following item apply in substitution therefor.

    • (3) Where the total length of the mid-body of a ship, other than an Arctic class 1 ship, is fitted with side tanks that comply with section 6 of this Schedule

      • (a) the values shown in Column IV of an item of Table II, and

      • (b) with respect to the mid-body, the values shown in Columns V and VI of an item of Table II

      do not apply and the values shown in those Columns of the preceding item apply in substitution therefor.

    • (4) Subject to subsection (5), for each Arctic class ship in Column I of an item of Table III,

      • (a) the web frames supporting main longitudinal frames, and

      • (b) the stringers supporting main transverse frames

      in each area specified in the heading to each of Columns II to IV shall, without exceeding the yield stress of the materials from which they are made, be capable of withstanding the ice loading shown in that Column of that item.

    • (5) Where the flare of the side shell plating is less than eight degrees outboard from the vertical for a distance of five per cent or more of the length of the mid-body of an Arctic class ship between the lower boundary of the lower transition area and the lower boundary of the upper transition area, the ice loadings shown in Column III of an item of Table III do not apply and the ice loadings shown in Column II of that item apply in substitution therefor.

  • 6 The side tanks referred to in subsection 5(3) of this Schedule and fitted in an Arctic class ship set out in Column I of an item of Table IV shall

    • (a) have a width measured from the outer shell of not less than that shown in Column II of that item;

    • (b) extend vertically from the outer bottom of the ship up to the deck at which the main watertight bulkheads of the ship terminate;

    • (c) be so constructed that, if the shell plating or turn of bilge plating is deformed or penetrated by ice, any internal stiffening structure will buckle before it penetrates the inner side of the tank; and

    • (d) contain no waste.

    • 7 (1) Subject to subsection (2), for an Arctic class ship set out in Column I of an item of Table II, the thickness of the shell plating in each area specified in the heading to each of Columns II to VII shall not be less than the spacing of the main frames multiplied by the factor obtained from the formula

      factor = 2 ÷ 3√P ÷ f

      where

      • (a) “p” is the pressure shown in each of Columns II to VII of that item;

      • (b) “f” is the yield stress of the shell plating material; and

      • (c) “p” and “f” are expressed in the same units.

    • (2) The thickness of the stem plate shall be not less than 1.3 times the thickness of the adjacent shell plating in the bow area determined in accordance with subsection (1).

    • 8 (1) For an Arctic class ship set out in Column I of an item of Table II, the section modulus of the main transverse frames with the adjacent shell plating in each area specified in the heading to each of Columns II, IV and VII shall not be less than the value given by the formula

      (ps (b-400)) ÷  8f cm3

       where

      • (a) “p” is the pressure in megapascals shown in each of Columns II, IV and VII of that item;

      • (b) “s” is the main transverse frame spacing in millimetres;

      • (c) “b” is the span of the main transverse frame in millimetres; and

      • (d) “f” is the yield stress of the main transverse frame material in megapascals.

    • (2) For an Arctic class ship set out in Column I of an item of Table II, the section modulus of the main longitudinal frames with the adjacent shell plating shall not be less than the value given by the formula

      ( b2 spk) ÷ f cm3

       where

      • (a) “b” is the span of the main longitudinal frame in millimetres in the bow area, mid-body area or stern area, whichever area is applicable;

      • (b) “s” is the main longitudinal frame spacing in millimetres in the bow area, mid-body area or stern area, whichever area is applicable;

      • (c) “p” is, subject to subsection (3), the pressure in megapascals shown in Column II, IV or VII, of the item, whichever column is applicable with respect to the area specified in the heading to the column;

      • (d) “k” is,

        • (i) 1 ÷ 20300, in the case of framing in the bow area

        • (ii) 1 ÷ 18600, in the case of framing in the mid-body area

        or stern area; and

      • (e) “f” is the yield stress of the main longitudinal frame material in megapascals in the bow area, mid-body area or stern area, whichever area is applicable.

    • (3) Where longitudinal framing is used in the bow of a ship, the pressures shown in Columns II and III of an item of Table II shall be multiplied by the factor 1.2, except that in no case need the increased pressures so obtained exceed 10.34 MPa.

Subdivision and Stability

    • 9 (1) Every Arctic class ship that is used solely as an icebreaker shall, when at its worst operating condition with respect to stability and freeboard, be able to withstand the flooding of any one compartment and remain afloat in a satisfactory condition of equilibrium.

    • (2) Every Arctic class ship, other than a ship that is used solely as an icebreaker, shall, when loaded to its worst operating condition with respect to stability and freeboard, be able to withstand the flooding of any two adjacent fore and aft compartments and remain afloat in a satisfactory condition of equilibrium.

    • (3) The necessary calculations to ensure compliance with subsections (1) and (2), shall be based on the following assumptions of damage:

      • (a) the side damage

        • (i) in a longitudinal direction, extends within one compartment on a ship described in subsection (1) and within two adjacent compartments on a ship described in subsection (2),

        • (ii) in a transverse direction, extends outboard of the outermost longitudinal watertight bulkhead or for a distance of one-fifth of the breadth (B) where no such bulkhead is fitted, and

        • (iii) in a vertical direction, extends from the baseline to the underside of the main watertight bulkhead deck; and

      • (b) the bottom damage

        • (i) in a longitudinal direction, extends within one compartment on a ship described in subsection (1) and within two adjacent compartments on a ship described in subsection (2),

        • (ii) in a transverse direction, extends over any distance equal to one-sixth of the breadth (B) or for a distance of five metres, whichever is the lesser, and

        • (iii) in a vertical direction, extends from the level of the keel to the underside of the inner bottom or for a distance of six metres where no inner bottom is fitted.

    • (4) Notwithstanding subsection (3), where lesser extents of damage could have greater effect than the extents of damage described therein, the necessary calculations to ensure compliance with subsections (1) and (2) shall also be based on those lesser extents of damage.

    • (5) For every Arctic class ship, intermediate stages of flooding resulting from the damage referred to in subsections (3) and (4) shall be considered when making the calculations to ensure compliance with subsections (1) and (2).

  • 10 Every Arctic class ship shall be constructed or equipped so that, when the ship is riding up or sliding off the ice,

    • (a) the ship has positive stability; and

    • (b) the deck edge of any part of the ship does not submerge.

Rudder and Steering Gear

    • 11 (1) The rudder, rudders posts, rudder stocks, pintles and steering gear of every Arctic class ship shall be strengthened as necessary to withstand the anticipated loading that a ship of that Arctic class may experience when navigating in those zones and at those times of year in which a ship of that Arctic class is permitted to operate.

    • (2) The main steering gear of every Arctic class ship shall be fitted with a shock absorbing device and shall be capable of moving the rudder from 35 degrees on one side to 30 degrees on the other in

      2.56 √L seconds

      where

      L 
      is in metres
    • (3) Every Arctic class ship shall, in addition to the main steering gear, be fitted with

      • (a) an auxiliary steering gear capable of being readily connected to the tiller and, in the case of a ship of that category fitted with twin rudders operated by a single steering gear, an arrangement so that each rudder can be readily disconnected and secured; or

      • (b) an effective alternative means of steering the ship such as multiple propellers or side thrust arrangements.

    • (4) Every Arctic class ship shall be fitted with ice horns directly abaft each rudder in such a manner that

      • (a) the upper edge of the rudder is protected within two degrees port and starboard of mid-position when going astern; and

      • (b) ice is prevented from wedging between the top of the rudder and the ship’s hull.

TABLE I

Values expressed in metresValues expressed as a percentage of the length (L) of the ship
Column IColumn IIColumn IIIColumn IVColumn VColumn VIColumn VIIColumn VIIIColumn IXColumn X
ItemArctic ClassDAWBWUTLTCEFS
11A1.220.761.070.300.610.762.52015
221.520.911.520.460.610.912.52015
331.831.372.290.460.611.372.52015
442.441.833.660.610.911.832.52015
563.662.744.570.911.372.742.52520
674.883.666.101.221.833.662.53025
786.104.577.621.522.294.572.53025
8107.325.499.141.832.745.492.53025

TABLE II

Ice Pressures in megapascals
Column IColumn IIColumn IIIColumn IVColumn VColumn VIColumn VII
ItemArctic ClassBow AreaLower Bow AreaMid-body AreaLower Transition AreaUpper Transition AreaStern Area
111.72***0.69*****0.69*
21A2.761.451.791.240.902.24
324.142.212.761.791.383.45
435.512.903.652.551.794.55
546.893.654.553.172.285.65
668.274.415.173.592.556.48
779.655.105.864.142.907.24
8810.345.526.554.553.248.27
91010.345.526.554.553.248.27
  • * In an Arctic Class 1 ship, only that part of

    • (a) the bow area and stern area lying between the horizontal projections of the upper and lower edges of the mid-body area need be considered; and

    • (b) the mid-body area forward of amidships need be considered.

  • ** In an Arctic Class 1 ship, ice pressure need not be considered as a factor in the design of the hull in the lower bow area, lower transition area and upper transition area, and the strength standards usually applied to ocean-going ships shall apply in these areas.

TABLE III

Minimum ice loading expressed in tonnes per metre run, for stringers or web frames in the areas specified in the column headings below
Column IColumn IIColumn IIIColumn IV
ItemArctic ClassBow AreaMid AreaStern Area
1172.1**
21A82.065.572.1
3298.382.088.5
43131.198.3114.8
54163.8114.7131.1
66229.4147.5179.3
77262.1163.8196.6
88328.0196.6245.8
910540.7229.4262.1
  • NOTE: The loading values shown in this Table are based upon a stringer or web frame spacing of 1.2 m. For any other spacing, these loading values shall be increased or decreased, respectively, in direct proportion to the amount that the actual spacing is greater than or less than 1.2 m.

  • * In an Arctic Class 1 ship, ice loads need not be considered as a factor in the design of the hull in the mid-body area and stern area, and the strength standards usually applied to ocean-going ships shall apply in these areas.

TABLE IV

Column IColumn II
ItemArctic ClassWidths in metres Minimum Side Tank
11not applicable
21A0.91
320.91
431.07
541.22
661.52
771.83
881.83
9101.83

TABLE V

[Repealed, SOR/78-180, s. 10]

  • SOR/78-180, ss. 8 to 10;
  • SOR/85-626, s. 3(E).
 
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