Load Line Regulations
SCHEDULE 2(Subparagraph 17(1)(c)(i))Determination of Freeboards — Diamond Load Lines
Interpretation
1 (1) The following definitions apply in this Schedule.
- after perpendicular
after perpendicular means the perpendicular taken at the after end of the length of a vessel. (perpendiculaire arrière)
- depth for freeboard
depth for freeboard or D means the distance equal to the moulded depth amidships plus the thickness of the stringer plate, with no allowance for sheathing. However, in the case of a vessel that does not have right-angled gunwales or that has rounded gunwales with a radius greater than four per cent of the breadth, that distance shall be adjusted so that the area of the topside section is equal to that of a vessel with right-angled gunwales and with the same round of beam. (creux de franc-bord ou D)
- effective length
effective length or E means,
(a) in respect of an enclosed superstructure that is not a raised quarter-deck,
(i) if it has a height of Hs or more, the length of the superstructure, or
(ii) if it has a height of less than Hs, the length of the superstructure times the quotient of the height of the superstructure divided by Hs;
(b) in respect of an enclosed superstructure that is a raised quarter-deck, the lesser of 0.6 L and
(i) if it has a height of 2/3 Hs or more, the length of the superstructure, or
(ii) if it has a height of less than 2/3 Hs, the length of the superstructure times the quotient of the height of the superstructure divided by Hs; and
(c) in respect of a trunk,
(i) if it has a height of Hs or more, the length of the trunk times the quotient of the mean breadth of the trunk divided by the breadth, or
(ii) if it has a height of less than Hs, the length of the trunk times the quotient of the mean breadth of the trunk divided by the breadth times the quotient of the height of trunk divided by Hs. (longueur effective ou E)
- length of the superstructure
length of the superstructure or S, in respect of a superstructure of a vessel, means the length of the part of the superstructure that is between the forward perpendicular and the after perpendicular of the vessel. (longueur de la superstructure ou S)
- summer draught
summer draught means the distance measured from the top of the keel of a vessel to the upper edge of the load line that would mark the vessel’s summer freeboard referred to in subsection 8(1). (tirant d’eau d’été)
- trunk
trunk means an efficiently constructed structure that is on a freeboard deck of a vessel and has a breadth of less than 92 per cent of the breadth of the vessel. (trunk)
(2) For the purposes of this Schedule, all length and height measurements shall be in metres and taken to three decimal places.
(3) Words and expressions used in this Schedule and defined in section 1 of Schedule 1 have the same meaning as in that section.
Basic Freeboard Calculation
2 (1) The basic freeboard in millimetres shall be
(a) 850 × p1 × D, in the case of a Type A vessel; and
(b) 1000 × p1 × D, in the case of a Type B vessel.
(2) In subsection (1), p1 is equal to p + (L/D – L/Ds) × A for vessels that are 122 m or less in length and equal to p for vessels that are more than 122 m in length where
- p
- is the value set out in column 2 of an item of Table 1 to this section for a length set out in column 1 or determined for a length that is intermediate to two lengths set out in column 1 of consecutive items to Table 1 by linear interpolation between those lengths;
- L/D
- is the ratio of length to depth for freeboard except that it shall not be more than
(a) 15 if L is 122 m or less;
(b) 21 if L is 214 m or more; or
(c) the ratio obtained for intermediate lengths by linear interpolation between the ratios set out in paragraphs (a) and (b);
- L/Ds
- is the value set out in column 2 of an item of Table 2 to this section for a length set out in column 1 or determined for a length that is intermediate to two lengths set out in column 1 of consecutive items to Table 2 by linear interpolation between those lengths; and
- A
- is the value set out in column 2 of an item of Table 3 to this section for a length set out in column 1 or determined for a length that is intermediate to two lengths set out in column 1 of consecutive items to Table 3 by linear interpolation between those lengths.
TABLE 1
Item Column 1 Column 2 Length of Vessel (metres) Value of “p” 1 24 0.10957 2 26 0.11191 3 28 0.11426 4 30 0.11661 5 32 0.11898 6 34 0.12136 7 36 0.12375 8 38 0.12615 9 40 0.12856 10 42 0.13098 11 44 0.13341 12 46 0.13585 13 48 0.13831 14 50 0.14077 15 52 0.14324 16 54 0.14573 17 56 0.14822 18 58 0.15072 19 60 0.15324 20 62 0.15576 21 64 0.15830 22 66 0.16085 23 68 0.16340 24 70 0.16597 25 72 0.16854 26 74 0.17113 27 76 0.17373 28 78 0.17633 29 80 0.17895 30 82 0.18158 31 84 0.18421 32 86 0.18686 33 88 0.18952 34 90 0.19219 35 92 0.19486 36 94 0.19755 37 96 0.20025 38 98 0.20295 39 100 0.20567 40 102 0.20840 41 104 0.21113 42 106 0.21388 43 108 0.21664 44 110 0.21940 45 112 0.22218 46 114 0.22496 47 116 0.22776 48 118 0.23056 49 120 0.23338 50 122 0.23620 51 124 0.23876 52 126 0.24125 53 128 0.24367 54 130 0.24601 55 132 0.24827 56 134 0.25045 57 136 0.25255 58 138 0.25457 59 140 0.25650 60 142 0.25836 61 144 0.26014 62 146 0.26184 63 148 0.26346 64 150 0.26500 65 152 0.26646 66 154 0.26783 67 156 0.26913 68 158 0.27035 69 160 0.27149 70 162 0.27255 71 164 0.27353 72 166 0.27443 73 168 0.27524 74 170 0.27598 75 172 0.27664 76 174 0.27722 77 176 0.27772 78 178 0.27814 79 180 0.27848 80 182 0.27874 81 184 0.27891 82 186 0.27901 83 188 0.27903 84 190 0.27899 85 192 0.27886 86 194 0.27865 87 196 0.27835 88 198 0.27797 89 200 0.27750 90 202 0.27694 91 204 0.27683 92 206 0.27634 93 208 0.27578 94 210 0.27517 95 212 0.27450 96 214 0.27377 97 216 0.27299 98 218 0.27214 99 220 0.27124 100 222 0.27028 101 224 0.26926 102 226 0.26818 103 228 0.26704 104 230 0.26585 105 232 0.26459 106 234 0.26328 107 236 0.26191 108 238 0.26049 109 240 0.25900 110 242 0.25746 111 244 0.25585 112 246 0.25402 113 248 0.25218 114 250 0.25034 115 252 0.24850 116 254 0.24667 117 256 0.24483 118 258 0.24299 119 260 0.24115 120 262 0.23932 121 264 0.23748 122 266 0.23564 123 268 0.23381 124 270 0.23197 125 272 0.23013 126 274 0.22829 127 276 0.22646 128 278 0.22462 129 280 0.22278 130 282 0.22094 131 284 0.21911 132 286 0.21727 133 288 0.21543 134 290 0.21360 135 292 0.21176 136 294 0.20992 137 296 0.20808 138 298 0.20625 139 300 0.20441 140 302 0.20257 141 304 0.20073 142 306 0.19890 TABLE 2
Item Column 1 Column 2 Length of Vessel (metres) Value of “L/Ds” 1 24 6.46654 2 26 6.64083 3 28 6.81513 4 30 6.98942 5 32 7.16372 6 34 7.33801 7 36 7.51231 8 38 7.68660 9 40 7.86089 10 42 8.03519 11 44 8.20948 12 46 8.38378 13 48 8.55807 14 50 8.73237 15 52 8.90666 16 54 9.08096 17 56 9.25525 18 58 9.42955 19 60 9.60384 20 62 9.77814 21 64 9.95243 22 66 10.12672 23 68 10.30102 24 70 10.47531 25 72 10.64961 26 74 10.82390 27 76 10.99820 28 78 11.17249 29 80 11.34679 30 82 11.52108 31 84 11.69538 32 86 11.86967 33 88 12.04397 34 90 12.21826 35 92 12.39255 36 94 12.56685 37 96 12.74114 38 98 12.91544 39 100 13.08973 40 102 13.26403 41 104 13.43832 42 106 13.61262 43 108 13.78691 TABLE 3
Item Column 1 Column 2 Length of Vessel (metres) Value of “A” 1 24 0.008714 2 26 0.008330 3 28 0.007954 4 30 0.007587 5 32 0.007228 6 34 0.006878 7 36 0.006537 8 38 0.006204 9 40 0.005880 10 42 0.005564 11 44 0.005257 12 46 0.004959 13 48 0.004669 14 50 0.004388 15 52 0.004115 16 54 0.003851 17 56 0.003596 18 58 0.003349 19 60 0.003111 20 62 0.002882 21 64 0.002661 22 66 0.002449 23 68 0.002245 24 70 0.002050 25 72 0.001863 26 74 0.001686 27 76 0.001516 28 78 0.001356 29 80 0.001204 30 82 0.001060 31 84 0.000926 32 86 0.000800 33 88 0.000682 34 90 0.000573 35 92 0.000473 36 94 0.000381 37 96 0.000298 38 98 0.000223 39 100 0.000158 40 102 0.000100 41 104 0.000052 42 106 0.000012 43 108 0.000000
Correction for Type B Vessels
3 The basic freeboard for a Type B vessel that is less than 153 m in length and has enclosed superstructures with an effective length of not more than a quarter of the length of the vessel shall be increased by b millimetres where
b = 2.5 × (153 – L) × (0.25 – E/L)
Correction for Superstructures and Trunks
4 (1) If the sum of the effective lengths of the enclosed superstructures equals L, the basic freeboard shall be reduced by x millimetres where
x = (Hs × 500)
(2) If the sum of the effective lengths of the enclosed superstructures and trunks in respect of which the requirements set out in subsection (3) are met is less than L, the basic freeboard shall be reduced by x millimetres where
x = (E/2 L) × (1 + E/L) × (Hs × 500)
(3) The requirements referred to in subsection (2) are the following:
(a) the trunk shall be at least as strong as an enclosed superstructure;
(b) no hatchways shall be in the freeboard deck in way of the trunk other than small access openings with watertight covers;
(c) the trunk deck shall be a permanent working platform fitted with guardrails;
(d) if the trunk is detached, it shall be connected to the adjacent superstructures by permanent gangways;
(e) guardrails shall be fitted in way of the trunk on the exposed parts of the freeboard deck for at least half the length of exposed parts of the trunk;
(f) the trunk shall have a breadth at least 60 per cent of the breadth of the vessel; and
(g) if there is no superstructure on the vessel, the length of the trunk shall be at least 60 per cent of its length.
Correction for Sheer
5 Correction in the basic freeboard for sheer shall be determined in accordance with regulation 38 of the 1966 Convention. However, for the purpose of the determination, L shall be the lesser of the length of the vessel and 153 m.
Correction for Bow Height
6 (1) The following definitions apply in this section.
- assumed bow height
assumed bow height, in respect of a vessel, means the vertical distance at the forward perpendicular between
(a) the top of the exposed deck at side; and
(b) the water line that corresponds to the basic freeboard, as corrected in accordance with sections 3 to 6, where applicable, including any designed trim. (hauteur d’étrave présumée)
- standard bow height
standard bow height means
(a) 49.417 L × (1 – L/500) mm for a vessel of less than 168 m in length; or
(b) 8677 – 18.917 L mm for a vessel of 168 m or more in length. (hauteur d’étrave normale)
(2) Subject to subsection (3), if the assumed bow height is less than the standard bow height, the basic freeboard shall be increased by the difference.
(3) For the purpose of the definition assumed bow height, the top of the exposed deck at side is deemed not to include sheer or the height of a superstructure unless
(a) in the case of sheer, it extends for at least 15 per cent of the length of the vessel measured from the forward perpendicular; and
(b) in the case of the height of a superstructure, the superstructure is enclosed and extends from the stem to a point at least 0.06 L abaft the forward perpendicular.
Correction for Deck Line
7 (1) If the position of the upper edge of the deck line is placed in accordance with paragraph 2(b) of Schedule 3 above the position established by paragraph 2(a) of that Schedule, the basic freeboard shall be increased by the difference between those positions.
(2) If the position of the upper edge of the deck line is placed in accordance with paragraph 2(b) of Schedule 3 below the position established by paragraph 2(a) of that Schedule, the basic freeboard shall be decreased by the difference between those positions.
Fresh Water Freeboards
8 (1) The summer freeboard that is applicable during the summer season in fresh water shall be the freeboard determined in accordance with sections 2 to 7.
(2) The midsummer freeboard that is applicable during the midsummer season in fresh water shall be determined by deducting y millimetres from the summer freeboard where y is equal to the summer draught in metres multiplied by 25.
(3) The intermediate freeboard that is applicable during the intermediate season in fresh water shall be determined by adding y millimetres to the summer freeboard where y is equal to the summer draught in metres multiplied by the quotient of 2540 divided by the greater of 122 m and L.
(4) The winter freeboard that is applicable during the winter season in fresh water shall be determined by adding y millimetres to the summer freeboard where y is equal to the summer draught in metres multiplied by the quotient of 5080 divided by the greater of 122 m and L.
Salt Water Freeboards
9 (1) Salt water freeboards that are applicable to vessels that operate in salt water shall be determined by adding y millimetres to the corresponding fresh water freeboards where y is equal to the displacement in fresh water in tonnes at the summer load waterline divided by the product of 4.1 times the tonnes per centimetre immersion in fresh water at the summer load waterline.
(2) If the displacement in fresh water in tonnes at the summer load waterline cannot be determined, one forty-eighth of the summer draught shall be added to the corresponding fresh water freeboards.
Minimum Freeboard
10 Despite sections 8 and 9, the freeboard other than the open-hopper dredge freeboard shall not be less than 50 mm.
Open-hopper Dredges
11 (1) The dredging freeboard for open-hopper dredges shall be 62.5 per cent of the summer freeboard for a type B vessel or 150 mm, whichever is greater.
(2) The dredging freeboard for an open-hopper dredge is applicable only when
(a) the dredge is operating not more than 20 nautical miles from the mouth of a harbour of safe refuge;
(b) the height of waves in the area of operation is not more than 3 m or the wind velocity in the area is not more than 65 km per hour; and
(c) the dredge is carrying dredged material with a specific gravity that is not greater than the highest specific gravity of dredged material that the dredge is designed to dredge.
- SOR/2013-235, ss. 25, 26(E), 27(F)
- SOR/2023-105, s. 10
- Date modified: