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PART 1 — General

The following definitions apply in the Standard:

"amidships" is the midpoint of the length [L] of a ship where the forward terminal of that length coincides with the fore side of the stem. Length is defined in Section 1.2;

"breadth" is the maximum breadth of the ship, measured amidships to the moulded line of the frame in a ship with a metal shell and to the outer surface of the hull in a ship with a shell of any other material (see Figure 1.1);

"camber" is the vertical distance measured on the centre line plane of the ship, from the underside of the deck plating to a line athwartships between the points where the underside of the deck plating meets the inner side of the ship's shell plating (see Figure 1.2);

"cargo spaces" are enclosed spaces included in the calculation of the net tonnage that are appropriated for the transport of cargo which is to be discharged from the ship, if the spaces have also been included in the calculation of the gross tonnage. These cargo spaces are identified by the readily visible permanent markings CC (cargo compartment). The total volume of cargo spaces as defined above is designated as V_C;

"enclosed spaces" are all those spaces that are bounded by the ship's hull, by fixed or portable partitions or bulkheads or by decks or coverings other than permanent or moveable awnings. No break in a deck, or any opening in the ship's hull, in a deck or in a covering of a space, or in the partitions or bulkheads of a space, nor the absence of a partition or bulkhead, precludes a space from being included in an enclosed space. The following are not enclosed spaces:

1.  spaces below the upper deck open to the sea (See Section 2.4.2 (e) for further elaboration);

2.  excluded spaces – see definition "excluded spaces";

Note:  Spaces that fulfill any one of the three conditions set out in the definition "excluded spaces" are enclosed spaces.

"excluded spaces" The spaces referred to in clauses (A) to (E) are excluded spaces, and must not be included in the volume of enclosed spaces, unless the space fulfills any of the following three conditions:

1.  the space is fitted with shelves or other means for securing cargo or stores; (for example, stanchions, fences and railings to keep livestock in the corrals); or
   

2.  the openings are fitted with any means of closure; or
   

3.  the construction provides the possibility of the openings being closed.

In ships with rounded gunwales, the breadth (B) of the deck for use in this section is shown in Figure 1.12.

(A) (i) A space within an erection opposite an end opening extending from deck to deck, except for a curtain plate of a depth not exceeding by more than 25 millimetres the depth of the adjoining deck beams, if the opening has a breadth equal to or greater than 90% of the

breadth of the deck at the line of the opening of the space. This provision is to be applied, so as to exclude from the enclosed spaces, only the space between the actual end opening and a line drawn parallel to the line or face of the opening at a distance from the opening equal to one half of the width of the deck at the line of the opening (see Figure 1.3);

(A) (ii) If the width of the space, because of any arrangement except by convergence of the outside plating, becomes less than 90% of the breadth of the deck, only the space between the line of the opening and a parallel line drawn through the point where the athwartships width of the space becomes equal to, or less than, 90% of the breadth of the deck shall be excluded from the volume of enclosed spaces (see Figures 1.4, 1.5 and 1.6);

(A) (iii) If an interval that is completely open except for bulwarks or open rails separates any two 2spaces, the exclusion of one or both of which is permitted under subparagraphs (i) or (ii) or both, the exclusion does not apply if the separation between the two spaces is less than the least half breadth of the deck in way of the separation (see Figures 1.7 and 1.8);

(B) A space under an overhead deck covering open to the sea and weather, having no other connection on the exposed sides with the body of the ship than the stanchions necessary for its support. In such a space, open rails or a bulwark and curtain plate may be fitted or stanchions fitted at the ship's side, provided that the distance between the top of the rails or the bulwark and the curtain plate is not less than 0.75 metres or one third of the height of the space, whichever is the greater (see Figure 1.9);

(C) A space in a side-to-side erection that is directly in the way of the opposite side opening and is not less in height than 0.75 m or one third of the height of the erection, whichever is the greater. If the opening in such an erection is provided on one side only, the space to be excluded from the volume of enclosed spaces is limited inboard from the opening to a maximum of one-half of the breadth of the deck in the way of the opening (see Figure 1.10);

(D) A space in an erection immediately below an uncovered opening in the deck overhead, if the opening is exposed to the weather and the space excluded from enclosed spaces is limited to the area of the opening (see Figure 1.13);

(E) A recess in the boundary bulkhead of an erection that is exposed to the weather and the opening of which extends from deck to deck without means of closing, if the interior width is not greater than the width at the entrance and its extension into the erection is not greater than twice the width of its entrance (see Figure 1.11);

The space between the side longitudinal bulkhead of a deckhouse and the bulwark below a deck extending from side to side, supported by stanchions or vertical plates connected to the bulwarks, must be treated as an excluded space in accordance with paragraphs (B) and (C) (see Figure 1.14).

1.  For ships of 24 metres in length or more, means the measure of the overall size of a ship as determined in accordance with Part 2; and
   

2.  For ships of less than 24 metres in length, means the measure of the overall size of a ship as determined in accordance with Part 3.

"moulded depth" (D) of a ship is determined by measuring the vertical distance amidships:

1.  if the ship has a metal shell, from the moulded line of the upper deck at the side to the point where the line of the hull intersects the side of the keel (see Figure 1.15);
   

2.  if the ship is a wood or composite ship, from the moulded line of the upper deck at the side to the point at the lower edge of the keel rabbet (see Figure 1.15);
   

3.   if the ship is one in which the form at the lower part of the midship section is of a hollow character or on which thick garboards are fitted, from the moulded line of the upper deck at the side to the point where the moulded line of shell when continued inwards intersects the side of the keel (see Figure 1.15);
   

4.  if the ship has rounded gunwales, from the point of intersection of the moulded lines of the upper deck and side shell plating, the lines extending as though the gunwales were of angular design, to the point referred to in paragraphs (a) to (c), as the case may be (see Figure 1.15);
   

5.  if the ship has a stepped upper deck the raised part of which extends over amidships, from the point at which a line of reference extending along the lower part of the upper deck parallel to the raised part of that deck intersects amidships to the point referred to in paragraphs (a) to (c) as the case may be (see Figure 1.17); and
   

6.  if the ship is an open ship, from the top of the gunwale to the point referred to in paragraphs (a) to (c), as the case may be.

"moulded draught" (d) The moulded draught referred to in the Net Tonnage formula in Section 2.2 shall be one of the following draughts:

1.  if the ship is a Load Line Convention ship, the draught corresponding to the summer load line assigned to the ship in accordance with that Convention. A timber load line must not be used to calculate moulded draught;
   

2.  if the ship is a passenger ship, the draught corresponding to the deepest subdivision load line assigned in accordance with SOLAS;
   

3.  if the ship is not a Load Line Convention ship, but has been assigned a load line in accordance with the laws of the state whose flag the ship is entitled to fly, the draught corresponding to the summer load line so assigned;
   

4.  if the ship is a ship to which no load line has been assigned and in respect to which the draught is restricted in accordance with the laws of the state whose flag the ship is entitled to fly, the maximum permitted draught; and
   

5.  in the case of any other ship, 75% of the moulded depth amidships determined in accordance with the definition "Moulded Depth".

1.  if the ship has a metal shell, the outer surface of the frame of the hull without the plating (moulded frame line); and
   

2.  if the ship has a shell of a material other than metal, the outer surface of the shell.

1.  For ships 24 metres in length or more, is the measure of the useful capacity of the ship determined in accordance with Part 2.

2.  For ships of less than 24 metres in length, is the measure of the useful capacity of the ship determined in accordance with Part 3.

"passenger" is as defined in Section 2 of the CSA.

1.  the uppermost complete deck exposed to weather and sea that has permanent means of weathertight closing of all openings in the weather part thereof, and below which all openings in the sides of the ship are fitted with permanent means of watertight closing (see Figure 1.16); and

2.  in the case of a ship that has a stepped upper deck, the lowest line of the exposed deck and the continuation of that line parallel to the upper part of the deck is taken as the upper deck (see Figures 1.16 and 1.17).

A discontinuity in the upper deck that extends over the full breadth of the ship and is in excess of 1 metre in length is treated as a step (see Figure 1.18).

Steps situated outside the length (as defined in Section 1.2) are not to be considered.

A discontinuity in the upper deck that does not extend to the side of the ship is treated as a recess located below the upper deck level (see Figure 1.19).

In a ship that has openings in its side below the uppermost deck, if the openings are not closed but limited inboard by weathertight bulkheads and decks, the deck below the openings is considered the upper deck (see Figure 1.20).

"watertight", in respect of a means of closure, means that it is capable of preventing the passage of water through an opening in either direction, under the maximum head of water to which the opening may be exposed.

"weathertight", in respect of a means of closure, means capable of preventing the passage of water into a ship in any sea condition.

"tonnage length" means the horizontal distance between the extremes of the upper deck (see Figure 1.22a), or in the case of a stepped upper deck, the extremes of the projected line of upper deck (see Figure 1.22b).

 1.2 — MEASUREMENT OF LENGTH (L) ^

LENGTH (L) must be determined using the explanation below to determine which Part of this Standard is applicable.

Length is determined by calculating the greater of:

1.  96% of the total length measured on a waterline at 85% of the least moulded depth measured from the top of keel; and
   

2.  the length from the fore side of the stem to the axis of the rudder stock on the waterline referred to in (a) above.

In a ship designed with a rake of keel, the waterline on which this length is measured shall be parallel to the designed waterline.

The lengths (a) and (b) are depicted below, and in Figure 1.0.

Measurements

All measurements are to be taken in metres to the nearest centimetre. All lengths are to be measured in a fore and aft direction, breadths athwartships and heights or depths vertically. This order is to be followed on all tonnage calculations.

Volume

The volume in relation to any ship or space in a ship is to be in cubic metres.

Degree of Accuracy

Calculations are to be carried out with the following degrees of accuracy:

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