Part 1 - General

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1.1 Measurement of Length ( L )

1.1.1 Length of a vessel ( L ) is defined in section 6, Part 2 of the Vessel Registration and Tonnage Regulations ( VRTR ) made pursuant to the Canada Shipping Act 2001 as the greater of:

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

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

1.1.2 The lengths corresponding to those defined in subsections 1.1.1 (a) and (b) are depicted below, and in Part 4 – Figures, Figure 1.1.

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

1.1.4 If, for the purpose of Canadian registration or maintenance of Canadian registration, calculation of vessel’s tonnage is required by respective provisions of VRTR , length ( L ) of a vessel must be determined using the explanation above to decide which method of tonnage measurement is applicable to the vessel (see Part 2 or Part 3 of this Standard as applicable).


1.2 Definitions

The following definitions apply in this Standard:

1.2.1 Enclosed Spaces

  • Subject to subsection, enclosed spaces are all those spaces that are bounded by the vessel'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 vessel'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. (a) spaces below the upper deck open to the sea (See Section (e) for further elaboration);
    2. (b) excluded spaces – see definition for “excluded spaces.”
  • Spaces that fulfill any one of the three conditions set out in the subsection (a) to (c) are enclosed spaces.

1.2.2 Excluded Spaces

  • Subject to sub-section, the spaces referred to in subsections (a) to (e) below are excluded spaces and must not be included in the volume of enclosed spaces:
    1. (a)
      1. (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 2.3);
      2. (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 2.4, 2.5 and 2.6);
      3. (iii) If an interval that is completely open except for bulwarks or open rails separates any two (2) spaces, 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 2.7 and 2.8);
    2. (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 vessel 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 vessel'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 2.9);
    3. (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 2.10);
    4. (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 2.13);
    5. (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 2.11);
  • If a space referred to in subsections (a) to (e) fulfills any of the following three conditions such a space shall be treated as an enclosed space:
    1. (a) 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. (b) the openings are fitted with any means of closure; or
    3. (c) the construction provides the possibility of the openings being closed.
  • 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 2.14).
  • In vessels with rounded gunwales, the breadth (b) of the deck in way of the opening is measured as shown in Figure 2.12.

1.2.3 Gross Tonnage ( GT ) is the measure of the overall size of a vessel.

1.2.4 Net Tonnage ( NT ) is the measure of the useful capacity of a vessel.

1.2.5 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.

1.2.6 Weathertight, in respect of a means of closure, means capable of preventing the passage of water into a vessel in any sea condition.

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