Transport Publication 13430 E
3.1 General
3.1.1 Tonnage measurement of a vessel that is less than 24 metres in length ( L )* shall be carried out in accordance with the provisions of this part.
* Length of a vessel (L) as defined in section 6, Part 2 of the Vessel Registration and Tonnage Regulations (see also section 1.1 of this Standard). - (back)
3.2 Definitions
The following definitions apply in this Part:
3.2.1 Vessel having a Barge Hull Form is a vessel the hull of which approximates rectangular box shape.
3.2.2 Break is the space bounded longitudinally by a step in the upper deck and another such step or the end of the vessel, transversely by the sides of the vessel and vertically by the lowest line of the upper deck and higher part thereof (see figures 3.1(b) and 3.6);
3.2.3 Gross Tonnage Coefficient ( GTC )
- In case of a vessel designed for sailing GTC = 0.08
- In case of a vessel not designed for sailing GTC = 0.16
- In case of a vessel having a barge hull form GTC = 0.20
3.2.4 Net Tonnage Coefficient ( NTC )
- In case of a sailing vessel (including vessels equipped with an auxiliary propulsion engine) NTC = 0.95
- In case of a power-driven vessel NTC = 0.75
- In case of a non-propelled vessel NTC = 1.00
3.2.5 Step is the longitudinal discontinuity in the upper deck that extends over the full breadth of the vessel (see figures 3.1 (b) and 3.6);
3.2.6 Tonnage Measurement Breadth ( TMB ) is the maximum breadth of a vessel measured horizontally at the middle of the Tonnage Measurement Length ( TML ) from the outside of outer planking or plating on one side of the hull to the outside of outer planking or plating on the other side excluding any fenders or rubbing strakes (see figures 3.1(a) and (b) and 3.2).
3.2.7 Tonnage Measurement Depth ( TMD )
- 3.2.7.1 Tonnage Measurement Depth ( TMD ) is the depth of a vessel measured at the middle of the Tonnage Measurement Length ( TML ) from the top edge of the upper deck at the side of the vessel to the bottom of the keel (see figures 3.1 (b); 3.3 and 3.4).
- 3.2.7.2 If a vessel has a stepped upper deck, the height of break shall not be included in TMD : TMD shall be measured from the projected line corresponding to the top edge of the upper deck at the side of the vessel.
- 3.2.7.3 If a vessel does not meet the requirements for upper deck as defined in subsection 3.2.9, TMD of the vessel shall be measured from the line drawn through the top of the upper strake or gunwale/bulwark (see figure 3.1 (a)).
3.2.8 Tonnage Measurement Length ( TML ) is the length of a vessel measured horizontally (parallel to the designed waterline) from the fore side of the foremost fixed permanent structure to the aft side of the aftermost fixed permanent structure excluding appendages that do not contribute to the volume of the vessel (see figures 3.1 (a) and (b)).
3.2.9 Upper Deck is the uppermost complete deck exposed to weather and sea, which is situated above the vessel’s designed waterline, has permanent means of weathertight closing of all openings in the weather part thereof, and below which all openings in the sides of the vessel are fitted with permanent means of watertight closing; in the case of a vessel 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 3.1 (b) and 3.6);
3.3 Units of Measurement and Degree of Accuracy
3.3.1 All measurements are to be taken in metres to the nearest centimeter. Calculations are to be carried out to two decimal places, the second figure to be increased by one if the third is 5 or more.
3.4 Measurement of Vessels
3.4.1 Subject to subsections 3.4.2 and 3.4.3, all vessels are to be measured and their tonnage determined by an appointed tonnage measurer.
3.4.2 Monohull vessels of 15 m in TML or less having not more than a single tier of deckhouses and/or superstructures (including breaks that, for this purpose, are also being regarded as spaces equivalent to one tier of superstructures) whose total combined length does not exceed 70% of TML may be measured and have their tonnage determined under this Part by their owners (see figure 3.5).
3.4.3 In case of tonnage of eligible vessels being formally assigned as described in section 3.7, the length may be measured by the vessels’ owners according to the definition in the Small Vessel Regulations (SVR).
3.4.4 All measurements may be taken from plans but sufficient check measurements must always be taken at the vessel to ensure accuracy.
3.5 Gross Tonnage
3.5.1 The Gross Tonnage ( GT ) of a vessel is
- 3.5.1.1 the sum of the tonnage of the hull and the tonnage of spaces situated above the upper deck (if applicable); or
- 3.5.1.2 if the vessel is less than 12 m in length as defined in the Small Vessel Regulations, the number in the “Assigned Formal Tonnage” column of the table in section 3.7 corresponding to the vessel’s length.
3.5.2 Tonnage of Hull
- 3.5.2.1 The tonnage of the hull shall be determined by the formula:
- Tonnage of Hull = TML x TMB x TMD x GTC
- Where:
- TML – Tonnage Measurement Length (as defined in subsection 3.2.8).
- TMB – Tonnage Measurement Breadth (as defined in subsection 3.2.6).
- TMD – Tonnage Measurement Depth (as defined in subsection 3.2.7).
- GTC – Gross Tonnage Coefficient (as defined in subsection 3.2.3).
- 3.5.2.2 In case of a multi-hull vessel “tonnage of the hull” consists of the tonnages calculated for each hull in accordance with subsection 3.5.2.1 and also the tonnages of each enclosed bridge structure connecting the hulls and situated below the upper deck (if any). Tonnage of an enclosed bridge structure shall be calculated in accordance with subsection 3.5.3.1 except that the measurements shall be taken to the inner side
of structural boundary surfaces.
3.5.3 Tonnage of spaces situated above the upper deck
- 3.5.3.1 Subject to subsection 3.5.3.2 tonnage of all enclosed spaces situated above the upper deck shall be determined by the formula:
- Tonnage of a space = ML x MB x MH / 2.83
- Where:
- ML – Mean Length of a space;
- MB – Mean Breadth of a space;
- MH – Mean Height of a space.
- (a) Enclosed spaces are defined in s. 1.2.1.
- (b) The measurement of all spaces shall be taken to the outside of shell of the hull or to the outside of structural boundary surfaces.
- (c) If a space has a complex shape it shall be divided into parts that are treated as separate spaces.
- (d) If upper deck has a side-to-side break the break is regarded as a “space situated above the upper deck” (see also definitions for upper deck and break in section 3.2).
- 3.5.3.2 Subsection 3.5.3.1 is not applicable to monohull vessels of 15 m in TML or less having not more than a single tier of deckhouses and/or superstructures (including breaks that, for this purpose, are also being regarded as spaces equivalent to one tier of superstructures) whose total combined length does not exceed 70% of TML (see figure 3.5).
- 3.5.3.3 Excluded spaces above the upper deck. An owner may elect to have the following spaces excluded from the tonnage of spaces situated above the upper deck:
- (a) Those excluded spaces as set out in s. 1.2.2.
- (b) Propelling Machinery Spaces. Spaces forming part of the propelling machinery space or serving for the admission of light and air thereto.
- (c) Machinery Spaces. Spaces containing machinery such as anchor gear, steering gear, pumps, refrigerating machinery (not for cargo), etc. However, spaces containing machinery used in the handling of cargo, dredging operations and the such, shall be included in the tonnage of spaces situated above the upper deck.
- (d) Wheelhouse. Only navigational spaces of wheelhouses may be excluded from the tonnage of spaces situated above the upper deck. If a wheelhouse is solely comprised of navigational spaces, then 100% of the volume of the wheelhouse may be excluded. If a wheelhouse is comprised of both navigational spaces and any other spaces then only 50% of the volume of the wheelhouse may be excluded.
- (e) Chain lockers.
- (f) Companions. Companionways and access hatches which protect stairways and ladderways leading to compartments situated below, also openings over such stairways and elevator shafts and related machinery.
- (g) Shelter Spaces. Shelter space on small passenger vessels 10 metres in length (
LOA
) or less providing weather protection only for use free of charge in ships may be excluded from the tonnage of spaces situated above the upper deck provided that:
- (i) the space is used solely for the shelter of unberthed passengers;
- (ii) no form of service of meals or refreshments is provided in the space;
- (iii) seating for deck passengers is not in the form of upholstered armchairs or settees;
- (iv) tables are not normally permitted. The occasional table may be provided; and
- (v) no carpets are to be provided.
3.6 Net Tonnage
3.6.1 Subject to subsection 3.6.2, the Net Tonnage ( NT ) of a vessel shall be determined by the formula:
- NT = GT x NTC
- Where:
- GT – Gross Tonnage determined in accordance with section 3.5.
- NTC – Net Tonnage Coefficient (as defined in subsection 3.2.4).
3.6.2 In case of a vessel having its Gross Tonnage (GT) formally assigned in accordance with subsection 3.5.1.2, Net Tonnage (NT) is the same as its Gross Tonnage (GT).
3.7 ASSIGNED FORMAL TONNAGE
3.7.1 For the purpose of assigning formal tonnage, length of a vessel is the length as defined in the Small Vessel Regulations (SVR).
3.7.2 The Assigned Formal Tonnage (AFT) described below is applicable to any vessel of less than 12 m in length without any other limitations (e.g. number of hulls, vessel’s breadth or depth, type of vessel, type of propulsion, shape of hull, availability and number of tiers of superstructures/deckhouses, etc.).
3.7.3 The Assigned Formal Tonnage (AFT) is the number in the respective column of the table below corresponding to the vessel’s length.
Table 3 – Assigned Formal Tonnage
|
SVR Length |
Assigned Formal Tonnage GT = NT |
|
Less than 8.5 m |
4.99 |
|
8.5 m or more but less than 10 m |
9.99 |
|
10 m or more but less than 12 m |
14.99 |