MARINESHELF publishes articles contributed by seafarers and other marine related sites solely for the benefit of seafarers .All copyright materials are owned by its respective authors or publishers.
Deadweight Tonnage refers to the carrying capacity of a vessel. Deadweight tonnage can be
figured by taking the weight of a vessel which is not loaded with cargo and
subtracting that figure from the weight of the loaded vessel.
Displacement Tonnage is the actual weight of a vessel. The term is expressed as a
displacement weight in order to reflect the amount of water which is displaced
by the vessel's hull. The draft of a
vessel can then be used to determine the weight using markings on the hull
called load lines
Vessel Draft refers to the distance between the
vessel's waterline and the lowest point of the vessel, usually the keel. The
draft will change if the vessel becomes heavier or lighter.Very simply, draft
is the depth of a vessel at any given time.
Gross Tonnage is a measure of
volume inside a vessel. This includes all areas from keel to funnel and bow to
stern.
Measurement of the total interior volume of a vessel in cubic
meters is multiplied in a formula by a second factor which is determined by the
volume of the vessel.
The formula is:
K=0.2+0.02*log10(V)
Gross Tonnage (GT) = K*V
Where V = Interior volume of a vessel in cubic meters
Gross Tonnage is used to determine the number of crew, safety
rules, registration fees, and port dues. It is the standard most often used to
define a vessel.
Traffic is controlled in
coastal waters and inland passages with marker buoys. Buoys in coastal areas
are known as Lateral Markers, when found in traffic lanes they are known as
channel markers. Both types of markers serve the same purpose. They guide a
vessel through an area known to be safe for passage, and provide a traffic
separation scheme similar to a road on land.
These “Rules of the Road” are very similar to those you follow
while driving an automobile on land, so we will use that as an example when
talking about marine traffic.
IALA A and IALA B
If you are driving a car in an overseas country it is sometimes
necessary to drive on the opposite side of the road than you usually do. This
is the same for ships, but fortunately there are only two schemes IALA A and
IALA B. IALA stands for International Association of Lighthouse Authorities.
IALA A is
used in Europe, some areas of Africa, most of Asia, plus Australia and New
Zealand; IALA B is used in North America, South
America, Japan, the Philippines, and Korea.
Traffic Marker Buoys
Marker buoys come in two colors, green and red. Red buoys mark
one side of a traffic lane and green marks the other side. Think of the area in
the middle as a road or highway. On land a road has painted stripes marking
safe areas for travel; a solid line marks both sides of the road and is meant
not to be crossed, think of the red and green buoys as these lines. A road has
a line painted in the middle to divide traffic by direction; in a maritime
environment the center divider is invisible. The separation line is exactly in
the center of the marked course.
IALA A Rules
In Europe, Australia, New Zealand, plus parts of Africa and Asia
the IALA A rules are in force. This means that when traveling you should keep
the green buoy on the right or starboard side of the vessel.
The shape of the marker also gives you traffic information. A
triangular or cone-shaped top indicates the marker should be kept on the
starboard side of the vessel.
IALA B Rules
The IALA B traffic separation scheme is used in North and South
America, Japan, the Philippines, and Korea. It is the opposite traffic flow of
the IALA A scheme. This is like driving on the opposite side of the road while
overseas.
In this case, while traveling keep the red buoy on the right or
starboard side of the vessel.
The same triangular or cone-shaped top will be present on
markers which should be kept on the starboard side of the vessel.
Both traffic patterns have the same rules when it comes to
marker shape. A triangular marker is always kept on the starboard side of the
vessel no matter if it is red or green. While markers to the port side of the
vessel will be square or flat topped
Entering and Exiting Traffic
Separation Schemes
When entering a traffic separation area, proceed with caution
and be alert. This is like a highway on ramp for ships and smaller craft. At
busy times many vessels will be trying to enter these lanes. Try to align your
vessel in the direction of travel within the lane. Essentially extending the
lane beyond the actual lane markers will help you smoothly transition from open
waters to the traffic lane. The entrance to a traffic separation scheme is
subject to rules of Right of Way.
The Right of Way is one of the most important parts of the Rules
of the Road and needs to be understood completely for safe operation.
Sometimes automobile traffic in busy areas takes on a special
set of rules that is different from standard operation, and is usually only
understood by local drivers.
The same thing is true on the water. Local vessels like water
taxis or tender boats might not follow these traffic lanes, this is not
necessarily breaking the rules because the vessels need to operate outside the
lanes to do their job.
Exiting a traffic scheme is similar to entering. If you are
traveling out into open water it is best to extend your heading past the end of
the final marker. If your vessel is large or slow moving, traffic behind your
vessel might be eager to pass. Wait until traffic clears before changing your
course because not all vessels will sound the proper horn signal when
attempting to pass. Be careful, Right of Way is important, but avoiding
collision is more important than being right.
You may need to exit a traffic lane before reaching the end of
the marked passage to reach your destination. Buoys are marked with numbers
like street numbers. Red buoys always have an even number and green are marked
with odd numbers. Maneuvering between marker buoys is acceptable as long as it
can be done safely. Check for traffic outside the lane and for any orange and
white buoys marking obstructions. If the way is clear you may proceed.
If you must cross the oncoming lane of traffic, wait for an
appropriate gap in traffic and turn a perpendicular course across the lane.
Keep other vessels in mind when slowing down or turning out of a
lane. Ships have limited maneuverability at low speeds and take a long time to
stop. If you cannot turn across a lane without obstructing traffic, exit on the
opposite side and wait for traffic to clear then proceed across both lanes to
your destination.
Traffic Lane Crossings
Where two traffic lanes cross there is a special marker buoy. It
is striped horizontally with red and green bands. This is similar to an
intersection of a primary and secondary road. The top band designates the
primary traffic route and the lower band designates the secondary route. Right
of Way rules govern how traffic flows at these crossings, primary and secondary
designations do not determine which vessel may cross first.
Maritime Rules of the Road
All
Vessels are Required to Follow the Rules of the Road. Traffic is Controlled by
Lane Markers, Navigational Aids, and Right of Way. The Rules are a Basic skill
of Seamanship and are Internationally Recognized. Understanding the Rules of
the Road is Necessary for Safe Operation of Any Type or Size of Vessel in Any
Waters.
International
Convention on Tonnage Measurement of Ships, 1969
(London,
23 June 1969)
THE CONTRACTING
GOVERNMENTS,
DESIRING to establish uniform principles and rules with respect to the
determination of tonnage of ships engaged on international voyages;
CONSIDERING that this end may best be achieved by the conclusion of a
Convention;
HAVE AGREED as follows:
Article 1
General
obligation under the Convention
The Contracting Governments
undertake to give effect to the provisions of the present Convention and the
Annexes hereto which shall constitute an integral part of the present
Convention. Every reference to the present Convention constitutes at the same
time a reference to the Annexes.
Article 2
Definitions
For the purpose of the
present Convention, unless expressly provided otherwise:
(1) "Regulations"
means the Regulations annexed to the present Convention;
(2)
"Administration" means the Government of the State whose flag the
ship is flying;
(3) "international
voyage" means a sea voyage from a country to which the present Convention
applies to a port outside such country, or conversely. For this purpose, every
territory for the international relations of which a Contracting Government is
responsible or for which the United Nations are the administering authority is
regarded as a separate country;
(4) "gross
tonnage" means the measure of the overall size of a ship determined in
accordance with the provisions of the present Convention;
(5) "net tonnage"
means the measure of the useful capacity of a ship determined in accordance
with the provisions of the present Convention;
(6) "new ship"
means a ship the keel of which is laid, or which is at a similar stage of
construction, on or after the date of coming into force of the present
Convention;
(7) "existing ship"
means a ship which is not a new ship;
(8) "length"
means 96 per cent of the total length on a waterline at 85 per cent of the
least moulded depth measured from the top of the keel, or the length from the
fore side of the stem to the axis of the rudder stock on that waterline, if
that be greater. In ships designed with a rake of keel the waterline on which
this length is measured shall be parallel to the designed waterline;
(9)
"Organization" means the Inter-Governmental Maritime Consultative
Organization.
Article 3
Application
(1) The present Convention
shall apply to the following ships engaged on international voyages;
(a) ships registered in
countries the Governments of which are Contracting Governments;
(b) ships registered in
territories to which the present Convention is extended under Article 20; and
(c) unregistered ships
flying the flag of a State, the Government of which is a Contracting
Government.
(2) The present Convention
shall apply to:
(a) new ships;
(b) existing ships which
undergo alterations or modifications which the Administration deems to be a
substantial variation in their existing gross tonnage;
(c) existing ships if the
owner so requests; and
(d) all existing ships,
twelve years after the date on which the Convention comes into force, except
that such ships, apart from those mentioned in (b) and (c) of this paragraph,
shall retain their then existing tonnages for the purpose of the application to
them of relevant requirements under other existing International Conventions.
(3) Existing ships to which
the present Convention has been applied in accordance with sub-paragraph (2)(c)
of this Article shall not subsequently have their tonnages determined in
accordance with the requirements which the Administration applied to ships on
international voyages prior to the coming into force of the present Convention.
Article 4
Exceptions
(1) The present Convention
shall not apply to:
(a) ships of war; and
(b) ships of less than 24
metres (79 feet) in length.
(2) Nothing herein shall
apply to ships solely navigating:
(a) the Great Lakes of
North America and the River St. Lawrence as far east as a rhumb line drawn from
Cap des Rosiers to West Point, Anticosti Island, and, on the north side of
Anticosti Island, the meridian of longitude 63W;
(b) the Caspian Sea; or
(c) the Plate, Parana and
Uruguay Rivers as far east as a rhumb line drawn between Punta Rasa (Cabo San
Antonio), Argentina, and Punta del Este, Uruguay.
Article 5
Force
majeure
(1) A ship which is not
subject to the provisions of the present Convention at the time of its
departure on any voyage shall not become subject to such provisions on account
of any deviation from its intended voyage due to stress of weather or any other
cause of force
majeure.
(2) In applying the
provisions of the present Convention, the Contracting Governments shall give
due consideration to any deviation or delay caused to any ship owing to stress
of weather or any other cause of force
majeure.
Article 6
Determination
of tonnages
The determination of gross
and net tonnages shall be carried out by the Administration which may, however,
entrust such determination either to persons or organizations recognized by it.
In every case the Administration concerned shall accept full responsibility for
the determination of gross and net tonnages.
Article 7
Issue of
certificate
(1) An International
Tonnage Certificate (1969) shall be issued to every ship, the gross and net
tonnages of which have been determined in accordance with the present Convention.
(2) Such certificate shall
be issued by the Administration or by any person or organization duly
authorized by it. In every case, the Administration shall assume full
responsibility for the certificate.
Article 8
Issue of
certificate by another government
(1) A Contracting
Government may, at the request of another Contracting Government, determine the
gross and net tonnages of a ship and issue or authorize the issue of an
International Tonnage Certificate (1969) to the ship in accordance with the present
Convention.
(2) A copy of the
certificate and a copy of the calculations of the tonnages shall be transmitted
as early as possible to the requesting Government.
(3) A certificate so issued
shall contain a statement to the effect that it has been issued at the request
of the Government of the State whose flag the ship is or will be flying and it
shall have the same validity and receive the same recognition as a certificate
issued under Article 7.
(4) No International
Tonnage Certificate (1969) shall be issued to a ship which is flying the flag
of a State the Government of which is not a Contracting Government.
Article 9
Form of
certificate
(1) The certificate shall
be drawn up in the official language or languages of the issuing country. If
the language used is neither English nor French, the text shall include a
translation into one of these languages.
(2) The form of the
certificate shall correspond to that of the model given in Annex II.
Article
10
Cancellation
of certificate
(1) Subject to any exceptions
provided in the Regulations, an International Tonnage Certificate (1969) shall
cease to be valid and shall be cancelled by the Administration if alterations
have taken place in the arrangement, construction, capacity, use of spaces,
total number of passengers the ship is permitted to carry as indicated in the
ship's passenger certificate, assigned load line or permitted draught of the
ship, such as would necessitate an increase in gross tonnage or net tonnage.
(2) A certificate issued to
a ship by an Administration shall cease to be valid upon transfer of such a
ship to the flag of another State, except as provided in paragraph (3) of this
Article.
(3) Upon transfer of a ship
to the flag of another State the Government of which is a Contracting Government,
the International Tonnage Certificate (1969) shall remain in force for a period
not exceeding three months, or until the Administration issues another
International Tonnage Certificate (1969) to replace it, whichever is the
earlier. The Contracting Government of the State whose flag the ship was flying
hitherto shall transmit to the Administration as soon as possible after the
transfer takes place a copy of the certificate carried by the ship at the time
of transfer and a copy of the relevant tonnage calculations.
Article
11
Acceptance
of certificate
The certificate issued
under the authority of a Contracting Government in accordance with the present
Convention shall be accepted by the other Contracting Governments and regarded
for all purposes covered by the present Convention as having the same validity
as certificates issued by them.
Article
12
Inspection
(1) A ship flying the flag
of a State the Government of which is a Contracting Government shall be
subject, when in the ports of other Contracting Governments, to inspection by
officers duly authorized by such Governments. Such inspection shall be limited
to the purpose of verifying:
(a) that the ship is
provided with a valid International Tonnage Certificate (1969); and
(b) that the main
characteristics of the ship correspond to the data given in the certificate.
(2) In no case shall the
exercise of such inspection cause any delay to the ship.
(3) Should the inspection
reveal that the main characteristics of the ship differ from those entered on
the International Tonnage Certificate (1969) so as to lead to an increase in
the gross tonnage or the net tonnage, the Government of the State whose flag
the ship is flying shall be informed without delay.
Article
13
Privileges
The privileges of the
present Convention may not be claimed in favour of any ship unless it holds a
valid certificate under the Convention.
Article
14
Prior
treaties, conventions and arrangements
(1) All other treaties,
conventions and arrangements relating to tonnage matters at present in force
between Governments Parties to the present Convention shall continue to have
full and complete effect during the terms thereof as regards:
(a) ships to which the
present Convention does not apply; and
(b) ships to which the
present Convention applies, in respect of matters for which it has not
expressly provided.
(2) To the extent, however,
that such treaties, conventions or arrangements conflict with the provisions of
the present Convention, the provisions of the present Convention shall prevail.
Article
15
Communication
of information
The Contracting Governments
undertake to communicate to and deposit with the Organization:
(a) a sufficient number of
specimens of their certificates issued under the provisions of the present
Convention for circulation to the Contracting Governments;
(b) the text of the laws,
orders, decrees, regulations and other instruments which shall have been
promulgated on the various matters within the scope of the present Convention;
and
(c) a list of
non-governmental agencies which are authorized to act in their behalf in
matters relating to tonnages for circulation to the Contracting Governments.
Article
16
Signature,
acceptance and accession
(1) The present Convention
shall remain open for signature for six months from 23 June 1969, and shall
thereafter remain open for accession. Governments of States Members of the
United Nations, or of any of the Specialized Agencies, or of the International
Atomic Energy Agency, or parties to the Statute of the International Court of
Justice may become Parties to the Convention by:
(a) signature without
reservation as to acceptance;
(b) signature subject to
acceptance followed by acceptance; or
(c) accession.
(2) Acceptance or accession
shall be effected by the deposit of an instrument of acceptance or accession
with the Organization. The Organization shall inform all Governments which have
signed the present Convention or acceded to it of each new acceptance or
accession and of the date of its deposit. The Organization shall also inform
all Governments which have already signed the Convention of any signature
effected during the six months from 23 June 1969.
Article
17
Coming
into force
(1) The present Convention
shall come into force twenty-four months after the date on which not less than
twenty-five Governments of States the combined merchant fleets of which
constitute not less than sixty-five per cent of the gross tonnage of the world's
merchant shipping have signed without reservation as to acceptance or deposited
instruments of acceptance or accession in accordance with Article 16. The
Organization shall inform all Governments which have signed or acceded to the
present Convention of the date on which it comes into force
(2) For Governments which
have deposited an instrument of acceptance of or accession to the present
Convention during the twenty-four months mentioned in paragraph (1) of this
Article, the acceptance or accession shall take effect on the coming into force
of the present Convention or three months after the date of deposit of the
instrument of acceptance or accession, whichever is the later date.
(3) For Governments which
have deposited an instrument of acceptance of or accession to the present
Convention after the date on which it comes into force, the Convention shall
come into force three months after the date of the deposit of such instrument.
(4) After the date on which
all measures required to bring an amendment to the present Convention into
force have been completed, or all necessary acceptances are deemed to have been
given under sub-paragraph (b) of paragraph (2) of Article 18 in case of
amendment by unanimous acceptance, any instrument of acceptance or accession
deposited shall be deemed to apply to the Convention as amended.
Article
18
Amendments
(1) The present Convention
may be amended upon the proposal of a Contracting Government by any of the
procedures specified in this Article.
(2) Amendment by unanimous acceptance:
(a) Upon the request of a
Contracting Government, any amendment proposed by it to the present Convention
shall be communicated by the Organization to all Contracting Governments for
consideration with a view to unanimous acceptance.
(b) Any such amendment
shall enter into force twelve months after the date of its acceptance by all
Contracting Governments unless an earlier date is agreed upon. A Contracting
Government which does not communicate its acceptance or rejection of the
amendment to the Organization within twenty-four months of its first
communication by the latter shall be deemed to have accepted the amendment.
(3) Amendment after
consideration in the Organization:
(a) Upon the request of a
Contracting Government, any amendment proposed by it to the present Convention
will be considered in the Organization. If adopted by a majority of two-thirds
of those present and voting in the Maritime Safety Committee of the
Organization, such amendment shall be communicated to all Members of the Organization
and all Contracting Governments at least six months prior to its consideration
by the Assembly of the Organization.
(b) If adopted by a
two-thirds majority of those present and voting in the Assembly, the amendment
shall be communicated by the Organization to all Contracting Governments for
their acceptance.
(c) Such amendment shall
come into force twelve months after the date on which it is accepted by
two-thirds of the Contracting Governments. The amendment shall come into force
with respect to all Contracting Governments except those which, before it comes
into force, make a declaration that they do not accept the amendment.
(d) The Assembly, by a
two-thirds majority of those present and voting, including two-thirds of the
Governments represented on the Maritime Safety Committee and present and voting
in the Assembly, may propose a determination at the time of its adoption that
an amendment is of such an important nature that any Contracting Government
which makes a declaration under sub-paragraph (c) of this paragraph and which
does not accept the amendment within a period of twelve months after it comes
into force, shall cease to be a party to the present Convention upon the expiry
of that period. This determination shall be subject to the prior acceptance of
two-thirds of the Contracting Governments.
(e) Nothing in this
paragraph shall prevent the Contracting Government which first proposed action
under this paragraph on an amendment to the present Convention from taking at
any time such alternative action as it deems desirable in accordance with
paragraphs (2) or (4) of this Article.
(4) Amendment by a
conference:
(a) Upon the request of a
Contracting Government, concurred in by at least one-third of the Contracting
Governments, a conference of Governments will be convened by the Organization
to consider amendments to the present Convention.
(b) Every amendment adopted
by such a conference by a two-thirds majority of those present and voting of
the Contracting Governments shall be communicated by the Organization to all
Contracting Governments for their acceptance.
(c) Such amendment shall
come into force twelve months after the date on which it is accepted by
two-thirds of the Contracting Governments. The amendment shall come into force
with respect to all Contracting Governments except those which, before it comes
into force, make a declaration that they do not accept the amendment.
(d) By a two-thirds
majority of those present and voting, a conference convened under sub-paragraph
(a) of this paragraph may determine at the time of its adoption that an
amendment is of such an important nature that any Contracting Government which
makes a declaration under sub-paragraph (c) of this paragraph, and which does
not accept the amendment within a period of twelve months after it comes into
force, shall cease to be a Party to the present Convention upon the expiry of
that period.
(5) The Organization shall
inform all Contracting Governments of any amendments which may come into force
under this Article, together with the date on which each such amendment will
come into force.
(6) Any acceptance or
declaration under this Article shall be made by the deposit of an instrument
with the Organization which shall notify all Contracting Governments of the
receipt of the acceptance or declaration.
Article
19
Denunciation
(1) The present Convention
may be denounced by any Contracting Government at any time after the expiry of
five years from the date on which the Convention comes into force for that
Government.
(2) Denunciation shall be
effected by the deposit of an instrument with the Organization which shall
inform all the other Contracting Governments of any such denunciation received
and of the date of its receipt.
(3) A denunciation shall
take effect one year, or such longer period as may be specified in the
instrument of denunciation, after its receipt by the Organization.
Article
20
Territories
(1) (a) The United Nations,
in cases where they are the administering authority for a territory, or any
Contracting Government responsible for the international relations of a
territory, shall as soon as possible consult with such territory or take such
measures as may be appropriate in an endeavour to extend the present Convention
to that territory and may at any time by notification in writing to the
Organization declare that the present Convention shall extend to such
territory.
(b) The present Convention
shall, from the date of receipt of the notification or from such other date as
may be specified in the notification, extend to the territory named therein.
(2) (a) The United Nations,
or any Contracting Government which has made a declaration under sub-paragraph
(a) of paragraph (1) of this Article at any time after the expiry of a period
of five years from the date on which the Convention has been so extended to any
territory, may by notification in writing to the Organization declare that the
present Convention shall cease to extend to any such territory named in the notification.
(b) The present Convention
shall cease to extend to any territory mentioned in such notification one year,
or such longer period as may be specified therein, after the date of receipt of
the notification by the Organization.
(3) The Organization shall
inform all the Contracting Governments of the extension of the present
Convention to all territories under paragraph (1) of this Article, and of the
termination of any such extension under the provisions of paragraph (2) stating
in each case the date from which the present Convention has been or will cease
to be so extended.
Article
21
Deposit
and registration
(1) The present Convention
shall be deposited with the Organization and the Secretary-General of the
Organization shall transmit certified true copies thereof to all Signatory
Governments and to all Governments which accede to the present Convention.
(2) As soon as the present
Convention comes into force, the text shall be transmitted by the
Secretary-General of the Organization to the Secretariat of the United Nations
for registration and publication, in accordance with Article 102 of the Charter
of the United Nations.
Article
22
Languages
The present Convention is
established in a single copy in the English and French languages, both texts
being equally authentic. Official translations in the Russian and Spanish
languages shall be prepared and deposited with the signed original.
IN WITNESS WHEREOF the undersigned being duly authorized by their respective
Governments for that purpose have signed the present Convention.
DONE at London this twenty-third day of June 1969.
ANNEX 1
REGULATIONS
FOR DETERMINING GROSS AND NET TONNAGES OF SHIPS
Regulation
1
General
(1) The tonnage of a ship
shall consist of gross tonnage and net tonnage.
(2) The gross tonnage and
the net tonnage shall be determined in accordance with the provisions of these
Regulations.
(3) The gross tonnage and
the net tonnage of novel types of craft whose constructional features are such
as to render the application of the provisions of these Regulations
unreasonable or impracticable shall be as determined by the Administration.
Where the tonnage is so determined, the Administration shall communicate to the
Organization details of the method used for that purpose, for circulation to
the Contracting Governments for their information.
Regulation
2
Definition
of terms used in the Annexes
(1) Upper Deck
The upper deck is the
uppermost complete deck exposed to weather and sea, which 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. In a ship having 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.
(2) Moulded Depth
(a) The moulded depth is
the vertical distance measured from the top of the keel to the underside of the
upper deck at side. In wood and composite ships the distance is measured from
the lower edge of the keel rabbet. Where the form at the lower part of the
midship section is of a hollow character, or where thick garboards are fitted,
the distance is measured from the point where the line of the flat of the
bottom continued inwards cuts the side of the keel.
(b) In ships having rounded
gunwales, the moulded depth shall be measured to the point of intersection of
the moulded lines of the deck and side shell plating, the lines extending as
though the gunwales were of angular design.
(c) Where the upper deck is
stepped and the raised part of the deck extends over the point at which the
moulded depth is to be determined, the moulded depth shall be measured to a
line of reference extending from the lower part of the deck along a line
parallel with the raised part.
(3) Breadth
The 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.
(4) Enclosed spaces
Enclosed spaces are all
those spaces which are bounded by the ship's hull, by fixed or portable partitions
or bulkheads, by decks or coverings other than permanent or movable awnings. No
break in a deck, nor 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, shall preclude a space from being included in the
enclosed space.
(5) Excluded Spaces
Notwithstanding the
provisions of paragraph (4) of this Regulation, the spaces referred to in
sub-paragraphs (a) to (e) inclusive of this paragraph shall be called excluded
spaces and shall not be included in the volume of enclosed spaces, except that
any such space which fulfils at least one of the following three conditions
shall be treated as an enclosed space:
- the space is fitted with
shelves or other means for securing cargo or stores;
- the openings are fitted
with any means of closure;
- the construction provides
any possibility of such openings being closed:
(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 (one inch)
the depth of the adjoining deck beams, such opening having a breadth equal to
or greater than 90 per cent of the breadth of the deck at the line of the
opening of the space. This provision shall 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 (Figure 1
in Appendix 1).
(a) (ii) Should the width
of the space because of any arrangement except by convergence of the outside
plating, become less than 90 per cent 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 per cent of the breadth of the deck shall be excluded from the volume of
enclosed spaces (Figures 2, 3 and 4 in Appendix 1).
(a) (iii) Where an interval
which is completely open except for bulwarks or open rails separates any two
spaces, the exclusion of one or both of which is permitted under sub-paragraphs
(a)(i) and/or (a)(ii), such exclusion shall not apply if the separation between
the two spaces is less than the least half breadth of the deck in way of the
separation (Figures 5 and 6 in Appendix 1).
(b) A space under an
overhead deck covering open to the sea and weather, having no other connexion
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 (2.5 feet) or one-third of the height of the space, whichever
is the greater (Figure 7 in Appendix 1).
(c) A space in a
side-to-side erection directly in way of opposite side openings not less in
height than 0.75 metres (2.5 feet) 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 shall be
limited inboard from the opening to a maximum of one-half of the breadth of the
deck in way of the opening (Figure 8 in Appendix 1).
(d) A space in erection
immediately below an uncovered opening in the deck overhead, provided that such
an opening is exposed to the weather and the space excluded from enclosed
spaces is limited to the area of the opening (Figure 9 in Appendix 1).
(e) A recess in the
boundary bulkhead of an erection which is exposed to the weather and the
opening of which extends from deck to deck without means of closing, provided
that 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
(Figure 10 in Appendix 1).
(6) Passenger
A passenger is every person
other than:
(a) the master and the
members of the crew or other persons employed or engaged in any capacity on
board a ship on the business of that ship; and
(b) a child under one year
of age.
(7) Cargo Spaces
Cargo spaces to be included
in the computation of net tonnage are enclosed spaces appropriated for the
transport of cargo which is to be discharged from the ship, provided that such
spaces have been included in the computation of gross tonnage. Such cargo spaces
shall be certified by permanent marking with the letters CC (cargo compartment)
to be so positioned that they are readily visible and not to be less than 100
millimetres (4 inches) in height.
(8) Weathertight
Weathertight means that in
any sea conditions water will not penetrate into the ship.
Regulation
3
Gross
tonnage
The gross tonnage (GT) of a
ship shall be determined by the following formula:
GT = K1V
where: V = Total volume of
all enclosed spaces of the ship in cubic metres,
K1 = 0.2 + 0.02log10V (or as tabulated in Appendix 2).
Regulation
4
Net
Tonnage
(1) The net tonnage (NT) of
a ship shall be determined by the following formula:
NT = K2Vc 4d2 + K3 (N1 + N2),
3D 10
in which formula:
(a) the factor 4d2 shall not
be taken as greater than unity;
3D
(b) the term K2Vc 4d2 shall not
be taken as less than 0.25 GT; and
3D
(c) NT shall not be taken
as less than 0.30 GT, and in which:
Vc = total volume of cargo spaces in cubic metres,
K2 = 0.2 + 0.02 log10Vc (or as tabulated in Appendix 2),
K3 = 1.25 (GT + 10,000)/10,000
D = moulded depth amidships
in metres as defined in Regulation 2(2),
d = moulded draught
amidships in metres as defined in paragraph (2) of this Regulation,
N1 = number of passengers in cabins with not more than 8 berths,
N2 = number of other passengers,
N1 + N2 = total
number of passengers the ship is permitted to carry as indicated in the ship's
passenger certificate; when N1 + N2 is less than 13, N1 and N2 shall be taken as zero,
GT = gross tonnage of the
ship as determined in accordance with the provisions of Regulation 3.
(2) The moulded draught (d)
referred to in paragraph (1) of this Regulation shall be one of the following
draughts:
(a) for ships to which the
International Convention on Load Lines in force applies, the draught
corresponding to the Summer Load Line (other than timber load lines) assigned
in accordance with that Convention;
(b) for passenger ships,
the draught corresponding to the deepest subdivision load line assigned in
accordance with the International Convention for the Safety of Life at Sea in
force or other international agreement where applicable;
(c) for ships to which the
International Convention on Load Lines does not apply but which have been
assigned a load line in compliance with national requirements, the draught
corresponding to the summer load line so assigned;
(d) for ships to which no
load line has been assigned but the draught of which is restricted in
compliance with national requirements, the maximum permitted draught;
(e) for other ships, 75 per
cent of the moulded depth amidships as defined in Regulation 2(2).
Regulation
5
Change of
net tonnage
(1) When the
characteristics of a ship, such as V, Vc, d, N1 or N2 as
defined in Regulations 3 and 4, are altered and where such an alteration results
in an increase in its net tonnage as determined in accordance with the
provisions of Regulation 4, the net tonnage of the ship corresponding to the
new characteristics shall be determined and shall be applied without delay.
(2) A ship to which load lines
referred to in sub-paragraphs (2)(a) and (2)(b) of Regulation 4 are
concurrently assigned shall be given only one net tonnage as determined in
accordance with the provisions of Regulation 4 and that tonnage shall be the
tonnage applicable to the appropriate assigned load line for the trade in which
the ship is engaged.
(3) When the
characteristics of a ship such as V, Vc, d, N1 or N2 as
defined in Regulations 3 and 4 are altered or when the appropriate assigned
load line referred to in paragraph (2) of this Regulation is altered due to the
change of the trade in which the ship is engaged, and where such an alteration
results in a decrease in its net tonnage as determined in accordance with the
provisions of Regulation 4, a new International Tonnage Certificate (1969)
incorporating the net tonnage so determined shall not be issued until twelve
months have elapsed from the date on which the current Certificate was issued;
provided that this requirement shall not apply:
(a) if the ship is
transferred to the flag of another State, or
(b) if the ship undergoes
alterations or modifications which are deemed by the Administration to be of a
major character, such as the removal of a superstructure which requires an
alteration of the assigned load line, or
(c) to passenger ships
which are employed in the carriage of large numbers of unberthed passengers in
special trades, such, for example, as the pilgrim trade.
Regulation
6
Calculation
of volumes
(1) All volumes included in
the calculation of gross and net tonnages shall be measured, irrespective of
the fitting of insulation or the like, to the inner side of the shell or
structural boundary plating in ships constructed of metal, and to the outer
surface of the shell or to the inner side of structural boundary surfaces in
ships constructed of any other material.
(2) Volumes of appendages
shall be included in the total volume.
(3) Volumes of spaces open
to the sea may be excluded from the total volume.
Regulation
7
Measurement
and calculation
(1) All measurement used in
the calculation of volumes shall be taken to the nearest centimetre or
one-twentieth of a foot.
(2) The volumes shall be
calculated by generally accepted methods for the space concerned and with an
accuracy acceptable to the Administration.
(3) The calculation shall
be sufficiently detailed to permit easy checking.
APPENDIX
1
FIGURES
REFERRED TO IN REGULATION 2(5)
In the following figures:
O = excluded space.
C = enclosed space.
I = space to be considered
as an enclosed space.
Hatched in parts to be
included as enclosed spaces.
B = breadth of the deck in
way of the opening.
