Art. 94 - Extract from the Regulations for the
Measurement of Tonnage recommended by the International Tonnage Commission assembled at
Constantinople, In 1873.
(Minutes of proceedings XXI, Appendix II)
A - Rule I : General Principles:
B - RULE 2 - For Laden Ships:
(Art. 9) - When ships have their
cargo on board, or when for any other reason their tonnage cannot be ascertained by means
of Rule 1, proceed in the following manner :
Measure the length on the upper deck from the outside of the outer plank at the stem to
the aftside of the stern-post, deducting there from the distance between the aftside of
the stem-post and the rabbet of the stern-post at the point where the counter-plank
crosses it.
Measure also the greatest breadth of the ship to the outside of the outer planking or
wales.
Then, having first marked on the outside of the ship, on both sides thereof, the height of
the upper deck at the ship's sides, girt the ship at the greatest breadth in a direction
perpendicular to the keel from the height so marked on the outside of the ship, on the one
side, to the height so marked on the other side by passing a chain under the keel; to half
the girth thus taken add half the main breadth; square the sum, multiply the result by the
length of the ship taken as aforesaid; then multiply this product by the factor 0.
17(seventeen hundredths) in the case of ships built of wood, and by the factor 0. 18
(eighteen hundredths) in the case of ships built of iron. The product will give
approximately the cubical contents of the ship, and the general tonnage can be ascertained
by dividing by 100 or by 2.83, according to the measurements taken in English feet or in
meters.
(Art.10) - If there be a break, a poop, or other permanent covered and closed-in sSEAPACEs (as defined in the general principles) on the upper deck, the tonnage of such sSEAPACEs shall be ascertained by multiplying together the mean length, breadth and depth of such sSEAPACEs and dividing the product by 100 or 2.83, according to the measurements taken in English feet or meters, and the quotient so obtained shall be deemed to be the tonnage of such space, and shall be added to the other tonnage in order to determine the gross tonnage or total capacity of the ship.
C - Deductions :
To be made from the Gross Tonnage in order to ascertain the
Net Tonnage:
(Art.11) - To find from the gross tonnage of vessel as above set
forth the official, or net registered tonnage, either for sailing vessels or for steam
ships, the following mode of operations must be resorted to :
(1) Sailing Vessels :
(Art.12) - For sailing vessels deduct : the sSEAPACEs exclusively
and entirely occupied by the crew and the ship's officers, those taken up by the cookhouse
and latrines exclusively used by the ship's officers and crew whether they be situated
above or below the upper deck; the covered and closed in sSEAPACEs, if there 'be any situated
on the upper deck, and used for working the helm, the capstan, the anchor gear, and for
keeping the charts, signals and other instruments of navigation.
Each of the sSEAPACEs deducted as above may be limited according to the requirements and
customs of each country, but the deductions must never exceed in the aggregate 5 percent of the gross tonnage.
(Art.13) - The measurement of these sSEAPACEs is to be effected
according to the rules set forth the measurement of covered and closed-in sSEAPACEs on the
upper deck, for result, obtained by deducting the total of such allowances from the gross
tonnage, represents the net or tonnage of sailing vessels.
(2) Steam Ships :
(Art. 14) - For vessels propelled by steam or any other
mechanical power, deduct:
A - The same sSEAPACEs as for sailing vessels (Art. 12) with the limitation to 5 percent of the gross tonnage.
B - The sSEAPACEs occupied by the engines, boilers, coal bunkers, shafttrunks of screw steamers, and the sSEAPACEs between decks and in the covered and closed-in erections on the upper deck surrounding the funnels, and required for the introduction of air and light into the engine-rooms and for the proper working of the engines themselves.
Such deductions cannot exceed 50 per cent of the gross tonnage.
(Art. 15) - The measurement of
the sSEAPACEs allowed for both in sailing vessels and in steam ships (section A of Art. 14)
is to be effected according to the rules set forth in Articles 12 and 13 for sailing
vessels.
SSEAPACEs for which allowances are made in steam ships only (section B of Art. 14) are
measured according to the following rules.
(3) Ships having coal-bunkers with movable partitions :
(Art.16) - In ships that do not have fixed bunkers
but transverse bunkers with movable partitions, with or without lateral bunkers,
measure the space occupied by the engine-rooms, and add to it, for screw steamers
75 percent, and for paddle steamers, 50 percent of such space.
By the space occupied by the engine-rooms is to be understood that occupied
by the engine-room itself and by the boiler-room together with the spaces strictly
required for their working, with the addition of the space taken up by the shaft-trunk
in screw steamers and the spaces between decks which enclose the funnels and
are necessary for the admission air and light into the engine-rooms.
These spaces are measured in the following manner :
Measure the mean depth of the space occupied by the engines and boilers from
its crown to the ceiling at the limber strake, measure also three, or, if necessary,
more than three breadth of the space at the middle of its depth, taking one
of such measurements at each end and another at the middle of the length: take
the mean of such breadths; measure also the mean length of the space between
the foremost and aftermost bulkheads or limits of its length, excluding such
parts, if any, as are not actual occupied by or required for the proper working
of the engines and boilers.
Multiply together these three dimensions of length, breadth and depth, and the
product will be the cubical contents of the space below the crown.
Then find the cubical contents of the space or spaces, if any, between the crown
aforesaid and the uppermost or poop deck, as the case may be, which are framed
in for the machinery or for the admission of light and air, by multiplying together
the length, depth and breadth thereof.
Add such contents as well as those of the space occupied by the shafttrunks
to the cubical contents of the space below the crown; divide the sum by 100
or by 2.83, according to the measures taken in feet or meters and the result
shall be deemed to be the tonnage corresponding to the engine and boiler room
which serves as basis for the deductions referred to.
If in any ship in which the space aforesaid is to be measured, the engines and
boilers are fitted in separate compartments, the contents of shall be measured
separately in like manner, according to the above rules, and the sum of their
several results shall be deemed to be the tonnage of the engine-rooms which
serves, as aforesaid, as basis for the total deductions.
(4) Ships with fixed coal-bunkers
(Art. 17) - In ships with fixed coal-bunkers measure the mean
length of the engine and boiler-room, including the coal-bunkers. Ascertain the area of
three transverse sections of the ship (as set forth in the rules given in Art. 3 and 4 for
the calculation of the gross tonnage) to the deck which covers the engines.
One of these three sections must pass through the middle of the aforesaid length, and the
two others through the two extremities.
Add to the sum of the two extreme sections four times the middle one, and multiply
the sum thus obtained by the third of the distance between the sections. This
product divided by 100, if the measurements are taken in English feet, or by
2.83 if they are taken in meters, gives the tonnage of the space in question.
If the engines, boilers and bunkers are in separate compartments they are separately
measured, as above set forth, and the results are added together.
In screw steamers the contents of the shaft-trunk are measured by ascertaining
the mean length, breadth and height, and the product of the multiplication of
these three dimensions divided by 100 or 2.83 according to the measurements
taken in feet or in meters, gives the tonnage of such space.
The tonnage of the following spaces between decks, and in the covered and closed-in
erections on the upper deck, is ascertained by the same method :
(Art. 18) - Instead of the
measurement of fixed bunkers, the rules for bunkers with movable partitions as set forth
in Art. 16 may be applied.
(Art. 19) - In the case of tugs the allowances are
not limited to 50 per cent of the gross tonnage; all the space occupied by machinery,
boilers and coal-bunkers may be deducted.
Nevertheless, if such vessels are not excursively employed as tugs, the deductions in
question cannot exceed 50 percent of the gross tonnage.