The tonnage of the space occupied by the goods shall be ascertained in the manner prescribed below by Article IX, Rule I, for the measurement of poops or other closedin spaces.

Nothing in this article shall in any manner affect the provisions of Articles II, III, and IV.

cubical contents of

ART. VIII. The cubical contents of the spaces included, by these rules, in gross Measurement of the tonnage may, in any country where the Moorsom system of measurement has been spaces may be by the adopted, be ascertained under that system as applied in measuring vessels for Moorsom system in national registry, provided that system is substantially similar to the Moorsom system each country, or by the of measurement as set forth in Article IX of these rules.

ART. IX. In countries that have not adopted the Moorsom system of measuring spaces within vessels, the cubical contents of any of the spaces included in gross tonnage shall be ascertained according to the Moorsom system as set forth in the following rules: Rule I for the measurement of empty vessels; Rule II for laden vessels; Rule III for open vessels.

RULE I.-For measuring the gross tonnage of empty vessels.

SECTION 1. The length for the admeasurement of ships having one or more decks is taken on the tonnage deck, which is

(a) The upper deck for vessels having one or two decks.

(b) The second deck from below for vessels having more than two decks. Measure the length of the ship in a straight line along the upper side of the tonnage deck from the inside of the inner plank (average thickness) at the side of the stem to the inside of the midship stern timber or plank there, as the case may be (average thickness), deducting from this length what is due to the rake of the bow in the thickness of the deck and what is due to the rake of the stern timber in the thickness of the deck, and also what is due to the rake of the stern timber in one-third of the round of the beam; divide the length so taken into the number of equal parts required by the following table, according to the class in such table to which the ship belongs:

Class 1: Ships of which the tonnage deck is, according to the above measurement, 50 feet long or under, into 4 equal parts.

Class 2: Ships of which the tonnage deck is, according to the above measurement, above 50 feet long and not exceeding 120 feet, into 6 equal parts.

Class 3: Ships of which the tonnage deck is, according to the above measurement, above 120 feet long and not exceeding 180 feet, into 8 equal parts.

Class 4: Ships of which the tonnage deck is, according to the above measurement, above 180 feet long and not exceeding 225 feet, into 10 equal parts.

Class 5: Ships of which the tonnage deck is, according to the above measurement, above 225 feet long, into 12 equal parts.1

In the case of a break or breaks in a double-bottom for water ballast, the length of the vessel is to be taken in parts according to the number of breaks, and each part divided into a number of equal parts according to the class in the above table to which such length belongs.

SEC. 2. Then the hold being first sufficiently cleared to admit of the required depths and breadths being properly taken, find the transverse area of the ship at each point of division of the length or each point of division of the parts of the length, as the case may require, as follows: Measure the depth at each point of division, from a point at a distance of one-third of the round of the beam below the tonnage deck, or, in case of a break, below a line stretched in continuation thereof, to the upper side of the floor timber (upper side of the inner plating of the double bottom) at the inside of the limber strake, after deducting the average thickness of the ceiling which is between the bilge planks and the limber strake, subject, however, to the provisions of these rules, Article IV, section 4, regarding the measurement or exemption of double-bottom spaces. In the case of a ship constructed with a double-bottom for water ballast if the space between the inner and outer plating thereof is not available for the carriage of cargo, stores, feed-water, coal, or other fuel, then the depth shall be taken to be the upper side of the inner plating of the double-bottom, and that upper side shall, for the purposes of measurement, be deemed to represent the floor timber of the vessel. This rule for measuring the depth of the hold applies to double-bottom ships having top of double bottom not horizontal.

If the depth at the midship division of the length does not exceed 16 feet, divide each depth into 5 equal parts; then measure the inside horizontal breadth at each of the four points of division, and also at the upper point of the depth, extending each measurement to the average thickness in that part of the ceiling which is between the points of measurement. Number these breadths from above (i. e., numbering the upper breadth 1, and so on down to the fifth breadth); multiply the second and fourth by 4, and the third by 2; add these products together, and to the sum add the first breadth and the fifth. Multiply the quantity thus obtained by one-third of the common interval between the breadths, and the product shall be deemed the transverse area of the upper part of the section; then find the area between the fifth and lower point of the depth by dividing the depth between such points into four equal parts, and measure the horizontal breadths at the three points of division and also at the

A greater number of divisions is permissible provided there be an even number of divisions.

Moorsom system as prescribed in these rules. Rules for the measurement of contents of spaces.

Rule for the measurement of empty vessels.

upper and lower points, and proceed as before, and the sum of two parts shall be deemed to be the transverse area; but if the midship depth exceed 16 feet, divide each depth into 7 equal parts instead of 5, and measure, as before directed, the horizontal breadths at the six points of division, and also at the upper point of the depth; number them from above, as before; multiply the second, fourth, and sixth by 4, and the third and fifth by 2; add these products together, and to the sum add the first breadth and the seventh. Multiply the quantity thus obtained by one-third of the common interval between the breadths, and the products shall be deemed the transverse area of the upper part of the section; then find the lower part of the area as before directed, and add the two parts together, and the sum shall be deemed to be the transverse area.

This section applies to vessels with double bottoms, the tops of which have a rise from the middle line to each side. In vessels in which the top of the double bottom is horizontal, or in which there is no double bottom, the depths are to be divided by 4 or 6 (instead of 5 or 7), according as their midship depths do not or do exceed 16 feet respectively. In such cases no subdivision of the lower part is to be made.

SEC. 3. Number the transverse sections or areas respectively 1, 2, 3, etc., No. 1 being at the extreme limit of the length at the bow, or of each part of the length, and the last number at the extreme limit of the length at the stern or the extreme limit at the after end of each part of the length; then, whether the length be divided according to the table into 4 or 12 parts, as in classes 1 and 5, or any intermediate number, as in classes 2, 3, and 4, multiply the second and every even-numbered area by 4, and the third and every odd-numbered area (except the first and last) by 2; add these products together, and to the sum add the first and last, if they yield anything; multiply the quantity thus obtained by one-third of the common interval between the areas, and the product will be the cubical contents of the space, or cubical contents of each part if the ship is measured in parts under the tonnage deck. The tonnage of this volume is obtained by dividing it by 100, if the measurements are taken in English feet, and by 2.83 if the measurements are taken in meters. The multiplier 0.353 may be used instead of the divisor 2.83.

SEC. 4. If the ship has a third deck the tonnage of the space between it and the tonnage deck shall be ascertained as follows: Measure in feet the inside length of the space at the middle of its height from the plank at the side of the stem to the lining on the timbers at the stern, and divide the length into the same number of equal parts into which the length of the tonnage deck is divided, as above directed; measure (also at the middle of its height) the inside breadth of the space at each of the points of division, also the breadth at the stem and the breadth at the stern; number them successively 1, 2, 3, etc., commencing at the stem; multiply the second and all the other even-numbered breadths by 4, and the third and all the other odd-numbered breadths (except the first and last) by 2; to the sum of these products add the first and last breadths; multiply the whole sum by one-third of the common interval between the breadths, and the result will give in superficial feet the mean horizontal area of the space; measure the mean height of the space, and multiply by it the mean horizontal area, and the product will be the cubical contents of the space; divide this product by 100 (or by 2.83 if the measurements are taken in meters) and the quotient shall be deemed to be the tonnage of the space, and shall be added to the tonnage of the ship ascertained as aforesaid; and if the ship has more than three decks, the tonnage of each space between decks above the tonnage deck shall be severally ascertained in the manner above described, and shall be added to the tonnage of the ship ascertained as aforesaid.

SEC. 5. If there be a break, a poop, or any other permanently covered or closed-in space on or above the upper deck (as defined above in Article III) the tonnage of such space shall be ascertained as follows: Measure the internal mean length of the space in feet, and divide it into two equal parts; measure at the middle of its height three inside breadths, namely, one at each end and the other at the middle of the length; then to the sum of the end breadths add four times the middle breadth, and multiply the whole sum by one-third of the common interval between the breadths; the product will give the mean horizontal area of the space; then measure the mean height and multiply by it the mean horizontal area; divide the product by 100 (or by 2.83 if the measurements are taken in meters) and the quotient shall be deemed to be the tonnage of the space.

SEC. 6. In measuring the length, breadth, and height of the general volume of the ship or that of the other spaces, reduce to the mean thickness the parts of the ceiling which exceed the mean thickness. When the ceiling is absent, or when it is not permanently fixed, the length and breadth shall be reckoned from the main frames of the ship, not from the web or belt frames. The same principle is to hold in the case of deck erections, that is, the breadth is to be reckoned from the main framing or stiffeners of the same, when ceiling is not fitted. When the main framing of the ship is curved or carried upward and inboard so as to permit the building of topside tanks or compartments outboard of the main framing, the breadth of the ship shall be reckoned from the outboard framing of such outboard tanks, thus including these tanks in the measurement.

RULE II.-For measuring the gross tonnage of laden ships.

SEC. 7. When ships have cargo on board, or when for any other reason their tonnage can not be ascertained by means of Rule I, proceed in the following manner: Measure the length on the uppermost full-length deck from the outside of the outer plank at the stem to the aft side of the sternpost, deducting therefrom the distance between the aft side of the sternpost and the rabbet of the sternpost at the point where the counterplank crosses it. Measure also the greatest breadth of the ship to the outside of the outer planking or wales at the middle perpendicular. Then, having first marked on the outside of the ship on both sides thereof the height of the uppermost fulllength deck at the ship's sides, girt the ship at the middle perpendicular 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 in the case of ships built of wood, and by the factor 0.18 in the case of ships built of iron or steel. The product will give approximately the cubical contents of the ship, and the tonnage can be ascertained by dividing by 100 or by 2.83, according as the measurements are taken in English feet or in meters.

SEC. 8. If there be a break, a poop, or other permanently covered and closed-in spaces (as defined above in Article III) on or above the uppermost full-length deck, the tonnage of such spaces shall be ascertained by multiplying together the mean inside length, breadth, and depth of such spaces and dividing the product by 100, or 2.83, according as the measurements are taken in English feet or meters, and the quotient so obtained shall be deemed to be the tonnage of the spaces, and shall be added to the other tonnage in order to determine the gross tonnage or total capacity of the ship

RULE III. For measurement of open vessels.

Rule for the measure

ment of laden vessels.

Rule for the measure

SEC. 9. In ascertaining the tonnage of open ships, the upper edge of the upper strake of the shell plating is to form the boundary line of measurement, and the depths ment of open vessels. shall be taken from an athwartship line, extended from upper edge to upper edge of the said strake at each division of the length.

DEDUCTIONS FROM THE GROSS TONNAGE TO ASCERTAIN THE
NET TONNAGE.

(A) DEDUCTIONS FOR VESSELS NOT PROPELLED BY ENGINES.

ART. X. The following spaces (enumerated below in secs. 1 to 10 of this article) shall be deducted from the gross tonnage in order to ascertain the net tonnage of vessels not propelled by engines, and no other spaces shall be deducted. Unless other wise expressly stipulated, these spaces shall be deducted whether located above or below the upper deck.

The volume or cubical contents of deducted spaces shall be ascertained in the manner specified in Article VIII or Article IX of these rules. The remainder. resulting from deducting from the total space included in gross tonnage the sum of the cubical contents of the spaces whose deduction from gross tonnage is permitted by these rules, shall be the net or register tonnage of vessels not propelled by engines and unrigged craft upon which tolls and other charges based upon tonnage shall be paid by vessels of commerce, Army and Navy transports, colliers, supply ships, and hospital ships (as defined in Art. I) for passage through the Panama Canal. One hundred cubic feet, or 2.83 cubic meters, shall constitute one gross or net ton.

Spaces for the use, or possible use, of passengers (as defined in Art. VI) shall not be deducted from the gross tonnage, except in so far as their deduction may be specifically provided for in the following sections (1 to 10) of this article of these rules.

and cargo carried on

Spaces available for the stowage of stores (other than boatswain's stores) or cargo Definition of stores shall not be deducted from gross tonnage. In case of Army and Navy transports, Army and Navy transcolliers, supply ships, and hospital ships, as defined in Article I, the term "stores ports, colliers, supply (other than boatswain's stores) or cargo" shall include, in addition to goods or cargo ships, and hospital ordinarily carried as freight on vessels of commerce, the following articles: ships.

On transports, food, stores, luggage, accouterments, and equipment for passengers.

On colliers, coal, coaling gear, and fuel oil not for the use of the colliers. On supply ships, stores, supplies of all kinds, distilling machinery and distilled water (other than feed water stored in double-bottom compartments), machines, tools and material for repair work, mines and mining material, torpedoes, arms, and ammunition.

On hospital ships, food stores for passengers, medical stores, and hospital equip

ment.

Guns mounted on transports and supply ships, for defense of the ships, and ammunition required for use in such guns shall not be classed as cargo.

-SECTION 1. The tonnage of the spaces or compartments occupied by, or appropri- Deductions from ated to the use of, the officers and crew of the vessel shall be deducted. The term gross tonnage allowed vessels not propelled "officers and crew" shall include the personnel inscribed on the ship's rolls, i. e., by engines.

The marking and

shall be according to national laws.

the ship's officers, engineers, doctors, apothecary, sick attendants, sailors, apprentices, firemen, mechanics, and wireless operators; but shall not include clerks, pursers, stewards, and other members of the personnel provided by the ship for the care of the passengers. The spaces or compartments occupied by the officers and crew shall include their berthing accommodations, spaces provided for medical attention, mess rooms, ward and dressing rooms, bath and wash rooms, water-closets, latrines, lavatories, or privies for their exclusive use, and passageways exclusively serving these

spaces.

SEC. 2. On hospital ships the spaces or compartments occupied by doctors, apothe cary, and sick attendants duly inscribed on the ship's rolls, shall form part of the deduction under section 1 of this article. Spaces provided for the medical attention of the officers and crew of a hospital ship shall likewise be deducted; but spaces fitted for the transportation, or for the medical attention, of other persons than those duly listed in the ship's rolls shall not be deducted.

SEC. 3. The space occupied by the master's cabin shall be deducted.

SEC. 4. Cook houses, galleys, bakeries, laundries, and rooms for ice machines, when used exclusively to serve the officers and crew, and the condenser space, and distilling rooms, when used exclusively for condensing and distilling the water for the officers and crew, shall be deducted.

SEC. 5. Spaces used for the anchor gear, steering gear, and capstan; the wheel house, the dynamo rooms; the chart room used exclusively for keeping charts, signals, and other instruments of navigation; lookout houses; spaces for keeping electric searchlights and wireless telegraph appliances; and other spaces actually used in the navigation of the ship, shall be deducted. Such spaces upon vessels of commerce as may be devoted to the mounting of guns and to the stowage of ammunition for the guns thus mounted shall be deducted. The deduction of all spaces, other than those devoted to the mounting of guns, enumerated in this section must be reasonable in extent and be subject to the limitations stipulated below in Article XI.

SEC. 6. In case of a ship propelled wholly by sails, any space, not exceeding 24 per cent of the gross tonnage, used exclusively for storage of sails shall be deducted.

SEC. 7. Spaces used exclusively for boatswain's stores shall be deducted. The deduction is not, however, to exceed 1 per cent of the gross tonnage in ships of 1,000 tons gross and upwards, nor more than 75 tons in any ship however large. In vessels from 500 to 1,000 tons gross the limit is fixed at 10 tons and in vessels from 150 to 500 tons at not more than 2 per cent of the gross tonnage. In vessels under 150 tons at not more than 3 tons.

SEC. 8. The space occupied by donkey engine and boiler shall be deducted if the donkey engine and boiler are connected with the main pumps of the ship, or if they are located in a permanently covered or closed-in structure on or above the upper deck. SEC. 9. Passages and passageways shall be deducted if they serve deducted spaces exclusively for the officers and crew.

SEC. 10. Water-ballast spaces, other than spaces in the vessel's double bottom, shall be deducted if they are adapted only for water ballast, have only ordinary manholes for access and are not available for the carriage of cargo, stores, or fuel. If used to carry oil or other fuel, these spaces shall be regarded as part of the vessel's fuel space and shall not be subject to separate deduction.

ART. XI. Each of the spaces enumerated in Article X, sections 1 to 10, unless use of exempted spaces otherwise specifically stated, shall be subject to such conditions and requirements as to marking or designation and use or purpose as are contained in the navigation or registry laws of the several countries, but no space, other than fuel spaces deducted under Article XIII of these rules, shall be deducted unless the use to which it is to be exclusively devoted has been appropriately designated by official marking. In no case, however, shall an arbitrary maximum limit be fixed to the aggregate deduction made under Article X.

Deductions from

gross tonnage allowed vessels propelled by engines.

(B) DEDUCTIONS FOR VESSELS PROPELLED BY ENGINES.

ART. XII. The net or register tonnage upon which tolls and other charges based upon tonnage shall be paid by vessels of commerce, Army and Navy transports, colliers, supply ships, and hospital ships, as defined in Article I, propelled by engines, for passage through the Panama Canal, shall be the tonnage remaining after the following deductions have been made from the gross tonnage. One hundred cubic feet, or 2.83 cubic meters, shall constitute 1 gross or net ton. Vessels propelled partly by sails and partly by engines shall be classed as "ves els propelled by engines:"

SECTION 1. The spaces specified above in Article X shall be deducted from the space included in gross tonnage to ascertain net tonnage in the case of vessels propelled by engines as in the case of vessels not propelled by engines.

SEC. 2. The space occupied by the engines, boilers, coal bunkers, fuel-oil tanks, double-bottom fuel and feed-water compartments, shaft trunks of vessels with screw propellers, spaces, within a closed-in side-to-side erection, that are framed in around' the funnels or that are required for the introduction of light and air to the engine room to the extent that the framed-in spaces around the funnels and the light and air casings are located below the deck or covering of the first or lowest tier of such erections, if any, on the upper deck, as defined in Article IV, section 3, and are contained in closed-in side-to-side erections, spaces necessary for the proper working of the

engines, and spaces occupied by the donkey engine and boiler when situated within the boundary of the engine room or within the light and air casings above the engine room and when used in connection with the main machinery for propelling the vessel. When the shafts of screw propellers pass through open spaces not inclosed within tunnels, the spaces allowed in lieu of the tunnels must be of reasonable dimensions suitable for the vessel in question. When any portion of the engine or boiler rooms is occupied by a tank for fresh water, the space thus taken up shall not be deducted. Donkey-engine and boiler spaces, when deducted according to Article XIV below, shall not be made a separate deduction.

The portion of the framed-in spaces around the funnels and of the light and air casings that extend above the deck or covering of the first or lowest tier of side-to-side erections, if any, on the upper deck, as defined in Article IV, section 3, and surrounding the said space or spaces are exempted from measurement and form no part of the space deducted under this section.

SEC. 3. The deductions made for propelling power, including all those provided for in section 2 of this article, shall in no case exceed 50 per cent of the gross tonnage, except in case of tugs employed exclusively as tugs. In other respects the spaces enumerated in section 2 shall, except as otherwise specifically stated, be subject to the requirements as to designation or marking and use or purpose contained in the navigation or registry laws of the several countries.

SEC. 4. The deductions made for propelling power provided for in section 2 of this article shall be made according to the provisions of Article XIII or of Article XIV, as the owner of the vessel may elect.

SEC. 5. Double-bottom compartments that are set aside to be used exclusively for the stowage of feed water for the ship's boilers shall be deducted.

ART. XIII. In ships that do not have fixed bunkers, but transverse bunkers Propelling power dewith movable partitions, with or without lateral bunkers, and in ships with fuel tanks duction for vessels with bunkers having movor double-bottom fuel compartments which may be used to stow cargo or stores, able partitions, or havmeasure the space occupied by the engine rooms, and add to it for vessels with screw ing fuel-oil compartpropellers 75 per cent and for vessels with paddle wheels 50 per cent of such space to stow cargo or stores. ments that may be used By the space occupied by the engine rooms is to be understood that occupied by the engine room itself and the boiler room, together with the spaces strictly required for the working of the engines and boilers, with the addition of the spaces taken up by shaft trunks (in vessels with screw propellers), the spaces which inclose the funnels and the casings necessary for the admission of light and air into the engine room to the extent that such spaces are located below the upper deck or below a deck with openings (usually designated as tonnage openings) which may be so closed as to permit the carriage of cargo or stores under the deck or a portion thereof, and donkeyengine and boiler spaces when the donkey engine and boiler are situated within the boundary of the main engine room or of the light and air casing above it and when they are used in connection with the main machinery for propelling the vessel. When the shafts of screw propellers pass through open spaces not inclosed within tunnels, the spaces allowed in lieu of tunnels must be of reasonable dimensions suitable for the vessel in question. When a portion of the space within the boundary of the engine or boiler rooms is occupied by a tank or tanks for fuel oil or fresh water, the space considered to be within the engine room shall be reduced by the space taken up by the tank or tanks for fuel oil or fresh water.

The cubical contents of the above-named spaces occupied by the engine room shall be ascertained 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, breadths 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 actually 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, by multiplying together the length, breadth, and depth, find the cubical contents of the space or spaces, if any, which are framed in for the machinery, for inclosing the funnels, or for the admission of light and air, and which are located between the crown of the engine room and the uppermost deck or covering of the first or lowest tier of side-to-side erections, if any, on the upper deck, as defined in Art. IV, section 3. Add such contents, as well as those of the space occupied by the shaft trunk and by any donkey engine and boiler located within the boundary of the engine room or of the light and air casing above the engine room and used in connection with the main engines for propelling the ship, to the cubical contents of the space below the crown of the engine room; divide the sum by 100 or by 2.83, according as the measurements are taken in feet or meters, and the result shall be deemed to be the tonnage of the engine and boiler room and shall be the tonnage taken as the basis for calculating the deduction for propelling power. If in any ship in which the space for propelling power is to be measured the engines and boilers are in separate compartments, the contents of each compartment shall be ⚫measured separately in like manner, according to the above method; and the sum of the tonnage of the spaces included in the several compartments shall be deemed to be the tonnage of the engine and boiler rooms, and shall be the tonnage taken as the basis for calculating the deduction for propelling power.