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the decks, the superstructures, hatchways, etc.;

(3) Deck plans showing the arrangement and uses of different compartments and deductible spaces;

(4) Drawings showing the arrangement of the engine, boiler, and fuel compartments; and

(5) A tonnage plan showing half breadths of the sections at the points of division of the tonnage length of the vessel into a certain number of equal parts in accordance with the rules for the measurement of spaces under the tonnage deck. The scale or scales of these drawings are to be indicated thereon.

The collector of customs is to be advised of any subsequent changes in the vessel and furnished copies of the corrected plans, or a statement of such changes.

If there are no blueprints or drawings available and if the collector is satisfied that it is impracticable to require such plans to be prepared and made available, considering the size and nature of the vessel as well as the cost and time involved, the vessel shall be measured without requiring their production.

(b) Sketches. When blueprints or drawings are not produced, necessary rough sketches may be made during the course of admeasurement showing the inboard profile, the midship cross-section, the hull and deck arrangements, and related matters, recording any necessary dimensions and showing details of important features such as the depth of side and bottom frames or floor timbers; the dimensions, location, and use of structures and hull spaces; and the thickness of the inner and outer skin. Such rough sketches shall be retained and filed with the other admeasurement papers. The rough sketches made shall not be redrawn to scale unless the admeasurer is satisfied that such action is necessary to insure that accurate dimensions have been lifted, to avoid the necessity for readmeasurement, or to insure against a claim of error which may reasonably be expected to be made in a particular case by the owner or agent. § 2.10 Measurements to be taken at an early stage.

Admeasurement should begin as soon as the vessel is sufficiently advanced in construction to permit its being done,

usually when the decks are laid, the hold cleared of encumbrances to admit the required depths and breadths being properly taken; before the engine and boilers are installed and accommodations are partitioned off.

§ 2.11

Uniform system required.

(a) The following directions are given showing the progressive steps to be followed in the process of admeasurement. It is important not only that the rules be followed, but that required measurements be taken and calculations made in a uniform and correct manner that one general system may prevail throughout the service respecting this subject.

(b) Measurements taken aboard are to be recorded in the "Memorandum of Dimensions" known as Form 1413.

§ 2.13 Measuring instruments.

(a) The measurements should be made with a waterproof tape, graduated into feet and tenths of a foot, and as nearly inelastic as possible.

(b) Sliding rods which are of three sizes: One 3 feet long for taking depths from 3 to 5.8 feet; another 6 feet long for taking depths from 6 to 11 feet, or, with the extension piece attached, to 16 feet; and a third one 11 feet long for taking depths from 11 to 21 feet, or, with the extension piece attached, to 26 feet. The movable or index rod in each has an arrow index traversing a decimal scale on the fixed rod. Greater depths may be taken by inserting into the ends of the index rods, an extension piece, provided with sockets for this purpose one or more joints of lift rods described below:

The fixed rod is graduated in feet (in red) and tenths and half-tenths (in black). and when the ends of the rods are well together the arrow on the index rod points to the figure indicating the constant length of the fixed rod, and as the index rod is moved up the arrow indicates the length from the upper end thereof to the lower end of the fixed rod. Bear in mind, however, that when you use any of the attachments referred to above you must add to the reading on the fixed rod the net length of the attachment used; e. g., if the 6-foot rod is extended to its limit, 11 feet, which is reached when the arrow on the index rod is fair with the upper end of the fixed rod, and the extension piece is attached, which is done by slipping the bands on the lower end of it over the upper end of the index rod until the upper edge of the upper band is fair with the upper end of the index rod, and by fastening (on the

groove side of the index rod) with set screws in the said bands, the length will not be 11 feet, as shown by the reading, but 16 feet, the reading plus the increment due to the attachment (11 feet+5 feet). This increment may be further increased by inserting into the end of the extension piece one or more joints of lift rods, each of which is about 8.95 feet when adjusted. At the station of the area to be measured in single-deck vessels the rod is to be placed on the ceiling, or floor beam or timber when no ceiling is present, alongside the keelson or line of the keel, perpendicular or square thereto, and also parallel to the middle longitudinal plane of the ship, and forced up firmly under the deck and fixed in such position by the set screws; from the depths thus found take one-third of the round or one-half of the pitch of beam to get the depth of the area.

The depth of an area taken as above is to be divided into the required number of equal parts. (See § 2.29 (d).) With the rod fixed in position as above, set off on it from its lower end one of these equal parts, or common interval between the breadths, using white or other colored chalk or material that will make a visible mark, which gives the position of the first breadth above the bottom breadth, and from this when the rod is taken down the positions of the remaining breadths are to be set off at the said common interval.

The positions of all the breadths being thus severally marked on the rod, it is then to be set up again and firmly fixed or held in position, and the breadths may be readily and correctly measured by means of the tape held at right angles across the rod at each of the positions marked thereon.

In measuring vessels with more than one deck, where the second deck from the bottom is the tonnage deck, it will be necessary to use two of these rods in combination, one directly over the other, one in the hold under the first deck, as directed for single-deck vessels, and the other in the space between this deck and the tonnage deck. In this combination the tonnage depth is found by adding together the two depths and the thickness of the deck between the rods and deducting from this combined depth onethird of the round or one-half pitch of beam; then proceed as before directed.

(c) A 2-foot rule with a hinge is required for taking the rake of the bow and stern and for other purposes.

(d) A carpenter's square will be found useful for setting the sliding rod perpendicular to the keelson.

(e) For taking the breadths in the hold which are beyond the reach of the measuring officers two lift rods will be needed, each about 8 feet long (made by joining two sections), one having a pulley at the end over which the tape may be drawn when the rods are held in po

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In addition to what are commonly known as masts, spars set up at the center line of the bridging at the top of king-posts of certain vessels for signals and wireless antennae, etc., are to be considered as masts. The number of king-posts and derrick posts, etc., independent of the supported masts are to be separately stated after the number of said masts; e. g., "Two masts and eight king-posts," or as the case may be.

§ 2.17 Ceiling, cargo battens, etc.

(a) Ceiling. Ceiling hereafter referred to is considered the permanent planking fitted directly on the inboard side of the frames, or floors, or the top of the double bottom. The maximum allowance for ceiling is 3 inches on the bottom and 3 inches on each side. When ceiling is found to be less than 3 inches thick, allow the actual thickness thereof; that is, take dimensions to the face of the ceiling so found. Depths and breadths shall not be decreased due to grounds supporting ceiling nor shall allowance be made for ceiling on the under side of deck beams.

(b) False ceiling. In small vessels with "false ceiling" in a portion of their cabins, in their holds, or forming a part of their seats or lockers, etc., therein, and which stands off from their framesthat is, not fitted to them as ordinary ceiling-take the breadths through the said "false ceiling" to the inner faces of the vessel's frames, dcducting therefrom the thickness of the "false ceiling" on

each side. If, however, there is a ceiling fitted on the frames in addition to the of "false ceiling," take the breadths to the ceiling on the frames, making no allowance for the "false ceiling."

(c) Cargo battens, insulation. Paraegraph (a) of this section applies to cargo battens (spar ceiling) and refrigeration insulation.

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§2.18 Register length.

(a) The length measured on the tonnage deck, from the fore part of the outer planking (where it is rabbeted) on the side of the stem of wooden vessels, or fore end of lap of outer plating of steel or iron vessels, to the after side of the main sternpost, shall be accounted the vessel's register length. (See Figures 2 and 3 (§ 2.65).)

(b) In the case of screw vessels with no sternpost, take the length to the forward side of the rudder-stock or line of same extended through the deck.

(c) The register length of scows and barges, with a square bow and stern sloping up from the bottom to the deck, and with neither stem nor sternpost, is to be taken on the deck from the extreme point of the hull at the bow to the extreme point of the hull at the stern; that is, the over-all length of the hull, not including guards or rubbing strakes, is to be considered the register length of such vessel.

$2.19 Register breadth.

(a) A measure from the outboard face of the outer skin on one side to the same point opposite, taken at or below the upper deck and at the widest part of the hull is the register breadth. (See Fig

ure 4 (§ 2.65).)

(b) A practical method for finding the register breadth is, to add twice the sum of the depth of the vessel's side frames and thickness of outer skin, plus an allowance for thickness of ceiling, insulation or cargo battens if fitted, to the greatest tonnage breadth.

§ 2.20 Register depth.

(a) The register depth is taken at the middle of the tonnage length from the under side of the tonnage deck, or line of same, down to the top of the floors at the side of the keelson; or to the ordinary foor timbers or plates when fitted; or to the inner bottom plating (tank top) of a cellular double bottom; as the case may be, in a direction perpendicular to the keel.

(b) Should ceiling be fitted on the above mentioned bottom members, the register depth shall be measured to the top of same and to this dimension shall be added the height of grounds, battens or other type of support for the ceiling. (See Figures 4 and 5 (§ 2.65).)

(c) If the vessel is measured in parts, as explained later, the register depth is taken at one-half the tonnage length of the vessel.

§ 2.21 Upper deck to the hull.

The uppermost complete deck, which extends from stem to stern and from side to side at all points of its length and below which there are no openings through the hull as required in shelter deck spaces and also having its hatchways or other openings provided with means for closing them against the action of the sea and weather upon the space below enclosed by the sides of the vessel, making the said space a fit place for the stowage of general cargo, is to be considered the upper deck to the hull.

§ 2.22 Enumerating the decks.

In enumerating the number of decks, only those which are without such openings as exempt the spaces beneath from being included in the tonnage under the upper deck are to be considered. Other decks, if any, containing such openings as exempt the spaces beneath from inclusion in tonnage should be separately described after the number of decks proper; e. g., "Two decks and shelter deck," or as the case may be. Partial decks, forward or aft, such as orlop decks, are not considered as decks.

§2.23 Register height.

If the vessel has three or more decks to the hull, then the height from the top of the tonnage deck planking and/or plating to the under side of the planking and/or plating of the uppermost deck shall be deemed the register height of the uppermost deck above the tonnage deck.

§ 2.24 Round of beam.

(a) The round of beam (camber) is the perpendicular distance down from the crown of the under side of the tonnage-deck plank or plating at the center to a line stretched athwart the vessel from end to end of the top of the beam and is to be ascertained at every place

where it is to be used in the measurement. (See Figures 6 and 16 (§ 2.65).)

(b) The round of beam of the tonnage-deck, which must be known before taking the tonnage length, as well as before measuring the depths of the tonnage sections, may be taken either at the under side of the deck by stretching a small line tightly from end to end at the top of the beam, which will show the round or camber of the beam at the center; or it may be taken, if more convenient, at the upper side of the deck by stretching a line tightly across, held at equal heights from the deck at each side of the vessel, so as just to touch the crown of the deck at the middle line; then the distance from the deck to the line at the vessel's sides gives the round of beam. (See Figure 6 (§ 2.65).) It is necessary to take the round of beam at each point of division of the length except when the vessel has a flat deck or one practically so. In lieu of the above methods, it may be ascertained on the basis of one-fourth of an inch to the foot of beam at each section in iron or steel vessels of the usual camber of beam. This method is more accurate and easier of application than the others.

(c) When the round of beam is 0.15 foot or less, it may be ignored.

§ 2.25 Pitch of beam.

(a) In vessels whose tonnage deck has a pitch instead of a round from its side at the shell plating to its center, find the height of the pitch of the beam at each tonnage section. It may be done in any practical manner.

(b) The height of the pitch of the beam is the perpendicular distance from the apex at the under side of the tonnage deck plank or plating at the center of the deck down to a straight line from end to end of the top of the beam. (See Figure 7 (§ 2.65).)

§ 2.26 Tonnage deck.

(a) The tonnage deck is the upper deck to the hull in vessels having not more than two decks, and the second deck from the keel in vessels having more than two decks.

(b) If the tonnage deck consists of several partial decks extending with breaks from stem to stern, and if the partial decks are at different heights, the line of the lowest deck will be taken as the tonnage deck, and the headroom

above such line under the higher deck or decks will be measured as a break.

(c) Engine and boiler casings, peak tanks and cofferdams are not considered as breaking the continuity of a deck. (See Figures 8 and 9 (§ 2.65).)

§ 2.27 Tonnage length.

The tonnage length is the longitudinal distance on the under side of the tonnage deck, or line of same from a point where the line of the inboard faces of the side frames, or ceiling thereon if any, intersects the side of the stem, to a point aft on the inboard face of the stern timber or cant frame, or ceiling if fitted thereon. (See Figures 10 and 11 (§ 2.65).)

§ 2.28 Depth of a transverse section.

(a) Depth. The depth of a tonnage section is a measurement taken at its proper point of division of the tonnage length, from a point at a distance below the tonnage deck equal to onethird of the round or one-half of the pitch of the beam, down to the upper side of the floor timbers or floor plates; or bottom floors alongside the keelson; or longitudinals; or the tank top of a cellular double bottom, as the case may be.

(b) Ceiling. If ceiling is fitted on the bottom floor members, depths of transverse sections terminate on the upper face of the ceiling of average thickness. (See Figure 4 (§ 2.65).) For tonnage depths where ceiling is fitted on tank top, see Figure 5 (§ 2.65).

(c) Raised platform. In vessels with a raised platform in the bottom and no ceiling fitted on the bottom frame members, the depths are to be taken down through the platform to the upper side of the floor timbers or floor plates as described above, deducting therefrom the thickness of the ceiling of the platform in question.

(d) Depths in way of interruptions to tonnage deck. Should depths of transverse sections fall where the tonnage deck is interrupted, due to a break, hatches, etc., then depths are taken from the line of continuation of the tonnage deck.

(e) Rise of double bottom. In vessels having a double bottom the tank top of which, in way of tonnage sections, rises from the center line to the wings, the tonnage depth of each section will terminate at one-half height of the dead rise. (See Figure 12 (§ 2.65).)

(f) Fall of double bottom. In vessels having a double bottom the tank top of

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§2.29 Tonnage depths.

(a) The tonnage depth. The depth generally referred to as "the tonnage depth" is located at the middle point of he division of the tonnage length and is s found in a manner similar to the other te depths of transverse sections.

(b) Tonnage depth in a vessel measbe ured in parts. Should a vessel be reequired to be measured in parts, and each

part measured as a separate unit; then a tonnage depth shall be found for each n. part or unit at one-half its tonnage length. (See Figure 14 (§ 2.65).)

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(c) Tonnage depth is the first depth measured. The tonnage depth governs the number of parts into which it and all the remaining depths of the part in which said depth is located, is divided.

(d) Divisions of tonnage depth. If the tonnage depth at the middle of the tonnage length of the vessel or part of same does not exceed 16 feet, divide each depth into 4 equal parts; but if the depth at the middle of said length exceeds 16 feet, divide each depth into 6 equal

parts.

(e) Intervals. The common intervals between the points of division of depths, also one-third common intervals are to be carried to the nearest hundredth of a foot.

(f) Purpose for dividing tonnage depths. Depths are divided to indicate points at which tonnage breadths are to be measured.

ide §2.30 Tonnage breadths.

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(a) Breadths. An inside horizontal breadth is to be measured at each point of division of the depth marked on the sliding rods placed in position as directed in 2.13(b) and also at the upper and ge lower points of the depth. Extend each ak measurement to the inboard face of the ordinary frames, or line of same, or ge inboard face of ceiling, or battens, or insulation of average thickness if fitted. (See Figure 15 (§ 2.65).) Care must be taken that the sections shall be parallel to each other and at right angles to the Axis of the vessel.

(b) Upper breadth. In finding the upper breadth of each transverse section make no allowance for the excess of the deck-beam shelves, etc., over the per

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missible thickness of ceiling, if any, thereunder.

Referring to Figure 16 (§ 2.65), observe that after the deck is laid the upper breadth (represented by the line U B) passes through the deck on each side. Hence, it is impossible to take it at its true position. In such cases take it on the deck, allowing within the extended line of frames the thickness of the ceiling if any on the frames under deck, as shown by line T B in the figure.

Owing to deck-beam shelves or other obstructions, it can be more conveniently and accurately taken here than under the deck, and, besides it will be only a few inches from its true position. In vessels which have upright sides the said breadth so taken will be correct, but in the case of vessels with inclining sides the necessary allowance must be made for the deviation of the sides from the upright in the few inches above the true position of the said breadth.

(c) Bottom breadths. Bottom breadths are taken only so far as the flat of the floor extends. (See B B, Figures 4 and 5; Figure 15; and B B, Figures 17 and 18 (§ 2.65).)

When bottom frames rise immediately from the keelson, or combined keel and keelson, and bona fide floor timbers or floor plates are not fitted, bottom breadths are equal to the breadth of keelson, or combined keel and keelson as the case may be. (See B B, Figure 19 (§ 2.65).)

The bottom breadths of transverse sections of vessels of longitudinal construction falling in the hold where there is no double bottom and where there is a dead rise of the bottom out to the sides of the vessel may be considered to be equal to that part of the bottom plating not affected by dead rise.

(d) Bottom breadths in case of rise or fall of double bottom. Bottom breadths falling in way of a double bottom the top of which rises or falls from the midship longitudinal plane to the wings are measured from and to the inboard end of the frame brackets (or ceiling thereon if fitted), connecting the double bottom with the frames. B, Figures 12 and 13 (§ 2.65).) § 2.31 Measuring the tonnage length.

(See B

(a) The cubic capacity of the space below the tonnage deck is determined by use of the tonnage length together with the areas of a prescribed

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