Measurement of tonnage.
THE HONGKONG GOVERNMENT GAZETTE, 30TH AUGUST. 1890.
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Rules of Measurement of Tonnage under the Tonnage Deck prescribed by section 21, Merchant Shipping Act. 1854, as modified, for Measurement of Vessels with Double Bottoms for Water Ballast.
XXI. The tonnage of every ship to be registered, with the exceptions mentioned in the next section, shall, previously to her being rezistered, be ascertained by the following Rule, herein-after called Rule I.; and the tonnage of every ship to which such Rule can be applied, whether she is about to be registered or not, shall be ascer- other ships of which tained by the same Rule:
RULE 1.
For ships to be registered; and
the hold is clear.
Ships measured
under Rule II. may be re-measured under Rule 1. See Mer.
Ship. Act Amend- ment Act, 1855, section 14. Lengths.
Transverse areas.
(1.) Measure the length of a 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 (frame) 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 (frame) 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.
2.
TABLE.
Ships of which the tonnage deck is according to the above measurement 50 feet long or under. into 4 equal parts: Ships of which the tonnage deck is according to the above measurement above 50 feet long and not exceeding 120, into 6 equal parts:
3. Ships of which the tonnage deck is according to the above measurement above 120 feet long and not exceeding 180, into 8 equal parts:
4. Ships of which the tonnage deck is according to the above measurement above 180 feet long and not exceeding 225, into 10 equal parts:
5. Ships of which the tonnage deck is according to the above
measurement above 225 feet long, into 12 equal parts:
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.
(2.) Then, the hold being first sufficiently cleared to admit of the required depths and breadths being properly taken, find the transverse area of such 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 such 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 limber strake; then, if the depth at the midship division of the length do not exceed 16 feet, divide each depth into five† equal parts; then measure the inside hori- zontal 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 of that part of the ceiling which is between the points of measurement; number these breadthis from above (¿.e., numbering the upper breadth one, and so on down to the fifth breadth); multiply the second and fourth by four, and the third by two: 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 beteven 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 upper and lower points, and proceed as before, and the sum of the two parts shall be deemed to be the transverse area; but if the midship depth exceed
* Extract from section b. Act 1889.
† Extract from report of Royal Commission on Tonnage, p. 799,