COMPARISON OF THE GROSS TONNAGE RULES OF GREAT BRITAIN, THE SUEZ CANAL CO., GERMANY, AND THE UNITED STATES. The foregoing account of gross tonnage attempts to explain the leading characteristics of the measurement rules of Great Britain, the Suez Canal Co., Germany, and the United States. The spaces included within gross tonnage and those exempted from measurement are enumerated, and the different treatment given to above-deck spaces is explained. To facilitate comparison of these four codes of rules, their differences and similarities may well be set forth by textual and tabular enumeration. The provisions of the several rules regarding spaces included in measurement are as follows: 1. In each set of rules gross tonnage is assumed to include all parts of a vessel that are permanently inclosed. The capacity of such spaces is determined by Moorsom's measurement system applied with but slight variation by the several rules. 2. In each case the spaces under the tonnage deck and between the tonnage and upper decks are included in gross tonnage. 3. Hatchways in excess of one-half of 1 per cent of the gross tonnage, exclusive of hatchways, are included in the tonnage. 4. In theory closed-in spaces above the upper deck are included in the measurement and tonnage and open spaces are exempted. Measurement rules and practice, however, vary as regards these spaces. The treatment accorded superstructures and "shelter-deck" spaces in the measurement rules of Great Britain, the Suez Canal Co., Germany, and the United States are compared in detail below in Table I. The provisions in the four sets of gross tonnage rules under consideration in regard to spaces exempted from measurement may be compared as follows: 1. Double-bottom spaces used for water ballast are exempted from measurement, unless. (in the case of the national but not of the Suez Rules) they are available for cargo, stores, or fuel. The methods of measurement are such as to exempt spaces between the ship's frames and its floor beams. 2. The same below-deck spaces are included in all four codes of measurement rules. 3. The application of the Moorsom system of measurement varies slightly with the different rules, and the under deck tonnage of the same vessel might be slightly different when measured by different rules. The treatment accorded each of the several above-deck structures and the below-deck spaces is shown for each of the four sets of rules in Table I. TABLE I. Measurement of gross tonnage under the measurement rules of Great Britain, the Suez Canal Co., Germany, and the United States. TABLE I.—Measurement of gross tonnage under the measurement rules of Great Britain, the Suez Canal Co., Germany, and the United States-Continued. By applying the several sets of rules described in this chapter to the measurement of the same vessel, the results obtained indicate the main differences in the rules. In the latter part of 1911 the surveyor at the port of New York, at the request of the Commissioner of Navigation, had the British, Suez, and American rules applied to each of eight vessels, and the American, German, and Suez rules were applied to two other vessels. In the note appended to this chapter the details of the measurement of each of these vessels are presented. The following summary table compares the gross tonnage of the eight vessels whose tonnage was determined by British, Suez, and American rules: TABLE II.-Gross tonnage of steamers measured by British, Suez, and American rules. The first vessel mentioned in Table II, the Kentuckian, is an American ship with three decks, and the second vessel, the Voltaire, is an English steamer, also with three decks. In measuring both vessels all three rules included in the measurement all spaces under the upper deck. In other words, the space under the upper deck was not treated as a shelter-deck space. The third ship mentioned, the Stephen, is a British vessel with two decks and a third deck treated by the British measures as a shelter deck. Under the Suez and American rules, however, the space under this deck was considered to be closed-in and for this reason, mainly, the gross tonnage under the British rules is a thousand tons less than under the Suez and American rules. The Santa Rosalia is a British well-deck cargo steamer, to which the same below-deck tonnage is given by all three measurements. The differences in gross tonnage are due to the spaces exempted by the several rules as applied to superstructures. The Kirkdale and Ikala are twodecked British steamers, the gross tonnage of which, under the Suez and American rules, exceeds the tonnage under the British rules mainly because the Suez and American rules consider as closed large bridge spaces which are held under the British rules to be open. The Tunstall is a onedeck turret steamer built in Great Britain. Its under deck and turret tonnage by the three rules is nearly the same, but the gross tonnage of the vessel is made appreciably larger by the American rules than by the other two measurements because of the inclusion in the American measurement of large bridge spaces exempted by the other rules. The Benwood is a British freight steamer with one deck. Its tonnage under the Suez and American rules is greater than as measured by the British rules, because of the inclusion of superstructures which under the British rules were considered open. For most of the eight vessels listed in the preceding table the gross tonnage is made least by the British rules and highest by the American rules. The lower tonnage figures under the British rules are due mainly to the exemption of above-deck spaces which the American and Suez rules consider closed, and thus subject to measurement. The Suez gross tonnage is somewhat less than the American, because the Suez rules consider open, and thus exempt from measurement, certain above-deck spaces that are not exempted by the American rules. The following table compares the gross tonnage of two German vessels as determined by the application of the Suez, German, and American rules. The Patricia mentioned in the table is a relatively large freight and passenger steamer with four decks. The Duisburg is a medium-sized two-deck cargo steamer. TABLE III.-Gross tonnage of two German steamers measured by Suez, German, and American rules. The measurements of the steamer Patricia under the German rules were accepted by the American admeasurers at New York without change. The Suez rules exempted portions of superstructures that were included in the German and American measurements. The wide discrepancy between the gross tonnage of the Duisburg, as measured by the German rules and as determined by the American and Suez rules, is due to the exemption, under the German rules, of large spaces which the other rules considered as "closed-in" and subject to measurement. The German definition of open and closed superstructures follows the English definition and practice, whereas the Suez and American rules, as has been explained, consider superstructures as closed-in whenever they are or may be used for the accommodation of passengers and cargo. The effect of the definition of closed and open spaces upon the tonnage of vessels is well illustrated by the Duisburg. Under the German and British law the bridge house and poop of this ship were considered as open spaces above the upper deck. The surveyor of New York, however, considered the bridge and a part of the poop as permanent closed-in spaces, and added 1,817 cubic meters, equal to 642 tons, to the vessel's gross tonnage. When measured by the Suez rules, the entire poop and bridge were treated as closed-in, and 2,173 cubic meters, equivalent to 767 tons, were added to the vessel's gross tonnage. Other variations in the measured spaces account for the difference in the Duisburg's tonnage as determined by the Suez, German, and American rules. Details of the MEASUREMENT AND TONNAGE OF VESSELS TO WHICH THE BRITISH, SUEZ, AMERICAn, and German MEASUREMENT RULES WERE APPLIED IN THE DETERMINATION OF GROSS TONNAGE,1 VESSELS TO WHICH THE MEASUREMENT RULES WERE APPLIED. The steamship Kentuckian is an American steamship, representative of the fleet of the American-Hawaiian Steamship Co., the largest American fleet which will make use of the canal. She is described as a three-decked ship, but Lloyd's Register describes her as a two-decked ship with deep framing and a shelter deck. The ship is a freight steamer with accommodations, however, for a number of cabin passengers. She carries 280,000 gallons of oil as fuel, the daily consumption being 10,000 gallons at a speed of about 11 knots. The British steamship Voltaire is a passenger and freight steamer belonging to the Lamport & Holt Line, of the type in trade between New York and Rio Janeiro. She is a three-decked ship with 1,200 tons coal capacity, and, on an average daily consumption of 60 tons, steams at a speed of about 12 knots. The British steamship Stephen is a freight steamer, with accommodations for some passengers, of the type in trade between New York and the River Amazon, owned by the Booth Steamship Co. She has two decks and a shelter deck, with a coal capacity of 1,100 tons, and, on 32 tons consumption per day, has an average speed of about 11 knots. The steamship Santa Rosalia is a modern British well-deck cargo carrier, steaming 10 knots, on a daily coal consumption of 33 tons, and has 1,896 tons coal capacity. The British steamship Kirkdale is a two-decked ship (spar deck) cargo steamer, steaming 10 knots, on a daily coal consumption of 30 tons, with a coal capacity of 1,800 tons. The British steamship Ikala is a two-decked ship to which at New York the surveyor of customs appears to have added the bridge space, making substantially the difference between the American and British measurement. This bridge space was not included in the Suez Canal certificate issued in 1901. If, however, cargo should be carried in that space hereafter it would be added to the Suez measurement. The steamship Ikala is being converted into an oil-burning steamer. The British steamship Tunstall is a one-decked (turret) steamer. The British steamship Benwood is a one-decked freighter. The bridge and poop were added to the gross tonnage at New York on the ground that they were permanent closed-in spaces. The German steamship Patricia, of the Hamburg-American Line, was built in 1899, and is a four-decked passenger and freight steamer, steaming from 12 to 13 knots, on a daily coal consumption of 96 tons, and has a coal capacity of 1,620 tons. These details are copied with certain changes and abbreviations from the statement submitted by the Commissioner of Navigation to the Committee on Interstate and Foreign Commerce of the House of Representatives, Jan. 20, 1912. Consult Hearings before Committee on Interstate and Foreign Commerce, House Doc. No. 680, 62d Cong., 2d sess., pp. 857-872. The German steamship Duisburg is a cargo vessel of 12 knots; daily coal consumption, 40 tons; coal capacity, 1,000 tons; built for trade between Germany and Australia. Under the German and British laws the bridge house and poop are reckoned as shelter spaces above the upper deck not permanently closed-in. The surveyor at New York, in November, 1910, treated the bridge and part of the poop as permanent closed-in spaces, adding 1,817 cubic meters to the vessel's gross tonnage. At Suez the entire poop and bridge are treated as closed-in with a consequent addition of 2,173 cubic meters. [Measured at New York, Nov. 22, 1911. Built at Sparrows Point, Md., 1910.] Description and dimensions.—Register length, 403.2 feet; register breadth, 53.7; register depth, 28.1; height under spar deck, 7.5; tonnage length, 415.4; number of divisions of length, 16; tonnage depth amidships, 27.7; number of divisions of depth, 6; number of decks, 3; number of masts, 2; head, plain; stern, elliptic. Galley, cookhouses, water-closets, and lavatories, exclusively used for officers and crew. Gross tonnage.. BRITISH STEAMSHIP "VOLTAIRE," OF LIVERPOOL.1 [Built of steel, at Portick, 1907.] Tons. 4,825. 77 1,450. 24 104.24 47.16 65.17 .56 15.77 45.90 13.65 6, 568. 61 Deck houses.... Side houses. Descriptions and dimensions.-Number of decks, 3; number of masts, 2; head, straight; stern, elliptic; register length, 485.3 feet; register breadth, 58.25 feet; register depth, 26.2 feet. Under tonnage deck Between decks.. Tonnage stated in the British register issued at Liverpool, Mar. 13, 1907. Tons. 6, 023. 52 1, 956. 91 560.31 Chart house.. Light and air.. Gross tonnage.... 30.02 6.10 40.79 8, 617.65 1 There being no omissions not authorized by the laws of the United States, the British tonnage was accepted by the New York surveyor. |