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959
SHIBBUILDING


that the machinery also conforms with the requirements of the rules and has obtained a separate certificate. V

Certain steam vessels obtain a El which encloses the * in front of the class mark. This signifies that the-arrangement of the watertight bulkheads is such as theoretically to ensure the fioatability of the ship when the sea has access to one or two of her compartments. The tests for steel material to be used in building the ships, as required by the same societiesfmay be tabulated as follows:- appointed by the British government, and, one .of the questions considered was that of the load line.. In'the final report =in, 1874, the conclusion was arrived at that a settlement of a§ load line should, in the main, be guided by reserve, buoyancy as a first consideration. The commissioners were, however, of opinion that an act~0f parliament, framed to enforce any scale of free board, would be mischievous, if not impossible, as would .be any universal rule for the, safe loading of merchant ships., ~,

In 18745, in a paper read before the Institution of Naval Architects Ultimate Tensile Strength. V 'Elongation in Length of S in., Temperature Test. i .T .l Lloyd's Register

sq. in. - § in. thick and upwards.

British Corporation . ', , ., ,

Registro Nazionale Italiano

Norske Veritas .-Bureau

Veritas .

sq. in.

Record of American Shipping .

per sq. in. ~,

Between 26 and 31 tons per 20% for plates, IO mm. in, V, 7 ' A ~ sq. in. V thickness and upwards.,

Germanischer Lloyd

I1 1|

YY . ' 11)| Y!

Between 27 and 32 tons per, ,, ,,

Between 28 and 32 tons per Not less than 20% for plates Sample heated to a low cherry, 80°, F. and doubled overa Q

radius of 1% times the thickness

of, the plate tested.

Between 58,000 and 68,000 lb 22 for plates weighing 18 Tb per sq. ft. and upwards.

I

red and cooled in water at

For plates less than § in. in thickness the first four societies in the above table allow an elongation of 16%; the Bureau Veritas allows an elongation varying between 20% and IO%, for plates between § {, 'ths and ggths of an inch in thickness; the Record of American Shipping allows an elongation of 18 % for plates weighing less than 18 lb per square foot; the Germanischer Lloyd allows an elongation of 16 % for plates between 10 mm. and 5 mm. in thickness and 14% for plates less thani mm. in thickness. For Steel plates to be flanged cold Lloyd's egister and the British Corporation require a minimum tensile strength of 26 tons, and for sectional- material:such as angles, bulb-angles and channels the tensile strength may beas high as 33 tons. For rivet steel the tensile strength must be between 25 and 30 tons per square inch, with a minimum elongation of 25 % on a gauge length of eight times the diameter of the bar. Hot and cold bending and forge tests for angle bars are also prescribed. The regulation of certain matters connected with the design of merchant ships falls upon the Marine Department of the Board of Trade. The authority of the Board is the Merchant B°"" °' Shipping Act of 1394. which consolidated previous T"“d° enactments. These matters include the measurement xx: of tonnage, and provision for the safety and comfort of passengers and crew. The former is discussed, in a separate article (see TONNAGE), but it may be mentioned here that the following countries have at various dates accepted the British rules for tonnage: United States, Denmark, Austria-Hungary, Germany, France, Italy, Spain, Sweden, Netherlands, Norway, Greece. Russia, Finland, Hayti, Belgium and japan. The amount of deduction for propelling power varies in Spain, Sweden, Netherlands, Greece, Russia and Belgium, but option is granted to owners to have the engine-room remeasured under the rules of allowance for engine-room relating to British ships. Special certificates are at present also issued, on application, to vessels trading to Italian ports, as the Italian authorities do not at present recognize certain sections of the Act of 1894 in regard to deductions from tonnage and exemptions from measurement. Special tonnage certificates are also issued for the Suez Canal, where the measurements of ships and deductions from tonnage vary from British rules, and are detailed at length by the Board of Trade in their Instructions to Surveyors. With regard to safety and comfort the surveyors have to see, among other matters, that the crews are properly accommodated and the passengers not:too crowded; that the oats and life-saving appliances are sufficient; that the lights and signals are in order; that the free board is sufficient and ship otherwise seaworthy; that grain cargoes are properly stowed; and that coal cargoes are adequately ventilated. Any question of doubt as to the strength of assenger vessels has to be referred to the Board of Trade, and in i)uture midship sections, with all particulars marked thereon, are to be submitted in the case of all new steamships building under survey for which passenger certificates are required. A passenger certificate is required whenever a Steamer carries more than twe ve passengers. In granting it the Board of Trade recognizes five different services, ranging from foreign-going steamers to excursion Steamers in smooth water. The Board of Trade rules for scant lings are not published officially.

A Bill, introduced into parliament in 1869, dealing with the load line question, contained a clause requiring the draught of water to be recorded at which a vessel is floating when leaving port. L°g'Lg"° This Bill did not pass; but in the following year the "" °' Merchant Shipping Code Bill was brought in, containing h°""" the same provision, and, in addition, requiring a scale showing the draught of water to be marked on stem and stern 'post of every British ship. This became law in 1871. The same Act empowered the Board of Trade torecord the draught of water of all sea-going ships on leaving port by surveyors duly authorized. In March 1873 a Royal Commission on “ Unseaworthy Ships" was by Mr B. Martell, who was thenthe chief surveyor to Lloyd'5 Register, tables of »freeb0ard were suggested from data collected at all the principal ports in the United ingdom. These tables wereibased on the principle of reserve buoyancy, and were intended to apply to the loading of the various types of sea-going, ships then to be, dealt with. As an indication of the form of the vessel, it was sug ested that.a tonnage coefficient of nneness should, be used, in' order 'tgat 'the tables proposed might be readily adapted toall sea-goingsliips, whether at that time at sea or in port. In 187% a short Act was passed, to remain in force only until October of the ollowing year, .'w 'ich embodied as its chief. feature the re uirement of what was afterwardsfuniversally known' as the “ Plimsolll 'mark " (after the late Mr S., Plim;soll, MBL, the prime mover in securing legislation for the prevenytionpf overloading in British ships). A l British ships were to, haveYthe'p0sition of the deck shown on the side of the ship, and every forei n-going British ship was to havefa circular disk marked below"§ 1e deck line, indicating the maximum, draught to which it was intended- to load. The Act in no* wa fixed the amount of f fee board; this was left to the shipowner. " he provisions of the 1875 Act were confirmed by a more com rehensive Act in 1876, which extended the compulsory marking of)the' deck line and disk toall British ships, except those under 80 tons engaged in fishing and"the coasting trades, also exceptin yachts or war vessels. Before this Actjwas passed the Board 0f'Trade took action, by ap ointing a committee to consider the possibility of framing rules Esrfthe regulation of free board. The committee was to be composed of 'representatives of the Board of Trade, Lloyd's Register, and 'the L'iverpool' Underwriters Registry. This attempt to establish an 'authorized scale of free board failed. Meanwhile the subjectwafs not Iostsight of;fthe collection of data was continued, investigations 'were carried out, and six years later (in, I'882) the committeepof Lloy¢ifS'Register iSsued free board tables, and undertook, to assign free board, on the”basis of the tables issued, on owners making application', forQ the Same. In the course of three years 944 vessels had free boards thus assigned to them, and in the case of 775 of this number the owners voluntarily accepted the free boards assigned. In December".1883, the Load Line Committee was appointed by the Board of Trade; and after two years' careful deliberation and investigation, 'irivolvingvvmuch labour, the committee presented its report. 'This report was accompanied by tables, which agreed closely with those previously issued by Lloyd's Register; and they were accepted, bye the committee of that society. in September 1885. Between'18.85, and*5June 1890 (the latter being the date the Load Line Actkwas p ssed) 2850 steam and sailing vessels had free boards fixed by Lloy3?s1Register, and of -these 2520 were taken from the tables. After the passing of the Act in 1890 appointments to assign free boards were f granted to Ll0yd's Register, Bureau Veritas and the British Corporation. In 1893 the original'tables'were'modified with respect to some 'of the ports in the United States on the Atlantic, the sailing from or to which in the winter was to subject the ship' to a few' inches additional free board. In 1898'they were further modified fa) to 'exempt shipsoverggo ft. in, lengthgfrom the additional free board just *mentioned, an to' limit the additional free board inf smaller 'ships;' (15) to give some concession to turret-deck Steamers; and '(c)i'in' some other minor matters; ' T '

In 1906 the Shipping Laws were amended so that all foreign vessels loading at British orts requiredrto be provided eitherfwith affreeboard assigned' undier the British tables, or under tablesvofaforeigln country which had been certified by the' British Bord 'of Trade' s being equally effective with the Britishfreeboard tables. In the same year the British tables were revised throughout in the light of the experiences of previous, years, of practical administration, by a committee whose members were drawn from the Board of Trade and the three assigning bodies#-Ll0g>d's, British

Corporation, and the Bureau Veritas. Imp01'tant'm0di eat ions were