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from the free-board required by Table C, in accordance with the foregoing scale.
When the break of the quarter-deck is not less thanths the length of the vessel abaft amidships, twice the above-mentioned allowance may be made, and for intermediate lengths of erection the allowance is to be obtained by interpolation.
For raised quarter-decks of less than our feet in height, whether in part awning-decked vessels or vessels to which paras. 11 and 12 apply, and extending over four-tenths of the length and forming an integral portion of the vessel, the allowance for the erections should be diminished as shown in the following table:
Moulded Depth of Vessel in Feet.
For 90 A class allow in less than for 100 A.
For shorter lengths of raised quarter-decks a proportionate correction should be made.
Well-decked vessels classed 100 A, having erections extending over ths of their length with strengthened bridge bulkheads, freeing port area 25 per cent. in excess of the rule, and hatchway coamings at least 30 inches high, may have an allowance of th the summer freeboard after all other corrections are made, but the allowance is not to exceed 2 inches.
Well-decked vessels of lower class, or with longer wells, &c., are to have a smaller allowance in accordance with the following scale :—
For erections covering 65 to 70 per cent. of the vessel's length, allowinch le-s than that for 70 per cent. and above; and for coamings 24 to 30 inches high, allowinch less than if 30 inches and above.
Sub-para. (a).—The difference will not be affected by correction for length, as the allowance will be practically the same in both tables.
A proportionate allowance may be made for erections having a combined length of ths, in which case the reduction in freeboard will be ths of the difference between freeboards in Table A. (after correction for sheer) and Table C.
Sub-para. (c).-The engine and boiler openings, if protected only by a raised quarter-deck, will require an addition in freeboard varying from I inch in vessels of 15 feet moulded depth to 2 inches in vessels of 20 feet moulded depth.
If with a small bridge-house in front of, but not covering, the openings, an addition of half the above amount.
The table is to be used in connection with paras. 11, 12, and 13, but is not applicable to deck erections provided for by para. 14.
Sub-para. (e).--If the crew are not berthed in the bridge-house, and the arrangements to enable them to get backwards and forwards from their quarters are not satisfactory, an addition should be made to the freeboard of 1 per cent. of the moulded depth of the ship, except in cases where the well is 80 feet or more in length, or where the vessels are under 150 feet in length.
Sub-para. (f).-The minimum freeing port area is to be as follows:
Length of Bulwarks in "Well,"
65 and above, 1 square foot to each 5 feet length of bulwark.
SCALE OF FREEING PORT AREA.
Length of Vessel.
If the freeing port area is less than that stated above, an addition is to be made to the freeboard of 1 per cent. of the moulded depth.
The additional freeboard for North Atlantic winter for well-deck vessels is to be as follows:
Freeing Port Area on each side
For lengths of erection covering Tooths, the difference of the freeboard. ths; for ths allow ths.
but the above addition should never be less than in the case of an awning-decked ship of the same dimensions.
Para. 12.-For vessels having no forecastle, but with the other deck erections prescribed in this paragraph, estimate the allowance for erections supposing there is a forecastle 1th the length of the vessel, and deduct 1 times the allowance that would be made under para. 15 if the vessel were fitted with such a forecastle only.
This rule also applies to vessels having no forecastle, but with a bridge-house, as provided for in para. 13.
ths, allow a deduction of For ths allow a deduc
THE SHIPPING WORLD YEAR BOOK.
For ths allow a deduction of ths, and for ths allow ths, the difference of the freeboards.
For erections which extend over less than oths the length of the ship, the allowance is to be in proportion.
For instance, if ths are covered, allow ths of 33 per cent.
In the case of vessels under 15 ft. moulded depth, in which the combined length of enclosed erections exceeds ths of the vessel's length, or in which the combined length of erections enclosed, and open, is equivalent to more thanths of the vessel's length, subparagraphs (e) and (f) of the preceding paragraph are to apply; but the full addition of one per cent. of the moulded depth under each of these sub-paragraphs is to be made only when the erections cover ths or more of the length; for lengths of erections intermediate between ths and ths, the required addition is to be in proportion; thus, when oths of the vessel's length is covered, the addition to the freeboard is to be per cent. of the moulded depth under each sub-paragraph.
Paras. 12 and 13.-The allowance in a sailing ship for a bridgehouse in addition to a poop or forecastle, or in addition to a forecastle only, is obtained by the rules laid down in paras. 12 and 13, as the case may be, and is calculated upon the difference between the freeboards of Tables A and C; in other words, the allowance for a forecastle, bridge-house, and poop, or for a forecastle and bridge-house in a sailing-ship, is the same as would be given for similar erections in a steamer of the same dimensions.
Fara. 13.-When the combined length of the topgallant forecastle and bridge-house isths of the length of the ship, a deduction from the freeboard may be made of ths, and this is the maximum deduction for this type of vessel.
For erections which extend over less than ths of the length of the ship the allowance is to be in proportion.
For instance, ths covered allow rds of 25 per cent.
In all the rules governing the deductions to be made from the freeboard it is to be understood as follows:-When the torgallant forecastle is not closed by an efficient bulkhead at the after end, the length is never to be estimated at a greater full value than th the length of the ship, but any extension beyond this may be estimated at one-half the value. For instance, if a vessel 240 ft. long has an open forecastle 80 ft. long, its value for deductions is 30+25=55 ft. When the topgallant forecastle has an efficient bulkhead with an elongation abaft that bulkhead not enclosed at the after end, the full value of the closed-in portion is to be estimated either as th the length of the ship or the entire length of the enclosed portion, whichever may be the greatest.
Open bridge-houses.-When the bridge-house extends from side to side of the ship, its value for deductions must be considered on its merits, which will depend upon the security of all deck openings, doors, bunker lids or otherwise.
Where these are all properly protected, and the alley-ways are open at both ends, one-half the length may be estimated as the value for deductions. Where, in addition, the fore end is enclosed by an efficient bulkhead, ths the length may be estimated as the value for deductions.
Bridge-houses in steamers not covering engines and boilers may have an allowance not exceeding that which would be given for half the length of a bridge-house of the same character covering engines and boilers.
Para. 14.-In the case of a vessel having a forecastle and raised quarter-deck, the latter of less than the usual height, the length of raised quarter-deck to be allowed should be in proportion to its height as compared with the standard height. L x H
-length allowed if the height is less than 4 ft.
When the combined length of the erections is ths of the length of the vessel, deduct 10 per cent. of the reserve buoyancy or 12 per cent. of the freeboard required for the flush-decked vessel after. correction for length.
When th of the length of the vessel, deduct 4 per cent. of the reserve buoyancy, or 6 per cent. of the freeboard required for the flush-decked vessel after correction for length. In cases where less thanth of the length of the vessel is covered by erections the allowance should be in proportion to that given for erections covering 4th of the length.
Para. 15.-When there is a poop only, the allowance is to be half of that which in this paragraph is given for a forecastle only of the same length. This is also applicable to a raised quarter-deck, subject to the modifications in the preceding note.
When the poop has no bulkhead, or the bulkhead does not extend across the vessel, one-half its length may be allowed, provided always proper freeing ports are fitted.
Para. 16. Sheer.-Sheer of a gradual character is to be defined as follows:
At th the length of the vessel from the stem or sternpost the sheer is to be 55 per cent. of the sheer at stem or sternpost; at th the length from stem or sternpost 26 per cent., and at ths the length 7 per cent. In cases where there is no forecastle the sheer is to be measured at the stem and sternpost, and corrections made for it in all respects as in the case of flush-decked vessels.
When the bridge-house is enclosed, the sheer should be taken at the ends and the freeboard corrected for sheer in estimating the allowance for erections. When the bridge-house is not enclosed at both ends, the sheer should be measured at 4th the length of the vessel, from the stem or sternpost, and the freeboard should not be corrected for sheer in estimating the allowance for erections.
Sub-para. (a).--Surveyors should note that clauses 11 and 12 apply either to vessels of the ordinary well-decked type or to vessels having a poop and forecastle with a disconnected bridge-house.
Sub-para. (f).-In flush-deck vessels the total standard mean sheer means the sheer measured at the stem and sternpost. In vessels having poops and forecastles, it means the sheer measured at points distant th of the vessel's length from stem and sternpost.
In vessels obtaining an allowance for deck erections under para. 11, where the sheer drops abaft amidships, the height of the raised quarter-deck is to be taken from the level of the top of the midship beam.
In applying the rule given in para. 16 (d), the extent of the depressed part of the sheer covered by deck erections is to be allowed for.
Para. 17. Round of Beam.-In flush deck sailing vessels the excess of round of beam, for which an allowance is made, shall not exceed the standard ound of beam; and for sailing vessels having erections on deck, the allowance shall be further reduced in proportion to the extent of the main deck uncovered.
The deductions for summer in vessels having deck erections is to be intermediate between those required by Tables A and C in proportion to the length of the ship covered by those erections.
All vessels equal in strength to Lloyd's spar-decked rule, or which, although in excess of that rule, do not come up to Lloyd's requirements for ships of full scantlings to the upper deck are to be considered as spar-decked ships, the freeboard for which will vary with their strength.
When the height between decks is greater or less than 7 ft., the consequent modification in freeboard will vary from rd to 3rds the excess or deficiency of height, the exact proportion to depend upon the strength of the vessel.
In spar-decked vessels where the height between main and spar decks exceeds 7 ft., the numbers for scantlings should be found assuming the height between decks to be 7 ft.; if both these numbers are in the same grades as the actual scantling numbers of the vessel, the correction for height between decks is to be 3rd of the excess of height above 7 ft. If both the scantling numbers so found are in higher grades than those of the actual vessel rds of the excess of height is to be added, and if either one of these scantling numbers is in a higher grade, of the excess of height is to be added. The same principle will apply in cases where the height between decks is less than 7 ft.
Since the freeboard is measured from the spar deck, it will be increased if the 'tween deck height is more, and decreased if it is less, than 7 feet.
In computing the freeboard of spar-decked vessels having scantlings in excess of Lloyd's requirements, a comparison is to be made between their scantlings, the scantlings of vessels of the same dimensions classed 100A built to the three-decked rule, and of vessels built to the 100A spar-decked rule, and the freeboard is to be proportionate between that given in Table A and that given in Table B, after deducting 12 per cent. from the former; but in no case must the freeboard so assigned be less than that provided in Table A for a vessel of the same dimensions, sheer, and camber, or round of beam, and deck erections.
In the comparison of scantlings and assignment of freeboard to spar-decked vessels having scantlings in excess of Lloyd's requirements, the following method is to be adopted :