ual character, the following method of computing the effective mean sheer is to be used: "Let S = mean of the actual sheers at stem and sternpost; "Let Si = mean of sheers at length from stem and sternpost ÷ .55. "If S is greater than S1 the effective mean sheer to be used in the computation of freeboard is S1. "If S is less than S1 the effective mean sheer to be used is S+Si 2 "In those cases in which the sheer is required to be taken at of the vessel's length from stem or from sternpost the sheer as actually measured at the prescribed point may be used in ordinary cases without any correction on account of a departure of the sheer line from the gradual character. of "When correcting the depth of hold for excess or deficiency of sheer (paragraph 3, page 23), the mean of the sheers at vessel's length from stem and from sternpost divided by .55 should in all cases be taken as the vessel's actual sheer for this purpose. 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 stem and sternpost and the freeboard corrected for sheer in estimating the allowance for erections. When the bridgehouse is not enclosed at both ends, the sheer should be measured as if there were no bridge-house, and the freeboard should or should not be corrected for sheer in estimating the allowance for erections, according as the sheer is measured at the stem or at length from the stem. SUB-PARA. (a).- Surveyors should note that paras. 11 and 12 apply either to vessels of the ordinary well-decked type or to vessels having a poop and forecastle with a disconnected bridgehouse. SUB-PARA. (d). The extent of the depressed part of the sheer covered by deck erections is to be allowed for in applying this rule. SUB-PARA. (e). — In vessels obtaining an allowance for deck erections under para. 11 and having considerably less than the normal sheer, the freeboard should be modified in consideration of the decrease of height of deck in the "well." SUB-PARA. (f). — In flush-deck vessels the total standard means the sheer measured at the stem and sternpost. In vessels having poops and forecastles, it means the sheer measured at points distant 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. PARA. 19-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 round 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. Table A. 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. Table B. 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. to When the height between decks is greater or less than 7 feet, the consequent modification in freeboard will vary from 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 deck exceeds 7 feet, the numbers for scantlings should be found assuming the height between decks to be 7 feet; 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 of the excess of height above 7 feet. If both the Scantling numbers so found are in higher grades than those of the actual vessel, 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 feet. 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. ual character, the following method of computing the effective mean sheer is to be used: "Let S mean of the actual sheers at stem and sternpost; "Let Si: = mean of sheers at length from stem and sternpost ÷ .55. "If S is greater than Si the effective mean sheer to be used in the computation of freeboard is S1. "If S is less than S1 the effective mean sheer to be used is S+ Si 2 "In those cases in which the sheer is required to be taken at of the vessel's length from stem or from sternpost the sheer as actually measured at the prescribed point may be used in ordinary cases without any correction on account of a departure of the sheer line from the gradual character. of "When correcting the depth of hold for excess or deficiency of sheer (paragraph 3, page 23), the mean of the sheers at vessel's length from stem and from sternpost divided by .55 should in all cases be taken as the vessel's actual sheer for this purpose. 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 stem and sternpost and the freeboard corrected for sheer in estimating the allowance for erections. When the bridgehouse is not enclosed at both ends, the sheer should be measured as if there were no bridge-house, and the freeboard should or should not be corrected for sheer in estimating the allowance for erections, according as the sheer is measured at the stem or at length from the stem. SUB-PARA. (a). · Surveyors should note that paras. 11 and 12 apply either to vessels of the ordinary well-decked type or to vessels having a poop and forecastle with a disconnected bridgehouse. SUB-PARA. (d). The extent of the depressed part of the sheer covered by deck erections is to be allowed for in applying this rule. SUB-PARA. (e). — In vessels obtaining an allowance for deck erections under para. 11 and having considerably less than the normal sheer, the freeboard should be modified in consideration of the decrease of height of deck in the "well." SUB-PARA. (f). - In flush-deck vessels the total standard means the sheer measured at the stem and sternpost. In vessels having poops and forecastles, it means the sheer measured at points distant of the vessel's length from stem and stern post. 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. PARA. 19— 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 round 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. Table A. 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. Table B. 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 feet, the consequent modification in freeboard will vary from to 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 deck exceeds 7 feet, the numbers for scantlings should be found assuming the height between decks to be 7 feet; 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 of the excess of height above 7 feet. If both the Scantling numbers so found are in higher grades than those of the actual vessel, 3 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 feet. 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 100 A built to the three-decked rule, and of vessels built to the 100 A 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: 1. The difference between the freeboard by Table A (less 12 per cent) and that by Table B to be divided by five, of it being considered with reference to the longitudinal strength, and of it with reference to the transverse strength, these allowances to be the maximum deduction on each account. 2. In the comparison of steel ships, notwithstanding the general reduction of 20 per cent for steel as compared with iron thicknesses, outside plating in the way of the double bottoms is not to be further reduced by unless its thickness is or over. No reduction is to be made in any case unless there are floors connected with every frame. 3. In the calculation of strength the following method is to be adopted: (a) Thin iron or steel plating in weather decks and the inner plating of double bottoms are to have their sectional area reduced for the purpose of the strength calculation as follows: 1. When the deck beams or floors are fitted on every frame of the usual spacing: Thickness in 20ths. . 5 6 7 8 9 6 .7 9 1 1 2. When the deck beams or floors are fitted on alternate frames: Thickness in 20ths... 5 .4 6 7 8 9 .5 .6 .7 .8 When the decks are sheathed with wood, with fastenings not more than 24 inches apart, the factors given in (1) are to be used, whether the beams are on every frame or on alternate frames, but if the fastenings are 48 inches apart, then the fac |