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former being enclosed at the fore end with an efficient bulkhead, and when the engine and boiler openings are entirely covered either by the poop or raised quarter-deck or by a strong iron or steel deck-house enclosing the machinery casings, a deduction may be made from the freeboard given in the tables according to the following scale:

When the combined length of the erection is:

of the length of the vessel, deduct 32 per cent of the difference between the freeboards in Table A (after correction for length) and Table C (after correction for length).

of the length of the vessel, deduct 24 per cent of the difference between the freeboards in Table A (after correction for length) and Table C (after correction for length).

of the length of the vessel, deduct 16 per cent of the difference between the freeboards in Table A (after correction for length) and Table C (after correction for length).

of the length of the vessel, deduct 8 per cent of the difference between the freeboards in Table A (after correction for length) and Table C (after correction for length).

For erections which cover less than of the length of the vessel, the allowance should be in proportion to that for covered. When, however, the engine and boiler openings are not entirely covered by the poop or quarter-deck or by a strong iron or steel deck-house, the allowance for erections should be I of that provided by the foregoing scale.

15. When a steam vessel is fitted with a top-gallant forecastle only, the reduction of freeboard is to be in accordance with the preceding paragraph for a poop not covering the engine and boiler openings and a forecastle of the same combined length.

When there is a short poop only, or a raised quarter-deck of a height not less than that laid down in paragraph 11, enclosed at the forward end with an efficient bulkhead and covering the engine and boiler openings, the deduction from the freeboard is to be half the allowance that is given for a poop or quarterdeck of the same character and a forecastle having the same combined length. When the poop or raised quarter-deck does not cover the engine and boiler openings of the foregoing allowance is to be given.

16. When the erections on a sailing vessel consist of a short poop and top-gallant forecastle only, the former enclosed at the fore-end with an efficient bulkhead, the deduction from the freeboard given in the tables should be according to the following scale:

When the combined length of the erection is:

of the length of the vessel, deduct 10 per cent of the reserve

buoyancy, or 12 per cent of the freeboard required for the flushdecked vessel after correction for length;

of the length of the vessel, deduct 8 per cent of the reserve buoyancy, or 10 per cent of the freeboard required for the vessel flush-decked after correction for length;

of the length of the vessel, deduct 6 per cent of the reserve buoyancy, or 8 per cent of the freeboard required for the vessel flush-decked after correction for length;

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 than of the length of the vessel is covered by erections, the allowance should be in proportion to that given for erections covering of the length.

17. When a sailing vessel is fitted with a top-gallant forecastle only, the reduction in reserve buoyancy should be one-half that prescribed by the previous paragraph for the case where, in addition to the forecastle, the vessel is fitted with a poop of the same length. 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.

18. SHEER.

The tables are framed for vessels having a mean sheer of deck measured at the side, as shown in the following table:

LENGTH OVER WHICH SHEER
IS MEASURED.

100 150 200 250 300 350 400

Mean Sheer in Inches Over the
Length Specified.

20 25

30 35 40 45 50

Flush-deck Vessels.-Sheer to be
measured abreast stem and
sternpost...
Vessels having short poops and fore-
castles.-Sheer to be measured
at points distant the length
of the vessel from each end..... 14 18
Vessels having short forecastles
only.-Sheer to be measured
abreast the sternpost and at a
point distant the length from
the stem..

22 26 30 34 38

14 18 23 27 31 35 40

(a) In flush-deck vessels and in vessels to which paras. 11 and 12 apply, when the sheer of deck is greater or less than the above and is of a gradual character, divide the difference in inches between it and the mean sheer provided for by 4 and the result in inches is the amount by which the freeboard amidships should be diminished or increased according as the sheer is greater or less. (b) In vessels having short poops and forecastles, and in those having short forecastles only, the freeboard should be corrected in respect of the excess or deficiency in reserve buoyancy due to variations in sheer from the standard amount over the length uncovered by substantial erections, as provided in the above table. One-fourth the difference between the mean sheer specified and that measured as described is approximately the amount by which the freeboard should be modified in respect of sheer.

(c) The divisor 4 is to be used when the sheer is of a gradual character, and is not strictly applicable either to those cases in which the sheer is suddenly increased at the bow or stern, or to those in which it does not maintain its normal rate of increase to the ends of the vessel.

(d) In all cases the rise in sheer forward and aft is measured with reference to the deck at the middle of the length, and where the lowest point of the sheer is abaft the middle of the length, one-half the difference between the sheer amidships and the lowest point should be added to the freeboard specified in the tables for flush-deck vessels and for vessels having short poops and forecastles only.

(e) Where, as in some instances, vessels fitted with long poops or raised quarter-decks connected with bridge-houses have the deck line rising rapidly from amidships to the front of the bridge, and from that point onwards gradually approaching the normal sheer line, the freeboard may be slightly modified in consideration of the increase of height of deck in the "well."

(f) In flush-deck vessels and in vessels having short poops and forecastles the excess of sheer for which an allowance is made shall not exceed one-half the total standard mean sheer for the size of the ship.

(g) No decrease should be made in the freeboard of spar- and awning-deck vessels, in respect of excess of sheer.

19. ROUND OF BEAM. In calculating the reserve of buoyancy an allowance has been made of one-quarter of an inch for every foot of the length of the midship beam for the round up. When the round of the beam in flush-decked vessels is greater than given by this rule divide the difference in inches by 2 and diminish or increase the freeboard by this amount. For vessels with erections on deck the amount of the allowance

4

should depend on the extent of the main deck uncovered. This rule for round of beam does not apply to spar- or awning-deck vessels.

20. As a general illustration of the way in which the tables should be used in modifying the freeboard on account of erections on deck, extreme proportions and variations in sheer, the following may be taken as an example.

A vessel is 234 ft. long, 29 ft. broad, and has a moulded depth of 17.0 ft., the coefficient of fineness being .72. Suppose the vessel to have a poop and bridge-house of the united length of 121 ft., and a forecastle 20 ft. in length, and let the sheer forward, measured at the side, be 4 ft. 6 ins., and aft, 2 ft. 1 in.

Freeboard by Tables A if of the normal
length, without erections, and with the
normal amount of sheer.

Ft. In.

2

11

The mean sheer by rule is 33.4 ins. or 6 ins.
less than that in the vessel, and the re-
duction in freeboard is 6 ins. divided by 4 0 11
Freeboard of vessel without erections and with
39 ins. mean sheer.

Freeboard by Tables C as awning-decked..

Difference

14

237

0 9:

2 0

The combined length of the erections is 11 or 1% of the length of the vessel, and the allowance for erections under clause 11 will be therefore of 24 ins., or 91⁄2 ins. We have therefore:

Amount deducted from freeboard for ex-
cess of sheer..

Deduct.

in.

11/

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Amount deducted if vessel be fitted with
an uncovered iron main deck (clause 6)
10 X 31.

2

13

The length being 30 ft. in excess of that
for which the tables are framed, the
addition to the freeboard in respect of
the same is one-half of 0 of 1.1 in., or

11⁄2

11

That is 11 ins. to be deducted from 2 ft. 11 ins., leaving a

winter freeboard of 1 ft. 11 in.

Corresponding summer freeboard, 1 ft. 9 ins.

21. Vessels loaded in fresh water may have less freeboard than that given in the several tables according to the following scale:

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MEMO.-The weight of a cubic foot of salt water is taken, in the above table, to be 64 lbs., and that of fresh water 62.5 lbs.

22. The freeboards assigned by the following tables are not intended to apply to vessels when navigating inland waters or rivers, and when a stretch of such water has to be traversed such deeper loading will be permissible as may be due to the weight of fuel required for consumption between the points of departure and the open sea.

23. The freeboards of vessels having ports, scuppers, or other openings in their sides is to be regulated by the following considerations. When the openings are in the nature of watertight ports for cargo, coals, etc., and are therefore not intended to be opened except in harbor, no modification of the freeboard as determined by the foregoing tables will be necessary, provided the covers of the openings are sufficiently strong and are efficiently secured. In the case, however, of vessels having scuppers through the sides from a 'tween deck space below the upper deck or side scuttles or other openings of a similar nature, when the freeboard as determined by the foregoing tables does not provide a sufficient height from the load-line to the sills of the side scuttles, or to the deck which is drained by the scuppers, th freeboard is to be increased; and the amount of the increase,

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