PART IVLoad Lines for Sailing Ships.
RULE LXVIIILines to be Used in Connection with the Disc.
Winter and Tropical load lines are not marked on sailing ships. The maximum load line to which sailing ships may be laden in salt water in Winter and in the Tropical Zone is the centre of the disc (see Figure 3).
RULE LXIXConditions of Assignment of Load Line.
The conditions of assignment are those contained in Part II of these Rules.
RULE LXXComputation of Freeboard.
Freeboards are computed from the Freeboard Table for Sailing Ships in the same manner as the freeboards for steamers are computed from the Freeboard Table for Steamers, except as follows:—
RULE LXXIDepth for Freeboard (D).
In sailing ships having a greater rate of rise of floor than 1 ½ inches per foot, the vertical distance from the top of keel (Rule XXXIV), is reduced by half the difference between the total rise of floor at the half-breadth of the ship and the total rise at 1 ½ inches per foot. 2 ½ inches per foot of half-breadth is the maximum rate of rise for which a deduction is made.
Where the form at the lower part of the midship section is of a hollow character, or thick garboards are fitted, the depth is measured from the point where the line of the flat of the bottom continued inwards cuts the side of the keel.
The depth used with the Freeboard Table is to be taken as not L less than 
RULE LXXIICoefficient of Fineness (c).
The coefficient used with the Freeboard Table is to be taken as not less than .62 and not greater than .72.
RULE LXXIIISuperstructures in Wood Ships.
In wood ships the construction and closing arrangements of superstructures for which deductions are made from the freeboard are to be to the satisfaction of the Assigning Authority Rule LXXIV
Deductions for Superstructures.
Where the effective length, pi superstructures is 1.0 L, the deduction from the freeboard is 8 inches at 80 feet length of ship, and 28 inches at 330 feet length and above; deductions at intermediate lengths are obtained by interpolation. Where the total effective length of superstructures is less than 1.0 L, the deduction is a percentage obtained from the following Table :—
| Type of Superstructures. | Total Effective Length of Superstructures (E). | Line. | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | .1 L | .2 L | .3L | .4L | .5L | .6L | .7 L | .8L | .9L | 1.0L | ||
* Where the effective length of Bridge is less than .2 L, the percentages are obtained by interpolation between lines B and A. Percentages for intermediate lengths of superstructures are obtained by interpolation. | ||||||||||||
| % | % | % | % | % | % | % | % | % | % | % | ||
| All types without Bridge | 0 | 7 | 13 | 17 | 23.5 | 30 | 47 ½ | 70 | 80 | 90 | 100 | A |
| All types with Bridge* | 0 | 7 | 14.7 | 22 | 32 | 42 | 56 | 70 | 80 | 90 | 100 | B |
RULE LXXVMinimum Freeboards.
No addition to the freeboard is required for Winter freeboard, nor is a deduction permitted for Tropical freeboard.
An increase in freeboard of 3 inches is made for voyages across the North Atlantic North of latitude 36° N. during the winter months.
In computing the fresh water freeboard for a wood ship, the draught is measured from the lower edge of the rabbet of keel to the centre of the disc.
RULE LXXVIFreeboard Table for Sailing Ships.
Minimum Summer, Winter, and Tropical Freeboards for Iron and Steel Flush Deck Sailing Ships, which comply with the Standards laid down in the Rules.
| L. | Freeboard. |
|---|---|
| Feet. | Inches. |
| 80 | 9.2 |
| 90 | 110 |
| 100 | 12.9 |
| 110 | 14.9 |
| 120 | 17.0 |
| 130 | 19.1 |
| 140 | 21.3 |
| 150 | 23.5 |
| 160 | 25.8 |
| 170 | 28.2 |
| 180 | 30.6 |
| 190 | 33.0 |
| 200 | 35.4 |
| 210 | 37.9 |
| 220 | 40.4 |
| 230 | 42.9 |
| 240 | 45.5 |
| 250 | 48.1 |
| 260 | 50.8 |
| 270 | 53.5 |
| 280 | 56.3 |
| 290 | 59.1 |
| 300 | 61.9 |
| 310 | 64.7 |
| 320 | 67.6 |
| 330 | 70.5 |
(i)The freeboards at; intermediate lengths are obtained by interpolation.
(ii)Where c exceeds .62, the freeboard is multiplied by the factor 
(iii)Where D exceeds 
(iv)Where the actual depth to the surface of the freeboard deck amidships is greater or less than D, the difference between the depths (in inches) is added to or deducted from the freeboard.
RULE LXXVIIFreeboard for Wood Sailing Ships.
The freeboard for a wood sailing ship is the final freeboard the ship would obtain if she were of iron and steel, with the addition of such penalties as the Assigning Authority may determine, having regard to the classification, construction, age and condition of the ship.
Wood ships of primitive build such as dhows, junks, prahus, &c, are to be dealt with by the Administration so far as is reasonable and practicable under the Rules for Sailing Ships.