46 C.F.R. § 42.20-60 Deduction for superstructures and trunks.
Title 46 - Shipping
(a) Where the effective length of superstructures and trunks is 1.0L, the deduction from the freeboard shall be 14 inches at 79 feet length of vessel, 34 inches at 279 feet length, and 42 inches at 400 feet length and above; deductions at intermediate lengths shall be obtained by linear interpolation. (b) Where the total effective length of superstructures and trunks is less than 1.0L the deduction shall be a percentage obtained from Table 42.20–60(b)(1) or Table 42.20–60(b)(2): (c) For vessels of Type “B”: (1) Where the effective length of a bridge is less than 0.2L, the percentages shall be obtained by linear interpolation between lines I and II; (2) Where the effective length of a forecastle is more than 0.4L, the percentages shall be obtained from line II; and, (3) Where the effective length of a forecastle is less than 0.07L, the percentages in Table 42.20–60(b)(2) of this paragraph shall be reduced by: 5(0.07L−f)/0.07L
L is the length of vessel as defined in §42.13–15(a), f is the effective length of the forecastle. [CGFR 68–60, 33 FR 10065, July 12, 1968, as amended by CGFR 68–126, 34 FR 9015, June 5, 1969]
Title 46: Shipping
PART 42—DOMESTIC AND FOREIGN VOYAGES BY SEA
Subpart 42.20—Freeboards
§ 42.20-60 Deduction for superstructures and trunks.
Table 42.20-60(b)(1)_Percentage of Deduction For Type ``A'' Vessels---------------------------------------------------------------------------------------------------------------- Total effective length of superstructures and trunks ---------------------------------------------------------------------------- 0 0.1L 0.2L 0.3L 0.4L 0.5L 0.6L 0.7L 0.8L 0.9L 1.0L----------------------------------------------------------------------------------------------------------------Percentage of deduction for all 0 7 14 21 31 41 52 63 75.3 87.7 100 types of superstructures \1\......----------------------------------------------------------------------------------------------------------------\1\ Percentages at intermediate lengths of superstructures and trunks shall be obtained by linear interpolation.
Table 42.20-60(b)(2)_Percentage of Deduction for Type ``B'' Vessels [Percentage of deduction \1\]---------------------------------------------------------------------------------------------------------------- Total effective length of superstructures and trunks ----------------------------------------------------------------------------------- Line 0 0.1L 0.2L 0.3L 0.4L 0.5L 0.6L 0.7L 0.8L 0.9L 1.0L----------------------------------------------------------------------------------------------------------------Vessels with forecastle and I 0 5 10 15 23.5 32 46 63 75.3 87.7 100 without detached bridge....Vessels with forecasle and II 0 6.3 12.7 19 27.5 36 46 63 75.3 87.7 100 detached bridge............----------------------------------------------------------------------------------------------------------------\1\ Percentages at intermediate lengths of superstructures and trunks shall be obtained by linear interpolation.
