Review and Update of U.S. Coast Guard Vessel Stability Regulations and Guidance (2019)

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Appendix D Results of Lightship Weight Sensitivity Analysis for Selected Small Passenger Vessels 131

132 USCG VESSEL STABILITY REGULATIONS AND GUIDANCE 65 ft/179-Passengers Tour Boat FIGURE D-1 Subject vessel for hypothetical sensitivity study: 65 ft/179-passengers Subchapter T small passenger vessel.

APPENDIX D 133 TABLE D-1a 65 ft/179-Passengers Tour Boat—Vessel Particulars Vessel type: Aluminum, flush deck, single-chine hull, main deck cabin; open upper deck LBP (ft) 64.90 Beam (ft) 20.20 Depth (ft) 8.10 Draft (ft) 4.58 Lightship (LT) 26.85 VCG in Lightship condition (ft-ABL) 8.62 Least GM condition Full load departure Displacement in that condition (LT) 47.41 VCG (ft-ABL) corrected for F.S. 9.97 GM (ft) corrected for F.S. 7.59 NOTE: F.S. = free surface; ft = feet; ft-ABL = feet above baseline; GM = metacentric height; KM = height of metacenter above the keel; LBP = length between perpendiculars; LT = long ton(s); pct = percentage; VCG = vertical center of gravity.

134 USCG VESSEL STABILITY REGULATIONS AND GUIDANCE TABLE D-1b Summary Results of the Impact of Lightship Weight Growth on Intact and Damaged Stability on 65 ft/179-Passengers Subchapter T Small Passenger Vessel LOAD CONDITION Cond II Depart Cond II Depart Cond II Depart Cond III Return Cond III Return Cond III Return Intact Requirement As certified +2% of LS +3% of LS As certified +2% of LS +3% of LS 46 CFR § 171.050–Passenger heel GM > 3.50–4.00 FT 7.59 7.46 7.42 7.93 7.81 7.70 46 CFR § 170.170 (a)–Weather criterion GM > 4.20–4.80 FT 7.59 7.46 7.42 7.93 7.81 7.70 46 CFR § 170.173(e) Criterion for vessels of unusual proportion and form. (e) For the purpose of demonstrating…or the following criteria is required: (1) For partially protected routes, there must be (i) Positive righting arms to at least 35 degrees of heel; 37.50 37.50 >35 36.50 >35 >36 (ii) No downflooding point to at least 20 degrees; and 30.00 30.00 30.00 30.00 30.00 30.00 (iii) At least 15 foot-degrees of energy to the smallest of the following angles: (A) Angle of maximum righting arm. (GOVERNS) (B) Angle of downflooding. 15.27 15.00 14.91 15.08 14.85 14.75 (C) 40 degrees. Damaged 46 CFR § 171.080(f) requires vessels built after April 15, 1996, to meet the following criteria with any one compartment flooded: (1) Positive righting arms for a minimum range beyond equilibrium of 10 degrees (Partially protected waters/Great Lakes in summer) 22.73 23.01 (2) No downflooding point within the range in (1) above. (3) Area under righting arm curve of at least 0.015 meter-radians (2.82 ft-degrees) to the least of: (i) The angle of downflooding 7.33 7.80 (ii) The angle of vanishing stability (4) GZ (righting arm) = C × {[Heeling moment/Dips] + 0.131} ft (but not less than 0.328 ft) 0.51 0.53 (5) Not applicable to this vessel (6) Angle of equilibrium not to exceed (i) 7 degrees for flooding of one compartment; 0.00 0.00 (ii) 12 degrees for flooding of two compartments; or (remaining not applicable to this vessel) (7) The margin line must not be submerged when the vessel is in equilibrium 0.47 0.47 (8) and (9) Not applicable to this vessel Where GZwind = 0.75 × {[2.506 × 730 × 8.65]/[45 × 2240] + 0.131} = 0.216 Where GZpass = 0.75 × {[0.5 × 183 × 185 × 3.0]/[45 × 2240] + 0.131} = 0.476 GOVERNS NOTE: LS = lightship weight.

APPENDIX D 135 TABLE D-1b Summary Results of the Impact of Lightship Weight Growth on Intact and Damaged Stability on 65 ft/179-Passengers Subchapter T Small Passenger Vessel LOAD CONDITION Cond II Depart Cond II Depart Cond II Depart Cond III Return Cond III Return Cond III Return Intact Requirement As certified +2% of LS +3% of LS As certified +2% of LS +3% of LS 46 CFR § 171.050–Passenger heel GM > 3.50–4.00 FT 7.59 7.46 7.42 7.93 7.81 7.70 46 CFR § 170.170 (a)–Weather criterion GM > 4.20–4.80 FT 7.59 7.46 7.42 7.93 7.81 7.70 46 CFR § 170.173(e) Criterion for vessels of unusual proportion and form. (e) For the purpose of demonstrating…or the following criteria is required: (1) For partially protected routes, there must be (i) Positive righting arms to at least 35 degrees of heel; 37.50 37.50 >35 36.50 >35 >36 (ii) No downflooding point to at least 20 degrees; and 30.00 30.00 30.00 30.00 30.00 30.00 (iii) At least 15 foot-degrees of energy to the smallest of the following angles: (A) Angle of maximum righting arm. (GOVERNS) (B) Angle of downflooding. 15.27 15.00 14.91 15.08 14.85 14.75 (C) 40 degrees. Damaged 46 CFR § 171.080(f) requires vessels built after April 15, 1996, to meet the following criteria with any one compartment flooded: (1) Positive righting arms for a minimum range beyond equilibrium of 10 degrees (Partially protected waters/Great Lakes in summer) 22.73 23.01 (2) No downflooding point within the range in (1) above. (3) Area under righting arm curve of at least 0.015 meter-radians (2.82 ft-degrees) to the least of: (i) The angle of downflooding 7.33 7.80 (ii) The angle of vanishing stability (4) GZ (righting arm) = C × {[Heeling moment/Dips] + 0.131} ft (but not less than 0.328 ft) 0.51 0.53 (5) Not applicable to this vessel (6) Angle of equilibrium not to exceed (i) 7 degrees for flooding of one compartment; 0.00 0.00 (ii) 12 degrees for flooding of two compartments; or (remaining not applicable to this vessel) (7) The margin line must not be submerged when the vessel is in equilibrium 0.47 0.47 (8) and (9) Not applicable to this vessel Where GZwind = 0.75 × {[2.506 × 730 × 8.65]/[45 × 2240] + 0.131} = 0.216 Where GZpass = 0.75 × {[0.5 × 183 × 185 × 3.0]/[45 × 2240] + 0.131} = 0.476 GOVERNS NOTE: LS = lightship weight.

136 USCG VESSEL STABILITY REGULATIONS AND GUIDANCE 90 ft/340-Passengers Excursion Vessel FIGURE D-2 Subject vessel for hypothetical sensitivity study: 90 ft/340-passengers Subchapter K excursion/dinner boat vessel.

APPENDIX D 137 TABLE D-2a 90 ft/340-Passengers Excursion Vessel—Vessel Particulars Vessel type: Excursion. Steel, flush deck, single-chine hull, main deck cabin; open upper deck LBP (ft) 84.00 Beam (ft) 30.00 Depth (ft) 7.08 Draft (ft) 5.23 Lightship (LT) 116.66 VCG in Lightship condition (ft-ABL) 9.57 Least GM condition Full load departure Displacement in that condition (LT) 153.41 VCG (ft-ABL) corrected for F.S. 10.50 GM (ft) corrected for F.S. 11.43 NOTE: F.S. = free surface; ft = feet; ft-ABL = feet above baseline; GM = metacentric height; KM = height of metacenter above the keel; LBP = length between perpendiculars; LT = long ton(s); pct = percentage; VCG = vertical center of gravity.

138 USCG VESSEL STABILITY REGULATIONS AND GUIDANCE TABLE D-2b Summary Results of the Impact of Lightship Weight Growth on Intact and Damaged Stability on 90 ft/340-Passengers Subchapter K excursion/dinner boat vessel LOAD CONDITION FL Depart FL Depart FL Depart FL Depart 90% Burned Out 90% Burned Out 90% Burned Out Intact Requirement As certified +2% of LS +3% of LS +6% of LS As certified +3% of LS +6% of LS 46 CFR § 171.050–Passenger heel GM > 5.35–5.75 ft 11.43 11.40 11.27 11.13 11.42 11.26 11.12 46 CFR § 170.170 (a)–Weather criterion GM > 5.50–5.70 ft 11.43 11.40 11.27 11.13 11.42 11.26 11.12 46 CFR § 170.173(e) Criterion for vessels of unusual proportion and form. (e) For the purpose of demonstrating…or the following criteria is required: (1) For partially protected routes, there must be (i) Positive righting arms to at least 35 degrees of heel; 37.40 37.00 36.75 36.08 37.00 36.50 36.00 (ii) No downflooding point to at least 20 degrees; and 35.72 32.55 33.68 30.57 35.50 34.00 32.50 (iii) At least 15 foot-degrees of energy to the smallest of the following angles: (A) Angle of maximum righting arm. (GOVERNS) 17.36 16.70 16.47 15.68 17.46 16.56 15.90 (B) Angle of downflooding. (C) 40 degrees. Damaged 46 CFR § 171.080(f) requires vessels built after April 15, 1996, to meet the following criteria with any one compartment flooded: (1) Positive righting arms for a minimum range beyond equilibrium of 10 degrees (Partially protected waters/Great Lakes summer) 10.05 9.46 9.11 11.30 (2) No downflooding point within the range in (1) above. (3) Area under righting arm curve of at least 0.015 m-radians (2.82 ft-degrees) to the least of: (i) The angle of downflooding 8.88 7.99 7.45 11.30 (ii) The angle of vanishing stability (4) GZ (righting arm) = C × {[Heeling moment/Disp] + 0.131} ft (not less than 0.328 ft) 1.42 1.38 1.34 10.77 (5) Not applicable to this vessel (6) Angle of equilibrium not to exceed (i) 7 degrees for flooding of one compartment; 0.00 0.00 0.00 0.00 0.00 0.00 (ii) 12 degrees for flooding of two compartments; or (remaining not applicable to this vessel) (7) The margin line must not be submerged when the vessel is in equilibrium 0.41 0.00 0.30 0.51 (8) Not applicable to this vessel (9) Not applicable to this vessel NOTE: LS = lightship weight.

APPENDIX D 139 TABLE D-2b Summary Results of the Impact of Lightship Weight Growth on Intact and Damaged Stability on 90 ft/340-Passengers Subchapter K excursion/dinner boat vessel LOAD CONDITION FL Depart FL Depart FL Depart FL Depart 90% Burned Out 90% Burned Out 90% Burned Out Intact Requirement As certified +2% of LS +3% of LS +6% of LS As certified +3% of LS +6% of LS 46 CFR § 171.050–Passenger heel GM > 5.35–5.75 ft 11.43 11.40 11.27 11.13 11.42 11.26 11.12 46 CFR § 170.170 (a)–Weather criterion GM > 5.50–5.70 ft 11.43 11.40 11.27 11.13 11.42 11.26 11.12 46 CFR § 170.173(e) Criterion for vessels of unusual proportion and form. (e) For the purpose of demonstrating…or the following criteria is required: (1) For partially protected routes, there must be (i) Positive righting arms to at least 35 degrees of heel; 37.40 37.00 36.75 36.08 37.00 36.50 36.00 (ii) No downflooding point to at least 20 degrees; and 35.72 32.55 33.68 30.57 35.50 34.00 32.50 (iii) At least 15 foot-degrees of energy to the smallest of the following angles: (A) Angle of maximum righting arm. (GOVERNS) 17.36 16.70 16.47 15.68 17.46 16.56 15.90 (B) Angle of downflooding. (C) 40 degrees. Damaged 46 CFR § 171.080(f) requires vessels built after April 15, 1996, to meet the following criteria with any one compartment flooded: (1) Positive righting arms for a minimum range beyond equilibrium of 10 degrees (Partially protected waters/Great Lakes summer) 10.05 9.46 9.11 11.30 (2) No downflooding point within the range in (1) above. (3) Area under righting arm curve of at least 0.015 m-radians (2.82 ft-degrees) to the least of: (i) The angle of downflooding 8.88 7.99 7.45 11.30 (ii) The angle of vanishing stability (4) GZ (righting arm) = C × {[Heeling moment/Disp] + 0.131} ft (not less than 0.328 ft) 1.42 1.38 1.34 10.77 (5) Not applicable to this vessel (6) Angle of equilibrium not to exceed (i) 7 degrees for flooding of one compartment; 0.00 0.00 0.00 0.00 0.00 0.00 (ii) 12 degrees for flooding of two compartments; or (remaining not applicable to this vessel) (7) The margin line must not be submerged when the vessel is in equilibrium 0.41 0.00 0.30 0.51 (8) Not applicable to this vessel (9) Not applicable to this vessel NOTE: LS = lightship weight.

140 USCG VESSEL STABILITY REGULATIONS AND GUIDANCE 120-ft Vehicle Ferry Barge FIGURE D-3 Subject vessel for hypothetical sensitivity study: Passenger and vehicle ferry barge; Subchapter T; 149 passengers/24 autos/light trucks or 4 semitrailers.

APPENDIX D 141 TABLE D-3a 120-ft Vehicle Ferry Barge—Vessel Particulars Vessel type: Passenger/vehicle ferry barge; Subchapter T; 149 passengers/24 autos/light trucks or 4 semitrailers LBP (ft) 120.00 Beam (ft) 35.00 Depth (ft) 4.75 Draft (ft) 3.00 Lightship (LT) 127.69 VCG in Lightship condition (ft-ABL) 4.70 Least GM condition Maximum load: 3’–0” draft Displacement in that condition (LT) 302.00 VCG (ft-ABL) corrected for F.S. 8.69 GM (ft) corrected for F.S. 31.66 NOTE: F.S. = free surface; ft = feet; ft-ABL = feet above baseline; GM = metacentric height; KM = height of metacenter above the keel; LBP = length between perpendiculars; LT = long ton(s); pct = percentage; VCG = vertical center of gravity.

142 USCG VESSEL STABILITY REGULATIONS AND GUIDANCE TABLE D-3b Summary Results of the Impact of Lightship Weight Growth on Intact and Damaged Stability on Passenger/Vehicle Ferry Barge; Subchapter T; 149 Passengers/24 Autos/Light Trucks or 4 Semi-Trailers LOAD CONDITION MAXIMUM DECK LOAD—four 80,000 lb GVW trucks Intact Stability Criteria As certified +3% of LS +5% of LS +10% of LS 46 CFR § 171.050–Passenger heel GM = [(W/Δ)(2/3)(b)]/(tan(T)) = 1.68 ft 32.98 32.55 32.31 31.73 46 CFR § 170.170 (a)–Weather criterion GM = [PAH]/Wtan(T) = 0.09 ft 32.98 32.55 32.31 31.73 PFM 1-89(2) FOR PROTECTED WATERS (e) For the purpose of demonstrating acceptable stability…compliance with § 170.173 or the following criteria is required: (1) For Protected routes, there must be (i) Positive righting arms to at least 25 degrees of heel; over 40 over 40 over 40 over 40 (ii) No downflooding point to at least 15 degrees; and 15.04 15.00 14.68 14.41 (iii) At least 10 foot-degrees of energy to the smallest of the following angles: (A) Angle of maximum righting arm. (GOVERNS) 41.55 40.83 40.64 39.11 (B) Angle of downflooding. (C) 40 degrees. Damaged Stability Criteria 46 CFR § 171.080(f) requires vessels built after April 15, 1996, to meet the following criteria with any one compartment flooded: Note: For this analysis, only the values of the most critical compartment are given. (1) Positive righting arms for a minimum range beyond equilibrium of 5 degrees (Protected waters) 10.87 10.69 10.57 10.26 (2) No downflooding point within the range in (1) above. 10.87 10.69 10.57 10.26 (3) Area under righting arm curve of at least 0.015 meter-radians (2.82 ft-degrees) to the least of: (i) The angle of downflooding 24.76 23.54 22.74 20.8 (ii) The angle of vanishing stability (4) GZ = C × {[Heeling moment/Disp] + 0.131} ft (but not less than 0.328 ft) 3.596 3.5 3.39 3.184 (5) Not applicable to this vessel (6) Angle of equilibrium not to exceed (i) 7 degrees for flooding of one compartment; 0.00 0.00 0.00 0.00 (ii) 12 degrees for flooding of two compartments; or (remaining not applicable to this vessel) (7) The margin line must not be submerged when the vessel is in equilibrium 0.5 0.45 0.42 0.35 (8) Not applicable to this vessel (9) Not applicable to this vessel NOTE: GVW = gross vehicle weight; GZ = Righting Arm; lb = pound; LS = lightship weight.

APPENDIX D 143 TABLE D-3b Summary Results of the Impact of Lightship Weight Growth on Intact and Damaged Stability on Passenger/Vehicle Ferry Barge; Subchapter T; 149 Passengers/24 Autos/Light Trucks or 4 Semi-Trailers LOAD CONDITION MAXIMUM DECK LOAD—four 80,000 lb GVW trucks Intact Stability Criteria As certified +3% of LS +5% of LS +10% of LS 46 CFR § 171.050–Passenger heel GM = [(W/Δ)(2/3)(b)]/(tan(T)) = 1.68 ft 32.98 32.55 32.31 31.73 46 CFR § 170.170 (a)–Weather criterion GM = [PAH]/Wtan(T) = 0.09 ft 32.98 32.55 32.31 31.73 PFM 1-89(2) FOR PROTECTED WATERS (e) For the purpose of demonstrating acceptable stability…compliance with § 170.173 or the following criteria is required: (1) For Protected routes, there must be (i) Positive righting arms to at least 25 degrees of heel; over 40 over 40 over 40 over 40 (ii) No downflooding point to at least 15 degrees; and 15.04 15.00 14.68 14.41 (iii) At least 10 foot-degrees of energy to the smallest of the following angles: (A) Angle of maximum righting arm. (GOVERNS) 41.55 40.83 40.64 39.11 (B) Angle of downflooding. (C) 40 degrees. Damaged Stability Criteria 46 CFR § 171.080(f) requires vessels built after April 15, 1996, to meet the following criteria with any one compartment flooded: Note: For this analysis, only the values of the most critical compartment are given. (1) Positive righting arms for a minimum range beyond equilibrium of 5 degrees (Protected waters) 10.87 10.69 10.57 10.26 (2) No downflooding point within the range in (1) above. 10.87 10.69 10.57 10.26 (3) Area under righting arm curve of at least 0.015 meter-radians (2.82 ft-degrees) to the least of: (i) The angle of downflooding 24.76 23.54 22.74 20.8 (ii) The angle of vanishing stability (4) GZ = C × {[Heeling moment/Disp] + 0.131} ft (but not less than 0.328 ft) 3.596 3.5 3.39 3.184 (5) Not applicable to this vessel (6) Angle of equilibrium not to exceed (i) 7 degrees for flooding of one compartment; 0.00 0.00 0.00 0.00 (ii) 12 degrees for flooding of two compartments; or (remaining not applicable to this vessel) (7) The margin line must not be submerged when the vessel is in equilibrium 0.5 0.45 0.42 0.35 (8) Not applicable to this vessel (9) Not applicable to this vessel NOTE: GVW = gross vehicle weight; GZ = Righting Arm; lb = pound; LS = lightship weight.