46 CFR § 170.090 - Calculations.

§ 170.090 Calculations.

(a) All calculations required by this subchapter must be submitted with the plans required by § 170.075 of this subpart. Calculations must account for the weight of all loads carried aboard the vessel.

(b) If it is necessary to compute and plot any of the following curves as part of the calculations required in this subchapter, these plots must also be submitted:

(1) Righting arm or moment curves.

(2) Heeling arm or moment curves.

(3) Cross curves of stability.

(4) Floodable length curves.

(c) The assumed weight per person for calculations showing compliance with the regulations of this subchapter must be representative of the passengers and crew aboard the vessel while engaged in the service intended. Unless the Officer in Charge, Marine Inspection (OCMI) permits or requires the use of other values in writing, the assumed weight per person of passengers and crew must not be less than that the Assumed Average Weight per Person (AAWPP) calculated in accordance with paragraphs (d) and (e) of this section.

(d)

(1) The AAWPP is 185 lb from December 1, 2011 until the AAWPP is first updated pursuant to the provisions of this section. As of the effective date of the first AAWPP update after December 1, 2011, this paragraph (d)(1) will be superseded and cease to be effective.

(2) The formula in paragraph (e) of this section will be used to determine an update to the AAWPP. It requires the use of data in the most recent report released by the Centers for Disease Control and Prevention (CDC) through the National Center for Health Statistics (NCHS), or any successors to those centers. This report can be found on the CDC's Web site.

(3) Each time the CDC releases a report containing mean weights of United States adult males and females, the Coast Guard will apply the formula in paragraph (e) of this section to that data. The resulting value will become the new AAWPP only if the sum equals or exceeds 10 pounds more than the AAWPP then in effect. The Coast Guard will notify the public of the new AAWPP in the Federal Register and other appropriate media.

(4) Updates to the AAWPP used in calculations showing compliance with this subchapter will be promulgated as interpretive rules and become effective in accordance with the provisions of this section without further rulemaking procedures.

(5) Notwithstanding any other provisions of this section, the Coast Guard may choose, in its discretion, to conduct further rulemaking procedures at any time to amend this subchapter, including updates of the AAWPP.

(6) Updates to the AAWPP used in calculations showing compliance with this subchapter will be published in a separate Federal Register notice and other appropriate media, except when the Coast Guard conducts further rulemaking procedures under paragraph (d)(5) of this section.

(7) Notwithstanding any other provisions of this section, the Coast Guard may choose, in its discretion, to delay or dispense with any update of the AAWPP. In the event the Coast Guard elects to dispense with or delay an update that would otherwise issue as an interpretive rule pursuant to the provisions of this section, the Coast Guard will inform the public of the decision and explain the reasons in a Federal Register notice.

(e) To obtain an AAWPP update, add the mean weight of all U.S. males aged 20 years and older to the mean weight of all U.S. females aged 20 years and older, and divide the sum by 2. To this average of the mean weights, add 7.5 pounds of assumed clothing weight, and round the resulting sum to the nearest whole number in pounds.

(f) Updates to the AAWPP will become effective beginning one calendar year after publication in the Federal Register of a notice described in paragraphs (d)(3) and (d)(6) of this section, except the initial AAWPP issued pursuant to paragraph (d)(1) of this section will become effective on December 1, 2011. Notwithstanding any other provisions of this title, the Coast Guard may implement updates to the AAWPP at any time with less than one year of public notice when required for public safety reasons.

(g) The most recent Federal Register notice that publishes the AAWPP as determined by this section is also on file at the Coast Guard Headquarters. Contact Commandant (CG–ENG–2), Attn: Naval Architecture Division, U.S. Coast Guard Stop 7509, 2703 Martin Luther King Jr. Avenue SE., Washington, DC 20593–7509, or go to: http://www.uscg.mil/hq/cg5/cg5212

[CGD 79–023, 48 FR 51010, Nov. 4, 1983, as amended by USCG–2007–0030, 75 FR 78083, Dec. 14, 2010; 76 FR 16698, Mar. 25, 2011; USCG–2012–0832, 77 FR 59788, Oct. 1, 2012; USCG–2013–0671, 78 FR 60163, Sept. 30, 2013]