Title 46

SECTION 144.155

144.155 Verification of compliance with design standards for a sister vessel.

§ 144.155 Verification of compliance with design standards for a sister vessel.

(a) Verification of compliance required by § 144.135 is not required for a sister vessel, provided that:

(1) The original vessel has been verified as complying with this part;

(2) The owner authorizes the use of the plans for the original vessels for the new construction of the sister vessel;

(3) The standards used in the design and construction of the original vessel have not changed since the original verification of compliance;

(4) The sister vessel is built to the same verified plans, drawings, schematics, calculations, and other documents and equipped with machinery of the same make and model as the original vessel, and has not been subsequently modified;

(5) The sister vessel is built in the same shipyard facility as the original vessel; and

(6) For a sister vessel subject to a stability standard, that the conditions in Table 144.155 of this section are met:

Table 144.155

If - Then -
(i) The delivery date of the sister vessel is not more than 2 years after a previous stability test date of either the original vessel or an earlier sister vessel, The approved lightweight characteristics of that earlier vessel are adopted by the sister vessel;
(ii) Paragraph (a)(6)(i) of this section does not apply, and the lightweight characteristics determined from a deadweight survey of the sister vessel are shown to meet both the following criteria:
(A) the lightweight displacement differs by not more than 3 percent of the earlier vessel's lightweight displacement, and
(B) the longitudinal center of gravity (LCG) differs by not more than 1 percent of the length between perpendiculars (LBP) of the earlier vessel's LCG,
The vertical center of gravity (VCG) of the earlier vessel is adopted by the sister vessel and used with the lightweight displacement and LCG determined from the deadweight survey of the sister vessel;
(iii) Neither paragraph (a)(6)(i) nor (ii) of this section apply because both the criteria in paragraphs (a)(6)(ii)(A) and (B) of this section are not met and lightweight characteristics were determined from a stability test on either the original vessel or a sister vessel, The vessel must undergo a stability test in accordance with 46 CFR part 170, subpart F;
(iv) No vessel of the class of sister vessels previously underwent a stability test, One vessel of the class must undergo a stability test in accordance with 46 CFR part 170, subpart F, and each sister vessel to which a stability standard applies must meet either paragraph (a)(6)(ii) or (iii) of this section.

(b) A statement that verifies sister vessel status for each element of paragraph (a) of this section from an individual or entity meeting the requirements of § 144.140 must be retained and produced upon request.