(a) Except as provided in paragraphs (b) through (g) of this section, each tank vessel must undergo drydock, internal structural, and cargo tank internal examinations as follows:
(1) Except under paragraph (a)(2) of this section, vessels that operate in salt water must be inspected in accordance with the intervals set forth in table 31.10-21(a). Where table 31.10-21(a) indicates a 2.5 year examination interval, it means a vessel must undergo two examinations within any five year period. No more than three years may elapse between any two examinations. [GRAPHIC] [TIFF OMITTED] TR30JY96.000
(2) Vessels that operate in fresh water at least six months in every 12 month period since the last drydock examination must be examined in accordance with the intervals set forth in table 31.10-21(b). Where table 31.10-21(b) indicates a 2.5 year examination interval, it means a vessel must undergo two examinations within any five year period. No more than three years may elapse between any two examinations.[GRAPHIC] [TIFF OMITTED] TR30JY96.001
(b) During each inspection or reinspection for certification, all wing voids, rakes, cofferdams, and other void spaces on tank barges must be opened and checked from on-deck for the presence of water or cargo indicating hull damage or cargo tank leakage. If water or cargo is not present, these spaces need not be gas freed, ventilated, cleaned, or otherwise prepared for personnel entry. If water or cargo is present, an internal structural examination may be required.
(c) If, during an internal structural examination, cargo tank internal examination, or underwater survey, damage or deterioration to the hull plating, structural members, or cargo tanks is discovered, the Officer in Charge, Marine Inspection, may require the vessel to be drydocked or otherwise taken out of service to further assess the extent of the damage and to effect permanent repairs.
(d) Vessels less than 15 years of age (except wooden hull vessels) that are in salt water service with a 2.5 year drydock interval (as indicated in table 31.10-21(a) of this section) or that are in fresh water service with a five year drydock interval (as indicated in table 31.10-21(b) of this section) may be considered for an underwater survey instead of alternate drydock examinations, provided the vessel is fitted with an effective hull protection system. Vessel owners or operators must apply to the Officer in Charge, Marine Inspection, for approval of underwater surveys instead of alternate drydock examinations for each vessel. The application must include the following information:
(1) The procedure to be followed in carrying out the underwater survey.
(2) The location where the underwater survey will be accomplished.
(3) The method to be used to accurately determine the diver location relative to the hull.
(4) The means that will be provided for examining through-hull fittings.
(5) The means that will be provided for taking shaft bearing clearances.
(6) The condition of the vessel, including the anticipated draft of the vessel at the time of the survey.
(7) A description of the hull protection system.
(e) Vessels otherwise qualifying under paragraph (d) of this section, that are 15 years of age or older may be considered for continued participation in or entry into the underwater survey program on a case-by-case basis, if--
(1) Before the vessel's next scheduled drydocking, the owner or operator submits a request for participation or continued participation to Commandant (CG-CVC);
(2) During the vessel's next drydocking after the request is submitted, no appreciable hull deterioration is indicated as a result of a complete set of hull gaugings; and
(3) The results of the hull gauging and the results of the Coast Guard drydock examination together with the recommendation of the Officer in Charge, Marine Inspection, are submitted to Commandant (CG-CVC) for final approval.
(f) Each vessel which has not met with the applicable examination schedules in paragraphs (a) through (e) of this section because it is on a voyage, must undergo the required examinations upon completion of the voyage.
(g) The Commandant (CG-CVC) may authorize extensions to the examination intervals specified in paragraph (a) of this section. [CGD 84-024, 52 FR 39649, Oct. 23, 1987, as amended at 53 FR 32230, Aug. 24, 1988; 53 FR 34872, Sept. 8, 1988; CGD 95-072, 60 FR 50461, Sept. 29, 1995; CGD 91-045, 61 FR 39792, July 30, 1996; CGD 96-041, 61 FR 50726, Sept. 27, 1996; CGD 95-028, 62 FR 51198, Sept. 30, 1997; USCG-2009-0702, 74 FR 49226, Sept. 25, 2009] Sec. 31.10-21a Periodic gauging of tank vessel midbodies more than30 years old that carry certain oil cargoes--TB/ALL.
(a) As used in this section, the term ``midbody'' means the 40-percent midship length (0.40L) of the tank vessel. The age of the midbody is determined from its year of original construction.
(b) Midbodies of all tank vessels certificated to carry a pollution category I oil cargo listed in 46 CFR table 30.25-1 must undergo an initial gauging survey and periodic regauging surveys as follows:
(1) An initial midbody gauging survey must be accomplished no later than the next drydocking inspection after the midbody becomes 30 years old.
(2) Regaugings:
(i) Midbodies of double hull tank vessels, or single hull tank vessels with independent tanks, that operated in fresh water at least 6 months in every 12-month period since the last drydock examination must be regauged at intervals not exceeding 10 years;
(ii) Midbodies of all other tank vessels must be regauged at intervals not exceeding 5 years.
(c) The midbody gauging survey must be comprised of at least three transverse (girth) belts of deck, bottom, side, inner hull, trunk, and longitudinal bulkhead plating and attached longitudinal members. The number and specific locations of the gauging points shall be to the satisfaction of the Officer in Charge of Marine Inspection (OCMI).
(d) Except as provided in paragraph (f) of this section, within 60 days of the vessel's required compliance date the owner or operator shall submit the following to the OCMI that issued the vessel's current Certificate of Inspection:
(1) The gauging survey results.
(2) An engineering analysis signed by a registered Professional Engineer licensed by any state of the United States or the District of Columbia, or signed by a Coast Guard-approved organization, that--
(i) Certifies the vessel's compliance with the minimum section modulus and plating thickness requirements of subpart 32.59 of this chapter; or
(ii) Proposes structural repairs and/or modifications that will bring the vessel up to the required strength standards.
(e) The vessel owner or operator shall keep a permanent copy of the Coast Guard-approved gauging report available for inspection by the OCMI.
(f) Instead of the submittals required by paragraphs (c) and (d) of this section, current classification with the American Bureau of Shipping or another recognized classification society, or a load line certificate issued in accordance with the International Convention on Load Lines or the International Voyage Load Line Act, may be submitted as evidence of compliance with the requirements of this section. [CGD 91-209, 58 FR 52602, Oct. 8, 1993]