Section 157.10c - Segregated ballast tanks, crude oil washing systems, and dedicated clean ballast tanks for certain new and existing tankships of 20,000 to 40,000 DWT(a) This section applies to each tankship of 20,000 DWT or more, but less then 40,000 DWT, except each one that- (1) Is constructed under a building contract awarded after June 1, 1979;(2) In the absence of a building contract, has the keel laid or is at a similar stage of construction after January 1, 1980;(3) Is delivered after June 1, 1982; or(4) Has undergone a major conversion, for which-(i) The contract is awarded after June 1, 1979; or(ii) Conversion is completed after June 1, 1982.(b) On January 1, 1986, or 15 years after the date it was delivered to the original owner or 15 years after the completion of a major conversion, whichever is later, a vessel under this section that carries crude oil must have-(1) Segregated ballast tanks that have a total capacity to allow the vessel to meet the draft and trim requirements in § 157.09(b) ; or(2) A crude oil washing system that meets the design, equipment, and installation requirements of §§ 157.122 through 157.138 .(c) On January 1, 1986, or 15 years after the date it was delivered to the original owner or 15 years after the completion of a major conversion, whichever is later, a vessel under this section that carries product must have- (1) Segregated ballast tanks that have total capacity to allow the vessel to meet the draft and trim requirements in § 157.09(b) ; or(2) Dedicated clean ballast tanks that meet the design and equipment requirements under §§ 157.220 , 157.222 , and 157.224 and have total capacity to allow the vessel to meet the draft and trim requirements in § 157.09(b) .(d) If the arrangement of tanks on a vessel under this section is such that, when using the tankage necessary to comply with the draft and trim requirements in § 157.09(b) , the draft amidships exceeds the minimum required draft by more the 10 percent, or the arrangement results in the propeller being fully immersed by more than 10 percent of its diameter, alternative arrangements may be accepted provided- (1) At least 80 percent of the propeller diameter is immersed; and(2) The moulded draft amidships is at least 80 percent of that required under § 157.09(b)(1) .CGD 82-28, 50 FR 11626, Mar. 22, 1985; 50 FR 12800, Apr. 1, 1985