{"data":{"id":"us/46-cfr-154.459","jurisdiction":"us","citation":"46 CFR 154.459","heading":"General.","body":"(a) Each cargo tank must have a secondary barrier that meets Table 3 and except as allowed in Table 3, the hull must not be the secondary barrier.\n(b) If the Commandant (CG-ENG) specially approves an integral tank for a design temperature at atmospheric pressure lower than −10 °C (14 °F), the integral tank must have a complete secondary barrier that meets § 154.460.\n(c) If the Commandant (CG-ENG) specially approves a semi-membrane tank under the requirements of an independent tank type B, the semi-membrane tank may have a partial secondary barrier specially approved by the Commandant (CG-ENG).\n(d) If Table 3 allows the hull to be a secondary barrier, the vessel's hull must:\n(1) Meet §§ 154.605 through 154.630; and\n(2) Be designed for the stresses resulting from the design temperature.\nTable 3—Secondary Barriers for Tanks\nTank type Cargo temperature (T) at atmospheric pressure\nT≥−10 °C (14 °F) T\u003c-10 °C (14 °F)≥55 °C (−67 °F) T\u003c−55 °C (−67 °F)\nIntegral No secondary barrier required Tank type not usually allowed 1 Tank type not allowed.\nMembrane ......do Complete secondary barrier 1 Complete secondary barrier.\nSemi-membrane ......do ......do Do.\nIndependent:\nType A ......do ......do Do.\nType B ......do Partial secondary barrier 1 Partial secondary barrier.\nType C ......do No secondary barrier required No secondary barrier required.\n1 The hull may be a secondary barrier.","path":["Title 46—Shipping","CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY","SUBCHAPTER O—CERTAIN BULK DANGEROUS CARGOES","PART 154—SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES","Subpart C—Design, Construction and Equipment"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-46.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:22Z","sha256":"640b12c2361bf79e4ceb135c42d1bbf34c6e5655048cca650736fcc167604c38","source_id":"us-cfr","stale":true,"prev":"us/46-cfr-154.453","next":"us/46-cfr-154.460"},"notice":"GroundRules: Original legal text. Not legal advice."}