(a) A cargo tank must have at least one covered manhole opening into the vapor space described in § 153.354.
(b) An access through a vertical cargo tank surface must be at least 60 cm by 80 cm (approx. 23.6 × 31.5 in.) and no more than 60 cm above a foothold grating, or surface on both sides of the access way.
(c) An access through a horizontal cargo tank surface must be at least 60 cm by 60 cm (approx. 23.6 × 23.6 in.).
(d) An access trunk must be no less than 76 cm (approx. 29.9 in.) in diameter.
authority: 46 U.S.C. 3703; Department of Homeland Security Delegation No. 0170.1. Section 153.40 issued under
49 U.S.C. 5103. Sections 153.470 through 153.491, 153.1100 through 153.1132, and 153.1600 through 153.1608 also issued under
33 U.S.C. 1903 (b)
source: CGD 73-96, 42 FR 49027, Sept. 26, 1977, unless otherwise noted.
cite as: 46 CFR 153.254