Editorial Note on Part 157
Editorial Note: Nomenclature changes to part 157 appear by USCG-2008-0179, 73 FR 35015, June 19, 2008.

§ 157.155 COW operations: General. ( a ) The master of a tank vessel having a COW system under § 157.10(e), § 157.10a(a)(2), or 157.10c(b)(2) shall ensure that— ( 1 ) Before crude oil washing a cargo tank, the level in each tank with crude oil that is used as a source for crude oil washing is lowered at least one meter;
( 2 ) A tank used as a slop tank is not used as a source for crude oil washing until: ( i ) Its contents are discharged ashore or to another tank; and
( ii ) The tank contains only crude oil;
( 3 ) During COW operations: ( i ) The valves under § 157.122(i)(1) are shut; or
( ii ) The blanks under § 157.122(i)(2) are installed;
( 4 ) The rotation of each COW machine mounted to or close to the bottom of each cargo tank is verified by: ( i ) A visual inspection of a means located outside of the cargo tank that indicates movement of the machine during COW operations;
( ii ) An audio inspection during COW operations; or
( iii ) An inspection on a ballast voyage, with water as the fluid flowing through the machine;
( 5 ) During the audio inspection under paragraph (a)(4)(ii) of this section, the COW machine being inspected is the only one operating in that tank;
( 6 ) Before the inspection under paragraph (a)(4)(iii) of this section, the tank that has the COW machine being inspected in it, is gas freed;
( 7 ) Each COW machine that is inspected under paragraph (a)(4)(iii) of this section is inspected at least once after every sixth COW operation of that machine, but no less that once every 12 months;
( 8 ) After each stripping operation is completed, each tank: ( i ) Is sounded by a means under § 157.128(b); and
( ii ) Contains no oil except a minimal quantity near the stripping suction;
( 9 ) Before the tank vessel begins each ballast voyage, each cargo tank and each cargo main, stripping, and COW piping is stripped of crude oil and the strippings are conveyed ashore through the piping under § 157.11(d)(3) or § 157.11(e)(4);
( 10 ) Before water washing the cargo tanks, the piping of the COW system is drained of crude oil;
( 11 ) When the cargo tanks are not being water washed, the hydrant valves under § 157.122(g) are blanked off;
( 12 ) If COW machines that are used as anchors for the piping of the COW system are removed, the means available under § 157.122(l) for anchoring the piping are installed;
( 13 ) The fire main is not connected to the COW system; and
( 14 ) On combination carriers, if flexible hoses under § 157.122(o) are used, those hoses are protectively stowed when not installed in the COW piping system.
( b ) In addition to meeting paragraph (a) of this section, the master of a tank vessel having a COW system under § 157.10a(a)(2) or § 157.10c(b)(2) shall ensure that— ( 1 ) Before ballasting cargo tanks upon leaving a port, each cargo pump, manifold, and piping that is used for ballasting the cargo tanks is drained of all crude oil; and
( 2 ) Before ballasting or deballasting cargo tanks, except when ballasting cargo tanks to leave a port, the cargo piping that is used for ballasting or deballasting the cargo tanks is water washed.
[CGD 77-058b, 45 FR 43709, June 30, 1980, as amended by CGD 82-28, 50 FR 11628, Mar. 22, 1985]