CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER D—TANK VESSELS (parts 30 to 39) > PART 39—VAPOR CONTROL SYSTEMS > SUBPART 39.20—Design and Equipment (§39.20-1 to §39.20-13) > 39.20-3—Cargo gauging system—TB/ALL.

39.20-3—Cargo gauging system—TB/ALL.

(a) Each cargo tank of a tank vessel that is connected to a vapor collection system must be equipped with a cargo gauging device which:
(1) Provides a closed gauging arrangement as defined in § 151.15.10 of this chapter that does not require opening the tank to the atmosphere during cargo transfer;
(2) Allows the operator to determine the liquid level in the tank for the full range of liquid levels in the tank;
(3) Indicates the liquid level in the tank at the location where cargo transfer is controlled; and
(4) If portable, is installed on the tank during the entire transfer operation.
(b) Except when a tank barge complies with § 39.20-9(a) of this part, each cargo tank of a barge must have a high level indicating device that:
(1) Provides a visual indication of the liquid level in the cargo tank when the cargo level is within 1.0 meter (3.28 feet) of the tank top;
(2) Has the maximum liquid level permitted under § 39.30-1(e) of this part at even keel conditions conspicuously and permanently marked on the indicating device; and
(3) Is visible from all cargo control areas on the tank barge.