46 CFR § 35.30-10 - Cargo tank hatches, ullage holes, and Butterworth plates - TB/ALL.

§ 35.30-10 Cargo tank hatches, ullage holes, and Butterworth plates - TB/ALL.

No cargo tank hatches, ullage holes, or Butterworth plates shall be opened or shall remain open without flame screens, except under the supervision of the senior members of the crew on duty, unless the tank opened is gas free.