46 CFR 113.30-20 – General requirements
(a) The communications stations listed in § 113.30-5(a) through (d), (f), (g), and (i) and other communications stations for the operation of the vessel, such as the captain’s and chief engineer’s offices and staterooms, emergency power room, carbon dioxide (or other extinguishing agent) control room, and firepump room, must not be on the same circuit as communications stations installed to meet the requirements of §§ 113.30-5(e) and 113.30-5(h).
(b) If a communications station is in the weather and on the same circuit as other required stations, there must be a cut-out switch on the navigating bridge that can isolate this station from the rest of the stations, unless the system possesses other effective means of station isolation during a fault condition.
(c) No jack-box or headset may be on a communication system that includes any station required by this subpart, except for a station installed to meet 46 CFR 113.30-5(h) or 46 CFR 113.30-25(f).