Section 27.203 - What are the requirements for fire detection on towing vessels?(a) You must have a fire detection system installed on your vessel to detect engine-room fires. Any owner of a vessel whose construction was contracted for before January 18, 2000, may use an existing engine-room-monitoring system (with fire detection capability) instead of a fire detection system, if the monitoring system is operable and complies with this section. You must ensure that-(1) Each detector, each control panel, and each fire alarm are approved under 46 CFR subpart 161.002 or listed by an independent testing laboratory; except that, if you use an existing engine-room-monitoring system (with fire detection capability), each detector must be listed by a nationally recognized testing laboratory (NRTL), as defined in 46 CFR 161.002-2 , for fire service;(2) The system is installed, tested, and maintained in line with the manufacturer's design manual;(3) The system is arranged and installed so a fire in the engine room automatically sets off alarms on a control panel at the operating station;(4) The control panel includes-(i) A power-available light;(ii) Both an audible alarm to notify crew at the operating station of fire and visible alarms to identify the zone or zones of origin of the fire;(iii) A means to silence the audible alarm while maintaining indication by the visible alarms;(iv) A circuit-fault detector test-switch; and(v) Labels for all switches and indicator lights, identifying their functions;(5) The system draws power from two sources, switchover from the primary source to the secondary source being either manual or automatic;(6) The system serves no other purpose, unless it is an engine-room-monitoring system (with fire detection capability) installed on a vessel whose construction was contracted for before January 18, 2000; and(7) The system is certified by a registered professional engineer, or by a recognized classification society (under 46 CFR part 8), to comply with paragraphs (a) introductory text and (a)(1) through (a)(6) of this section.(b) In spaces other than the engine room, non-approved fire detection systems may be acceptable as excess equipment provided that- (1) Components are listed by a nationally recognized testing laboratory (NRTL) as set forth in 29 CFR 1910.7 , and is designed, installed, tested, and maintained in accordance with an appropriate industry standard and the manufacturer's specific guidance; and(2) The system and units remain functional as intended.USCG-2000-6931, 69 FR 34069, June 18, 2004, as amended by USCG-2012-0196, 81 FR 48246, July 22, 2016