46 C.F.R. Subpart 112.05—General
Title 46 - Shipping
(a) The purpose of this part is to ensure a dependable, independent, and dedicated emergency power source with sufficient capacity to supply those services that are necessary for the safety of the passengers, crew, and other persons in an emergency and those additional loads that may be authorized under paragraph (c) of this section. (b) No load may be powered from an emergency power source, except: (1) A load required by this part to be powered from the emergency power source; (2) A bus-tie to the main switchboard that meets §112.05–3; and (3) Emergency loads that may be necessary to maintain or restore the propulsion plant, such as control systems, controllable pitch propellers, hydraulic pumps, control air compressors, and machinery necessary for dead-ship start-up. (c) Other loads may be authorized by the Commanding Officer, Marine Safety Center (MSC), to be connected to the emergency source of power to provide an increased level of safety in recognition of a unique vessel mission or configuration. When these loads are authorized, the emergency power source must— (1) Be sized to supply these loads using a unity (1.0) service factor; or (2) Be provided with automatic load shedding that removes these loads and operates before the emergency generator trips due to overload. The automatic load shedding circuit breakers must be manually reset. [CGD 74–125A, 47 FR 15267, Apr. 8, 1982, as amended by CGD 94–108, 61 FR 28286, June 4, 1996; 61 FR 36787, July 12, 1996] Each bus-tie between a main switchboard and an emergency switchboard must: (a) Disconnect automatically upon loss of potential at the emergency switchboard; (b) Be arranged to prevent parallel operation of an emergency power source with any other source of electric power, except for interlock systems for momentary transfer of loads; and (c) If arranged for feedback operation, open automatically upon overload of the emergency power source before the emergency power source is tripped off the line from the overload. (a) The emergency power source must meet table 112.05–5(a) and have the capacity to supply all loads that are simultaneously connected to it, except a load on a bus-tie to the main switchboard or non-required loads that are connected in accordance with §112.05–1(c). (b) The emergency power source must be independent of the ship's service lighting and powerplant and propulsion plant, except for the compressed air starting means allowed in §112.50–7(c)(3)(i). A stop control for an emergency generator must be only in the space that has the emergency generator, except a remote mechanical reach rod is permitted for the fuel oil shut-off valve to an independent fuel oil tank located in the space. (c) The complete emergency installation must function at full rated power when the vessel is upright or inclined to the maximum angle of heel that results from the assumed damage defined in 33 CFR part 155 or in subchapter S of this chapter for the specific vessel type or 22.5 degrees, whichever is greater; when the trim of the ship is 10 degrees, either in the fore or aft direction, or is in any combination of angles within those limits. (d) The emergency power source, its associated transforming equipment, and the emergency switchboard must be located aft of the collision bulkhead, outside of the machinery casing, and above the uppermost continuous deck. Each compartment containing this equipment must be readily accessible from the open deck and must not contain machinery not associated with, or equipment not in support of, the normal operation of the emergency power source. Equipment in support of the normal operation of the emergency power source includes, but is not limited to, ventilation fans, CO2 bottles, space heaters, and internal communication devices, such as sound powered phones. (e) No compartment that has an emergency power source or its vital components may adjoin a Category A machinery space or those spaces containing the main source of electrical power and its vital components. (f) Except for a cable for connecting equipment in the engineroom or boilerroom, no cable supplied from the emergency switchboard may penetrate the boundaries of the engineroom, boilerroom, uptakes, or casings of these spaces. These cables must be kept clear of the bulkheads and decks forming these boundaries. No emergency circuit in an engineroom or a boilerroom may supply equipment in any other space. (g) The emergency switchboard must be as near as practicable to the emergency power source but not in the same space as a battery emergency power source. (h) If the emergency power source is a generator, the emergency switchboard must be in the same space as the emergency power source. (i) The prime mover of an emergency generator must be either a diesel engine or a gas turbine. [CGD 74–125A, 47 FR 15267, Apr. 8, 1982, as amended by CGD 94–108, 61 FR 28286, June 4, 1996; 62 FR 23910, May 1, 1997]
Title 46: Shipping
PART 112—EMERGENCY LIGHTING AND POWER SYSTEMS
Subpart 112.05—General
§ 112.05-1 Purpose.
§ 112.05-3 Main-emergency bus-tie.
§ 112.05-5 Emergency power source.
Table 112.05-5(a)------------------------------------------------------------------------ Period of Type of emergency operation and Size of vessel and service power source or minimum capacity lighting of emergency power------------------------------------------------------------------------Passenger vessels: Ocean, Great Lakes, or Temporary emergency 36 hours.\1\ \2\ coastwise; or on an power source; and international voyage. final emergency power source (automatically connected storage battery or an automatically started generator). Other than Ocean, Great Final emergency power 8 hours or twice Lakes, or coastwise and not source (automatically the time of on an international voyage. connected storage run, whichever battery or an is less.\2\ automatically started generator).Cargo vessels; miscellaneous self-propelled vessels; tankships; barges with sleeping accommodations for more than 6 persons; mobile offshore drilling units; and oceanographic vessels: Ocean, Great Lakes, or Final emergency power 18 hours.\1\ \2\ coastwise and 500 GT or source (automatically more; on an international connected storage voyage and 500 GT or more; battery or an or all waters and 1600 GT automatically started or more. generator). Ocean, Great Lakes, or Emergency lighting 6 hours or twice coastwise and less than 500 provided by an the time of GT; or other than ocean, automatically run, whichever Great Lakes, or coastwise, connected or manually is less. 300 GT or more but less controlled storage than 1600 GT, and not on an battery; international voyage.. automatically or manually started generator; or relay- controlled, battery- operated lanterns.\3\ \4\.------------------------------------------------------------------------\1\ A 12-hour power supply may be especially considered for vessels engaged regularly in voyages of short duration.\2\ The capacity for the operation of the steering gear, as required by § 111.93, is for a period of 30 minutes continuous operation.\3\ The emergency lighting requirements of § 112.15-1 (b), (c), (f), and (g) must be met.\4\ Requirements of Subpart 112.39 must be met by the relay-controlled, battery-operated lanterns.
