46 CFR Ch. I (10–1–12 Edition)

§ 169.621 46 CFR Ch. I (10–1–12 Edition)

NOTE: A partial reduction of normal steer- (c) Overcurrent protection for steering capability as a result of malfunction or ing system electric circuits must meet failure is acceptable. This reduction should § 111.93–11 of this chapter, as applicable. not be below that necessary for the safe navigation of the vessel. VENTILATION (c) The strength and reliability of any component that is not provided in § 169.625 Compartments containing diesel machinery. duplicate must be suitable to the cog- nizant OCMI. Where redundant or (a) Spaces containing machinery backup equipment or components are must be fitted with adequate dripproof provided to meet the requirements of ventilators, trunks, louvers, etc., to paragraphs (a) and (b) of this section, provide sufficient air for proper oper- the following must be provided: ation of the propulsion and auxiliary (1) A means to readily transfer from engines. the failed equipment or component to (b) Air-cooled propulsion and auxil- the backup. iary engines installed below deck must be fitted with air intake ducts or pip- (2) Readily available tools or equip- ing from the weather deck. The ducts ment necessary to make the transfer. or piping must be arranged and sup- (3) Instructions for transfer proce- ported to safely sustain stresses in- dures, posted at the main steering loca- duced by weight and engine vibration tion. and to minimize transfer of vibration (4) A means to steady the rudder to the supporting structure. Prior to while making the transfer. installing ventilation for the engines, plans or sketches showing the machin- § 169.621 Communications. ery arrangement including air intakes, A reliable means of voice commu- exhaust stack, method of attachment nications must be provided between the of ventilation ducts to the engine, loca- main steering location and each alter- tion of spark arresting mufflers and ca- nate steering location. pacity of ventilation blowers must be submitted to the OCMI for approval. § 169.622 Rudder angle indicators. (c) Spaces containing machinery Each vessel must have a rudder angle must be fitted with at least two ducts indicator at the main steering location to furnish natural or mechanical sup- that meets the requirements of § 113.40– ply and exhaust ventilation. One duct 10 of this chapter, except where a tiller must extend to a point near the bottom or direct mechanical linkage is the pri- of the compartment, and be installed mary means of controlling the rudder. so that the ordinary collection of water in the bilge will not trap the duct. § 169.623 Power-driven steering sys- Where forced ventilation is installed, tems. the duct extending to the bottom of the compartment must be the exhaust. (a) Power-driven steering systems The total inlet area and the total out- must have means to be brought into let area of ventilation ducts must be operation from a dead ship condition, not less than one square inch for each without external aid. The system must foot of beam of the vessel. These min- automatically resume operation after imum areas must be increased when an electric power outage. such ducts are considered part of the (b) Control of power-driven steering air supply to the engines. systems from the main steering control (d) All ducts must be of rigid perma- location must include, as applicable— nent noncombustible construction, (1) Control of any necessary ancillary properly fastened, supported, and rea- device (motor, pump, valve, etc.); sonably gastight from end to end. (2) A pilot light to indicate operation (e) All supply ducts for ventilation of each power unit; and purposes must be provided with cowls (3) Visual and audible alarms to indi- or scoops having a free area not less cate loss of power to the control sys- than twice the required duct area. tem or power units and overload of When the cowls or scoops are screened, electric motors. the mouth area must be increased to

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compensate for the area of the screen (1) Rigid nonmetallic materials are wire. Dampers are prohibited in supply acceptable for use in bilge, ballast, and ducts. Cowls or scoops must be kept machinery-connected piping systems open at all times except when weather on vessels less than 120 feet in length, would endanger the vessel if the open- provided that bilge and fire systems do ings were not temporarily closed. Sup- not use the same piping. ply and exhaust openings must not be (2) Nonmetallic piping is prohibited located where the natural flow of air is in fuel systems except where flexible unduly obstructed, or adjacent to pos- hose is permitted. sible sources of vapor ignition, and (3) Rigid nonmetallic materials may must not be located where exhaust air be used in non-vital systems. may be taken into the supply vents. § 169.642 Vital systems. § 169.627 Compartments containing diesel fuel tanks. For the purpose of this part, the following are considered vital systems— Unless they are adequately venti- lated, enclosed compartments or spaces (a) A marine engineering system containing diesel fuel tanks and no ma- identified by the OCMI as being crucial chinery must be provided with a goose- to the survival of the vessel or to the protection of the personnel on board; neck vent of not less than 21⁄2 inches in diameter. The vent opening must not and be located adjacent to possible sources (b) On vessels greater than 120 feet in of vapor ignition. length— (1) Bilge system; § 169.629 Compartments containing (2) Ballast system; gasoline machinery or fuel tanks. (3) Fire protection system; Spaces containing gasoline machin- (4) Fuel oil system; and ery or fuel tanks must have natural (5) Steering and steering control sys- supply and mechanical exhaust ven- tem. tilation meeting the requirements of American Boat and Yacht Council BILGE SYSTEMS Standard H–2.5, ‘‘Design and Construc- tion; Ventilation of Boats Using Gaso- § 169.650 General. line. All vessels must be provided with a satisfactory arrangement for draining § 169.631 Separation of machinery and fuel tank spaces from accommoda- any compartment, other than small tion spaces. buoyancy compartments, under all practical conditions. Sluice valves are (a) Machinery and fuel tank spaces not permitted in watertight bulkheads must be separated from accommoda- except as specified in § 169.652(a). tion spaces by watertight or vapor tight bulkheads of double diagonal § 169.652 Bilge piping. wood, marine plywood, steel plate, or equivalent construction. (a) All vessels of 26 feet in length and (b) On vessels less than 90 feet in over must be provided with individual length, segregation may be by means of bilge lines and suction for each com- a watertight or vapor tight engine box. partment except that the space forward of the collision bulkhead may be serv- PIPING SYSTEMS iced by a sluice valve or portable bilge pump if the arrangement of the vessel § 169.640 General. is such that ordinary leakage can be (a) Vital piping systems, as defined in removed this way. § 169.642 of this subpart, must meet the (b) The bilge pipe on vessels 65 feet in material and pressure design require- length and under must be not less than ments of Subchapter F of this chapter. one inch nominal pipe size. On vessels (b) Except as provided in this para- greater than 65 but less than 120 feet in graph, nonmetallic piping system ma- length the bilge pipe must be not less terials must meet the applicable re- than one and one-half inches. Piping on quirements of 46 CFR 56.60–25. vessels of 120 feet or greater or of 100

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