Backfire Flame Control

(1) Every gasoline engine installed in a motorboat or motor vessel after April 25, 1940, except outboard motors, shall be equipped with an efficient means of backfire flame control. Installations made before November 19, 1952, need not meet the detailed requirements of this subpart and may be continued in use as long as they are in good condition. The following are acceptable means of backfire flame control for gasoline engines: (a) A backfire flame arrestor specifically approved by the U.S. Coast Guard. The flame arrestor shall be suitably secured to the air intake with flame tight connections. (b) An engine air and fuel intake system which provides adequate protection from propagation of backfire flame to the atmosphere equivalent to that provided by an approved flame arrestor. A gasoline engine which has such an air and fuel intake system and which is to be operated without an approved flame arrestor shall be labeled to meet requirements of the U.S. Coast Guard. RULES AND REGULATIONS GOVERNING EQUIPMENT REQUIRED ON CHAPTER 1660-02-03 VESSELS AND NAVIGATION RULES (c) Any attachment to the carburetor or location of the engine air intake by means of which flames caused by engine backfire will be dispersed to the atmosphere outside the vessel in which a way that the flames will not endanger the vessel or persons on board. All attachments shall be metallic construction with flame tight connections and firmly secured to withstand vibration, shock and engine backfire. Such installations do not require formal approval but will be accepted by the law enforcement officers on the basis of this subpart. (2) All motorboats or motor vessels, except open boats, the construction or decking over of which is commenced after April 25, 1940, and which use fuel having a flash point of 100°F or less, shall have at least 2 ventilator ducts fitted with cowls or their equivalent for the efficient removal of explosive or inflammable gases from the bilges of every engine and fuel tank compartment. There shall be at least one exhaust duct installed so as to extend from the open atmosphere to the lower portion of the bilge and at least one intake duct installed so as to a point at least midway or at least below the level of the carburetor air intake. The cowls shall be located and trimmed for maximum effectiveness so as to prevent displaced fumes from being recirculated. (a) However, boats built after July 31, 1978, shall not have to comply with the requirements for fuel tank compartments that— 1. Contain a permanently installed fuel tank if each electrical component is ignition protected; and, 2. Contain fuel tanks that vent to the outside of the boat. (b) In addition, boats built after July 31, 1980, which are in compliance with the following regulations shall be exempt from the requirement of 1660-02-03-.05, paragraph (2). (3) No person may operate a boat built after July 31, 1980, that has a gasoline engine for electrical generation, mechanical power, or propulsion unless it is equipped with an operable ventilation system that meets the following requirements; (a) Each compartment in a boat that has a permanently installed gasoline engine with a cranking motor must— 1. Be open to the atmosphere; or 2. Be ventilated by one or more power exhaust blower systems which meet the standards set up in CFR 183.610. (b) Each intake duct for an exhaust blower must be in the lower one-third of the compartment and above the normal level of accumulated bilge water. (c) Each boat that is required to have an exhaust blower must have a label that— 1. Is located as close as practicable to each ignition switch; 2. Is in plain view of the operator; and 3. Has at least the following information: Warning-Gasoline Vapors Can Explode. Before Starting Engine Operate Blower for 4 Minutes and Check Engine Compartment Bilge for Gasoline Vapors. RULES AND REGULATIONS GOVERNING EQUIPMENT REQUIRED ON CHAPTER 1660-02-03 VESSELS AND NAVIGATION RULES (4) Except for compartments open to the atmosphere, a natural or power ventilation system must be provided for each compartment in a boat that— (a) Contains a permanently installed gasoline engine; (b) Has openings between it and a compartment that requires ventilation; except that an accommodation compartment above a compartment requiring ventilation by a deck or other structure does not have to comply; (c) Contains a permanently installed fuel tank where an electrical component is not ignition protected; (d) Contains a fuel tank that vents into that compartment; or (e) Contains a non-metallic fuel tank with an aggregate permeability rate greater than the allowable standards established in CFR 183.620. (5) Natural ventilation means an airflow in a compartment in a boat achieved by having a— (a) Supply opening or duct from the atmosphere or from a ventilated compartment or from a compartment that is open to the atmosphere; and (b) An exhaust opening into another ventilated compartment or an exhaust duct to the atmosphere. (c) Each exhaust opening or exhaust duct must originate in the lower one-third of the compartment. (d) Each supply opening or supply duct and each exhaust opening or exhaust duct in a compartment must be above the normal accumulation of bilge water and be able to move the rate of air required as computed in CFR 183.630. (e) Each natural ventilation system must be constructed so that— 1. Each supply opening is forward facing and located on the exterior surface of a boat; or 2. Air will flow into or out of the supply openings at the necessary rate (as computed in CFR 183.630) when the boat is in a wind flowing from bow to stern at a velocity of 10 miles per hour when the engine is not operating. (6) As used in this section, the term “open boats” means those motorboats or motor vessels with all engine and fuel tank compartments and other spaces to which explosive or flammable gases and vapors from these compartments may flow, open to the atmosphere so as to prevent the entrapment of such gases and vapors within the vessel. (7) Where alterations are needed for existing motorboats or motor vessels to comply with these requirements they shall be accomplished as soon as practicable but in any case shall be completed by June 1, 1966.