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33 CFR Part 183

Subpart K--Ventilation

Source: CGD 76-082, 44 FR 73027, Dec. 17, 1979, unless otherwise noted.

Sec. 183.601 Applicability. This subpart applies to all boats that: (a) Have gasoline engines for electrical generation, mechanical power, or propulsion; and (b) Are built after July 31, 1980, except that a manufacturer may elect to comply with this subpart at any time after July 31, 1978.

Sec. 183.605 Definitions. As used in this subpart: ``Fuel'' means gasoline. ``Open to the atmosphere'' means a compartment that has at least 15 square inches of open area directly exposed to the atmosphere for each cubic foot of net compartment volume.

[CGD 76-082, 44 FR 73027, Dec. 17, 1979, as amended by CGD 85-098, 52 FR 19729, May 27, 1987]

Sec. 183.607 Incorporation by reference.

(a) The following standards are incorporated by reference. Copies may be obtained from the sources indicated. They are also available for inspection at Coast Guard Headquarters, Room 4210, 2100 Second Street, SW., Washington, DC 20593 and at the Office of the Federal Register Library, 800 North Capitol Street, NW., suite 700, Washington, DC 20408.

(1) AMCA Standard 210-74, Figure 12. Air Moving and Conditioning Association, 30 West University Drive, Arlington Heights, Illinois 60004.

(2) ASTM Standard D-471. American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103.

(3) UL Standard 1128. Underwriters Laboratories, Incorporated, 207 Ohio Street, Chicago, Illinois 60611.

(b) The Director of the Federal Register approved the incorporation by reference in paragraph (a)(2) on September 26, 1976 and the incorporations in paragraphs (a) (1) and (3) on March 24, 1978.

[CGD 76-082, 44 FR 73027, Dec. 17, 1979, as amended by CGD 82-010, 48 FR 8273, Feb. 28, 1983]

Sec. 183.610 Powered ventilation system.

(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 an exhaust blower system.

(b) Each exhaust blower or combination of blowers must be rated at an air flow capacity not less than that computed by the formulas given in Table 183.610, Column 2. Blower rating must be determined according to AMCA Standard 210-74, Figure 12, or UL Standard 1128.

Table 183.610

Col. 11 Col. 22 Col. 33
Below 34 Fr=50 Fo=20
34 to 100 Fr=1.5V Fo=0.6V
Over 100 Fr=V/2+100 Fo=0.2V+40

Net compartment volume of engine compartment and compartments open thereto (V) cubic feet.

2Rated blower capacity (Fr) cubic feet per minute.

3Blower system output (Fo) cubic feet per minute.

(c) Each exhaust blower system required by paragraph (a)(2) of this section must exhaust air from the boat at a rate which meets the requirements of Table 183.610, Column 3 when the engine is not operating.

(d) 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.

(e) More than one exhaust blower may be used in combination to meet the requirements of this section.

(f) 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


Sec. 183.620 Natural ventilation system.

(a) Except for compartments open to the atmosphere, a natural ventilation system that meets the requirements of Sec. 183.630 must be provided for each compartment in a boat that:

(1) Contains a permanently installed gasoline engine;

(2) Has openings between it and a compartment that requires ventilation, where the aggregate area of those openings exceeds 2 percent of the area between the compartments, except as provided in paragraph (c) of this section;

(3) Contains a permanently installed fuel tank and an electrical component that is not ignition protected in accordance with Sec. 183.410(a);

(4) Contains a fuel tank that vents into that compartment; or

(5) Contains a non-metallic fuel tank:

(i) With an aggregate permeability rate exceeding 1.2 grams of fuel loss in 24 hours per cubic foot of net compartment volume, or

(ii) If the net compartment volume is less than one cubic foot, having a permeability rate exceeding 1.2 grams of fuel loss in 24 hours.Reference fuel ``C'' at 40 degrees Celsius plus or minus 2 degrees Celsius from ASTM standard D-471-1979 is to be used in determining the permeability rate.

(b) Each supply opening required in Sec. 183.630 must be located on the exterior surface of the boat.

(c) An accommodation compartment above a compartment requiring ventilation that is separated from the compartment requiring ventilation by a deck or other structure is excepted from paragraph (a)(2) of this section.

[CGD 76-082, 44 FR 73027, Dec. 17, 1979, as amended by CGD 76-082(a), 46 FR 27645, May 21, 1981; CGD 85-059, 51 FR 37577, Oct. 23, 1986]

Sec. 183.630 Standards for natural ventilation.

(a) For the purpose of Sec. 183.620, ``natural ventilation'' means an airflow in a compartment in a boat achieved by having:

(1) A supply opening or duct from the atmosphere or from a ventilated compartment or from a compartment that is open to the atmosphere; and

(2) An exhaust opening into another ventilated compartment or an exhaust duct to the atmosphere.

(b) Each exhaust opening or exhaust duct must originate in the lower third of the compartment.

(c) 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.

(d) Except as provided in paragraph (e) of this section, supply openings or supply ducts and exhaust openings or exhaust ducts must each have a minimum aggregate internal cross-sectional area calculated as follows:A=5 ln (V/5);where:

(1) A is the minimum aggregate internal cross-sectional area of the openings or ducts in square inches;

(2) V is the net compartment volume in cubic feet, including the net volume of other compartments connected by openings that exceed 2 percent of the area between the compartments; and

(3) ln (V/5) is the natural logarithm of the quantity (V/5).

(e) The minimum internal cross-sectional area of each supply opening or duct and exhaust opening or duct must exceed 3.0 square inches.

(f) The minimum internal cross-sectional area of terminal fittings for flexible ventilation ducts installed to meet the requirements of paragraph (d) of this section must not be less than 80 percent of the required internal cross-sectional area of the flexible ventilation duct.

[CGD 76-082, 44 FR 73027, Dec. 17, 1979; 45 FR 7544, Feb. 4, 1980]