[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR182.465]

[Page 280]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 182--MACHINERY INSTALLATION--Table of Contents
 
               Subpart D--Specific Machinery Requirements
 
Sec. 182.465  Ventilation of spaces containing diesel machinery.

    (a) A space containing diesel machinery must be fitted with adequate 
means such as dripproof ventilators, ducts, or louvers, to provide 
sufficient air for proper operation of main engines and auxiliary 
engines.
    (b) Air-cooled propulsion and auxiliary diesel engines installed 
below deck, as permitted by Sec. 182.420, must be fitted with air supply 
ducts or piping from the weather deck. The ducts or piping must be so 
arranged and supported to be capable of safely sustaining stresses 
induced by weight and engine vibration and to minimize transfer of 
vibration to the supporting structure. Prior to installation of 
ventilation system for such engines, plans or sketches showing machinery 
arrangement including air supplies, exhaust stack, method of attachment 
of ventilation ducts to the engine, location of spark arresting mufflers 
and capacity of ventilation blowers must be submitted to the cognizant 
OCMI for approval.
    (c) A space containing diesel machinery must be fitted with at least 
two ducts to furnish natural or powered supply and exhaust ventilation. 
The total inlet area and the total outlet area of each ventilation duct 
may not be less than one square inch for each foot of beam of the 
vessel. These minimum areas must be increased as necessary when the 
ducts are considered as part of the air supply to the engines.
    (d) A duct must be of rigid permanent construction, which does not 
allow any appreciable vapor flow except through normal openings, and 
made of the same material as the hull or of noncombustible material. The 
duct must lead as directly as possible from its intake opening to its 
terminus and be securely fastened and supported.
    (e) A supply duct must be provided with a cowl or scoop having a 
free area not less than twice the required duct area. When the cowl or 
scoop is screened, the mouth area must be increased to compensate for 
the area of the screen wire. A cowl or scoop must be kept open at all 
times except when the weather is such as to endanger the vessel if the 
openings are not temporarily closed.
    (f) Dampers may not be fitted in a supply duct.
    (g) A duct opening may not be located where the natural flow of air 
is unduly obstructed, adjacent to possible sources of vapor ignition, or 
where exhaust air may be taken into a supply duct.
    (h) provision must be made for closing all supply duct cowls or 
scoops and exhaust duct discharge openings for a space protected by a 
fixed gas extinguishing system. All closure devices must be readily 
available and mounted in the vicinity of the vent.
    (i) A vessel of not more than 19.8 meters (65 feet) in length 
carrying not more than 12 passengers, with ventilation installations in 
accordance with ABYC Project H-32, ``Ventilation of Boats Using Diesel 
Fuel,'' will be considered as meeting the requirements of this section.

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