SDC FIXES SHALL BE USED ONLY IN COMBAT OR OTHER
EMERGENCY CONDITIONS AT THE DISCRETION OF THE VESSEL
DAMAGES SHALL BE REPAIRED BY STANDARD
MAINTENANCE PROCEDURES AS SOON AS PRACTICABLE.
Section I. INTRODUCTION
GENERAL. Ventilation systems are a potential means of flooding and also contribute to the spread of fire and
dangerous fumes. The duct work openings (supply and exhaust), penetrations of bulkheads and decks, associated fans
(supply and exhaust), and numerous other components offer many opportunities for progressive flooding and spread of
fire, smoke, and toxic fumes when the ship is in a damaged condition.
Section II. VENTILATION OF HALON-FITTED SPACES
LSV HALON SPACES. The Engine Room, Bow Thruster Room, Paint Locker and Emergency Generator Room
are fitted with HALON fire extinguishing systems. When HALON is released in this space, the ventilation system and
closures serving these spaces should be secured immediately to prevent dilution of the HALON as well as its removal
from the space.
The supply system and exhaust system are provided with interlocking switches which shut down the vent fans
when HALON is released into these spaces. This is accomplished automatically by pressure-operated switches which cut
out the vent fan motors when HALON is released in this space, thereby preventing the excessive dilution of the HALON
as well as its removal from the space. The emission of HALON also actuates a visual red light and an electric alarm bell.
The red light is located adjacent to the compartment entrance so as to be a visible warning to anyone against entering
the compartment. A flame arrestor is installed in the exhaust ducts.
Section III. SETTING OF CLOSURES
WATERTIGHT CLOSURES. Ventilation ducts which pierce watertight bulkheads or decks below the tightness
level are fitted with watertight closures at the penetrations, or, as in most cases where ducts pierce decks, the ducts are
constructed watertight up to the tightness level. Penetrations of the main transverse bulkheads below the second deck
are not permitted.
In the event that a Chemical, Biological, or Radiological (CBR) attack is imminent, all ventilation fans and
blowers must be secured in order to prevent contaminants from entering the ship. Ventilation should not be restored until
the ship is clear of the contaminated area and the ship has been decontaminated.
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