Textual Amendments
the ducts shall be made of non-combustible material which may be faced internally and externally with membranes having low flame-spread characteristics and, in each case, a calorific value not exceeding 45 MJ/m 2 of their surface area for the thickness used. The calorific value shall be calculated in accordance with the recommendations published by the International Organization for Standardization, in particular publication ISO 1716:2002, ‘ Reaction to the fire tests for building products — Determination of the heat of combustion ’ .;
the ducts are only used at the end of the ventilation device; and
the ducts are not situated less than 600 mm, measured along the duct, from an opening in an ‘ A ’ or ‘ B ’ class division, including continuous ‘ B ’ class ceiling.
fire dampers, including their relevant means of operation, although the testing is not required for dampers located at the lower end of the duct in exhaust ducts for galley ranges, which must be of steel and capable of stopping the draught in the duct; and
duct penetrations through ‘ A ’ class divisions, although the testing is not required where steel sleeves are directly joined to ventilation ducts by means of riveted or screwed connections or by welding.
constructed of steel having a thickness of at least 3 mm for ducts with a free cross-sectional area of less than 0,075 m 2 , at least 4 mm for ducts with a free cross-sectional area of between 0,075 m 2 and 0,45 m 2 , and at least 5 mm for ducts with a free cross-sectional area of over 0,45 m 2 ;
suitably supported and stiffened;
fitted with automatic fire dampers close to the boundaries penetrated; and
insulated to ‘ A-60 ’ class standard from the boundaries of the spaces they serve to a point at least 5 m beyond each fire damper;
or
constructed of steel in accordance with paragraphs .2.4.1.1 and .2.4.1.2; and
insulated to ‘ A-60 ’ class standard throughout the spaces they pass through, except for ducts that pass through spaces of category (9) or (10) as defined in Regulation II-2/B/4.2.2.
where a thin plated duct with a free cross sectional area equal to, or less than, 0,02 m 2 passes through ‘ A ’ class divisions, the opening shall be fitted with a steel sheet sleeve having a thickness of at least 3 mm and a length of at least 200 mm, divided preferably into 100 mm on each side of a bulkhead or, in the case of a deck, wholly laid on the lower side of the decks penetrated;
where ventilation ducts with a free cross-sectional area exceeding 0,02 m 2 , but not more than 0,075 m 2 , pass through ‘ A ’ class divisions, the openings shall be lined with steel sheet sleeves. The ducts and sleeves shall have a thickness of at least 3 mm and a length of at least 900 mm. When passing through bulkheads, this length shall be divided preferably into 450 mm on each side of the bulkhead. These ducts, or sleeves lining such ducts, shall be provided with fire insulation. The insulation shall have at least the same fire integrity as the division through which the duct passes; and
automatic fire dampers shall be fitted in all ducts with a free cross-sectional area exceeding 0,075 m 2 that pass through ‘ A ’ class divisions. Each damper shall be fitted close to the division penetrated and the duct between the damper and the division penetrated shall be constructed of steel in accordance with paragraphs .2.4.2.1 and .2.4.2.2. The fire damper shall operate automatically, but shall also be capable of being closed manually from both sides of the division. The damper shall be fitted with a visible indicator which shows the operating position of the damper. Fire dampers are not required, however, where ducts pass through spaces surrounded by ‘ A ’ class divisions, without serving those spaces, provided those ducts have the same fire integrity as the divisions which they penetrate. A duct of cross-sectional area exceeding 0,075 m 2 shall not be divided into smaller ducts at the penetration of an ‘ A ’ class division and then recombined into the original duct once through the division to avoid installing the damper required by this provision.
In general, the ventilation fans shall be so arranged that the ducts reaching the various spaces remain within a main vertical zone.
Stairway enclosures shall be served by an independent ventilation fan and duct system (exhaust and supply) which shall not serve any other spaces in the ventilation systems.
A duct, irrespective of its cross-section, serving more than one ‘ tween-deck ’ accommodation space, service space or control station, shall be fitted, near the penetration of each deck of such spaces, with an automatic smoke damper that shall also be capable of being closed manually from the protected deck above the damper. Where a fan serves more than one ‘ tween-deck ’ space through separate ducts within a main vertical zone, whereby each one is dedicated to a single ‘ tween-deck ’ space, each duct shall be provided with a manually operated smoke damper fitted close to the fan.
Vertical ducts shall, where necessary, be insulated as required by tables 4.1 and 4.2. Ducts shall be insulated as required for decks between the space they serve and the space being considered, as applicable.
a grease trap readily removable for cleaning unless an alternative approved grease removal system is fitted;
a fire damper located in the lower end of the duct at the junction between the duct and the galley range hood which is automatically and remotely operated and, in addition, a remotely operated fire damper located in the upper end of the duct close to the outlet of the duct;
a fixed means for extinguishing a fire within the duct. The fire extinguishing systems shall comply with the recommendations published by the International Organization for Standardization, in particular publication ISO 15371:2009 ‘ Ships and marine technology — Fire-extinguishing systems for protection of galley cooking equipment ’ ;
remote-control arrangements for shutting off the exhaust fans and supply fans, for operating the fire dampers mentioned in paragraph .5.1.1.2 and for operating the fire-extinguishing system, which shall be placed in a position outside the galley close to the entrance to the galley. Where a multi-branch system is installed, a remote means located with the above controls shall be provided to close all branches exhausting through the same main duct before an extinguishing medium is released into the system; and
suitably located hatches for inspection and cleaning, including one provided close to the exhaust fan and one fitted in the lower end where grease accumulates.
When passing through accommodation spaces or spaces containing combustible materials, the exhaust ducts from galley ranges shall be constructed in accordance with paragraphs .2.4.1.1 and .2.4.1.2. Each exhaust duct shall be fitted with:
a grease trap readily removable for cleaning;
an automatically and remotely operated fire damper located in the lower end of the duct at the junction between the duct and the galley range hood and, in addition, a remotely operated fire damper in the upper end of the duct close to the outlet of the duct;
arrangements, operable from within the galley, for shutting off the exhaust and supply fans; and
fixed means for extinguishing a fire within the duct.
Exhaust ducts from laundries and drying rooms of category (13) spaces as defined in Regulation II-2/B/4.2.2 shall be fitted with:]
filters readily removable for cleaning purposes;
a fire damper located in the lower end of the duct which is automatically and remotely operated;
remote-control arrangements for shutting off the exhaust fans and supply fans from within the space and for operating the fire damper mentioned in paragraph .7.2; and
suitably located hatches for inspection and cleaning.] ]
Editorial Information