PART A-1
SPECIFIC REQUIREMENTS FOR SHIPS USING NATURAL GAS AS FUEL
5 SHIP DESIGN AND ARRANGEMENT
5.3 Regulations – General
2 The text defining fv in paragraph 5.3.4.2 is
replaced by the following:
"fv is calculated by use of the formulations for
factor v contained in SOLAS regulation II-1/7-2.6.1.1 and reflects the probability
that the damage is extending vertically above the lowermost boundary of the fuel
tank. The formulations to be used are:"
6 FUEL CONTAINMENT SYSTEM
6.8 Regulations on loading limit for liquefied gas fuel tanks
3 The following regulation is added after existing regulation 6.8.2:
"6.8.3 For ships constructed on or after 1 January 2024, in cases where
the tank insulation and tank location make the probability very small for the tank
contents to be heated up due to an external fire, special considerations may be made
to allow a higher loading limit than calculated using the reference temperature, but
never above 95%."
9 FUEL SUPPLY TO CONSUMERS
9.5 Regulations for fuel distribution outside of machinery space
4 The following regulations are added after existing regulation 9.5.2:
"9.5.3 The requirements in 9.5.4 to 9.5.6 shall apply to ships constructed on or
after 1 January 2024 in lieu of the requirements in 9.5.1 and 9.5.2.
9.5.4 Where gaseous fuel pipes pass through enclosed spaces in the ship, they shall
be protected by a secondary enclosure. This enclosure can be a ventilated duct or a
double wall piping system. The duct or double wall piping system shall be
mechanically under pressure ventilated with 30 air changes per hour, and gas
detection as required in 15.8 shall be provided. Other solutions providing an
equivalent safety level may also be accepted by the Administration.
9.5.5 The requirement in 9.5.4 need not be applied for fully welded fuel gas vent
pipes led through mechanically ventilated spaces.
9.5.6 Liquefied fuel pipes shall be protected by a secondary enclosure able to
contain leakages. If the piping system is in a fuel preparation room or a tank
connection space, the Administration may waive this requirement. Where gas detection
as required in 15.8.1.2 is not fit for purpose, the secondary enclosures around
liquefied fuel pipes shall be provided with leakage detection by means of pressure
or temperature monitoring systems, or any combination thereof. The secondary
enclosure shall be able to withstand the maximum pressure that may build up in the
enclosure in case of leakage from the fuel piping. For this purpose, the secondary
enclosure may need to be arranged with a pressure relief system that prevents the
enclosure from being subjected to pressures above their design pressures."
10 POWER GENERATION INCLUDING PROPULSION AND OTHER GAS CONSUMERS
10.3 Regulations for internal combustion engines of piston type
5 New regulation 10.3.1.1.1 is added after existing regulation 10.3.1.1 as follows:
"10.3.1.1.1 For ships constructed on or after 1 January 2024, the exhaust system
shall be equipped with explosion relief systems unless designed to accommodate the
worst case overpressure due to ignited gas leaks or justified by the safety concept
of the engine. A detailed evaluation of the potential for unburnt gas in the exhaust
system is to be undertaken covering the complete system from the cylinders up to the
open end. This detailed evaluation shall be reflected in the safety concept of the
engine."
11 FIRE SAFETY
11.3 Regulations for fire protection
6 Regulation 11.3.3 is replaced by the following:
"11.3.3 The space containing the fuel containment system shall be
separated from the machinery spaces of category A or other rooms with high fire
risks. The separation shall be done by a cofferdam of at least 900 mm with
insulation of A-60 class. When determining the insulation of the space containing
the fuel containment system from other spaces with lower fire risks, the fuel
containment system shall be considered as a machinery space of category A, in
accordance with SOLAS regulation II-2/9. For type C tanks, the fuel storage hold
space may be considered as a cofferdam."
7 The following new regulation 11.3.3.1 is added after regulation 11.3.3:
"11.3.3.1 Notwithstanding the last sentence in 11.3.3, for ships constructed on or
after 1 January 2024, the fuel storage hold space may be considered as a cofferdam
provided that:
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.1 the type C tank is not located directly above machinery spaces of
category A or other rooms with high fire risk; and
-
.2 the minimum distance to the A-60 boundary from the outer shell of the
type C tank or the boundary of the tank connection space, if any, is not
less than 900 mm."