Chapter 11-1: Construction - structure, stability, installations
Regulation 42
2.2 The arrangement of the main electric lighting system shall be such that a fire or other casualty in
spaces containing the main source of electrical power, associated transforming equipment, if any, the main
switchboard and the main lighting switchboard, will not render the emergency electric lighting system
required by regulations 42.2.1 and 42.2.2 or 43.2.1, 43.2.2 and 43.2.3 inoperative.
2.3 The arrangement of the emergency electric lighting system shall be such that a fire or other casualty in
spaces containing the emergency source of electrical power, associated transforming equipment, if any, the
emergency switchboard and the emergency lighting switchboard will not render the main electric lighting
system required by this regulation inoperative.
3 The main switchboard shall be so placed relative to one main generating station that, as far as is
practicable, the integrity of the normal electrical supply may be affected only by a fire or other casualty in
one space. An environmental enclosure for the main switchboard, such as may be provided by a machinery
control room situated within the main boundaries of the space, is not to be considered as separating the
switchboards from the generators.
4 Where the total installed electrical power of the main generating sets is in excess of 3 MW, the main
busbars shall be subdivided into at least two parts which shall normally be connected by removable links or
other approved means; so far as is practicable, the connection of generating sets and any other duplicated
equipment shall be equally divided between the parts. Equivalent arrangements may be permitted to the
satisfaction of the Administration.
5 Ships constructed on or after 1 July 1998:
.1 in addition to paragraphs 1 to 3, shall comply with the following:
.1.1 where the main source of electrical power is necessary for propulsion and steering of the ship,
the system shall be so arranged that the electrical supply to equipment necessary for propulsion
and steering and to ensure safety of the ship will be maintained or immediately restored in the
case of loss of any one of the generators in service;
.1.2 load shedding or other equivalent arrangements shall be provided to protect the generators
required by this regulation against sustained overload;
.1.3 where the main source of electrical power is necessary for propulsion of the ship, the main
busbar shall be subdivided into at least two parts which shall normally be connected by circuit
breakers or other approved means; so far as is practicable, the connection of generating sets and
other duplicated equipment shall be equally divided between the parts; and
.2 need not comply with paragraph 4.
Regulation 42
Emergency source of electrical power in passenger ships
(Paragraphs 2.6.1 and 4.2 of this regulation apply to ships constructed on or after 1 February 1992)
1.1 A self-contained emergency source of electrical power shall be provided.
1.2 The emergency source of electrical power, associated transforming equipment, if any, transitional
source of emergency power, emergency switchboard and emergency lighting switchboard shall be located
above the uppermost continuous deck and shall be readily accessible from the open deck. They shall not be
located forward of the collision bulkhead.
1.3 The location of the emergency source of electrical power and associated transforming equipment, if
any, the transitional source of emergency power, the emergency switchboard and the emergency electric
lighting switchboards in relation to the main source of electrical power, associated transforming equipment,
if any, and the main switchboard shall be such as to ensure to the satisfaction of the Administration that a
fire or other casualty in spaces containing the main source of electrical power, associated transforming
equipment, if any, and the main switchboard or in any machinery space of category A will not interfere
with the supply, control and distribution of emergency electrical power. As far as practicable, the space
containing the emergency source of electrical power, associated transforming equipment, if any, the
transitional source of emergency electrical power and the emergency switchboard shall not be contiguous
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