7.1.1 The requirements of this Chapter apply to
units which are designed to undertake self-propelled passages without
external assistance and are not applicable to units which are fitted
only with means for the purpose of positioning or of assistance in
towing operations. These requirements are additional to those in Chapters 4,5 and 6.
7.1.2 Means should be provided whereby normal
operation of propulsion machinery can be sustained or restored even
though one of the essential auxiliaries becomes inoperative. Special
consideration should be given to the malfunction of:
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.1 a generator set which serves as a main source
of electrical power;
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.2 the sources of steam supply;
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.3 the arrangements for boiler feed water;
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.4 the arrangements which supply fuel oil for
boilers or engines;
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.5 the sources of lubricating oil pressure;
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.6 the sources of water pressure;
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.7 a condensate pump and the arrangements to maintain
vacuum in condensers;
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.8 the mechanical air supply for boilers;
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.9 an air compressor and receiver for starting
or control purposes; and
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.10 the hydraulic, pneumatic or electrical means
for control in main propulsion machinery including controllable pitch
propellers,
provided that the Administration, having regard to overall safety
considerations, may accept a partial reduction in capability from
full normal operation.
7.1.3 Main propulsion machinery and all auxiliary
machinery essential to the propulsion and the safety of the unit should,
as fitted in the unit, be capable of operating when the unit is upright
and when inclined at any angle of list up to and including 15 degrees
either way under static conditions and 221/2 degrees under dynamic
conditions (rolling) either way and simultaneously inclined dynamically
(pitching) 71/2 degrees by bow or stern. The Administration may permit
deviation from these angles, taking into consideration the type, size
and service conditions of the unit.
7.1.4 Special consideration should be given to
the design, construction and installation of propulsion machinery
systems so that any mode of their vibrations should not cause undue
stresses in this machinery in the normal operating ranges.