2.1.1 Unless the main steering arrangements for ship directional control comprise
two or more identical power units, in accordance with Pt 5, Ch 15, 2.1 General 2.1.4, every ship is to be provided with main steering
arrangements and auxiliary steering arrangements in accordance with the requirements of
the Rules. The main and auxiliary steering arrangements are to be so arranged that the
failure of one of them will not render the other one inoperative.
2.1.2 The main
steering arrangements for ship directional control are to be:
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Of adequate strength
and capable of steering the ship at maximum ahead service speed which
shall be demonstrated in accordance with Pt 5, Ch 15, 5.2 Trials;
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The parts comprising
the steering arrangements for ship directional control are to be so
dimensioned that they can withstand all the maximum stresses to which
they will be subjected in normal operating conditions. The steering
arrangements for ship directional control are to be sufficiently strong
to withstand abnormal forces (e.g. when the rudder is touching bottom
or a bank), the maximum possible damage in such cases being limited
to deformation or fracturing of the rudder or stock.
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The steering arrangements
for ship directional control are to be so designed that a rudder angle
of not less than 35° on either side can be obtained. On ships
where, due to operation in restricted waters or the passage of locks,
a higher degree of manoeuvrability is required, this angle is to be
suitably increased;
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Where the steering
arrangements for ship directional control are manually operated, one
complete turn of the hand wheel is to correspond to at least 3°
of rudder angle;
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Where the steering
arrangements for ship directional control are power driven, they are
to be capable of turning the rudder at an average rate of 4° per
second through the entire rudder arc when the rudder is fully immersed
and with the ship at maximum ahead service speed.
2.1.3 The auxiliary
steering arrangements for ship directional control are to be:
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Of adequate strength
and capable of steering the ship at a speed of not less than 13 km/h
and of being brought speedily into action in an emergency;
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The steering arrangements
for ship directional control are to be so designed that a rudder angle
of not less than 35° on either side can be obtained. On ships
where, due to operation in restricted waters or the passage of locks,
a higher degree of manoeuvrability is required, this angle is to be
suitably increased;
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The steering arrangements
for ship directional control and their source of power are to be designed
for an operation of not less than 30 minutes and to permit the ship
to proceed to a mooring;
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Where the steering
arrangements for ship directional control are manually operated, one
complete turn of the hand wheel is to correspond to at least 3°
of rudder angle;
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Where the steering
arrangements for ship directional control are power driven, they are
to be capable of turning the rudder at an average rate of 4° per
second through the entire rudder arc when the rudder is fully immersed,
and with the ship at a speed of not less than 13 km/h.
2.1.4 Where
the main steering arrangements for ship directional control comprise
two or more identical power units, an auxiliary steering gear need
not be fitted, provided that:
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In a passenger ship,
the main steering arrangements for ship directional control are capable
of operating the rudder as required by Pt 5, Ch 15, 2.1 General 2.1.2.(c) and Pt 5, Ch 15, 2.1 General 2.1.2.(e) while any
one of the power units is out of operation;
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In a cargo ship,
the main steering arrangements for ship directional control are capable
of operating the rudder as required byPt 5, Ch 15, 2.1 General 2.1.2.(c) and Pt 5, Ch 15, 2.1 General 2.1.2.(e) while operating
with all power units;
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The main steering
arrangements for ship directional control are arranged so that after
a single failure in its piping system or in one of the power units
the defect can be isolated so that steering capability can be maintained
or speedily regained.
2.1.5 Power
units of main and auxiliary steering arrangements for ship directional
control are to be:
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Arranged to re-start
immediately by manual initiation;
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Capable of being
brought into operation from a position on the wheelhouse. In the event
of a power failure to any one of the steering gear power units, an
audible and visual alarm is to be given on the wheelhouse;
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Arranged so that
transfer between units can be readily effected.
2.1.6 Steering
arrangements for ship directional control, other than of the hydraulic
type, will be accepted provided the standards are considered equivalent
to the requirements of this Section.
2.1.7 Manually
operated arrangements for ship directional control are only acceptable
when the operation does not require an effort exceeding 160 N under
normal conditions.