7.2.1 In craft
over 50 m in length, the main steering system is to be power operated.
7.2.2 Service
craft of length 50 m or less, or sailing yachts of length 50 m or
less, may have manual steering. Where wheel steering is fitted, an
alternative means of steering (which may be a hand tiller) is to be
readily available, and the performance of both systems is to be in
accordance with Pt 14, Ch 1, 7.2 Design and performance 7.2.8.
7.2.3 The main
steering gear is to be capable of steering the craft at the maximum
ahead speed and turning the rudder from hardover to hardover in 30
seconds.
7.2.4 Where
wire rope steering leads are fitted, they are to be of suitable construction.
Wire rope is to be stainless steel or suitably protected against corrosion
and the strength of the rope is to be as follows:
where d
su is the basic stock
diameter at quadrant or tiller given by Table 3.2.6 Rudder stock diameter in mm.
|
R
|
= |
radius
of quadrant, or length of tiller arm, in mm |
7.2.5 Steering
leads are to be as direct as possible, and sharp bends are to be avoided.
Sheaves are to be of adequate diameter and designed to prevent the
steering leads from jumping or jamming.
7.2.6 Means
are to be provided for adjusting the tension in the steering leads.
7.2.7 Where
considered necessary, an efficient locking or brake arrangement is
to be fitted to keep the rudder steady when a change from one type
of steering to the other is required.