1.1.1 The purpose of this section is to provide
guidance for the application of the Standards for Ship Manoeuvrability
(resolution MSC.137(76)) along with
the general philosophy and background for the Standards.
1.1.2 Manoeuvring performance has traditionally
received little attention during the design stages of a commercial
ship. A primary reason has been the lack of manoeuvring performance
standards for the ship designer to design to, and/or regulatory authorities
to enforce. Consequently some ships have been built with very poor
manoeuvring qualities that have resulted in marine casualties and
pollution. Designers have relied on the shiphandling abilities of
human operators to compensate for any deficiencies in inherent manoeuvring
qualities of the hull. The implementation of manoeuvring standards
will ensure that ships are designed to a uniform standard, so that
an undue burden is not imposed on shiphandlers in trying to compensate
for deficiencies in inherent ship manoeuvrability.
1.1.3 IMO has been concerned with the safety implications
of ships with poor manoeuvring characteristics since the meeting of
the Sub-Committee on Ship Design and Equipment (DE) in 1968. MSC/Circular.389
titled "Interim Guidelines for Estimating Manoeuvring Performance
in Ship Design", dated 10 January 1985, encourages the integration
of manoeuvrability requirements into the ship design process through
the collection and systematic evaluation of ship manoeuvring data.
Subsequently, the Assembly, at its fifteenth session in November 1987,
adopted resolution A.601(15), entitled
"Provision and Display of Manoeuvring Information on board Ships".
This process culminated at the eighteenth Assembly in November 1993,
where "Interim Standards for Ship Manoeuvrability" were adopted by
resolution A.751(18).
1.1.4 After the adoption of resolution A.751(18), the Maritime Safety Committee,
at its sixty-third session, approved MSC/Circular.644 titled “Explanatory notes to the Interim Standards for
ship manoeuvrability”, dated 6 June 1994, to provide Administrations
with specific guidance so that adequate data could be collected by
the Organization on the manoeuvrability of ships with a view to amending
the aforementioned Interim Standards. This process culminated at the
seventy-sixth session of the Maritime Safety Committee in December
2002, where “Standards for ship manoeuvrability” were
adopted by resolution MSC.137(76).
1.1.5 The Standards were selected so that they
are simple, practical and do not require a significant increase in
trials time or complexity over that in current trials practice. The
Standards are based on the premise that the manoeuvrability of ships
can be adequately judged from the results of typical ship trials manoeuvres.
It is intended that the manoeuvring performance of a ship be designed
to comply with the Standards during the design stage, and that the
actual manoeuvring characteristics of the ship be verified for compliance
by trials. Alternatively, the compliance with the Standards can be
demonstrated based on the results of full-scale trials, although the
Administration may require remedial action if the ship is found in
substantial disagreement with the Standards. Upon completion of ship
trials, the shipbuilder should examine the validity of the manoeuvrability
prediction methods used during the design stage.