2.1.1 The enhanced survey may be commenced at
the fourth annual survey and be progressed during the succeeding year
with a view to completion by the fifth anniversary date.
2.1.2 As part of the preparation for the enhanced
survey, the survey programme should be dealt with, in advance of the
enhanced survey. The thickness measurement should not be held before
the fourth annual survey.
2.1.3 The survey should include, in addition to
the requirements of the annual survey, examination, tests and checks
of sufficient extent to ensure that the hull and related piping, as
required in 2.1.5, is in a satisfactory condition and is fit for its
intended purpose for the new period of validity of the Cargo Ship
Safety Construction Certificate, subject to proper maintenance and
operation and to the renewal surveys being carried out.
2.1.4 All cargo tanks, ballast tanks, pump rooms,
pipe tunnels, cofferdams and void spaces bounding cargo tanks, decks
and outer hull should be examined, and this examination should be
supplemented by thickness measurement and testing deemed necessary,
to ensure that the structural integrity remains effective. The examination
should be sufficient to discover substantial corrosion, significant
deformation, fractures, damages or other structural deterioration.
2.1.5 Cargo piping on deck, including crude oil
washing (COW) piping, and cargo and ballast piping within the above
tanks and spaces should be examined and operationally tested to working
pressure to attending surveyors satisfaction to ensure that tightness
and condition remain satisfactory. Special attention should be given
to any ballast piping in cargo tanks and cargo piping in ballast tanks
and void spaces, and surveyors should be advised on all occasions
when this piping, including valves and fittings, are open during repair
periods and can be examined internally.
2.1.6 The survey extent of combined ballast/cargo
tanks should be evaluated based on the records of ballast history
and extent of the corrosion prevention system provided.