2 Answers

+2 votes
answered Jul 31, 2014 by jakangaru (2,010 points)

The inspections and reviews should include at least the following steps:

  • Pre-selection engineering review
    • The preselection engineering review should include include existing information by engineers. The review may also include some initial calculations.
  • Review of existing information
    • Review of existing information may include: vessel drawings, survey records, gauging reports, pre-selection inspection reports
  • Survey inspection
    • Prior to starting the conversion work the vessel should be subjected to an extensive inspection. The survey should fulfill the Special Periodical Survey requirements from Class.
    • In order to conduct and report the inspection in a proper fashion it is necessary that the inspection company has possession of the following information from the structural analysis work: minimum renewal thickness at conversion, anticipated corrosion, and details to be modified to verify whether assumptions for the connection details made in the fatigue analysis are correct.
    • The inspection of bottom plating should only be carried out after the plating has been prepared by either rough grit or hydro blasting.
  • On-site inspection
    • For each FSO/FPSO a comprehensive tank inspection program should be developed. This plan is based on a 2.5 year cycle, instead of the normal 5 year special survey cycle. In addition, tanks should be visually inspected by the crew each time they are entered for maintenance and repair.


+1 vote
answered Jul 31, 2014 by josvanden (3,240 points)

A little more details on the "Survey Inspection" step.

For Single Hull:

  • Overall visual inspection of vessel structure and outfitting in all cargo, slop, ballast, fuel oil, aft, and void spaces.
  • Measurement and mapping of all areas of pitting of bottom plating in cargo and slop tanks, pump and engine rooms.
  • Visual inspection of collar plates of all longitudinal protruding through water tight or oil tight bulkheads as well as all toes of all transverse bottom webs and horizontal girders.
  • Visual inspection of entire main deck and bottom plating.
  • Visual inspection of horizontal stringers and girders.

For Double Hull: same as Single Hull plus the followings

  • Visual inspection of knuckle areas.
  • Measurement and mapping of all areas of pitting of inner bottom plating in cargo and slop tanks.
  • Condition of the existing coating system in the wing and double bottom ballast tanks.

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