Hull Maintenance

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Hull Maintenance
Hull Inspection Manual
MTPNO864
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Hull Inspection Manual
A practical approach to ship maintenance that

• utilises DNVs hull knowledge base
• is developed in close cooperation with the
  ship manager
• incorporates the ship managers maintenance
  standard and work processes
• easy to use and understand for ships crew and
  superintendents
• focuses on where to look and what to look for
  and how to report the inspection

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Monitor the vital few.

• During ballasting in port oil film appears on the
  sea surface
• Port authorities require immediate action
• Ship to be repaired before leaving harbour

HFO heated tank high corrosion rate
SWB high salinity high corrosion rate
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Monitor the vital few.
Coating breakdown
Bulkhead Thickness
Pitting Corrosion Rate 1,5-2 mm/year
Original t 8 mm
4-5 years to identify the problem by - Visual
inspection
1,5 mm per year
Hole - Leakage
Corroded, punctured t 0-2 mm
Time
6 years
10 years
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Different service deliverables

• Services provided in order to establish and
  implement the hull inspection manual.

Implementation
Training Training of owners personnel involved
in hull inspections

• Hull Inspection Manuals
• Ship specific
• Critical areas
• Inspection report forms
• Rating system
• Owners maintenance philosophy
• Owners acceptance criteria

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Hull Inspection Manuals
Implementation
Training Training of owners personnel involved
in hull inspections

• Hull Inspection Manuals
• Ship specific
• Critical areas
• Inspection report forms
• Rating system
• Owners maintenance philosophy
• Ownersacceptance criteria

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Why Hull Inspection Manual

• Be in control and document it
• Early detection of deficiencies
• Support the owner in complying with
• ISM code 10.1 10.2
• OCIMF self assessment scheme
• Uniform technical hull standard across the fleet
• Used as a tool onboard for inspection
• Eases the communication between ship and shore

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Hull Inspection Manual
Developed in close co-operation with the owner
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Water Ballast Tanks Fatigue Cracks
The longitudinals, located between the ballast
and fully loaded waterline, are most exposed to
fatigue cracks.
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Water Ballast Tanks Bot Long / Floor Connections
Connections of inner bottom and bottom
longitudinals with floors, transverse bulkhead
and associated brackets.
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Cargo Tanks Stringer / Inner Side Connections
Connection of horizontal stringers to inner hull
at side. Especially the large flange terminations
and at the toe.
Side shell
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Fore Peak Webframes / Side Shell Longs
Cracking in side longitudinal bracket connection
to transverse web frames (various locations)
Cracking in web frame around scallops for side
longitudinals (various locations)
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Rating system for coating
Coating
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Rating of Corrosion
Corrosion
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Rating - structural deficiencies
Deformation
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Naming of structure
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Document condition by photos
Photos may be taken at the same position every
survey for monitoring of coating condition
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2.
3.
4.
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Example of reporting
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Example on reporting
Use of drawings
Based on this report DNV prepared reinforcement
proposal
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Project plan
2 weeks
2 weeks
2 weeks
2 weeks
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Hull Inspection Manual
The system - in your pocket
Inspection report forms
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Training
Implementation
Training Training of owners personnel involved
in hull inspections

• Hull Inspection Manuals
• Ship specific
• Critical areas
• Inspection report forms
• Rating system
• Owners maintenance philosophy
• Ownersacceptance criteria

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Training alternatives

• Hull Structure Course - SiO
• Tailor made hull inspection course
• Computer Based Training

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Hull Structure Course - Objective
How are the loads taken up by the structure?
Consequence of crack in this detail ?
Where is it likely to find damages?
Develop knowledge of basic hull strength and an
understanding of how to perform a better hull
survey.
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Hull Structure Course - Ship in Operation
Web Primer

• Class room course Two days
• Module 2 Basic hull strength
• Module 3 Structural connections
• Module 4 Hull structure failure types
• Module 5 Structural Breakdown, Bulk,Tank,Cont.
  LPG

Day 1 generic hull strength
2nd day Theory applied on your ship type
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Tailor made hull inspection manual course

• Basic knowledge
• Class
• Hull strength and critical areas
• Coating and corrosion protection
• The inspection
• Planning
• Execution
• Evaluation
• Documentation

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Computer based training
CBT or onboard training
OWNER Tech/Operation Key personnel
DNV
Tailor made hull inspection manual course
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Implementation
Implementation
Training Training of owners personnel involved
in hull inspections

• Hull Inspection Manuals
• Ship specific
• Critical areas
• Inspection report forms
• Rating system
• Owners maintenance philosophy
• Ownersacceptance criteria

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Implementation

• Onboard visualisation journey
• Preparation of computer based training
• Regular audits
• ..

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Thank you for your attention