Corrosion in ballast tanks

Marine Coatings

RINA Conference Feb 2010

Presented by: DR M Raouf Kattan - managing director

www.Safinah.co.uk

Doc No. 270CXXXP-RINA Oct 2005

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ACME = Corrosion

Air (Oxygen)

Cathode

Metal

Electrolyte

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New build costs

Misc 2%

Ohds 28%

Labour 19%

Paint 2%

Pipes etc 7%

Equip 22%

Main Eng 16%

Steel 8%

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5%

19%1%

50%

7%

7% 4%

3%

2%

2%

Repairs Spares Man Fee Dry DockLub oil Stores Provisons Crew CostsPaint Fuel

The cost of coatings

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The cost of failure

Ballast tank refurbishment– $50 - $100 per sqm

Total area for a Panamax bulk carrier - 70,000dwt - 80-100,000 sqm

New build price - $36-48 million

Percentage on average of catastrophic failure - 16%of first cost

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Prevention of corrosion

Provide a break in ACME– No Air - inert the space, some ballast water

treatment systems propose to do this, (but anaerobic corrosion)

– No Cathode - same metal to metal problems or non-metals

– No Metal - no real alternatives at present– No Electrolyte - treat the water or alternatives, no

ballast ships or water alternatives.

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Current solution

Create a physical barrier in the form of a coating to break the contact between the ACME elements.

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The solution does workWith good Surface preparation and application the Current range of products can create a suitable barrier that can last in theory up to 15 years or more

Doc No. 270CXXXP-RINA Oct 2005

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Causes of failure

Poor design

Material selection (paint selection/specification)

Production processes control

Surface preparation

Application

In service conditions/planned maintenance

Coating chemistry

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Have regulations helped

12 new regulations and guide lines over the last 15 years to do with ballast tanks.

Little evidence that they have improved the situation beyond what paint companies may have done to respond to client demand/environmental concerns.

Statistics hard to come by.

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Size of the problem

Safinah estimate some– 7117 bulk carriers and COT– Totalling 557.6 million dwt– 7 - 8 billion sqm of ballast tank afloat– Average vessel age range 11-14 years

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Expenditure

A US Study indicated $8.5 - $11 billion is spent each year– Cost of design measures– Cost of new building measures– Cost of through life

Safinah believe these estimates to be very conservative.

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The environment

A mix of– Air temp– Steel temp– Cargo temp– Sea temp– Ballast water treatment systems– Vessel design

Creates a distorted environment within the tank from outside shell to inside shell

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The solution envelope

Design review

Design guidelines (lessons learnt)

Functional specifications

New production technologies

Scheduling

Understanding the environment

Coating strategies

HS&E challenges

Planned maintenance

Education

Regulations across the chain of activities

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Get it right - it is cheaper