Download - R L Townsin M R Kattan safinah.co.uk
Antifoulings – Concerns, penalties and remedies especially for the
smaller fleet operator
October 7-8 - Athens, Greece The third International Symposium on Ship Operations, Management, and
Economics
R L Townsin
M R Kattan
www.safinah.co.uk
Focus of paper
The issues of:– Economy– Fuel consumption– And emissions
Are all in large part a product of the performance of the anti-fouling coating.
The intention is to provide some guidance in these matters to the smaller fleet operator
Which AF Product?
The key issue for the owner is one of predictability
However factors such as:– Speed– Activity– Trading pattern– New build production requirements– Dry-dock capability
Must all be taken into account to ensure predictable performance of the AF in service
Hull roughness
At both new build and in dry-dock it is critical to ensure a low hull roughness
This is often compromised by– Cost savings– Poor control of application– Etc.
Predictability
The key elements to predictability, irrespective of the type of anti-fouling technology to be used are:– Operating cost control– Charter party performance– Anti-fouling performance to reduce
unscheduled stops/delays (for hull cleaning/dry-docking).
Guarantees
Paint companies often now include guarantees– Fuel savings can be difficult to assign if
other factors such as engine overhaul coincide.
– What is really responsible for fuel saving or increased fuel consumption can be very dificul t to verify in practice
Development of specification
Key issue is to develop the right specification for your vessel.– Take into account the engineering needs of the
coating performance and develop a “functional” paint specification as you would for any other engineering system on board a vessel.
– Owner needs to establish a key set of criteria that the paint supplier must prove compliance with.
Measure of success
Enter next dry-dock foul free
Have some reserve AF left
No appreciable roughening of the hull
In service maintenance
This must be planned for hull and propeller.
Speed over performance monitoring should be set up so that hull/propeller performance can be confirmed and action taken as performance falters.
Strategy
A good strategy should have:– Attention to speed, activity levels and trade pattern– Good specification (functional) of anti-fouling
system.– Use of a torsion meter to monitor in service
performance– Use of Underwater hull cleaning (where possible)
as interim solutions if required– Conduct of a well managed dry-docking to
minimise hull roughness
Analysis
Considerable work has been done on how to calculate the resultant roughness penalties and key references are given in the paper.
Fouling penalties not so easy to assess but can be derived form speed/power monitoring.
Mini-trials during a voyage can be attempted
On board monitoring systems can be used
Performance data
In the absence of trials, monitoring systems etc and in the event of a dispute then reliance is made on deck and engine logs.
These are not aimed at collecting the data for vessel performance they can provide useful input to any analysis
Data – deck log
GPS position
Time of day
These can be used to calculate– Speed over ground– Ocean current s and winds need to be
corrected for to get speed through the water.
Data – ER Log
Fuel consumption often a disappointment
Torsion meter provides most accurate and valuable data (but rarely fitted or used)
Propeller
Largest measuring instrument on board– Use of a power diagram from manufacturer
can be used (details are in the written paper submission).
Summary
Guidance on choosing the right AF product
Good practice maintenance advice has been provided
Options for data gathering to allow performance monitoring to be made have been considered
The use of a shaft torsion meter has been advocated.
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