February 14 2013

February 14


Topic: “Introducing the Harmonized Common Structural Rules for Tankers
and Bulkers’’

Report by P. Lalangas

On February 14, 2013 the Greek Section had its fifth technical meeting for the
2012-13 season. In the presence of 36 members and 12 non-members Dr. John
Kokarakis, Vice President, Technology and Business Department at Bureau
Veritas (BV), Greece and Vice Chair of the Greek Section presented the above

As Dr. Kokarakis pointed out the “Common Structural Rules” (CSR) were
developed separately for Tankers and Bulk Carriers. The International
Association of Classification Societies (IACS) agreed to harmonize the rules,
producing a common part and a part for ship type specific requirements. Specific
requirements cover the inner bottom reinforcements due to steel coil loading,
side frames of bulk carriers and prescriptive rules for primary members of oil
tankers. Key elements in the harmonization process such as wave loads, fatigue,
finite element analysis and buckling were discussed and analyzed. Innovations
in the rules were presented such as the check of corrosion additions with the
addition of ships in the database of gauging. Another new element in the CSR
is the addition of procedures and rules for direct analysis of the fore-most and
the aft-most cargo hold regions. Buckling assessment has been enhanced in
the harmonized rules with the introduction of a new Closed Form Method. The
new rules include a mandatory list of details to be assessed by FE analysis.
Fatigue assessment procedures have been also enhanced and a new screening
assessment method is introduced. The presentation covered the main elements
of the harmonized rules and pinpointed the innovations.

The author presented the following major items in detail:

-The scope & general principles of the CSR rules.
-The corrosion additions for various structural items.
-Type of welds to be used in highly stressed areas.
-Fatigue evaluation and acceptance criteria
-Buckling checks to be made.
-Expected percentage weight increase in various tanker sizes due to the
CSR rules.

The meeting was concluded with the usual reception in an adjacent hall of the
Maran Tankers Management building.

NTUA Prof. Emeritus Andonis Antoniou congratulates the author
J. Kokarakis, his student from some 30 years ago.

 from left to right : C. Kontovas, EC Member;
J. Kokarakis, Author & Vice Chair; P. Lalangas Secretary/Treasurer and
S. Hatzigrigoris, Sub. EC Member.

the presentation can be found below
Presentation, Dr. Kokarakis, 14 Feb 2013.pdf