May 17 2012

May 17 2012


"Risks of IACS Classed "Container Carriers" Change Class Notation to
"General Cargo" that can Carry High Density Break Bulk Cargo
including Iron Ore/Steel products & Class Certification".

Technical Meeting Report by Kostas Maounis

On May 17th 2012, the Greek Section of SNAME, held its 9th Technical Meeting
for the 2011-2012 Season, with about 40 participants.

The title subject was presented by Mr Peter Contraros of PDC Maritime
Consultants London & Piraeus (Mr. Contraros is a permanent member of RINA's
delegation at IMO).
The Author described at first, all the design issues for the Conversion of
Container ship, into Cargo Ship, i.e Regulatory Requirements, Stability
issues, Damage Experience, Longitudinal
Strength, (particularly Buckling), Structural Behavior when carrying High
density cargoes,
unloading Iron Ore by Grabs and Bulldozers, Application of IACS UR S26, S27,
Modified Ship, Dangerous Goods, Limitations.

He also showed the geometrical differences between the two types of Ships.
He then proceeded to show three examples
which were used as a basis of the study, of dedicated Container carriers
carrying Class Certificates as
General Cargo, focusing on the IACS class notations, ship types, and related
cargo densities.

The author then stressed the fact that none out of these three modifications
were considered by class to be a " Major Conversion",
and that no damage (probabilistic) stability analysis was requested by
class. He also examined the risk of Iron Ore carrying Bulk
Carriers while ballasting and de Ballasting.

The study also included examples and photographs of damaged Bulk Carriers
and Containers during Port Operations.
He then proceeded to examine the risks (a) to Container Carriers converted
to Bulk Carriers due to relaxation of "Weather Tightness" of
Hatch Covers, (b) the much thinner Inner bottom plating thickness on a
containership, for carrying steel products.

In conclusion the conversion of a dedicated Container Carrier into a General
Cargo Ship, should (a) be considered to be a "Major Conversion "
Satisfying all the Strength and Stability criteria, (b) Prohibit to carry
any form of DRI ore, (c)the hull must be strengthened for the use of grabs
(d)Ballasting and de Ballasting should be controlled by prepared loading
conditions, (e)Hatch Covers to be modified for "Weather Tightness" at all

A lively discussion followed the presentation, and the meeting was concluded
with the traditional reception at the hospitable premises of Maran Tankers. 

( from left to right ):
H. Psaraftis, (Intern.Vice President) K. Maounis (Chairman); P. Contraros (Author); P. Lalangas (Secretary / Treasurer);
A. Papanikolaou (Chairman Elect)

the presentation can be found below
17.5.2012 Mr. Contraros' Presentation.pdf