Please note - Registration will close on Thursday, May 6, 2021. A link to join the webinar will be emailed to you on Friday, May 7, 2021.
The webinar has been approved for 1.0 PE/PDH.
Seakeeping performance is a measure of a ship’s ability to operate safely in poor sea conditions, particularly in heavy seas. Although seakeeping-sensitive design is now less an area of esoteric research and more an integrated ship design process, it continues to remain a significant challenge to try to parametrize it into a meaningful design criterion. This is due to extraordinary increases in ship particulars (with ships reaching beams of almost 60m), driven in part by the ever-growing demand in cargo capacity and delivery timetables, and by the large number of ships routed to sail more often in high seas. This webinar will give a basic overview of seakeeping theory, followed by a summary of the extreme motion response problems encountered in modern commercial ship design and operation. The focus of the webinar will be on nonlinear dynamics, including synchronous and resonant responses of containerships, leading to excessive vertical accelerations in heavy seas.
The supporting case study presented in this webinar includes the findings of an extensive series of model tests performed at MARIN in bathymetric and metocean conditions representative of those encountered by the Ultra-Large Containership MSC Zoe at the time of her accident. The accident occurred off the coast of the Netherlands in early 2019 and caused the loss of 350 containers and heavy pollution of a Particularly Sensitive Sea Area. It was found that although ships are designed with the idea of avoiding low stability, excessively high stability can also lead to hazardous situations. More specifically, it will be shown how the particularly large metacentric height led the ship to experience roll resonance in the encountered beam waves and how the combined motions induced accelerations on deck that exceed design values supplied by classification societies, as well as possible contact with the seabed. The presentation will also cover the problem of parametric rolling applied to container ships with more conventional (reduced) stability and varying waterplane areas in waves, as such phenomenon can yield accelerations on deck that are far beyond what can be handled by the lashing equipment. At the end of the presentation a brief overview will be given of the work currently under progress, in which the behavior of smaller ship sizes (Feeder and Panamax classes) in the North Sea is put under scrutiny.
The authors are members of the H-07 Seakeeping Characteristics panel and seek input from the audience and potentially future participation and involvement, in the H-07 panel’s activities.
SPEAKERS/PRESENTERSDr. Adrian S. Onas, Professor of Naval Architecture, Webb Institute, Glen Cove, NY, USA
Dr. Adrian S. Onas is a Naval Architect with over 25 years of ship design, operation and research experience in the maritime industry and academia. Dr. Onas' interests include extreme events in nonlinear systems, theoretical and computational hydromechanics, transom stern hydrodynamics and innovative ship design. His experience includes a 15-year career with DNV, followed by an on-going academic appointment as Professor of Naval Architecture and Director of the Circulating Water Channel at Webb Institute since 2011. He is currently the Chair of the SNAME T&R Hydrodynamics Committee, within which he also leads the Seakeeping Characteristics Panel (H-07), and a member of the SNAME T&R Marine Forensics Committee. Dr. Onas holds a PhD in Ocean Engineering from Stevens Institute of Technology. He is a member of various professional societies including the Society of Naval Architects and Marine Engineers (SNAME), the Royal Institution of Naval Architects (RINA) and the International Hydrofoil Society (IHS).
Mr. Bastien Abeil, MARIN, Wageningen, The Netherlands
Mr. Bastien Abeil graduated in 2007 as a naval architect from Chalmers University (Sweden) and ENSTA Bretagne Engineering School (France). He joined MARIN as a Project Manager in the Ships Department, working essentially in the field of ship seakeeping. His experience covers both model testing and computational techniques. He is also a guest lecturer at ENSTA Bretagne, teaching ship seakeeping and operability.
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