2007-05-30

Date: May 30, 2007
Time: 9:30 am – 12:30 pm
Location: DOT Headquarters

1200 New Jersey Ave, SE – Conf. Room W21-124

Washington, DC

Attendees

Rich Sonnenschein (MARAD), Ch.

Mike Bergmann (CSC, Advanced Marine Division)

Bill Cleary

Bill Garzke (Consultant, CSC, Advanced Marine Division)

Bruce Johnson

Jane Louie (Gibbs & Cox)

Dave Maurer (AMSEC/Rosenblatt)

Tapan Mazumdar (NAVSEA)

Bill Peters (USCG, CG-3PSE-2)

Tom Waters (USCG, MSC-1)

by telecom:

Phil Alman (USCG, MSC-1)

Chris Barry (USCG ELC)

Vadim Belenky (ABS)

Rob Tagg (Herbert Software Solutions)

Old Business

1. Introductions

Rich Sonnenschein welcomed the attendees, noting a strong turnout, which included new members Jane Louie (Gibbs & Cox) and Dave Maurer (AMSEC/Rosenblatt). Three members and one guest also participated in the meeting by telecom.

2. SDC Update

Rich Sonnenschein reviewed highlights of the March 5, 2007, meeting of the joint SNAME/ASNE Ship Design Committee. T&R Panel SD-1 (Weights) has a new Chairman, Bill Boze (NGSS). Next SDC meeting, on June 27, to coincide with ASNE Day, will focus on facilitating shipbuilding cost reduction.

3. SLF-50 Recap

Bill Peters reviewed the major items covered, including:

• Intact Stability CODE - consensus was reached on mandatory requirements;
• Damage Stability - Explanatory Notes show progress, but are not complete;
• Passenger Ship safety – progress on flooding detection system requirements;
• Special Purpose Ships - a sliding scale between 50 and 200 other-than-crew;
• HSC Code – corresponding group to continue addressing bow diving issue;
• Tonnage – corresponding group for proposed, additional tonnage certificate;
• Small Fishing Vessels < 12m length and undecked – guidelines developed;
• Performance Based Criteria – plan to develop “vulnerability criteria” for various modes of failure, especially for unconventional hull types; also, the concept of “partial stability failures” was discussed, which (in addition to operational considerations due to human factors) can combine to cause catastrophic failure.
4. Inclining Experiment Guidance and Instruction Project

Tom Waters explained that early tests reveal some data acquisitions problems, and it may be necessary to go to an all-digital system.

5. Dynamic Stability of Vessels

Tapan Mazumdar and others discussed dynamic stability criteria, and the Navy’s difficulties with quasi-static models, in favor of new model tests and software to replace FREDYN. Proper assignment of scaling factors continues to be critical.

With regard to a proposed meeting of the Stability Panel with the Ship Design and Hydrodynamics Committees and other stability experts for a forum on assessing dynamic stability during the SNAME Annual Meeting, it appears that a large number of Panel members would be able to attend.

6. Review of Stability-Related PNA Draft Revision

Rob Tagg discussed the philosophical changes that have taken place with respect to PNA, which favor publication of soft-bound individual or inter-related chapters as they become available, rather than waiting for completion of the entire book. He appreciates the Panel’s comments on Chapter 3 (which he authored), and will soon advise us, concerning reviewers’ offers to submit input on naval and small vessel damage stability criteria. Dave Maurer added that high speed craft are also of very high interest.

7. Discussion of Wind and Wave Effects on Small Vessels

Bruce Johnson discussed results of an ongoing SNAME T&R research Project 053: "Development of a Full Scale Data Acquisition Method Required to Enable Performance Based Operator Guidance For Traditional Sailing PassengerVessels" which suggest that the capsize effects of high wind speeds tend to be overpredicted – probably due to their relatively short duration – and the effects of waves tend to be underpredicted since the oncoming waves cannot be measured on small vessels.  In highlighting the limitations of quasi-static approaches, Bruce observed that, at any given instant, the vessel is in a non-equilibrium state considering both wind speed and heel angle as shown by the full scale tests on Pride of Baltimore II.  In relatively steady conditions, meaningful averages appear to satisfy a quasi-dynamic stability assumption.  However, in storm conditions with large fluctuating wind and heeling angle variations, the assumption of even quasi-equilibrium is far from satisfactory.

8. Stability Panel Web Site

Rich Sonnenschein has uploaded files to the SNAME ftp site, which will form the Panel’s initial web page. Next step is to make them accessible to the public.

New Business

• Chris Barry raised the possibility that SNAME might want to get involved in developing design criteria for offshore wind turbine fans.
• Chris Barry mentioned that the Computer-Aided Ship Design Panel, as well as some people who want to do on-line stability training, are looking for a public domain version of SHCP – either source code or compiled – that could be legitimately distributed to the public.

Action Items

• Rich Sonnenschein will inform Bob Keane that the proposed joint meeting with the SDC and Hydrodynamics Committee, et al, during the SNAME Annual Meeting, has the Panel’s support
• Rich Sonnenschein will have the under-construction Panel web page made available to the public.
• Tapan Mazumdar and John Rosborough will advise on whether the Navy could contribute a public domain version of SHCP, as discussed above (New Business).

Adjournment/Next Meeting

The meeting was adjourned at noon; the next Panel meeting is scheduled for 9:30 a.m. on Thursday, September 27th, at US Coast Guard Headquarters in Washington, DC (to coincide with the next SLF Working Group meeting date).