2007-09-27

Date: September 27, 2007
Time: 9:30 am – 12:30 pm
Location: US Coast Guard Headquarters

2100 Second St, SW, Conf. Rm. 6319

Washington, DC

Attendees

Rich Sonnenschein (MARAD), Ch.

Phil Alman (NAVSEA)

Mike Bergmann (CSC, Advanced Marine Division)

Bill Cleary

Bruce Johnson

Jane Louie (Gibbs & Cox)

Tapan Mazumdar (NAVSEA)

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

Jason Smith (USCG, CG-3PSE-2)

Tom Waters (USCG, MSC-1)

by telecom:

Chris Barry (USCG ELC)

Vadim Belenky (ABS), guest

Christopher Kent (CSC, Advanced Marine Div.), guest

Dave Maurer (AMSEC/Rosenblatt)

Leigh McCue (VA Tech)

Old Business

1. Introductions

Rich Sonnenschein welcomed the attendees, and thanked them for the strong turnout, noting new member, Jason Smith, of the Coast Guard. The meeting was further enhanced by the participation of three additional members and two guests, via telecom.

2. SDC Update (Rich Sonnenschein)

Rich Sonnenschein reviewed highlights of the June 27, 2007, meeting of the joint SNAME/ASNE Ship Design Committee, which concentrated on domestic design and shipbuilding cost issues.

3. SLF-50 Recap / SLF-51 Prep – Bill Peters reviewed the major items covered, including:

2008 Code of Intact Stability – forwarded to MSC for adoption at their early October 2008 meeting, expected to apply to ships built after Jan 1, 2010. An intersessional group has been formed to develop the framework for a new generation of performance-based, Dynamic Stability Criteria (SLF 50-4/4; also workshop proceedings) for “unconventional” vessels. To distinguish “conventional” from “unconventional” hulls, vulnerability criteria have been identified as screening tools; these are basically represented by broaching, parametric roll, and dead ship condition. This concept also considers “partial stability failures”, which (in addition to operational considerations due to human factors) can combine to cause catastrophic failure.

Damage Stability - Explanatory Notes are completed, and these rules are expected to enter into force on Jan 1, 2009;

Passenger Ship Safety – Focusing on a standard method to evaluate cross-flooding, with venting criteria a new consideration;

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.

4. Inclining Experiment Guidance and Instruction Project

Tom Waters explained that there are no new developments since last meeting. Tom and others discussed the need to avoid thermal effects on U-tubes, which can degrade their accuracy. While inclinometers are popular in Europe, the US Navy much prefers U-tubes.

5. Dynamic Stability of Small Navy 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. Current focus is on properly predicting the effects of large waves.

Rich Sonnenschein reported that Hydrodynamics Committee participation was in question, however, the Ship Design Committee chair still supported the concept of an ad hoc group on Dynamic Stability meeting during the SNAME Annual Meeting. Inasmuch as the attendance at the SNAME Annual Meeting is in doubt for several active SD-3 Panel members (including the chair), Bruce Johnson made arrangements through the auspices of Panel O-49, which he chairs, to hold a one-hour T&R session on the afternoon of November 15th.

In order to make any progress in the short time allotted, careful planning and coordination, on the part of many, will be required prior to this session. A basic question is, Where do we want this to go? It is believed that through the activities of this group, SNAME can provide more vision as to how to approach this challenging effort.

Participation on the part of experts is urgently needed, and some of the guests on telcom expressed interest. It was also noted that one member, Phil Alman, is active on both SD-3 and H-10, and plans to attend the Annual Meeting. Phil also planned to attend Panel H-10’s meeting on Oct 1st, and bring up the subject of possible interest in their participating on an ad hoc Dynamic Stability group in this T&R session. Bruce Johnson volunteered to contact Ed Lewandowski, to see if he might also be available. The likely format of the T&R session (whose agenda is TBD) will be a few presentations on aspects of Dynamic Stability, followed by discussion of a formed ad hoc group to discuss laying the groundwork to create a set of performance-based criteria. It is hoped that this ad hoc group will set follow-on actions and goals, setting the stage for future activities.

6. Review of Stability-Related PNA Draft Revision

Especially for the benefit of non-participants in this volunteer review effort, recapped the Panel’s comments on draft Chapters 1 (hull form) and 2 (intact stability). PNA Editor Randy Paulling is still considering the Panel’s earlier comments on Chapter 1 and 2. The Panel has thus far provided only preliminary comments on Chapter 3 (subdivision & damage stability); as we need to finalize our input on this Chapter, all participants are requested to forward their comments to Rich Sonnenschein in the coming weeks.

7. SNAME Panel O-49 Activities update

Bruce Johnson mentioned that he had completed a draft of the portion of his text book dealing with intact stability at large angles of heel (or roll). He discussed his interest in potentially using Froude numbers for dimensionless stability assessment, but more model test data must be obtained and evaluated before drawing any conclusions.

8. Stability Panel Web Site

Rich Sonnenschein had previously uploaded files to the SNAME ftp site. Before making this content available to the public, however, he will forward all materials to Jane Louie, who has volunteered to enhance the Panel’s web page.

9. Distribution of Navy Version of SHCP

In response to last meeting’s New Business item, wherein 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, Tapan reported that the Navy’s version of SHCP can be made available to contractors under certain circumstances, but not on a public domain basis.

New Business

• Chris Barry raised the issue of making the evaluation of small craft (primarily, <25 in length), in accordance with (non-mandatory stability criteria, more accessible to the designers; Rich Sonnenschein suggested that, possibly as a good will gesture, members of the panel would volunteer to do some analysis if the necessary data is readily available. These criteria are not familiar to the Panel.
• During an informal discussion of SAWE’s new text on Inclining Experiments which, among members who had seen it, was observed to be strong in the area of weights, but less rigorous in matters related to stability, Bruce Johnson suggest that the Panel consider providing stability-related feedback to SAWE. The suggestion was accepted as a reasonable matter for the Panel to take on.
• Bill Cleary mentioned a recent RINA magazine article, regarding offshore vessel capsizes. He was not aware of there being any criteria in effect for intact stability, even though these vessels are being built in great numbers.

Action Items

• Rich Sonnenschein will update Ship Design Committee chair, Bob Keane, the Panel’s progress in arranging the T&R session and ad hoc group on Dynamic Stability.
• All Panel members planning on attending the SNAME Annual Meeting – and the T&R session on Dynamic Stability – are requested to so inform Rich Sonnenschein and Bruce Johnson.
• Rich Sonnenschein will forward all Stability Panel SD-3 web page materials to Jane Louie, who will coordinate with SNAME HQ.
• Bruce Johnson will contact Ed Lewandowski, regarding the ad hoc group on Dynamic Stability.
• Any stability related comments on the new SAWE text should be forwarded to Rich Sonnenschein.
• Chris Barry is requested to put something together for the Panel, to review existing stability rules for small vessels.
• Bill Cleary to investigate intact stability criteria status of offshore vessels.

Adjournment / Next Meeting

The meeting was adjourned at noon; the next Panel meeting is scheduled tentatively for 9:30 a.m. on Thursday, January 10, 2008, at the Dep’t. of Transportation Headquarters in Washington, DC.