August
2006
Table
of Contents:
Chesapeake Section |
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Canadian Atlantic Section |
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Texas Section |
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August
2006
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Chesapeake
Section March 22, 2006 Cruder (USCG inspector) and Bushfield (Alcoa Metallurgical Engineer) Update Section on Aluminum Failures in Domestic Passenger Vessels On Wednesday March 22nd nearly 50 members and guests attended the Chesapeake Section meeting held at the Washington Navy Yard on “Sensitized Marine Aluminum Plate and ASTM Standard Spec B928,” an update to a previous presentation given at the 2003 SNAME WMTC T&R Session. Harold Bushfield is a QA System Specialist at Alcoa who chaired the task groups at both the Aluminum Association and the ASTM responsible for writing ASTM B928. He is a metallurgical engineer, with an MBA and over 30 years experience in the aluminum industry. Marc Cruder is a traveling inspector who provides technical consultation to Coast Guard field units on repairs, policy implementation and regulatory compliance. He is a USCG Academy graduate with engineering experience afloat; he holds an unlimited horsepower Second Assistant Engineer’s license and is an accredited marine surveyor for yachts and commercial small craft. He has over 20 years experience with safety inspections of vessels.
Their excellent presentation described the discovery in fall 2001 on the M/V Jet Cat Express – only one month after launch - of leaks in the engine room which were caused by stress cracking. Investigations during the winter of 2001-2002 lead to the identification of over 400 vessels built using 5083-H321 temper aluminum plate; found to be susceptible to inter-granular corrosion. Many of the vessels involved required eventual replacement of their hulls or superstructures, which was undertaken by the aluminum industry in an unprecedented co-operative action team, called the Aluminum Boat Solutions Team. In general the plating that was found to have problems was all grades with a high Magnesium (Mg) content in tempers H116 and H321. Manufacturing specifications in force at the time did not require testing for inter-granular corrosion. The Coast Guard Headquarters-based Quality Assurance and Traveling Inspection Staff was engaged to co-ordinate and monitor the national response to dealing with these issues. Eventually it was discovered that in addition to the 400 small vessels, the material was used in fuel tanks of various vessels, including rigid hull inflatable boats operated by the USCG and recreational power boats. The Aluminum Boats Solutions Team working in conjunction with the USCG, through aggressive and diligent activities, identified all the vessels impacted. Once this was accomplished, they developed and scheduled individual remediation plans. ASTM tasked subcommittee B07.03 (Aluminum Alloy Wrought Products) to develop new specifications for the material to ensure that the alloys developed in accordance with these new specifications would be suitable for marine use. In 2003, new ASTM specification B928 was approved and published as “Standard Specification for High Magnesium Aluminum-Alloy Sheet and Plate for Marine Service”. The importance of this co-operative effort was duly noted by all members present; but all were very impressed that Alcoa, the Aluminum Association’s Product Standards Technical Committee, and the Aluminum Association took such decisive actions to “make the situation right” by repairing the vessels and in some cases completely replacing hulls. The authors have promised to redraft their reports into a paper for Marine Technology.
Canadian
Atlantic Section June 1, 2006 On June 1, 2006, the Canadian Atlantic Section held its regular monthly meeting at the "Bridge" Room of Canadian Forces Base Halifax (Stadacona). The presenter was Dr. John Porter of Defence Research and Development Canada (DRDC). Dr. Porter's presentation, "Misadventures in Materials Science Support to the Canadian Navy”, was a wide-ranging mixture of hard science, humor and lessons learned from the experience, particularly, in his recounting of some explosive experiments that were charged with investigating the shock effects of certain anomalies in the steel structural arrangements of the hulls of submarines. Some failed, whereas in other cases some succeeded spectacularly. The audience was provided with examples of the dangers and results of such work. Dr. Porter also described other work that was conducted in recent years by DRDC. This is an ongoing mixture ranging from day-to-day, shipboard problems, to long-term research projects. In recent years, DRDC have investigated sea load predictions, fatigue life, residual stress effects and welding procedures, all of which , in general, support a clearer understanding of the factors that govern hull and system overall fitness, and help to reduce the Fleet's life cycle costs. DRDC have also investigated the corrosion mechanisms of submarine hulls and their cast-alloy hull valves, and continues to conduct evaluations of NDE and repair technologies.
At the conclusion of the meeting there was an extended lively question and answer period, thanks were presented to the speaker, and a social gathering held for the members and friends.
Texas
Section June 13, 2006 On June 13th the Texas Section held a meeting that was attended by about 60 members and guests, for Mr. John F. Hatley’s presentation, "Marine Emission Fundamentals: Formation, Reduction & Control". Mr. Hatley is the Americas VP Ship Power, who with his enthusiastic and energetic manner in presenting the interesting material captured the close attention of all who attended. Together with Mr. Alexandre Eykerman, Area Sales Manager from Watsila, Mr. Hatley responded to a very lively question and answer session that followed the presentation. A lesson from this presentation is that while air emissions such as Nitrogen Oxides, Particulate Matter and Sulfur Oxides from sources such as locomotives, highway, aircraft and non-road are expected to decrease, the contribution from marine in NorthAmerica is expected to increase by 2030. In
appreciation for his efforts and contribution, Donald Burris, Texas Section
Vice-Chair presented John with a SNAME gift at the end of the meeting.
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