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April 2013 www.sname.org/sname/mt (mt notes) e Risk Continuum continued capacity than the regulations required, but it was still less than the total number of peo- ple on board. Titanic was a high-performance ves- sel: Her size and general capabilities were far beyond normal for ships of the era. e risk management failures were in imagina- tion in terms of what could go wrong and how to react if something did. In the case of the lifeboats, the prevalent thought was that lifeboats would be used to quickly ferry sur- vivors from the stricken vessel to shore or to another vessel rather than work as extended shelter. e frigid North Atlantic was neither close to shore nor lled with readily-avail- able assistance. Liberty ships Liberty ships were transport vessels built during World War II for use by the govern- ment of the United States and her allies. Some 2,700 ships were built between 1941 and 1945, with an average production time of 42 days. The Liberty ships generally met the objectives of providing cheap and rela- tively reliable transport to support the wartime activities, and in that regard were a resounding success. e risk and high-performance failure were related to the welded construction, in that the welded hull was prone to cata- strophic cracks, whereas a riveted hull has inherent crack arrestors at each strake. Coupled with some design problems related to creating stress concentrations and an incomplete understanding of steel and fracture mechanics, several of the vessels cracked in half without warning. is is an example of checking the beginning, middle, and end of the design problem when engag- ing in a design change. Glomar Explorer Built as a specialized vessel under a cover story of mining for manganese modules on the ocean oor, the true purpose of Glomar Explorer was to salvage a sunken Soviet sub- marine in deep waters o Hawaii. It is known as Project Azorian, or Project Jennifer, and gave rise to the expression neither conrm nor deny? a particular record or activity. In terms of risk management and high performance, it was truly a feat of engineer- ing and operation. The vessel is known to have recovered at least part of the wreckage at a depth between 5,000 and 6,000 m. What is even more amazing is that the design, con- struction, and operation were successful with the high degree of compartmentalization that is known to have permeated the project. Stena V-Max The Stena V-Max ( Stena Vision and Stena Victory ) were conceived in the late 1990s and delivered in 2002 to Concordia Maritime (part of the Stena Sphere) for trade between West Africa and Sunocos terminal in Philadelphia, Pennsylvania. Conventional single-hull very large crude carriers were being used on a lim- ited basis for this trade, which required two lighterings before entry into the Delaware River to discharge. e V-Max was designed for shallow draft to eliminate the rst lighter- ing oshore and to incorporate many features that improved the safety of the vessel. e V-Max was one of the earliest vessels to have fully double-skinned fuel tanks and was the largest tanker with twin-screw propulsion. e vessels were truly high performance: shallow draft for access to more ports, twin screw for greater reliability, faster laden and ballast voyage speeds, and a host of other fea- tures that generally made the vessels better performers in terms of speed and reliability. Ultimately, the vessels were able to complete more voyages than conventional vessels with less wear and tear and lower voyage (such as lightering) costs. e risk management and high performance were well aligned: the vessels high performance increased the resil- ience of the system. Challenger Deep Only four vehicles have made it to the bottom of the Challenger Deep, the deepest point in the worlds oceans at 10,900 m water depth: Trieste (1960), Kaiko (1995), Nereus (2009), and Deepsea Challenger (2012). Trieste was a manned dive as was Deepsea Challenger . Kaiko was an unmanned dive with a cable to surface for power, control, and com- munications. Nereus was an unmanned, autonomous (no cables to surface) dive. The high-performance aspect is self evident: Only four vessels have made the attempt in the past 53 years. e diculty of this task illustrates the use of excellent risk management. Trieste suered a crack in the viewport on its descent, cutting short its dive time, and Deepsea Challenger lost two of its thrusters. e technical, opera- tional, and support aspects of designing, constructing, and sending (and retrieving) a vehicle to a remote and hostile environ- ment are at the frontier and beyond many aspects of validated models. MTPeter Wallace is principal shipping advisor and naval architect at BG Group in Houston, Texas, and is a mem- ber of the (mt) editorial advisory board. The opinions in this article are his and not necessarily those of BG Group. Further Reading To learn more about managing risk, check out the following resources. Charles Perrow, Normal Accidents: Living with High-Risk Technologies Scott Snook, Friendly Fire: The Accidental Shootdown of U.S. Black Hawks over Northern Iraq Weick and Sutclie, Managing the Unexpected David Hancock, Tame, Messy and Wicked Risk Leadership ISO 31000:2009, Risk Management, Principles and Guidelines on Implementation ISO 31010:2009, Risk Management, Risk Assessment Techniques Henry Petroski, Design Paradigms, Case Histories of Error and Judgment in Engineering George Plimpton, The Ultimate Triumph.? Sports Illustrated , October 29, 1956 Sydney Dekker, Drift into Failure .