Proceedings magazine is a communication tool for the Coast Guard's Marine Safety & Security Council. Each quarterly magazine focuses on a specific theme of interest to the marine industry.
Issue link: http://uscgproceedings.epubxp.com/i/665311
27 Spring 2016 Proceedings www.uscg.mil/proceedings Steady State Surprisingly, most liquefed gases are not hazardous, explosive, or environmentally damaging to the water or ground when spilled, but each does contain some unique safety risks that must be acknowledged and addressed. One of the most common chal- lenges with liquefed gases is that they are, by nature, a live cargo — a liquid that wants to be a gas. Therefore, equipment and sys- tems must be put into place to prevent this. To keep it in its liquid state, liquefed gas must be under some combination of pres- surization and/or refrigeration. When under pressure, the tanks that store the liquid must be designed to withstand a large-volume, high-pressure load. When refrigerated, the tanks must be designed to keep the liquid well insulated. In some cases, the cargo is so cold that the tanks and other systems that come into contact with the cargo must use specialized materials to withstand cryogenic temperatures. Additionally, since almost all liquefied gases are hydrocarbons, they are fammable in nature, which is the characteristic that makes hydrocarbons so valuable. Because of this, measures must be taken to keep hazardous areas safe from ignition sources, monitored for leaks or fre, and protected if a release or fre occurs. The Record Despite the unique hazards associated with transporting liquefed gas and the public perception of liquefed gas car- riers, accidents related to gas carrier cargoes have been few, and the safety record of liquefed gas carriers is an acknowl- edged industry leader. That so few incidents have occurred demonstrates the success of the industry's safety culture. One case in point is the Gaz Fountain, a liquefed natural gas tanker that was hit by three maverick missiles in 1984 during the frst Gulf War while carrying a partial load of LPG. Even though several fres penetrated the containment system, they were successfully extinguished. The ship and most of the cargo were salvaged. 2 Another example was considered the worst grounding accident of a loaded liquefed gas carrier. The fully loaded LNG carrier Paul Kayser ran aground in 1979 off the coast of Gibraltar. 3 Despite signifcant bottom damage over the whole length of the cargo spaces and inner hull warping, there was no loss of cargo or damage to the cargo contain- ment system. 4 These incidents validate the long-established safety culture and robustness in the design, equipment, pro- cedures, and crew training associated with liquefed gas carriers. So how has an industry that carries volatile cargo endured such an enviable safety record? Though the advent of the ISM Code did formalize the safety culture on liquefed gas carriers, it was the concepts put into place when the industry began and incremental improvements to those base con- cepts that really established the safety processes for commu- nication, training, and actions aboard liquefed gas carriers. The industry leaders who developed and constructed the frst liquefed gas carriers created the foundation, and sub- sequent generations built more and more robust standards onto these principals as the vessels became larger and more sophisticated. The Regulations Some of these safety culture concepts were frst introduced by the pioneers of the industry, and over time they have been improved, expanded, and formalized by international and government regula- tions, industry standards, and company policies. In addition to the International Safety Management (ISM) Code, three international codes specifcally written for liquefed gas carriers all address the need for some type of operational procedure. Even the frst international code for liquefed gas carriers, the Code for Existing Ships Carrying Lique- fed Gases in Bulk, included expectations for loading, testing, and other procedures. Liquefed gas carriers built today are subject to the International Code for the Construction and Equipment of Ships Carrying Liquefed Gases in Bulk; the International Convention on Standards of Training, Certi- fcation and Watchkeeping for Seafarers; and other U.S. and interna- tional requirements that set the minimum safety culture requirements for specifc liquefed gas operations. These, in combination with the ISM Code, create the robust safety management plan that incorporates all types of operations, yet even with all these regulations, it is only the start. One of the reasons behind the industry's excellent safety record is the technical and operational guidance established by trade organization industry standards and company-specifc policies. Organizations such as the Society of International Gas Tanker and Terminal Operators share experiences, address common problems, and derive agreed criteria for best practices that are used to set the "gold standard" safety culture.