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
29 Spring 2016 Proceedings www.uscg.mil/proceedings Pressurized cargo systems are designed to with- stand higher pressures. All of these systems are constructed to support sloshing and other dynamic ship loads, and contain some type of secondary con- tainment system in case of a breach. Finally, the most basic layer of safety involves rec- ognizing the hazards associated with the cargo itself. Compared to other more commonly carried cargoes, there are many other characteristics of liq- uefed gases that make them more dangerous in some cases and safer in others. Differentiating what creates hazards from what doesn't drives the need for the remaining safety nets. For example, neither LNG nor its natural gas vapors are toxic, carcino- genic, corrosive, or even damaging to the water or ground if spilled. Additionally, liquefed gases aren't fammable when in a liquid state. However, when vaporized, the gas produced is. LNG vapor is also an asphyxiant, displacing the normal oxygen concentration to hazardous levels that could cause fatalities in certain concentrations. Understand- ing such risk and safety properties is important in developing other mitigation measures. A Continuing Challenge While the industry can be justifably proud of the exemplary safety record it's built up over the frst half of the century, current trends and changes to come within the industry give reason to remain vigilant. The number and types of liquefed gas car- riers needed to support the nation's "Energy Renais- sance" and increased use of liquefed gas throughout the maritime community are on the rise. Therefore, it's even more important that the long- running safety cul- ture mentality be preserved and continually reviewed to address current trends and future operations. While the Coast Guard has seen an increase in the number of liquefed gas carrier arrivals, we have also seen a dispro- portionate number of incidents (including near-misses) that have led to liquefed gas carrier detentions, due primarily to issues within vessel safety management systems. For exam- ple, a fre on a liquefed gas carrier in early 2015 was due in part to the crew not following its approved procedures, which led to a release in the pump room that came into con- tact with an ignition source and caught fre. Fortunately, the crew was able to extinguish the fre with minimal damage and injuries. Additionally, several Coast Guard inspections have identi- fed maintenance gaps with deluge systems on liquefed gas carriers. The deluge system utilizes high-velocity water suppression to mitigate the risks associated with liquefed gas releases. To cover the hazardous areas, water is simul- taneously diffused through a specifcally designed number of sprinkler heads. On more than one recent occasion, how- ever, the Coast Guard identifed multiple sprinkler heads clogged with rust, preventing coverage in many critical areas. They found these failures were caused by improper use of and updates to maintenance procedures. In both of these cases, proper implementation of the safety management system could have prevented each incident. LNG as Fuel Due to the environmental and cost benefits of liquefied gases — primarily LNG — some vessel operators have decided to shift to liquefed gases as a fuel. This adds another aspect requiring safety management. The Numbers We have reached a record: 1,751 liquefed gas carriers currently in the global feet; that number is expected to rise to more than 2,000 in the next few years; and 358 ships are on the order books as of late 2015. 1 These vessels have increased in size from 600 cubic meters to upwards of 266,000 cubic meters. This growth in total volume is expected to be needed to meet energy analysts' prediction for future demand. Experts forecast that global LNG trade will double within the next 20 years. 2 Additionally, a 25 percent increase in U.S. exports of liquefed petroleum gas (LPG) is expected in just the next three years. This includes the 13 new export facilities within the Gulf Coast alone that will triple the region's capacity by 2016. 3 The U.S. is likely to top the LNG and LPG producers list by 2020. Additional growth in the U.S.-fagged feet will come with LNG and other liquefed gases being used as fuel, including the 12 vessels under construction or already in service domestically and 144 internationally. Endnotes: 1. Shipping Intelligence Network. Retrieved September 1, 2015, from Clarksons Research Services: https://sin.clarksons.net/Register#/Fleet/Fleet/Vessel-Type. 2. J-Y Robin, 2014, "An Achievement," LNG Shipping at 50, page 9, found at www. sigtto.org/media/7087/lng-shipping-at-50compressed.pdf. 3. J. O'Connell, Nov. 25, 2014, "The Other Gas: While LNG gets all the headlines, it's LPG that's really making waves." Retrieved September 1, 2015, from The Mari- time Executive, found at www.maritime-executive.com/magazine/The-Other- Gas-2014-11-25.