Case Study Analysis Silver Ships

Date: February 5, 1999

Summary: Following a broad side collision at sea, the USS Radford experienced significant structural damage and flooding. Post damage inspections indicated that flooding was complete (free-flooded to the waterline). This report analysis the steps to stabilize the vessel for transit/repair and shows how POSSE was used to evaluate the ship's stability and structural strength. (MORE) Case Study V: Container Ship

Summary: This report details the analysis of a pattern of structural failures throughout a class of three container ships. The analysis established the failure scenarios and determined the root cause of the progressive failure to be poor detailed design. Based on the analysis a design modification was developed and turned into a dry-dock repair specification to (MORE)

Date: May 17, 1997

Summary: The LST 93 VALDIVIA ran aground after an engine failure during beaching exercises. The hull girder experienced longitudinal buckling along the keel and the seaward sideshell. The buckling was caused by the unusual load condition of having the hull supported by the beach on the port side, while the sea continuously impacted the starboard side. This report details the structural modeling to assess the effects of this hull damage on residual strength and the subsequent salvage response (MORE)

Case Study VII: Ex-CG20 (R.K. TURNER)
Date: July 5, 1998

Summary: This case study provides the U.S. Navy's analysis of a Live Fire Test and Evaluation (LFT&E) Weapons Effects Testing on the Ex-CG20 (Richmond K. Turner). The main purposes of the test was to accumulate threat weapons blast/fragmentation effects data from selected DD21 threat weapons (anti-ship missiles), and to provide data and observations on the behavior of a ship damaged by weapons effects and put under tow in low sea state conditions. The report provides a detailed description of the resulting structural failure (MORE)

Case Study IX: MSC CARLA
Date: July 5, 1998

Summary: The hull of MSC CARLA broke apart at the forward end of the new midbody. The bow portion sank after five days. The stern was towed into port. (MORE | PDF Version)

Date: 1970's

Summary: This case study summarizes common design, operation, and maintenance practices on board bulk carriers that contribute to on-going hazards. Operationally, bulkers are loaded very rapidly;however, when unloading, heavy equipment is used that can be tough on coatings and plating. Once the coating has been compromised many cargoes can be corrosive to the steel beneath. (PDF Version)

Date: April 14, 1912

Summary: The wreck of RMS Titanic is arguably the most famous marine casualty of modern times. On April 14, 1912 during her maiden voyage, RMS Titanic struck an iceberg southeast of Newfoundland, Canada. She floated for approximately two hours, eventually assuming an extreme trim by the bow and breaking in half. (PDF Version)

Date: N/A

Summary: Flooding in the ship's starboard #2 aft and #3 wing tanks caused a 25 degree list, which was counter-ballasted by flooding #2 aft port and #3 port ballast tanks. This resulted in an overstressed hull girder which failed after 6 days of exposure to heavy seas, causing theship to break in two and sink. (PDF Version)

Date: N/A

Summary: As mandated by the Oil Pollution Act of 1990, all single hull tank vessels, including barges will be phased out by 2015. Because complete replacement of the fleet with new barges is clearly not feasible, many operators are opting to retrofit their single hull barges to double hull. (PDF Version)

Date: July 5, 1998

Summary: R/V Western Flyer has experienced localized cracking to its aluminum structure during typical operations during virtually all of its twelve year life span. Various modifications have been implemented in an attempt to solve this problem. (MORE | PDF Version)

According to the International Chamber of Shipping (ICS), about 90 % of world trade volume is carried by ships (ICS 2013a). Indeed, shipping has been considered as a very important pillar of economic development since the eighteenth century (Cheng et al. 2013). Apart from the decline in international trade due to the economic downturn which took place in 2008, world seaborne trade has shown a trend of steady growth in the past decade (Fig. 1). The significant role that shipping plays in the Chinese economy is even more obvious, covering about 93 % of China’s international trade, 95 % of crude oil trade, and 99 % of iron ore trade.

The prosperity of the shipping industry has been inducing a high demand for maritime bunker fuel while at the same time accelerating the deterioration of our environment. According to the International Maritime Organization (IMO), in 2007, international shipping was responsible for approximately 870 million tons of CO2 emission (around 2.7 % of the global emission) (IMO 2009) and the amount is expected to grow as a result of the shipping industry development if no further emission control measures are going to take place. Therefore, the mitigation of environmental impact and reduction of energy consumption are urgently required, while gaining the benefits from shipping industry. Green shipping has emerged showing higher priority to energy efficiency improvement of ships via advanced vessel design and management, rather than simply increasing the scale of ship fleets.

Although there is no general definition for green shipping, its core idea is to achieve the goal of sustainable economy development by keeping a balance between productivity gain and environmental protection (Cheng et al. 2013). This has been well acknowledged among shipping companies and policy makers alike. On July 10, 2012, the China Classification Society (CCS) has promulgated a specification focusing on the energy efficiency, environmental protection, and working environment of ships, namely Rules for Green Ships, which was published on October 1, 2012. It aims to “Achieve the goals of low consumption, low emissions, low pollution and comfortable working environment for ships” (CSC 2012). Among the clean energy utilization technologies, an important topic that has been attracting attention these years is the study of liquefied natural gas (LNG) as a marine fuel.

LNG has a series of superiorities including odorless, non-toxic, and non-corrosive (Kumar et al. 2011). The relative low prices of LNG may also make it competitive to some extents to be an alternative for marine fuel. The comparison of weighted average import price of LNG, crude oil, and product oil in China can be seen in Fig. 2.

However, the calorific value of mixing gas composed of LNG and air is about 10.5 % lower than the composition of diesel and air, leading to a certain power coastdown of transformed dual fuel engines (Dong 2011). Taking the calorific value as an index for comparison of power performance, the low calorific value of LNG is 33.75 MJ/m3 while that of 0# diesel oil is 38.44 MJ/L, so the amount of LNG needed to achieve the same power performance as 1 L 0# diesel oil does is about 1.14 m3, which will be more if combustion efficiency is counted. This can be one of the main reasons to blunt the price advantages of LNG. Beyond that, the fluctuant price (differential) is easily affected by various external factors, which make it difficult to be assessed. Thus, LNG’s major advantages lie in environmental protection and the improvement of working environment rather than energy efficiency in the view of green shipping. Moreover, due to inherent property (virtually no sulfur content) and superior combustion performance that reduces the generation of nitrogen oxides (NOx) by 85–90 % and carbon dioxide (CO2) by 20–25 % compared with heavy fuel oil (Heir et al. 2011), LNG enables ships to meet the International Convention for the Prevention of Pollution from Ships (MARPOL) Annex VI’s requirements for both worldwide trade and operation in the Emission Control Areas1 (ECAs) without further post treatment. LNG’s superiority as a preferable alternative to traditional marine fuels has been further illustrated in researches (Nikopoulou et al. 2013; Acciaro 2014), with emphasis toward lessening environmental impact, compliance with more stringent regulations, or financial concerns. Although LNG was first put in use on LNG carriers in the 1960s (Burel et al. 2013), it has not been applied to other types of ships as a main propulsion fuel until 2000, and this delay is even more explicit in China. The existing reviews on the application of LNG in Chinese transportation industry are mainly about generic LNG-powered vehicles (e.g., Ma et al. 2013) or some specific parts of LNG industry, like LNG plants and receiving terminals (e.g., Shi et al. 2010; Lin et al. 2010). There is a scarcity of studies on the development of LNG as a marine fuel, especially in China.

Therefore, the aim of this article is to investigate (1) what is the current development of LNG-fueled ships in China and (2) how to evaluate its prospects. For these purposes, a quantitative analysis on the development prospect of LNG-fueled ships in inland waterways of China is conducted using a hybrid method of SWOT (strengths, weaknesses, opportunities, and threats) and AHP (analytic hierarchy process). The key factors that influence the development of LNG in Chinese shipping industry are identified in order to provide useful information on this emerging marine fuel for the stakeholders and policy makers. This work would contribute to the research on LNG as a fuel for ships and provide significant reference on the evaluation of its development prospect.

The rest of this paper is organized as follows. Section 2 introduces the current development of LNG-fueled ships in China as well as experimental results of China’s first diesel-LNG dual-fueled ship in inland waterways. Section 3 develops a hybrid method with combination of AHP and SWOT framework in order to achieve practicability of prospect analysis. The advantages of the newly reformed approach are analyzed and discussed in this section. By using the AHP-SWOT method, section 4 analyzes the development perspective of LNG-fueled ships in Chinese shipping industry followed by a discussion of validity of calculation results. Finally, the paper is concluded in section 5.

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