The measure and decision of technical risk in the development of naval vessels

The risks in development of navy vessels were explored, The resources of technical risk in the design and development of vessels were mentioned, It was pointed that technical risk dominated the other risk components. Based on the writers＇ understanding and experience from risk analysis and risk ,nanagement to the development of a navy vessel, four measure indexes of technical risk were presented. The decision criteria and the rules corresponding to the indexes were estahlished by the statistic information,

Shipbuilding Technologies in Song China

In the Song dynasty,when a high premium was placed on the development of foreign trade by sea,the undertakings of shipbuilding and navigation thrived to an unprecedented degree.According to archaeological discoveries,multiple important breakthroughs were attained in shipbuilding technology at that time.First,watertight bulkheads became structurally improved and technologically mature.Second,there were various ways to joint multiple planks and different parts of a keel,embodying highly refined woodworking craftsmanship.Thirdly,bilge keels were in use,as were axial rudders that could move up or down,wood-and-stone anchors,and iron anchors.These technologies endowed such ship forms as the Fujian ship(Fuchuan福船)with excellent capabilities,bringing Chinese shipbuilding technologies to a peak in the Song dynasty.

Fuel Cell Technology for Propulsion and Power Generation of Ships： Feasibility Study on Ocean Research Vessel Sagarnidhi

Rising fuel prices, increasing emission levels and impending environmental regulations made shipping industry to find an alternate for internal combustion engine in 21st century. Fuel cell is a sustainable, emerging technology with negligible pollution. More significantly for a research ship, emission levels need to be substantially low to have quality measurements. A feasibility study is carried-out First time in the world, to drive an ice class multi-disciplinary ORV （Oceanography Research Vessel） Sagarnidbi, using hydrogen powered fuel cell. Sagamidhi is equipped with special equipments viz., Deep Sea winch, specially designed cranes for Launching and retrieval of ROV （Remotely Operable Vehicle）, DSMC （Deep Sea Mining Crawler）, Tsunami systems, manned/unmanned submersible and ACS （Autonomous Coring System） and other facilities that support research in Indian, International and Antarctic waters. Beside this, the propulsion system along with DP （Dynamic Positioning）, centralized air conditioning and special equipments require enormous electrical power. The combustion of diesel oil in an engine, that coupled with an alternator generates electrical power required, along with NOx （Nitrous Oxides）, SOx （Sulphur Oxides） and PM （Particulate Matter） emissions. Shipping industry is the fourth largest contributor to air pollution and carbon emissions, particularly in coastal areas, and the growth rate makes the problem even more critical. Stringent international air pollution regulation and increasing fuel price paves the way for an alternative ＂green emission technology＂. Various fuel cells were analyzed with different combination of fuel, electrolyte and electrodes. From the analysis, it has been found that SOFC （Solid Oxide Fuel Cell） is most suitable for the present scenario. A fuel cell designed with hydrogen as fuel, zirconium oxides stabilized with yttrium oxide as electrolyte and zirconium electrodes is used for 1.5 MW power output and 0.5 MW through regenerator. Volume required for storage of hydrogen is in line with volume of fuel and a high standard safety measures were taken using sensors. The present system saves 3000 MT/annum of diesel oil costing 3,000,000 USD approximately.

Introduction to a Fuel Continuous Mixer for Marine Diesel Engines＇ Application

To use the renewable fuels for marine field is still very limited due to the need of newly developed technology, highly requested safety （for gas fuel） and high price of biodiesel. Therefore, with some advantages, such as： simple producing process, reasonable price and simple modification technology needed, the blended SVO （straight vegetable oil） is recommended as suitable fuel for the marine application. Even though, there are some disadvantages of the blended SVO, such as a weak stability, layer separation in low temperature and some others. In order to apply the blended SVO as alternative fuel for marine diesel engines without the mentioned disadvantages, the paper will introduce a method to design and produce a fuel continuous mixer to make a blended SVO （palm oil）.