Research on Operation Characteristic and Safety of Purse Seiner

Fisheries development by the growing attention of fisheries powers, and our use of inshore and offshore fishing resources is constrained by all aspects, one of the main reasons is the lack of advanced fishing technology and state-of-the-art fishing vessels. In recent years, the advent of large-scale tuna purse seine vessels, to the purse seine fishery bring new development, China has also begun the design and manufacture of large ocean-going tuna purse seine vessels. However, some domestic purse seine vessels is the transformation from trawlers and other, accompanied by an increase in purse-seine ship, fishing boat accident also occurred, it is necessary to strengthen the purse seine vessels safety. In this paper, the characteristics of purse seine vessels are described and discussed in detail the work of purse seine vessels and sailing characteristics. Introduced and studied purse seine vessels operating process, explore insecurity exist in the process of fishing operations. The thesis focused and net torque, roll influence, detailed analysis of catch overturning moment. 1. Consider and net torque conditions, by solving the roll control equations to study the ship rolling up. Torque under. Analysis and net the process ship by force the situation to determine the twist closing the purse at the end stage and net torque. Catch species decided to catch the sliding the starting angular size, sliding catch the start angle θ0 fish tank width affect the overturning moment size. With examples ship start angle θ0 = 3 °, 6 °, 12 °, sliding catch in the fish hold case were calculated, θ0 = 3 °, 6 ° when the ship of residual stability θ0 = 12 ° of residual stability still meet the specification. The results showed that the the slide starting angle is smaller, easy to ship unsafe. Different wind direction from the network, were calculated under the wind, the upper hand in the nets when the stability of the ship. Calculation example ship stability criteria, downwind nets broadside, the ship in a dangerous state; nets broadside on the wind direction from the network, the ship safer. Taking into account the specification requirements for fishing vessels operating maximum roll angle of 22.5 ° calculated stability criteria, for instance the ship slowly up the net, the ship complies with the requirements of operational safety. Thus, the ship easily and net operating upwind slow. Necessary, work boats towing net boats in the non-starting network of side, reduced from the net force on the net boats. In view of the above calculations and operating process analysis, respectively from manipulation, fishing operations and loading tripartite face the fence a ship security countermeasures, people pay attention to protect the safety of catches and fishing.