본 논문에서는 조타기 작동 신호에 대하여 AIS 통신을 이용하여 상호 교환함으로써 상대선의 선회정보를 보다 신속히 파악할 수 있는 선회조기감지시스템을 구축하였으며, 이를 실선에 적용하여 해당 시스템의 실효성을 검증하였다. 조타 신호가 조타기를 작동함과 동시에 AIS를 통하여 송신되어 상대선의 ECDIS에 사용된 타각만큼 유색으로 표시되는 것을 확인하였다. 선회조기감지시스템을 통하여 상대선의 변침 상황을 조기에 감지할 수 있었으며, 이를 통한 선박 상호간 충돌회피가 조기에 가능할 것으로 판단된다. 또한, 의심 선박에 대한 VTS의 적극적 관제가 가능하고, 해양안전종합정보시스템을 통한 해양사고 분석에도 활용 가능할 것이다.
현재 완도항은 서남해안 물류거점의 항만으로 발돋움하기 위한 여러 가지 노력을 하고 있다. 이의 일환으로 항만 시스템 개선 사업을 수년전부터 활발하게 계획하고 있으며, 그중에 항만 내 선박 통항 시스템개선의 필요성이 제기되어 왔다. 이 연구에서는 현재 완도항만 및 그 인근 해역의 전반적인 해상교통 시스템을 살펴보고, 보다 효율적인 해상교통 시스템의 확보를 위한 기존의 시스템에 대한 개선점을 제안하고자 한다. 이를 위하여, 항만내 항로, 항만 내외의 묘박지에 대한 효율성을 검토하여 새롭게 제안하였다.
Since very large and high-speed ships have been appeared in marine transportation from 1970s, these ships with poor maneuverability have made large-scale accidents frequently all over the world. The IMO(International Maritime Organization) recommended that ship designers should evaluate various maneuvering performance at initial stage and serve them to ship operators when they deliver a new ship. Meantime, it is expected that ships with large and wide superstructure would have poor maneuverability when they are affected by strong wind. Therefore, car carrier ship with large superstructure was selected to confirm how the ship responds to the external wind forces in this paper. The lateral and transverse projected areas above the water level were considered and ship behaviors were checked by change of rudder angles under severe wind conditions of different directions. In addition, hydrodynamic derivatives and coefficients were predicted from ship particulars and numerical calculations were carried out with the mathematical model of low speed maneuvering motions.
In marine transportation of bulk cargoes such as crude oil. ore, coal etc., a lot of full form ship which have poor manoeuvrability were presented in many countries. Since ship manoeuvrability depends upon many parameters namely hydrodynamic derivatives, interference factors etc., as external forces, it is of great importance that we investigate these values of parameters on analysis of manoeuvrability. In this paper, we investigated and analyzed interaction coefficients among hull-propeller-rudder for a full form ship by captive model test in circulating water channel, and then compared with experimental results by PMM test. A tanker model ship which has 0.83 as block coefficient and MMG mathematical models were used in this experiment. Almost same tendencies were found in qualitative analysis, even though more serial experiments were demanded in quantitative analysis.
In the present trends at which vessels would be supersizedly designed for adapting special cargoes in order for effective controls of logistics in marine transportation, it brings poor manoeuvrability of ships and makes environmental or economical loss seriously due to accidents of a large scale at sea. International Maritime Organization adopted manoeuvring standards and also recommended manoeuvring booklets for ship operators recently. We attempted to find variation of hydrodynamic derivatives when a bare hull was fitted with propeller and rudder, or propeller only by captive model test in the circulating water channel. On comparing experimental results with theoretical values derived from equations, almost same tenden-cies were found at hull-propeller-rudder and hull-propeller situations. Interactions with rudder displayed well at large drift angles.
Nowadays, the transportation of almost all cargoes depends on sea routes in international trade. In the transaction of trade, cargo transportation must be completed on the base of two contrary objectives, one of which is to protect the vessel, cargoes and crew aborad her safely through every step of the transportation and the other is to pursue profits from the transaction of the trade. In spite of the great development of the modern techniques in shipbuilding today, many sea disaters of big merchant vessels have been occurring successively in winter seasons every year on the sea routes of the North Pacific Ocean. Whenever the accident of losing a vessel in rough sea occurred , many experts of the country to which the vessel belonged had tried to take out the reason of the missing without manifesting the exact cause of the unhappy occurrence. In this paper, we calculated ocean wave status along the route of the North Pacific Ocean theoretically concluded by us as optimum on the basis of weather and sea conditions. In the calculation, we used ITTC wave spectrum formula and meteorological data of "Winds '||'&'||' Waves of the north Pacific Ocean" edited by Ship Research Institute of Japan on the basic data assembled by World Meterological Organization through past 10 years. We selected three sample vessels of most common size in the North Pacific Ocean Routes, a container, a log carrier and a bulk carrier and applied tree sample vessels to the calculated sea conditions for getting the rolling angles of the vessels and stress exerting on the hulls. Examining the calculated results, we concluded as follows; 1. Under the condition of these status7 by beaufort scale, "heave to" maneuvering is the best and safest way to steer every vessel. 2. The most dangerous part of sea area along the west bound optimum route of the North Pacific Ocean in winter season, is the southern sea area of the Kamchatka peninsula.a peninsula.
In the restricted sea way such as fair way in harbor, narrow channel etc, the safe ship-handling is a very important problem, which is greatly related with turning ability of ships. It is of great importance that ship-handlers can grasp the position of pivoting point varying with time increase at any moment for relevant steering activities. Mean while, in advanced ship-building countries they study and investigated pivoting point related with turning characteristics, hut their main interest lies in ship design, not in safe ship controlling and maneuvering. In this regards it is the purpose of this paper to provide ship-handlers better under standing of pivoting point location together with turning characteristics and then to help them in safe ship-handling by presenting fact that pivoting points vary according to configuration of ships. The author calculated the variation of pivoting point as per time increase for various type of vessels, based on the hydrodynamic derivatives obtained at test of Davidson Laboratory of Stevens Institutes of Technology , New Jersey, U.S.A. The results were classified and investigated according to the magnitude of block coefficient , length-beam ratio, length-draft ratio, rudder area ratio ete, and undermentioned results were obtained. (1) The trajectory of pivoting point due to variation of rudder angle are all the same at any time, though the magenitude of turning circle are changed variously. (2) The moving of pivoting point is affected by the magnitude of block coefficient, length-beam ratio, length-draft ratio, however the effect by rudder area ratio might be disregarded. (3) In controlling and maneuvering of vessels in harbor, ship-handlers might regard that the pivoting point would be placed on 0.2~0.3L forward from center of gravity at initial stage. (4) The pivoting point of VLCC or container feeder vessels which have block coefficient more than 0.8 and length-beam ratio less than 6.5 are located on or over bow in the steady turning. (5) When a vessel intends to avoid some floating obstruction such as buoy forward around her eourse, the ship-handler might consider that the pivoting point would be close by bow in ballast condition and cloase by center of gravity in full-loaded condition.