우리나라 근해 대형트롤 어선의 조업효율 개선을 위한 최적 선교 Layout의 도출에 관한 연구

Abstract

The purpose of this study is to find out the necessary knowledge and crew's activities on the bridge and the deck of existing trawler for the optimized bridge and deck layout design to trawl fishing in the future at the coastal sea of Korea. As a result, to reduce the workload of the crew, according to the safe navigation and fishing operation is to improve the profitability of the trawler. A survey research was conducted with the crew working on the bridge of existing Korean large trawler along with a field investigation on the equipment on bridges and decks to analyze the activities of the crew on the bridge and deck used the video-observation method as a semi-empirical method. Using the collected video data, there were analyzed about the bridge workers’ activities in the fields of the single tasks, dual task, frequency using of the equipment, traffic line, the behaviors of work and links between bridge devices. Also the crew's activities on deck of two trawlers with different deck layouts were observed, and a hierarchical task analysis method was used for the evaluation. The collected data from the aforementioned studies and advanced research of ergonomic workplace design principles and the regulations regarding bridge layout design presented by the IMO and the DNV were consulted to draw the optimum layout of the bridge and deck for the trawler. Furthermore, a blueprint evaluation tool to determine whether the bridge task was suitable or not in accordance with a CAD blueprint was established, and evaluated the acquired layouts for the purpose of this study. Thorough the research process it was possible to derivate the layout of the bridge and the deck of a trawler, that can reduce the locomotion of the crew as known cause of fatigue, that doesn't require long work time standing and frequent body rotations, and that makes one man bridge task easier. Identified in the study, the results of the bridge, characteristics of bridge workers, the bridge task of existing trawler, the results of bridge layout optimization for user in the future and the results of comparison analysis of the working process based on the difference of the deck layout are summarized as follows. Frequency and their rates responded to the questionnaire survey for evaluating demographic characteristics of bridge workers of Korean offshore large trawlers were obtained: 97.1% of bridge workers was more than 40 years old, 73.5% was graduated high school, and 76.4% and 22.1% of deck officer certificate were 4th to 6th class and 3rd class, respectively. In the work experience period 89.7% of deck officer and 41.2% of skipper were more than 9 years. In the average daily work 89.7% of the bridge workers worked more than 12 hours. Equipment installed in the bridge of Korean offshore large trawler were a radar, an ARPA radar, a GPS plotter, a DGPS receiver, an ECDIS and a clinometer and their retention rate were 134.6%, 100%, 123.1%, 115.4%, 42.3% and 42.3%, respectively. In the internal and external communication equipment the retention rate of a MF/HF telephone, a VHF telephone, a marine telephone, a satellite telephone and an interphone were 369.2%, 273.1%, 100%, 100% and 165.4%, respectively. In the equipment related to weather such as weather information receiver, a thermometer, a barometer and an anemometer had the retention rate of 100%, 61.5%, 46.2% and 3.8%, respectively. Fishing equipment such as a fish finder, a net monitor, a current meter and a scanning sonar had the retention rate of 146.2%, 134.6%, 34.6% and 15.4%, respectively. Other equipment such as a rotary window controller, a navigation light, a light controller, a coffee maker and a refrigerator were all 100% on board. The number of fishing operation was 5 times in daily average. The time duration of the fishing operation was 195.6 to 370.7 minutes and 280.8 minutes on average. The percentage of time took for casting, towing, and hauling were 6.0%, 89.2% and 4.9%, respectively. The duty for towing was divided into 6 as the warp adjustment, the U-turn and the resetting net, the exchange of fishing condition information among trawlers, fish products management, watch-keeping and others. In the case of traffic line of bridge workers, the moved average distance for 1 hour of the worker during navigation, casting net, towing net, and hauling net were 168.3 m, 292.3 m, 177.6 m and 286.0 m and having the time portion of 7.2%, 12.2%, 7.9% and 10.8%, respectively. Average speeds of the movement of bridge workers, 38.8 m/min, 39.1 m/min, 37.7 m/min and 44.3 m/min, respectively. In the case of work posture, for standing work, they were 74.0%, 83.7%, 74.2% and 89.2% while 16.3%, 4.1%, 9.5% and none for sitting work, respectively. Number of 90° body rotations per minute were 0.6 times, 1.6 times, 0.8 times and 1.9 times, 180° body rotations, 0.4 times, 1.2 times, 0.5 times and 1.6 times, respectively. In the work pattern of the bridge workers there were 13 to 15 single tasks: monitoring task (lookout, the radar, the GPS plotter, the gyro-compass card, a RPM indicator, a rudder angle indicator, the fish finder, the net monitor, the fishing deck), maneuvering task (the steering gear, the speed controller, the trawl winch), external communication, document work and etc. For dual tasks, the steering and monitoring (fishing deck monitoring, the radar, the lookout, the rudder angle indicator, the fish finder, the GPS plotter), external communication and document work, together with monitoring (the radar, the fish finder, the net monitor, the lookout, the GPS plotter), the trawl winch and the fishing deck monitoring. The equipment usage frequency ranking for navigation was the radar, the fish finder, the GPS plotter and the external communication system. For towing it was the radar, the net monitor, the fish finder, the GPS plotter, the steering gear, the external communication. For casting and hauling it was the trawl winch, the GPS plotter, and the radar (skipper) while the steering gear, the radar, the speed controller, the GPS plotter, the net monitor, the fish finder (mate). The operation sequence for the task of warp adjustment was the fish finder, the net monitor, the speed controller, the trawl winch, the speed controller, the net monitor and the radar. For the task of U-turn and resetting the net it was the radar, the speed controller, the trawl winch, the steering gear and the speed controller. While the net monitor and the GPS plotter were used in both tasks according to the situation. At the link analysis, the machine and equipment showed at the center of the link line were the radar, the steering gear and the trawl winch. The Equipment that has close relationship with the link line center could be ranked as follows: For radar, in the case of navigation the GPS plotter, the external communication (the VHF, the MF/HF), location of the microphone and the steering gear. In the case of the casting net the steering gear, the GPS plotter and the aft window. In the case of the towing net, the steering gear, the net monitor and the GPS plotter. In the case of the hauling net, the radar did not show at the center of the link line. The steering gear had close relationship with the GPS plotter, the speed controller, the external communication microphone's location for navigation, and the speed controller, the fish finder, the external communication microphone's location and the GPS plotter for casting and hauling, the GPS plotter, the net monitor, the fish finder for towing. Basic data for development of optimum method of the bridge of trawler were findings of this research, knowledge in ergonomics and regulations of IMO and DNV. As the result of improved bridge layout, the reduced moving distance per 1 hour were 85.0 m, 129.0 m, 77.5 m and 100.3 m for the navigation, the casting net, the towing net, and the hauling net, respectively, and the reduction rate of the moved distance were estimated to be 51.2%, 45.0%, 40.8% and 34.7%, respectively. The task difference of the trawler having the trawl winch built on the stern (trawl-A) and middle (trawl-B) of the deck was analyzed while two trawlers’ hauling and casting sequence of tasks were identical and the working processes were revealed to be 52 and 76, respectively. In the case of improvement factors obtained from the study, test vessel-A and test vessel-B cut 13 and 39 working processes, respectively, and their reduction effects were estimated to be 25.0% and 51.3% each.