Division of work for CTD observations

　Observations using the CTD water sampling system are performed in cooperation with (1) operators, (2) On-site workers, (3) Winch operator, and (4) ship bridge duty personnel (Figure 6).

Fig.6　Division of work for CTD observations

CTD観測　CTD observations

・オペレーター　Operator

船上局の操作　Operation of shipboard stations

データの監視　Data Monitoring

野帳の記録　Field notebook records

・現場作業者　On-site workers

採水器のセッティング　Setting up water sampling equipment

水中局の投入，揚収作業　Underwater station loading and unloading

・ウィンチマン　Winch operator

ウインチ，クレーンの操作　Operation of winches and cranes

・船橋当直者　Ship bridge duty personnel

操船　Handling a ship

① Operator

　The software on the onboard station and data recording PC are operated in the onboard operation room (Figure 7). During the observation, the winchman is instructed to stop, wind up, and unload the winch at the necessary timing while checking on the monitor that the data is being acquired normally. In addition, the date and time of the observation, ship's position (latitude and longitude), weather conditions, and other information are recorded in a logbook called a field notebook. The operator is also responsible for stopping the submersible station at a pre-determined water sampling depth, sending a water sampling signal from the onboard station, and closing the lid of the water sampler. The operator monitors data in real time, gives instructions to each person in charge of the work, and collects information, and thus serves as the control tower for the observation.

Fig.7　CTD Operations

② On-site workers

　The underwater station will be deployed on the observation deck. Before deploying the station, the lid of the water sampler is opened and the water sampling device is prepared for deployment in the sea. During the loading and unloading operations, the submersible station is secured with ropes to prevent it from swinging around due to the ship's motion. Once the underwater station has been lifted, the seawater sample is separated from the water sampler (water distribution) (Figure 8).

Fig.8　Water distribution

 

③ Winch operator

 Operates winches and cranes in the winch control room. During observation, the winch is stopped, hoisted, and unloaded in response to instructions from the operator.

 

④ Ship bridge duty personnel

 During the observation, the vessel is maneuvered to maintain the vessel's observation configuration while taking into account current, wind, and wave conditions in accordance with instructions from the operator, on-site workers, and winch operator. Maneuvering involves adjusting rudder angle, wing angle, and attitude control propellers called thrusters. Especially during the loading and unloading of underwater stations, skill is required to minimize the ship's rolling motion.