It is common that a single officer handles a ship in ocean area. In case of navigating in a congested water area or restricted water area, the number of officers is increased and the ratings are also arranged to support them. It can be thought that a bridge team is organized for accomplishment of higher ability for preventing accident in the difficult situation. The relation between the condition of single watch and one of bridge team is shown in Fig. 5. When the necessary ability required by environment is low, safe navigation will be maintained by single watch shown by situation "A". When the required ability goes up in narrow water area, safe navigation cannot be realized by single watch shown by situation "B". By organizing a bridge team for this condition, the ability increases shown by "C" and a countermeasure can be taken against the dangerous situation.

　

 In case of a bridge team, plural members share the necessary task, in order to accomplish the object task to realize safe navigation by them. They can complete many tasks with high accuracy within limited time that cannot be accomplished by a single officer. Mainly, following three functions shall be needed to activate the bridge team. One of them is to complete the shared task that is basic skill for ship handling and is also needed in single watch condition. Second one is to integrate the shared task to make a reasonable decision making for completion of the safe navigation. All of shared tasks are needed to do. Main function of integration is accomplished by communication. Third important function for realizing complete bridge team is to make good cooperation among the team members. The coordinated movements and collaboration that are carried out naturally in single watch condition should also be accomplished in the team. For example, when the member takes charge of look out to find a dangerous target vessel as visual information, at that time, other member taking charge of watch RADAR has to examine the detail information on it and informs another members. This is one function of cooperation that is carried out in a single person without consciousness.

　

 Bridge team can accomplish higher function than single watch when the tasks mentioned above are completed. On the contrary, the function of the team shows lower than single watch when one or more functions to be done in team are lacked. Most of accidents that are judged as a result of insufficient BTM or BRM correspond to this situation. Although the members complete their tasks that are positioning, observation of the movement of traffic vessels and so on, if the contents were not reflected for the handling, it is same as nothing to have been done. Then the team carries out navigation with insufficient task processing. In case of navigating in very hard environment, insufficient behavior often makes accidents. Situation "F'" in Fig. 5 shows such insufficient Bridge Team situation. The ability of the bridge team is lower than ability of single watch.

　

　

 As mentioned above the section, following functions are needed for competence of a bridge team.

　

　

 The achievement of basic tasks is needed not only in bridge teams, but also in single watch. It is not special functions for team activity. However, the communication and cooperation are indispensable function to achieve the common objects when plural persons share the tasks. They are necessary functions for a bridge team. The objective of Bridge Team Management is to activate the function of a bridge team. For improving the activity, all of members in a bridge team should accomplish their function. So, the Bridge Team Management shall be attained by all of members. On the other hand, it is needed for a team leader to manage the members in the team. The management is to make the members understand their shared tasks and to make them achieve their required functions. The functions of team leader are Bridge Resource Management.

　

5.1 Training on Bridge Team Management

　

 In Tokyo University of Mercantile Marine, training to improve the bridge team activities has been carried out more than 120 cases in these 5 years. Normal members of bridge team is organized by Captain, 2^nd officer, 3^rd officer and Q/M. Sometime, one more rating joins them as AB. 4 or 5 persons make a bridge team. In the training of Bridge Team Management, firstly, a lecture on the function being required in a bridge team to activate the function in the bridge team is made based on the concept mentioned in this paper. In the lecture, it is also pointed out that a chain of human errors will be broken and accidents will be protected when the communication among the members is fine. BTM is effective not only on improvement of bridge team activity but it is also useful to stop the extension of human error to accident.

　

 Next, the maneuvering characteristics of a ship using in following training are lectured. Before carrying out training in a ship handling simulator, briefing by the captain is executed for 30 to 60 minutes. The assessment on behavior of the team members is started from the captain briefing. The training of ship handling using the simulator is carried out 3 or 4 times. The contents of training scenarios are developed based on the necessary function of each member in several kinds of handling cases. The behavior of each member is assessed relating to team activity. One training using the simulator takes 40 to 120 minutes and contains the several kinds of events.

　

 As mentioned above, in case of an easy navigational environment, the ability of only leader is enough to maintain the safe handling. On the contrary, in case of a difficult condition of environment, communication and cooperation are very important for a bridge team. The assessments on the communication and the cooperation are executed for this situation. When the members do not achieve these necessary functions, the ship approaches to risky situation rapidly.

　

 A post-briefing is carried out for 1 to 2 hours right after finishing the training using the simulator. The briefing is carried out concerning the each member's behavior. Required functions in each event are explained for both cases of attaining the function and of insufficient. Normally, the attainment in 1^st training is about 50%, but the attainment of each member in 3^rd training becomes over 80%.

　

5.2 The function of Bridge Team and Maneuvering Results

　

 The maneuvering results are shown in this section to point out the importance of the necessary technique in a bridge team. The examples of dangerous situations caused by lacking the function which are necessary in a bridge team are shown.

　

　

　When a ship proceeded in Singapore Strait in east bound, she abnormally closed to a small ferry boat coming from a Singapore harbor to Indonesia. This situation is shown in Fig. 6. Discs indicate the positions of own ship and squares indicate ones of the ferry boat at every minute. 3/O detected the ferry boat in early stage but he had not informed it until 48 min had past since the start of the training. He had attained his shared task that is look-out but he had not attained the function of communication.

　

　

 The captain had been very busy for avoiding another vessel before receiving this information. The captain had not recognized the ferry boat. Although the 3/O detected the small ferry boat, the existence of ferry boat was not taken into consideration to handling when no one informed it. As a result, it is same as the situation without look-out in the team. In case of single watch, it is normal that navigator keeps watch on all of traffic vessels even while avoiding one specific vessel. The captain thought that the 3/O kept watch on traffic vessels and he would inform the traffic situation. It is the reason why the captain did not pay attention on the ferry boat. Therefore, in order to complete the tasks of team, each of the members have to attain not only the shared task but he also have to attain the task of integration to reflect the each function in team on team behavior. The technique to integrate communication is necessary for team activities. In case of the handling ship, though hard port as rudder angle was applied, she closed to the boat within 1 cable.

　

　

 When a ship proceeded in Singapore Strait in east bound, she abnormally closed to a small cargo boat coming from a Singapore harbor to Indonesia. This situation is shown in Fig. 7. Discs indicate the positions of own ship and squares indicate ones of the cargo boat at every minute. 3/O was in charge of watch on traffic vessels and communication to outsides using VHF. As he was busy to communicate with Singapore VTIS concerning the report on entering Singapore Strait, he could not detect the small cargo boat. As a result, both the ships closed abnormally without detecting. In the action of the team, it is commonly said that shared tasks are not always needed evenly among all members. Sometime, a person being in charge of plural tasks has to attain the plural tasks simultaneously. In this case, the other member has to carry out the tasks for him. In case of this handling result, 2/O executed the positioning of which he was in charge. He did not recognize the situation of the 3/O and did carry out nothing for him. As a result, the Captain found the boat at 1.1 miles distance at 4 min past start by using radar. It is very late recognition for VLCC to find the dangerous traffic vessels within 3 miles.

　

　

　

 When a ship proceeded in Singapore Strait in east bound, she abnormally slowed down for avoiding a collision with a small ferry boat coming from Singapore harbor to Indonesia. This situation is shown in Fig. 8. Discs indicate the positions of own ship and squares indicate ones of the ferry boat at every minute. 3/0 was in charge of watch on traffic vessels. As both of the captain and the 3/0 paid attention on a vessel following own ship, they could not find the small ferry boat coming from left side. The 3/0 had to pay attention not only specific vessels but he also had to watch on all the surrounding vessels. Basic required functions for team members are to attain the shared tasks completely. When the shared tasks are not attained, the team makes decision without the function. It is very dangerous situation. As a results of this example, the captain had to make abnormally slowing down to avoid a collision.

　

　

 By the reason of the page limitation, only 3 cases are shown as the examples of case of lack of necessary techniques for bridge teams. It is needed for bridge teams to improve different functions from single watch. It is an important objective for training of BTM to improve these necessary functions in a bridge team.

　

 Rarely happened maritime accidents in many traffic vessels may be treated as contingent events. In order to prevent occurrence of accidents, it is important to consider that there are distinct reasons to occur the accident. In this paper, the concept that accidents may happen when plural rarely happened events occur simultaneously is proposed. The meaning of organizing bridge team is clarified based on the proposed concept. Furthermore, it is shown that three functions are needed for bridge teams to complete the objectives. Especially, the functions on communication and cooperation are pointed out as the necessary function for bridge teams. As a special condition of bridge teams is to share tasks by plural members, communication that is the function to integrate shared tasks and cooperation that is a function of coordination in a team are important to improve the activity of bridge teams.

　

[1] KOBAYASHI, H. "Required Techniques in BRM", Proceedings of the 28th International Maritime Simulation Forum (IMSF), Genova, Italy, 2001

[2] TOYA, S., KOBAYASHI, H. and SENDA,S "Basic study on analysis of the function in bridge team", 11th International Navigation Simulator Lecturers' Conference. Kalmar, Sweden, pp.139-146, 2000

　

 Dr. Hiroaki Kobayashi is a professor of Tokyo University of Mercantile Marine. He is a chairman of International Marine Simulator Forum. He is the honorary chairman of Ship Handling Simulator Committee in Japan Institute of Navigation and a member of steering committee in International Navigation Simulator Lectures Conference in IMLA.

　

 His major fields are man-machine system analysis in ship handling, seamen's training, safety evaluation of ship maneuvering and ship maneuverability.

　

 He is chairman of Committee on the seamen's training using Ship Handling Simulator organized by Japan captain association.

　

 He holds a Bachelor's degree (Navigation) from Tokyo University of Mercantile Marine, a Bachelor's degree (Engineering) from Osaka University, a Master's degree (Engineering) from Hiroshima University and a Doctoral degree in Engineering from University of Tokyo.