5. TARGET OF ANALYSIS
We applied discourse analysis methods to actual cooperation, which were conducted in BRM trainings. The trainings were carried out by Japan Marine Science, Inc. as 3 days training course from May 28 to Jun I , 2002. In the course, 8 times simulator trainings were conducted. Each of simulator training is around 40 minutes. Among 8 times of trainings, we selected 2 trainings, No. 3 and No. 8, where the ship runs on the westbound lane off Singapore port. The scenario is most difficult among others, since the area is heavily congested, and an effective corporation is required for safe navigation. From here, we refer the training No.3 as Training A, No.8 as Training B.
The trail of the ship in a training, the ship navigated in the westbound lane off Singapore port (in Training B)
In each training scenario, Captain has a full responsibility for navigation. 2/O is assigned duties, such as lookout and communication. 3/O is assigned duties, such as positioning and engine control. Q/M is responsible for helm. And each crew is instructed to cooperate to avoid errors by communications, cross check and other human error factors.
Table.1 shows characteristics of trainings that we analyzed. There are significant differences in the number of utterances between Training A and Training B.
Table 1 Characteristics of analyzed training
|Num. of Utterances among crews
|Num. of Exchanges
Members are playing different roles in each of trainings. In the training B, an expert plays Captain role, on the contrary, non-expert works as Captain in the training A.
6. DISCOURSE ANALYSIS OF TEAM INTERACTIONS ON A BRIDGE
6.1. Communication Flow
Fig.8 shows communication flows among crews. The number on each of arrows shows the frequency of utterances. This diagram shows a clear structure that Captain is in the center of the organization and most of all communications occur between Captain and a crew. The number of communications in Training B is higher than that in Training A. Especially communication between Captain and Q/M shows high frequency.
Fig.8 Communication flow among crews
6.2 Exchanged Information
Fig.9 shows the distribution of exchanged information. Unit is the number of exchange, which consists of several utterances. In both training, communications about another vessel are frequently occurred. In Training B, communications about helm order shows high frequency This is the major factor of the difference of the total number of utterances between two trainings.
Fig.9 Frequency of Exchanges
Fig.10 shows the distribution of elements that composes communications about another ship. In both cases, distance to another ship is most frequently exchanged. In Training A positions of other ships are often mentioned, however, movements of other ships are attended in Training B. CPA is an acronym of Closest Point of Approach.
Fig.10 Distribution of elements regarding to another vessel
Fig.11 shows the distribution of elements that relate to maneuvering. This shows significant difference in a way of cooperative maneuvering. In Training A, Captain orders to Q/M by indicating a course and Q/M is responsible for controlling helm. However, in Training B, Captain orders by rudder angle. It requires frequent exchanges of information about the rudder angle and the ship rotation between Captain and Q/M. The differences in maneuvering method contributed to the difference of the number of conversations in each of training.