This is the 2809th most frequent Japanese word.
隊長
Commander; Leader of a group or squad.
In this sentence, 隊長 (captain) is used to signify the leader of a team, emphasizing their role in ensuring safety during a task.
隊長はチームを安全に導いた。
The captain led the team safely.
Here, 隊長 is used in a self-reference context, highlighting the duties and responsibilities associated with being the captain.
今日は隊長としての責任を果たさなければならない。
Today, I must fulfill my responsibilities as the captain.
In this context, 隊長 is referring to a person who has newly assumed the role of captain, showing the congratulatory aspect of leadership transition.