The top of this chain of command is the Chief engineer (or first engineer), who is in command of engine room and auxiliary areas that would relate. Then comes the first assistant engineer, or second engineer, second assistant engineer (third engineer, and then the third assistant engineer, or fourth engineer. These are the officers within the engine company of a standard ship.
The highest ranking officer in an engine department on a typical ship is the Chief Engineer (or first engineer). They oversee all engine room operations and related areas. The next in line is the First Assistant Engineer, or Second engineer, followed by the Third assistant engineer, and then the Fourth engineer.