The Chief Engineer is responsible for the condition of all systems and equipment on board a Starfleet ship or facility. S/he oversees maintenance, repairs and upgrades of all equipment. S/he is also responsible for the many repairs teams during crisis situations. The Chief Engineer is not only the Department head but also a Senior Officer, responsible for all the crew members in her/his department and maintenance of the duty rosters.
The Assistant Chief Engineer assists the Chief Engineer in the daily work; in issues regarding mechanical, administrative matters and co-ordaining repairs with other departments. If so required the Asst. Chief Engineer must be able to take over as Chief Engineer, and thus must be versed in current information regarding the ship or facility.
There are several non-specialized Engineers aboard of each vessel. They are assigned to their duties by the Chief Engineer and his Assistant, performing a number of different tasks as required (i.e. general maintenance and repair). Generally Engineers as assigned to more specialized Engineering person to assist in there work is so requested by the specialized Engineer.
The Engineer's Mate trains and supervises Engineering crewmen in departmental operations, repairs, and protocols; maintains duty assignments for all Engineering personnel; and is qualified to temporarily act as Chief Engineer if so ordered. The Engineer's Mate reports to the Chief Engineer.
The Transporter Chief is responsible for all transports to and from other ships and any planetary bodies. When transporting is not going on, the Transporter Chief is responsible for keeping the transporters running at peak efficiency. The team assigned to the Transporter Chief is made up from NCO personnel, assigned by the Asst. and Chief Engineer. The Transporter Chief reports to the Asst and Chief Engineer.