Assistant chief engineer

The assistant chief engineer or assistant engineer was the primary assistant or backup to the chief engineer.

In situations when the chief engineer is away from the engine room, the assistant chief engineer is responsible for overseeing engineering until the chief engineer returns. 

If a chief engineer is either incapacitated or killed in action, the assistant chief engineer is made chief engineer. 

List of assistant chief engineers
USS Enterprise (NCC-1701) USS Enterprise (NCC-1701-D) Varro generational ship USS Voyager Unnamed Y-500 class freighter
 * Lieutenant DeSalle (2267)
 * Jim Shimoda (2364)
 * Lieutenant Junior Grade Singh (2364)
 * Ensign Clancy (2365)
 * Derran Tal
 * Lieutenant Joseph Carey (2371-2378)
 * George Webb

Chef-ingénieur assistant Assistant chief engineer