What is the primary function of the devices shown in the illustration? GS-0156

Correct Answer: Option B — The locking plates are used to prevent the fastening devices from vibrating loose.

Locking plates are mechanical fasteners designed to prevent bolts or nuts from backing off due to engine vibration. By bending the tabs against the flat sides of the fastener head, the plate creates a positive mechanical lock, ensuring the integrity of the assembly as required by marine machinery maintenance standards.