This is the ships gas pedal, Power Level Actuator. It is a small linkage inside the LM2500 enclosure on a gas turbine powered ship. The linkage connects the input servo and the fuel control of the engine. The input comes to the engine from different possible sources.

Source one is located right in the engine room. Each engine has a throttle lever very similar to that of a regular boat. Push it forward and it increases your relative forward speed. Pull it back and the engine throttles down and eventually will switch the pitch on the props.

The next spot is in central control. The control here is a small knob. It is sort of like the volume control on your radio, no kidding! This will only control the power level in the engine so pitch of the prop must be controlled else where.

The last spot is on the bridge. This again is a control similar to that of your pleasure boat. Each of these control stations sends a signal to the engine servo and in turn moves the small lever on the engine itself.
One check that has to be done is taking the PLA off the engine, and then measure it. It has to be a certain length and it has a very tight tolerance. This is kind of a strange check since the PLA is lock wired at both ends and uses lock washers. But, the Navy knows what it is doing. But with the operating temperature of the engine I guess it could work its way loose.