Naval engineers are constantly striving to design a more reliable engineering plant that provides quick response and requires fewer personnel to operate it. With advances in engineering technology, the use of solid-state devices and the addition of logic and computer systems, some of these design goals were achieved in the automated central operating system (ACOS).

As shown in figure 6-22.  ACOS centralizes the engineering plant with all controls and indicators located at the central control station (CCS). The use of logic and computer systems reduces

Figure 6-22.-Typical central control station (CCS) for FFG-7 class ships.

the chance of operator error in performing engineering functions. Automatic bell and data loggers reduce the task of hourly readings previously taken by watch standers. Probably the single most important function is the automatic and continuous monitoring of the engineering plant conditions (parameters) and the subsequent automatic alarm if a condition exceeds a set limit.

This section will describe the ACOS that deals with the gas turbine reduction gear and the CRP propeller propulsion system that is currently being installed in new construction ships.

The ACOS provides the means for operating the ship's propulsion plant safely and efficiently. It furnishes the operators with the controls and displays required to start and stop the gas turbine engines. It also furnishes the operators with the controls necessary to change the ship's speed and direction by changing the gas turbine speed and the pitch of the propeller. These operations are performed at panels or consoles containing the necessary controls and indications for safe operation.

GENERAL DESCRIPTION

The propulsion plant may be operated from the following three stations:

1. The local control console

2. The central control console

3. The ship control console

Figure 6-23.-Propulsion control system.

Figure 6-23 is a simplified diagram of the entire propulsion control system.