Figure 14-13.--Emergency stop modes.
out-of-limits parameter may be sensed by either the
need to know the casualty control procedures for marine
control system or b y the operator. If the control system
gas turbine casualties. In this section, you will learn
senses an out-of-limits parameter, electronic logic
some of the procedures for securing a gas turbine
causes the engine to stop. If the operator senses the
engine. The three most common methods for securing
out-of-limits parameter, the operator should manually
gas turbine engines are (1) normal stop (normal
stop the gas turbine by using the manual emergency stop
5-minute cool down and stabilization period), (2)
switches.
emergency stop (operator or logic initiated by hazardous
out-of-limits parameter), and (3) fire stop (operator- or
NOTE: Certain logic stop functions may be
logic-sensed fire).
disabled if battle override is on.
Normal Stop Mode
Fire Stop Mode
The normal stop mode is the most common method
The fire stop mode is used when a fire is detected
used to stop a gas turbine. Referring to figure 14-12,
inside the gas turbine module (GTM). Figure 14-14
you can see that there are three submodes to the normal
shows the two methods by which the fire stop mode may
stop:
be used.
1. Manual--refers to the actual operator-induced
actions
2. Initiate--refers to the STOP initiate PUSH
BUTTON on the STAR/STOP panel of the
operating console
3. Logic--refers to the electronic logic as
Programmed into the control console
Emergency Stop Mode
The emergency stop mode (fig. 14-13) is the most
commonly used method to stop a gas turbine when a
Figure 14-14.--Fire stop modes.
hazardous, out-of-limits parameter is sensed. An
14-23
