Portable LSTHOF-42 cables in suitable lengths
are located in several strategic positions throughout the
form all the circuits required to supply power to
ship for use with the casualty power system.
equipment designated to receive casualty power. While
In general, the casualty power system provides a
the normal current-carrying capacity of LSTHOF-42
horizontal run of portable cable along the damage
cables is 93 amperes, its casualty rating is 200 amperes.
control deck with risers for the power supply and for
Under normal conditions, this cable will carry 200
loads extending to and from this level. Rigging and
amperes for 4 hours without damage to the cable.
unrigging casualty power cables are described in
chapter 3 of this manual.
The bulkhead terminals carry circuits through
bulkheads without impairing the watertight integrity of
In figure 14-11, the ship's service switchboards ( 1S
the ship.
and 2S) and the emergency switchboards (1E and 2E)
Power panels supplying equipment designated for
are provided with casualty power terminals installed on
the back of the switchboard. Each casualty power
casualty power service are equipped with terminals so
terminal is connected to the buses through a standard
that casualty power can be fed into the panels. These
250-ampere AQB circuit breaker. The circuit breakers
panels can also be used as a source of power for the
have an instantaneous (magnetic) trip element setting to
casualty power system if power is still available from
prevent tripping of the generator breaker or fusing of the
the permanent feeders to the panels. However, the
casualty power cable under short-circuit conditions.
decision to take power from the panel instead of the
Connections to the buses are between the generator
switchboard should be based on knowledge that
circuit breaker and the disconnect switch.
equipment on that panel will not be required for the
safety of the ship. Operating the equipment normally
MARINE GAS TURBINE CASUALTIES
supplied by the panel plus the equipment to be supplied
with casualty power may cause an overload on the
Normally, any casualty to a marine gas turbine unit
will require that the unit be secured. Therefore, you
circuit breaker supplying the panel. Portable switches
Figure 14-12.--Normal stop modes.
14-22
