type, in which a circulator forces the water to move
Book, the Damage Control Book, and the General
Information Book for your own ship.
continuously through the system. This allows hot water
to be available at the taps at all times and prevents the
Sprinkling Systems
waste of potable water. The water is heated in a hot
water tank by low-pressure auxiliary steam coils. This
Sprinkling systems are installed aboard ship in
system will be secured during battle conditions when
magazine turrets, turret handling rooms, hangar decks,
each battle dressing station is served by a separate
missile spaces, and other spaces where flammable
storage tank and a small hot water heater. The water is
materials are stowed. Water for these systems is
routed from the tank to the electric water heaters at the
supplied from the firemain through branch lines. A gate
stations.
valve is installed in each branch line, as close to the
firemain as practicable, and ahead of the sprinkling
Electronics Cooling Water System
control valves. The gate valve is normally kept in the
Cooling water systems are now provided on most
open position by a securing device (NOT a padlock).
ships to cool electronics equipment. In this system,
Most sprinkling systems aboard ship are of the dry
fresh water is usually circulated through the electronics
type, that is, they are not charged with water beyond the
equipment to carry away the heat generated during
sprinkling control valves except when they are in use.
operation. Potable water taken on from shore should
Some missile magazines are equipped with a wet
not be used to replenish the system. Only distilled water
type of sprinkling system. These systems are charged
(0.065 equivalents per million (epm) chlorides
with water up to the spray head valves. The sprinkling
maximum) should be used for replenishment. Where
control valves in some systems are operated
automatically, by heat-actuated devices. Others are
operated manually or hydraulically, either locally or
or below the prescribed limit. For specific information
from remote stations. Figure 15-37 shows a hydraulic
on the system, the ship's information book or other
oil-operated control system for operating magazine
sources of ship information should be consulted.
sprinkling control valves. On more recent ships, the
Firemain System
sprinkling control valves are actuated by a hydraulic
saltwater control system supplied by the firemain
In ships built to Navy specifications, the firemain
system.
material must be made of copper-nickel alloy with
In the space being protected, the piping, fitted with
copper-nickel or bronze fittings and bronze valves.
spray nozzles, is installed in such a manner that no
There are, however, a number of older ships with
portion of the installation will form an obstruction to
firemain systems made of ferrous materials.
handling or stowing material in the space. On older
The pumps used to maintain pressure in the
ships, the piping does not have spray nozzles. Instead,
firemain system may be steam-driven reciprocating
holes are drilled in the upper portion of the distribution
pumps or centrifugal pumps driven by steam turbines,
piping to permit water to spray on the overhead and
electric motors, or (in some cases) diesel engines.
bulkheads.
These pumps are classified according to their use as tire
Most piping material used in sprinkling systems is
pumps; fire and bilge pumps; fire and flushing pumps;
copper-nickel. An exception is the piping grid in dry
or fire, flushing, and drainage pumps. Firemain
systems, which is made of aluminum alloy. The
working pressures vary from 50 psi on small craft to
operating pressure is the same as that of the firemain.
175 psi on recently built ships.
For more complete details of sprinkling systems,
You must be thoroughly familiar with the location
consult your ship's General Information Book and
of the firemain, the pumps, the riser piping, the
Damage Control Book.
fireplugs, the cross connections, and the principal
isolation valves. Study the system aboard your ship by
Water Washdown Systems
tracing the piping from bow to stern, from deck to deck,
compartment by compartment. Then study the
Water washdown systems are essentially dry pipe
blueprints and diagrams of the system, and the
sprinkler systems. They have specially designed
information given in the Engineering Casualty Control
nozzles that are installed so that they will throw a large
spray pattern of water. These systems are installed
15-43