used on some ships). The anchor lights are energized
Minesweeping Lights
through individual on-off rotary snap switches on the
The MINESWEEPING LIGHTS (green) are an
signal and anchor light supply and control panel in the
array of three 32-point (360) lights placed to form a
pilot house. The after anchor light is placed at least 4.5
triangular shape. These fixtures are equipped with
meters (14.75 feet) lower than the forward anchor light
50-watt lamps. One of the lights is placed near the
(table 4-9).
foremast head and one at each end of the fore yardarm
(fig. 4-15). These lights indicate that it is dangerous for
Testing Navigation Lights
another ship to approach within 1000 meters (3280.8
feet) of the mine-clearance vessel.
The supply, control, and telltale panel for the
Ship's Task Lights
running lights is a nonwatertight, sheet metal cabinet
designed for bulkhead mounting. `This panel (fig. 4-20)
The SHIP'S TASK LIGHTS are a dual array of
is provided to aid a ship in keeping its running lights lit
three 32-point (360) lights, port and starboard of the
as prescribed by the rules for preventing collisions at
mast or superstructure. They are arranged in a
sea. It is installed in or near the pilot house and gives
vertical line, one pair over the other so that the upper
an alarm when one of the navigation lights (forward and
and lower light pairs are the same distance from, and
after masthead, stem, and side lights) has a failure of its
not less than 2 meters (6.6 feet) above or below, the
middle light pairs. The lights must be visible for a
primary filament and is operating on its secondary
distance of at least 3 miles. The upper and lower lights
filament.
of this array are red, and the center lights are a clear
All shipboard navigational lights are tested daily
white.
while at sea. The test is usually made 1 hour before
These lights are equipped with multiple 15-watt,
sunset by the Quartermaster. The following paragraphs
one-filament lamps and are connected to the navigation
describe the indicated warnings of the telltale panel
light supply and control (not the telltale) panel. They
when a malfunction occurs.
may be controlled as follows:
The upper and lower red lights may be burned
1. Failure of the primary filament/circuit of any
one of the lights (forward and after masthead,
steadily to indicate the ship is not under
command.
stem, or side lights), will de-energize a relay
The upper and lower red lights may be flashed
2. This relay
by rotating the switch crank handle on the supply
a. effects a transfer of power to the secondary
and control panel to indicate a man-overboard
filament of the affected light,
condition exists.
b. sounds a buzzer
The three lights may burn simultaneously
c. lights an indicator light, and
to indicate the ship is unable to get out of the
way of approaching vessels. (This may be
d. moves an annunciator target to read OUT
due to launching or recovering aircraft,
(reads RESET when de-energized).
replenishment-at-sea operations, and so forth)
To silence the buzzer, you turn the handle of the
The switch for this application is labeled SHIP'S
reset switch 90 to the horizontal position. However,
TASK LIGHTS.
the indicator lamp of the affected light stays lit until the
Forward and After Anchor
repair has been completed, and the reset switch is turned
Lights
back to the normal (RESET) position. Certain ships
have permanent towing lights installed and connected
The FORWARD and AFTER ANCHOR LIGHTS
to control switches in the telltale panel. The towing light
(white) are 32-point (360) lights. The forward anchor
switches are manual. When failure of the primary
light is located near the stem of the ship, and the after
filament occurs in towing lights connectedto this panel,
anchor light is at the top of the flagstaff. The fixtures
the switch must be manually turned to the position
are splashproof, each provided with a 50-watt,
marked SEC, to energize the secondary filament.
one-filament lamp (50/50-watt, dual-filament lamps are
4-21
