conjunction with the ship's task lights when both are
respective sides of the vessel, showing red to port and
green to stardoard. The fixtures are spraytight, each
installed.
provided with a 50-watt, two-filament lamp, and
equipped with an external shield arranged to show the
Constrained by Draft
light from dead ahead to 2 points abaft the beam on the
Lights
respective sides. On older vessels, these fixtures may
be 100-watt brass fixtures.
The CONS TRAINED BY DRAFT LIGHTS (red)
are a dual array of three 32-point (360) lights. This
Stern Light
light array is similar to a task light array except that the
middle light fixtures are equipped with dual-color
The STERN LIGHT (white) is a 12-point (135)
(red/white) lenses. (See fig. 4-23, view C.) This middle
light located on the stem of the vessel. It is a watertight
fixture is spraytight and equipped with a multiple socket
fixture provided with a 50-watt filament lamp and
(fig. 4-23, view D) provided with nine 15-watt,
equipped with an external shield to show an unbroken
one-filament lamps. Six lamps are used in the top
light over an arc of the horizon of 12 points of the
multiple bulb socket for the red light and three in the
compass-that is, from dead astern to 6 points on each
bottom socket for the white light. Each light is
side of the ship.
energized from separate circuits. The middle red lights
are used in conjunction with the top red lights and
Forward Towing Lights
bottom red lights for constrained-by-draft light
functions, while the middle white lights are used
FORWARD TOWING LIGHTS (white) and
with these lights for task light functions. The dual,
AFTER TOWING LIGHTS (yellow) are normally
for ships engaged in towing operations. The forward
three red light array is displayed simultaneously to
upper and lower towing lights are 20-point (225)
indicate the ship is unable to get out of the way of an
lights, identical to the previously described masthead
approaching vessel in a narrow channel, due to
lights. These lights are installed on the same mast
ship's deep draft. The switch for this light display is
with the forward towing operations. The forward upper
labeled SHIP'S CONSTRAINED BY DRAFT
and lower towing lights are 20-point (225) lights,
LIGHTS.
identical to the previously described masthead lights.
These lights are installed on the same mast with the
Clearance/Obstruction
forward or after masthead lights, and the vertical
Lights
separation is 2 meters (6.6 feet). The after towing light
is a 12-point (135) light, similar to the previously
described stern light except for its yellow lens. It is
The CLEARANCE/OBSTRUCTION LIGHTS
installed 2 meters (6.6 feet) directly above the white
(red/green) are a dual array of two 32-point (360)
stem light.
lights. The fixtures are identical to the middle
constrained-by-draft light (fig. 4-23, view C) except
Breakdown and Man Overboard
that the lens of the lower half of the fixture is green.
Lights
This array is placed port and starboard on the ship,
two fixtures in a vertical line, not less than 2 meters
The dual-array BREAKDOWN and MAN
(6.6 feet) apart at a horizontal distance of not less
OVERBOARD LIGHTS (red) are 32-point (360)
than 2 meters (6.6 feet) from the task lights in the
lights located 2 meters (6.6 feet) apart or (vertically)
athwartship direction (fig. 4-15). Each upper and lower
and mounted on brackets on port and starboard of
half of the fixture in the array is energized from separate
the mast or structure. This arrangement permits
circuits. This dual-light array is used by a ship engaged
visibility, as far as practicable, throughout 360 of
in dredging or underwater operations, such as salvage,
azimuth. The fixtures are spraytight and equipped
to indicate her ability to maneuver is restricted. The
with six 15-watt one-filament lamps. When these
two red lights in a vertical line indicate the side on which
lights are used as a man-overboard signal, they are
the obstruction exists, and the two green lights in a
pulsed by a rotary snap switch (fitted with a crank
vertical line indicate the side on which another ship may
handle) on the signal and anchor light supply and control
panel. These lights are mounted and operated in
pass.
4-20
