A modified YOKE is sometimes used at sea when
cruising independently in good weather and calm seas
and in port in peacetime. In the modified condition,
YOKE fi+ttings above the waterline are left open to
improve ventilation and habitability. All other XRAY
and YOKE fittings shipwide will be closed unless
logged on a case-by-case basis as discussed earlier.
An alternative to the setting of ZEBRA shipwide is
the setting of modified ZEBRA. An example of the
setting of modified ZEBRA would be setting Zebra on
the DC deck and below only if the area the ship was
transiting was a known or suspected hazardous
navigational area. This would provide a higher
survivability stance than condition YOKE. At the same
time modified ZEBRA is less restrictive in the rest of the
ship and will more readily allow the accomplishment of
other operational requirements. Modified ZEBRA may
result as an upgrade from condition YOKE or as a
downgrade from condition ZEBRA.
SPECIAL CLASSIFICATIONS
Circle XRAY and YOKE. These fittings are
access fittings to battle stations and compartments
containing equipment that require periodic checks or
fittings that must be opened for ammunition transfer, as
well as some systems.
Circle XRAY and YOKE fittings are normally
closed when condition XRAY or YOKE are set. They
may be opened without special authority when going to
or securing from general quarters, transferring
ammunition, during periodic space or equipment
checks, or during operation of damage control
equipment. Circle XRAY and YOKE fittings are
marked with a black X or Y in a black circle. They
should be secured once passage is complete.
Circle ZEBRA. These fittings are closed when
condition ZEBRA is set. They may be opened with the
permission of the CO only. This would be during
extended periods of general quarters for the preparation
and distribution of battle messing, to provide access to
sanitary facilities, to ventilate battle stations, to transit
from squadron ready rooms to the flight deck, and to
allow limited access throughout the ship as the CO
prescribes.
Open Circle ZEBRA fittings must be guarded so
they can be closed immediately because the ship is still
in a battle station position when ZEBRA is set. Circle
ZEBRA fittings are marked with a red Z surrounded by
a red circle.
DOG ZEBRA. These fittings are secured when
condition ZEBRA is set and whenever the ship is set for
“darken ship,” which is a night steaming condition, not a
material condition. During darken ship these fittings
and closures are closed to prevent light inside showing
to the outside. DOG ZEBRA fittings are marked with a
red Z surrounded by a black letter D.
NOTE
Darken ship is a night steaming condition, not a
material condition.
WILLIAM. These fittings are vital sea suctions,
ventilation fittings valves serving vital equipment, and
valves that must be open to maintain mobility and fire
protection. WILLIAM fittings are open during all
material conditions. They are secured only to control
damage, contamination, or to repair equipment served.
WILLIAM fittings are marked with a black colored
letter W.
Circle WILLIAM. These fittings, like WILLIAM
fittings, are normally open but are secured for protection
in CBR attack. Fittings that are marked with this
classification are those that provide ventilation opening
to the outside of the ship. Circle WILLIAM fittings are
marked with a black W surrounded by a black circle.
REVIEW 4 QUESTIONS
Q1. What is the most important feature of a ship to
ensure its survivability?
12-13
Student Notes:
