MATERIAL CONDITIONS OF READINESS There are three material conditions of readiness. Those conditions are named XRAY, YOKE, and ZEBRA. When set, each condition affords the ship with a level of protection, with XRAY being the least and ZEBRA the most. Some fittings or closures on a ship may not be classified although the majority of them are classified. They are identified by a classification plate affixed to the closure or fitting, or sometimes the classification is painted on the bulkhead next to the item. Ship’s instructions (and Navy instructions) specify what type of classification an item should hold, how it will be marked, and when that condition should be set. The commanding officer of the ship is authorized by instruction to alter this to a small extent if he/she desires but basically this system is standard Navywide. XRAY. Provides the least watertight integrity and the greatest ease of access throughout the ship. It is set when the threat to the ship is minimal. Condition XRAY is set during working hours when the ship is in port, when there is no danger of attack, and when there is no threat from bad weather. All fittings marked with a black X and circle X are closed when condition XRAY is set. YOKE.  Provides  a  greater  degree  of  watertight integrity  than  condition  XRAY  but  to  a  lesser  degree than the maximum condition. YOKE is normally set at sea and in port during wartime. All fittings marked with Xs  and  Ys,  Circle  X,  and  Circle  Y  are  closed  when condition YOKE is set. ZEBRA.   Provides   the   greatest   degree   of subdivision and watertight integrity to the ship. It is the maximum state of readiness for the ship’s survivability system.  Condition  ZEBRA  is  set  when  the  following situations occur: 1.   Immediately when GQ is sounded 2.   When entering or leaving port in wartime 3.   To localize damage and control fire and flooding when the crew is not at GQ 4.   At  any  time  the  CO  deems  the  maximum condition of survivability should be set All fittings marked with X or Y, Circle X, Circle Y, Z,  Circle  Z,  and  DOG  Zs  are  closed  when  condition ZEBRA is set. The  setting  of  material  conditions  is  normally carried out by the division or department responsible for the  compartment  and  is  accomplished  by  using  the compartment checkoff lists (CCOLs). In an emergency the  repair  party  personnel  responding  to  the  casualty assisted by those Sailors in the area will set the required condition to restrict the spread of damage. CCOLs are a tool used by repair party personnel to find the damage control fittings and closures in each compartment. The fittings and closures are identified by name (type) and a number that represent the location of the fitting by deck, the frame it is located at, and the side of the space similar to the compartment identification process. The CCOL list is posted in each space near the entrance and should be kept up to date by the division who owns the space. An example of a CCOL is shown in (fig. 12-2). The normal setting of a material condition should be logged in the Damage Control Closure Log by each division  or  repair  party  completing  the  setting.  Any exceptions to the setting should also be noted in the log so DCC/OOD are aware of the reduction in the ship’s ability to restrict the spread of potential damage. This log and the Inoperative Fitting Log are maintained in either DCC or on the quarterdeck by the OOD. If you have  a  need  to  break  (open)  a  fitting  that  should  be normally  set  in  a  specific  condition,  you  must  first request  it  open  and  then  log  it  in  before  opening  the fitting. If you don’t do this, you are in violation of the setting and have jeopardized your shipmate’s survival. When  you  have  completed  work  in  a  space  that  you needed a fitting/closure open, close it first, then log it closed.  Now  those  who  maintain  the  log  will  have  a clear picture of what is open and closed in a given area of  the  ship.  In  addition  to  the  closure  log,  a  log  for inoperative  fittings  and  closures  exists.  As  its  name implies, this log lists all DC-related fittings and closures on  the  ship  that  don’t  work  properly.  It  becomes  a tracking tool for future maintenance. A modified condition YOKE or modified condition ZEBRA is sometimes set, rather than the normal setting of  XRAY,  YOKE,  or  ZEBRA.  These  are  settings  of convenience at the discretion of the CO. 12-11 Student Notes: