Chapter 4- PREVENTIVE AND CORRECTIVE DAMAGE CONTROL 



officer who is qualified in damage control and 

 who is capable of taking over the supervision 

 of the repair party. 



Many repair stations have unit patrol sta- 

 tions at key locations in their assigned areas to 

 supplement the repair station. Operating in- 

 structions should be posted at each repair sta- 

 tion. In general, instructions should include the 

 purpose of the repair station; the specific as- 

 signments of space for which that station is 

 responsible; instructions for assigning and sta- 

 tioning personnel; methods and procedures for 

 damage control communications; instructions 

 for handling machinery and equipment located 

 in the area; procedures for nuclear, biological, 

 and chemical (NBC) defense; sequence and pro- 

 cedure for passing control from one station to 

 another; a list of current damage control bills; 

 and a list of all damage control equipment and 

 gear provided for the repair station. 



MATERIAL CONDITIONS OF READINESS 



Material conditions of readiness refers to 

 the degree of access and system closure to 

 limit the extent of damage totheship. Maximum 

 closure is not maintained at all times because 

 it would interfere with the normal operation of 

 the ship. For damage control purposes, naval 

 ships have three material conditions of readi- 

 ness, each condition representing a different 

 degree of tightness and protection. The three 

 material conditions of readiness are called 

 X-RAY, YOKE, and ZEBRA. These titles, which 

 have no connection with the phonetic alphabet, 

 are used in all spoken and written communica- 

 tions concerning material conditions. 



Condition X-RAY, which provides the least 

 protection, is set when the ship is in no danger 

 from attack, such as when it is at anchor in a 

 well protected harbor or secured at a home base 

 during regular working hours. 



Condition YOKE, which provides somewhat 

 more protection than condition X-RAY, is set 

 and maintained at sea. It is also maintained in 

 port during wartime and at other times in port 

 outside of regular working hours. 



Condition ZEBRA is set before going to sea 

 or entering port, during wartime. It is also set 

 immediately, without further orders, when 

 manning general quarters stations. Condition 

 ZEBRA is also set to localize and control fire 

 and flooding when not at general quarters sta- 

 tions. 



The closures involved in setting the material 

 conditions of readiness are labeled as follows: 



X-RAY, marked with a black X. These clo- 

 sures are secured during conditions X-RAY, 

 YOKE, and ZEBRA. 



YOKE, marked with a black Y. These clo- 

 sures are secured during conditions YOKE and 

 ZEBRA. 



ZEBRA, marked with a red Z. These clo- 

 sures are secured during condition ZEBRA, 



Once the material condition is set, no fitting 

 marked with a black X, a black Y, or a red Z 

 may be opened without permission of the com- 

 manding officer (through the damage control 

 assistant or the officer of the deck.) The re- 

 pair party officer controls the opening and 

 closing of all fittings in his assigned area during 

 general quarters. 



Additional fitting markings for specific pur- 

 poses are modifications of the three basic con- 

 ditions, as follows: 



CIRCLE X-RAY fittings, marked with a black 

 X in a black circle, are secured during condi- 

 tions X-RAY, YOKE, and ZEBRA. CIRCLE 

 YOKE fittings, marked with a black Y ina black 

 circle, are secured during conditions YOKE and 

 ZEBRA. Both CIRCLE X-RAY and CIRCLE 

 YOKE fittings may be opened without special 

 authority when going to or securing from gen- 

 eral quarters, when transferring ammunition, 

 or when operating vital systems during general 

 quarters; but the fittings must be secured when 

 not in use. 



CIRCLE ZEBRA fittings, marked with a red 

 Z in a red circle, are secured during condition 

 ZEBRA. CIRCLE ZEBRA fittings may be opened 

 during prolonged periods of general quarters, 

 when the condition may be modified. Opening 

 these fittings enables personnel to prepare and 

 distribute battle rations, open limited sanitary 

 facilities, ventilate battle stations, and provide 

 access from ready rooms to flight deck. When 

 open, CIRCLE ZEBRA fittings must be guarded 

 for immediate closure if necessary. 



DOG ZEBRA fittings, marked with a red Z 

 in a black D, are secured during condition 

 ZEBRA and during darken ship condition. The 

 DOG ZEBRA classification applies to weather 

 accesses not equipped with light switches or 

 light traps. 



WILLIAM fittings, marked with a black W, 

 are kept open during all material conditions. 

 This classification applies to vital sea suction 

 valves supplying main and auxiliary condensers, 

 fire pumps, and spaces that are manned during 



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