at  each  emergency  switchboard.  They  consist  of casualty power terminals that are connected to the bus  bars  through  circuit  breakers.  Some  ships have  small  diesel-driven  generators  which  are designed  for  casualty  power  use  only;  these generators are very small and have a minimum of control equipment. Casualty power terminals are installed on power panels that feed equipment designated to receive casualty power; these ter- minals may also be used as a source of supply to the casualty power system if power from the per- manent feeders to the panels is still available. The casualty power system is either a.c. or d.c., as appropriate for the particular installation. Only the a.c. system is described here. The d.c. system is similar to the a.c. system, but uses dif- ferent types of cables and fittings. The    portable,    thermoplastic-covered    or neoprene-covered  cables  for  the  a.c.  casualty power system are stowed in racks in convenient locations throughout the ship. Each cable contains three leads (conductors), colored black, white, and red. This same color code is used in all three-wire power circuits throughout the ship. On smaller ships, the bulkhead terminals for the casualty power system are arranged so as to allow for one horizontal run of the portable cable along the main deck, and generally, if possible, inside the deck house. On larger ships, generally there  are  terminals  for  two  horizontal  runs  of cable,  one  port  and  one  starboard.  These  are located on the second deck. The terminals extend through the bulkhead and project from it on each side, and do not impair the water-tight integrity of the compartments in which they are installed. The cable ends are inserted into the holes that are provided around the outer rim (curved surface) of the terminal. Both the rim and the face of each terminal have three groups of three holes each, into  which  fit  the  square-shanked,  insulated wrenches that are used to secure the cables in the terminal. Two square-shanked wrenches are pro- vided in the rack mounted on the bulkhead at each point where they will be required. These wrenches MUST be kept in the racks at all times when they are not actually in use. The  riser  terminals  for  the  casualty  power system are similar to the bulkhead terminals, ex- cept that they are connected to other riser ter- minals  by  vertical  runs  of  permanently  installed, armored cable. The risers and the riser terminals carry the casualty power from the level of the generators  to  the  main  deck  and  second  deck levels. Portable  switches  are  sometimes  provided  on the bulkheads, near the cable racks. These are sim- ple ON-OFF switches which have special holes for use with the portable cables. The terminals and the cables in an a.c. casualty power system are marked so that they can be iden- tified easily when the system is being connected. The faces of the terminals are marked A, B, and C, and the three leads on each cable are colored black, white, and red, respectively. When connect- ing the cables to the terminals, you connect the black lead to A, the white lead to B, and the red lead to C. Since the letters and the colors cannot be seen in darkness, the terminals are further iden- tified  by  molded  knobs  in  the  A,  B,  and  C areas—one knob for A, two for B, and three for C. The cable leads are identified by servings of twine—one for black, two for white, and three for red. Each serving of twine is about 1 inch wide. Thus each lead and its corresponding posi- tion in the terminal can be identified merely by feeling  the  leads  and  matching  the  number  of pieces of twine on each lead with the number of raised knobs on the terminal. (In older ships, the casualty power fittings may still have identifying V-shaped notches in the outer edge instead of raised knobs.) CAUTION: When connecting a run of casu- alty  power  cable,  ALWAYS  CONNECT  FROM THE LOAD BACK TO THE POWER SUPPLY! By rigging the system in this manner, you will avoid  working  with  an  energized  cable.  Also  be SURE to shut off the normal supply to any power panel before you connect the casualty power cable to the terminals on the power panel. EMERGENCY FIRE PUMPS Most ships have electric-driven fire pumps located  outside  the  engineering  spaces.  These pumps furnish water under presssure to their own piping system or to the ship’s firemain. Provisions are made for different sources of electrical power to these pumps: normal and alternate supply from the  ship’s  service  generators,  emergency  supply from  the  diesel-driven  emergency  generators,  and the casualty power system itself. ENGINEMAN  1  &  C 9-12