The casualty power system is used to supply emergency power for steering gear, fireroom and engineroom auxiliaries, fire pumps, drainage pumps, communications equipment, and other vital machinery needed to keep the ship afloat or to get it out of a danger area.

The casualty power system is a simple electrical distribution system used to maintain a source of electrical supply for the most vital machinery and equipment needed to keep the ship afloat and functioning. This casualty power system is in-tended to supply power during emergencies ONLY. The system is purposely kept simple so that it can be rigged quickly and with a minimum chance of error; but, the very simplicity of its design limits the extent of its use.

Sources of supply for casualty power use are provided at each ships service switchboard and 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 terminals may also be used as a source of supply to the casualty power system if power from the permanent 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, except that they are connected to other riser terminals 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 simple 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 identified 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 connecting 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 identified by molded knobs in the A, B, and C areasone knob for A, two for B, and three for C. The cable leads are identified by servings of twineone for black, two for white, and three for red. Each serving of twine is about 1 inch wide. Thus each lead and its corresponding position 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 casualty 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.