In addition to alerting personnel to the presence of a fire, the detection equipment can be used to control the air-conditioning system. There is some support for the view that, upon detection, air-handling equipment be shutdown automatically to avoid fanning the flames and spreading smoke. This is not the best plan, as nuisance alarms will result in needless disruption. The preferred technique is to cause the system to exhaust smoke by stopping recirculation, and switching to 100-percent outside air intake and room air discharge. As a rule, this can be done by adjusting air-conditioning damper controls and their interconnection with the fire detection system. However, it may be necessary to modify the air-conditioning system. The use of either technique is at the discretion of command policy. Fire  Extinguishment Fire extinguishment may be accomplished using one or more of the following four methods: l l l l Portable or hand extinguishers.  Operated  by military or civil service personnel to help control the fire before it gets out of hand. Hose lines. Used by military, civil service, or professional fire fighters to attack the fire with water. Automatic sprinkler systems.  Release water from sprinkler heads activated in the temperature range of 135°F to 280°F. Volume  extinguishment  systems.  Fill the room with a gas that interferes with the combustion process. To   ensure   the   effectiveness   of   portable extinguishers, several measures should be observed. Place  extinguishers  in  readily  accesssible  locations,  not in comers or behind equipment. Mark each location for rapid identification; for example, paint a large red spot or band on the wall or around the column above the point  where  each  extinguisher  is  mounted.  It  is important for each AIS technical manager to ensure proper inspection in accordance with command policy. Each extinguisher should have an inspection tag affixed to it with the signature of the inspecting petty officer or fire marshal and the inspection date. In all probability, the AIS facility technical manager will want to establish a first line of defense against fire involvement between the time of notification of, and response by, professional or highly trained firefighters, and will incorporate this as part of the command’s Disaster Control Plan. Every command, regardless of size, needs military personnel who are knowledgeable and trained in fire safety. Any practical and effective organization for fire protection must be designed to assure prompt action immediately at the point where a fire  breaks  out.  This  usually  necessitates  every organizational unit or area of a command having a nucleus of key personnel who are prepared, through instruction  and  training,  to  extinguish  fires  promptly  in their  beginning  stage.  Such  individuals  become knowledgeable in specialized fire protection and the systems applicable to the facility in question: how to turn in an alarm, which type of extinguisher to use for which type of fire, and how to use it. Further, such individuals can serve as on-the-job fire inspectors, constantly  seeking  out,  reporting,  and  correcting conditions that may cause fires. They can help ensure that  fire-fighting  equipment  is  properly  located  and maintained,  that  storage  does  not  cause  congestion  that could   hamper   fire   fighting,   and   that   general housekeeping is maintained at a reasonably high level to minimize fire risk. SUPPORTING UTILITIES PROTECTION Every  Navy  AIS  facility  is  dependent  upon supporting utilities, such as electric power and air conditioning,   and   may   have   to   depend   on communication circuits, water supplies, and elevators for its operation. Not all commands are self-sufficient; they contract some or all of these utilities from civil sources.   In   using   these   utilities,   AIS   technical managers  should  consider  the  probability  of  occurrence and the effects of breakdowns, sabotage, vandalism, fire, and flooding. These effects can then be related to the needs of the AIS facility as established by the risk analysis. We have selected electrical power to illustrate support utility protection. Variations of a normal waveform in the electric power supply can affect the operation of AIS hardware. The AIS hardware rectifies the alternating current, filters, and voltage; regulates the resulting direct current; and applies it to the AIS circuitry.  The  filtering  and  regulation  cannot  be expected to eliminate voltage variations beyond a reasonable range. If line voltage is 90 percent or less of nominal for more than 4 milliseconds, or 120 percent or more of nominal for more than 16 milliseconds, excessive fluctuations can be expected in the dc voltage applied   to   the   hardware   circuitry.   This   power fluctuation  causes  unpredictable  results  on  hardware, logic, and data transfer. These power line fluctuations, referred  to  as  transients,   are  usually  caused  by inclement   weather. 4-21