TM 10-3610-202-14 stowage bracket. (2) Break  the  seal  by  pulling  the  safety  pin  from the handle. (3) Point the horn at base of the flame. (4) Depress  trigger  for  discharge  and  direct  the stream at the base of the fire. (5) Replace   used   cylinder   with   a   new   cylinder immediately alter using. j. Blackout   Warning.      A   blackout   warning   system consisting  of  an  external  pushbutton  switch  and  an  internal buzzer  Is  provided  to  alert  shelter  personnel  to  extinguish  all lights before the door is opened during blackout periods.  The pushbutton   switch   is   mounted   on   the   outside   wall   of   the shelter to the left of the door.  The buzzer is mounted on the rear wall of the shelter above the main power service box.  A chain mounted blackout lockpin is Installed on the door center latch plate on the interior rear left-hand wall.  When the door is  closed  and  latched,  the  pin  passes  through  a  hole  in  the locking mechanism to prevent the door from being Inadvertently  opened  during  a  blackout  or  during  processing of photographic material. k. Shelter Door Filter.  An air filter is located near the center of the shelter door and incorporates an upward hinging weather cover over the filter opening on the door exterior. l. Telephone   Binding   Post.      Two   external   binding posts are located on the exterior rear shelter wall to the left of the door.  They are protected by a hinged weather cover arid are   provided   to   facilitate   connection   of   a   field   telephone between the units of the special warfare printing plant. m. Personnel  Ladder.    A  personnel  access  ladder  is mounted on a bracket bolted to the exterior shelter wall above the  fieldphone  connection.    This  U-shaped  bracket  supports the  top  step  of  the  ladder  while  the  ladder  frame  tubes  are steadied  In  two  retaining  brackets,  one  on  each  side  of  the rear  level  indicator.    A  holddown  strap  which  passes  around the   two   lower   steps   of   the   ladder   and   through   tiedown brackets   above   and   below   the   level   indicator,   secures   the ladder assembly during transit and storage.  The ladder itself is  used  to  provide  personnel  access  to  the  shelter  when  the unit is truck mounted. n. Level    Indicator.        Two    bubble-gage    type    level indicators are installed in the exterior shelter wall, one on the rear wall and one on the left-hand wall.  During operation, the shelter should be as level as possible so as not to affect the calibration of plant components. o. Main Power Service Box.  The main power service box mounted on the rear wall of the shelter to the right of the door,   contains   the   circuit   breakers   which   control   electrical power    to    the    shelter    components    and    afford    overload protection  to  these  circuits.    The  circuit  breakers  are  switch type  components  which  also  provide  a  convenient  means  of disconnecting power to all shelter circuits. p. Lights and Switches.    Illumination  of  the  shelter  is provided by two rows of ceiling lights, controlled by two light switches on the rear wall of the shelter to the left of the door. Each light fixture Incorporates a ballast, a lamp starter and a fluorescent    lamp    tube.        Six    light    fixture    assemblies    are installed  along  the  left-hand  ceiling  and  five  along  the  right- hand ceiling. 2-4. Stopping. WARNING Do not perform any electrical maintenance   or   make   any   electrical connection   or   disconnection   at   the main     power     receptacle     while     the generator set engine is running. a. Shutdown     the     generator     set     power     source     in accordance   with   the   applicable   Department   of   the   Army Technical Manual. b. Position all circuit breakers in the main power service box to the right of the shelter door to off. c. Position all equipment and shelter power switches to the off or neutral position. d. Disconnect the main power cable from the generator power source. e. Disconnect the cable from the main power receptacle. f. Coil and correctly stow main power cable. Section II.  OPERATION OF AUXILIARY EQUIPMENT The editorial and photomechanical unit of the special warfare  printing  plant  is  used  in  conjunction  with  the  press and duplicating shelter unit, operating procedures for which are contained in TM 10-3610- 203-14.   The  primary  mission  of  both  units  is  the  production of special psychological warfare leaflets. 2-6