Road  Networks During the plant erection stage, plans should be made for the layout of roads. Well-planned roads are needed  to  prevent  congestion,  decrease  the  time  haul units are in the plant, and for safety. Road networks are needed  for  the  following: 1.   Haul units bringing rock from the quarry 2.  Trucks  hauling  the  product  aggregate  to construction  sites 3.  Service  vehicles,  such  as  crew,  fuel,  and maintenance   vehicles If  possible,  plant  roads  should  be  one  way  and  be wide enough for the largest haul unit expected. They should be designed to support heavy loads. Plant roads must be maintained constantly. In dry areas where there is little rainfall, a water truck is required to wet down the roads to control the dust. In wet areas crushed rock should be used on the roads to keep  haul  units  from  sliding  off  into  ditches.  A maximum speed limit should be posted for vehicular traffic within the crusher area and on the haul roads. PLANT  ERECTION The  importance  of  proper  site  preparation  and proper   stationing   of   the   plant   cannot   be overemphasized.  Your  site  for  stationing  the  plant should  be  flat,  level,  and  well  compacted.  Crushing  and screening  plants  may  be  operated  for  short  periods  of time from the wheelbase. But it is advantageous on longer and more deliberate jobs, from a maintenance standpoint, not to operate the plant until it has been blocked and leveled with the tires clear of the ground. You  should  include  the  following  steps  in  the operational   start-up   phase: Operating instructions. All  appropriate  technical manuals  must  be  reviewed  and  studied  before  the beginning  of  plant  operations. Training.  You  should  train  all  personnel  assigned to  operate  and  maintain  the  plant.  During  this  training period  the  importance  of  site  preparation,  setup, maintenance, and safety should be emphasized. You should keep the proper tools, materials, and manuals at the  site.  A  high  rate  of  aggregate  production  should  not be  expected  until  personnel  become  familiar  with  the equipment. Tools. The tools used in maintenance and assembl y of the plant are included in the mechanic’s tool kit which is part of the NCF TOA. Basic issue items that are incorporated  with  each  plant  are  also  available. Leveling.  The  plant  should  be  leveled  before  initial operation and should be frequently checked while in operation. Leveling should be done on the frame for longitudinal leveling. A rigid, straight plank should be used across the unit frame rails for transverse leveling. The  leveling  should  be  checked  at  several  points throughout the unit. Blocking. Blocks  should  be  installed  under  each side of the tandem axles and under the dolly axle or the fifth wheel plate to raise the tires or landing gear clear of the ground. Place blocking or cribbing parallel to the longitudinal center line of the unit. Hydraulic jacks. Jacks should be on each side of the unit opposite each other and under the unit frame members. Raise and lower the jacks in equal increments to prevent bending of the frame. Screw type of stabilizing jacks. Tighten the screw type of stabilizing jacks to  maximum  torque  after  the crusher has been blocked and leveled. retorquing  should  be  continued  throughout  the Nuts  and  bolts.  Ensure  all  bolts  are  tight  by torquing the nuts, not the bolt heads.  Additionally, operation of the plant. This should be performed at critical locations and during the initial operation to assure  proper  seating  and  prevent  parts  from  loosening and  getting  out  of  adjustment.  Any  adjustments required, such as movement of trunnion wheels on the trunnion shaft, should be made during the first hours of operation. Jaw  plates  and  roll  shells  are  held  in  place  by wedges which are secured by keeper bolts. The wedges must be driven  home  with  a  sledge  hammer  while constantly applying torque with the wrench to achieve proper  tightening. Visual inspection.  To  prevent  damage  and  eventual breakage,   you   should   visually   inspect   the   plant constantly  to  detect  any  misadjustment  or  loss  of adjustment. Visual inspections should be made from ground  level,  from  the  platform,  and  from  walkways. All adjustments should be checked with the components operating while empty and rechecked while loaded with aggregate. 75-tph Plant The 75-ton-per-hour plant is used in any of four basic setups, depending upon the raw material available 6-15