than that afforded by Level C preservation and packaging. Level   C   is   the   level   of   preservation   that protects adequately against corrosion, deteriora- tion, and physical damage during shipment from the  supply  source  to  the  first  receiving  activity  for immediate use. The proper level of preservation depends on the  availability  of  information  on  the  probable handling, shipping, storing units, and conditions that  the  vehicles  and  equipment  will  undergo before  final  issue  to  the  command.  Physical characteristics of the vehicles and equipment must also  be  considered. An  approved  cleaning  technique  is  a  first  in preservation.   The   effectiveness   of   an   applied preservative may be measured by the quality of the  surface  preparation.  All  corrosion  and contaminants  have  to  be  removed  before  a  pre- servative is applied. No   single   cleaning   method   or   material   is suitable for all cleaning situations. The selection of a cleaning method, or combination of methods, depends  on  one  or  more  of  these  factors: 1.  Material  composition  of  part 2.  Complexity  of  construction  and  assembly 3.  Nature  and  extent  of  contaminants 4.  Amount  and  age  of  equipment 5.  Availability  of  cleaning  materials  and equipment Steam   cleaning   is   suitable   for   removal   of greases,   tar, road   deposits,   and   other contaminants. This   process   is   particularly adaptable to parts other than the ENGINE and GEARCASE  EXTERIORS  of  vehicles  and equipment   that   ordinarily   would   not   be   dis- assembled  before  preservation.  Engines  and gearcases  should  be  cleaned  by  spraying  with  a decreasing    solvent,    by  allowing  for  solvent penetration,  and,  finally,  by  flushing  with  a clean petroleum solvent or by wiping with a clean cloth. “Active  storage”  means  that  complex  equip- ment is maintained in serviceable condition by the operation  of  all  components  for  brief  periods  at regularly  scheduled  intervals.  When  lubricants  are redistributed,  friction  is  reduced  and  deterioration is  prevented  or  reduced  to  a  minimum.  Only unboxed automotive and construction equipment is  included  in  the  active  storage  program. Upon  reactivation,  material  preserved  and packaged   for   storage   or   shipment   requires depreservation  and  servicing  before  use.  Equip- ment  is  to  be  lubricated  under  the  manufacturer’s instructions.  Seals  and  closures  should  be removed. Housings, casings, and other enclosures should  be  drained  of  preservatives  and  refilled with specified operating fluids before operation. Those components that were removed for storage should  be  reinstalled. Upon   activation,   in   equipment   containing piston-cylinder  components,  such  as  internal combustion  engines  and  air  compressors,  rotate the  crankshaft  slowly  with  the  throttle  closed, ignition off, and compression release lever (if so equipped)  in  START  position. Avoid  abrasives  in  removing  preservatives. Remove   blocking,   wiring,   or   strapping   from clutch  levers  or  pedals  secured  in  a  partially disengaged position. Adjust drive belts on which tension has been released. Flush from the system any  corrosion  inhibitor  mixed  with  preservative oil. TECHNIQUES  OF  SCHEDULING An  effective  and  efficient  maintenance  pro- gram  requires  the  establishment  and  upkeep  of a preventive maintenance scheduling system and a  sound  shop  control  procedure.  According  to Management   of   Transportation   Equipment, NAVFAC  P-300,  vehicles  and  equipment  are  to be   scheduled   for   inspection   and   servicing according  to  the  time,  mileage,  or  operating  hours prescribed  by  the  manufacturer’s  recommenda- tions.  As  a  minimum,  the  schedule  is  to  ensure that each vehicle is inspected for safety at least every 12 months or 12,000 miles, whichever occurs first. The schedule can be formulated by determin- ing the estimated annual miles of each vehicle and dividing   by   the   manufacturer’s   recommended service interval. This will determine the number of  service  intervals  per  year  for  each  vehicle. Dividing  the  number  of  working  days  per  year (252) by the number of service intervals per year will develop the number of working days between 1-7