TM 10-3930-659-10 2-20.  OPERATE ON-BOARD CRANE. WARNING Crane  Is  heavy.    Assistant  Is  required  to  raise  or  lower  crane  to various operating positions.  Assistant may be required to help raise or lower load.  Failure  to  follow  this  warning  may  result  In  Injury  to personnel. a.  Crane can be raised or lowered by removing springlock pin (5) and retaining pin (9) from collar (6) and mast (4). Once crane is at desired level, insert springlock pin and retaining pin. b.  Crane hoist handle and cable spindle unit (2) can be moved up or down mast (4) by removing springlock pin (10) and  retaining  pin  (3).    Once  crane  hoist  handle  and  cable  spindle  unit  are  at  desired  level,  insert  springlock  pin  and retaining pin. c.  Crane boom  (8)  can  be  moved  in  or  out  by  removing  springlock  pin  (7)  and  retaining  pin  (1),  and  moving  crane boom in or out.  Once desired position is reached,  insert springlock pin and retaining pin. 2-56