TM 10-3930-669-34 WARNING • Inner  rail  assembly  weighs  330  lbs  (150  kg).    Attach  suitable  lifting   device   prior   to installation to   prevent possible injury to personnel. • All personnel must stand clear during lifting operations.  A swinging or shifting load may cause   injury or death to personnel. NOTE • Position secondary chains clear of inner rail prior to installation of inner rail. • Position two secondary chains through center rail prior to center rail installation. (12) Install two lock washers (60) and screws (59) in outer rail (61). (13) Install two anchors (56) on center rail (58) with lock nuts (57). (14) Install secondary chains (55) on anchors (56) with two pins (54) and four cotter pins (53). (15) Install two shims (52) and rollers (51) on inner rail (48). (16) Install inner rail (48) on mast assembly (15). 13-19