TM9-2320-361-10 2-31. OPERATION OF PIPELINE CONSTRUCTION MAINTENANCE TRUCKS (Contd) d. Lowering and Securing A-frame After Rear Operations. (1) Hook U-bolt (7) over tailboard sheave bracket (1). (2) Attach hook end of cable (2) to left center lashing ring (6). (3) Remove second chain (4) from bumperettes (5) and safety chains (3). CAUTION Do not let A-frame go past center (90°). It may free fall and damage equipment. (4) Operate rear winch (refer to b. of this para.) to raise A-frame (8) to almost vertical position (approximately 80°). Reset boom chains (9) to support A-frame (8) in this position. (5) Remove hook end of cable (2) from lashing ring (6) and attach to pintle hook (10). Leave about 2 feet of slack in cable (2). 2-154