MAINTENANCE 4.12 EVERY 1000 OPERATING HOURS OR EVERY 6 MONTH High-Strength Bolt Connections (continued) Check condition and fastening of railings (01/02) and of steps (03, 04, 05 and 23). See details (A - D) for mounting parts arrangement. Legend for illust. Z 20619 (A) Mounting assembly for steps (03) to steel pipe, ver- sion I (B) Mounting assembly for railing posts to steps (03) (C) Mounting assembly for steps (03) to boom welded brackets (D) Mounting assembly for steps (03) to steel pipe, ver- sion II 411