Wire Rope & Drum Operations
Wire rope inspection criteria, birdcaging, kinks, broken wire limits, drum wraps, fleet angle, load testing, and replacement standards.
- Explain reeving and parts of line and their effect on lifting capacity
- Describe drum wrap requirements and fleet angle limits
- Identify wire rope inspection criteria and damage types
- Define replacement standards for worn or damaged wire rope
Lesson 1
Reeving & Parts of Line
What Is Reeving?
Reeving is the arrangement of wire rope through the sheaves (pulleys) in the boom tip and the hook block. The way the rope is threaded determines the mechanical advantage of the hoisting system.
Parts of Line
Parts of line refers to the number of rope segments (falls) supporting the load between the boom tip sheaves and the hook block. More parts of line means:
- Greater lifting capacity - the load is shared across more rope segments
- Slower line speed - the drum must wind more rope for the same hook travel
- More sheave friction - efficiency decreases slightly with more parts
How Parts of Line Affect Capacity
| Parts of Line | Capacity Effect | Speed Effect |
|---|---|---|
| 1 part | Minimum capacity | Maximum speed |
| 2 parts | Double vs. single | Half speed |
| 4 parts | Quadruple vs. single | Quarter speed |
| 6+ parts | Maximum capacity | Slowest speed |
Exam Concept
Increasing parts of line increases capacity but decreases line speed. The load chart specifies the required number of parts of line for each capacity rating.
Reeving is the arrangement of wire rope through sheaves. More parts of line increase lifting capacity but decrease line speed. Always verify the load chart specifies the reeving configuration being used.