Advanced Rigging - DVD
Linemen often work on jobs that involve rigging loads to be lifted, moved, or stabilized. An important part of a safe and effective approach to rigging is a good understanding of the factors involved. This 39-minute DVD covers some of the factors that should be considered when rigging is part of the job, including rigging forces and tensions, safety factor, and weight and tension calculations.
Rigging Forces and Tensions, Part 1 – 6 minutes
Identifies and describes two types of loads involved in rigging for line work. Describes how to determine the weight exerted by a conductor on an insulator.
Rigging Forces and Tensions, Part 2 – 9 minutes
Defines “line tension” and explains how to determine the line tension exerted by a conductor. Defines “bisect tension” and describes how bisect tension can be determined by measuring distances.
Rigging Forces and the Safety Factor – 11 minutes
Describes how to use a bisect tension formula to determine the bisect tension exerted on a corner pole. Describes how to determine the approximate bisect tension exerted on a corner pole by finding the approximate angle of the line at the pole and using a rule-of-thumb chart. Define the term guy tension and describes how to determine the approximate guy tension required to hold against line or bisect tension. Defines the term safety factor in terms of rigging for line work and describes how to calculate the safety factor for a given job.
Weight and Tension Calculations – 13 minutes
Describes how conductor tension is affected when a conductor is raised or lifted to a new pole. Describes how to determine the weight and bisect tension exerted by conductors when they are moved to a new pole. Describes how to determine the guy tension needed to offset the bisect tension exerted by conductors after they are moved to a new corner pole. Explains how to establish a safety factor of 5 for the rigging used to lift a conductor and move it to a new pole.