Construction of Rigging Systems Refresher Barbara A. Knippenburg

Student Performance Objective: Given information from discussion and demonstration, rope, webbing, and hardware, the student will demonstrate the selection of an anchor point, construction of a single point anchor system, a simple mechanical advantage system, a Z-Rig system, a Piggyback Rig system and a System Safety Check. The student will successfully participate in drill activities and demonstrate the construction of anchor points and mechanical advantage systems to a 70% accuracy on a skills check-off sheet.

Overview: Anchor Points Single-Point Anchoring System Simple Mechanical Advantage System (2:1) Z-Rig System (3:1) Piggyback Rig System (4:1) System Safety Check

Anchor Points Purpose: Means of securing the ropes and other elements of the system to something solid

Anchor Points Selection –Natural –Structural –Man Made

Anchor Points Criteria Strength required Direction of pull Sharp edges Adequate operating space

Anchor Points Components Rope Webbing Anchor hardw are

Anchor Hardware Prusik Knot

Anchor Points Anchor Attachment Simple Loop (Figure 8 Follow-Through) Three Bight Wrap 3, pull 2 Tensionless Hitch Commercial Slings

Anchor Attachments Simple Loop – Joined with a Figure 8 follow through

Anchor Attachments Three Bight: Using webbing Or rope tied Into fixed loop. Loop is passed Around the Anchor Into a bight configuration

Anchor Attachments Wrap three pull two: Using webbing Or Rope, wrap the Anchor three Times and join ends. Pull Two wraps and attach a carabiner

Anchor Attachments Tensionless Hitch: Rope is wrapped around the anchor 5 or 6 times, then connect the rope back onto itself.

Mechanical Advantage Systems Uses: –Hauling –Hoisting

Mechanical Advantage Systems Components –Software Rope Webbing –Hardware Carabiners Pulleys Capture Devices

Computing Mechanical Advantage Number of moving pulleys and multiply by two Number of moving lines between load and anchor point plus the haul line Measure amount of rope pulled through the system and the distance load is moved, divide the amount of rope by the distance to get MA

Computing Mechanical Advantage Compound Systems Mechanical Advantage of initial system Mechanical Advantage of system attached to haul line Multiply together

Computing Mechanical Advantage Example: Compound System Initial system is 3:1 MA Second system is 4:1 MA Resulting MA?

Activity: Constructing a Single Point Anchor System Anchor Attachment Simple Loop (Figure 8 Follow-Through) Three Bight Wrap 3, pull 2 Tensionless Hitch Commercial Slings

System evaluation and safety check Anchor adequate Software/hardware rated for load Hardware locked Whistle test

Activity: Constructing a Simple Mechanical Advantage System (2:1)

Activity: Constructing a Simple Mechanical Advantage System (2:1)

Activity: Constructing a Z Rig System (3:1)

Activity: Constructing a Piggy Back Rig (4:1)

Activity: Constructing a Piggy Back Rig (4:1)

Performing a Safety Check Check each portion of the rig in any rigging system Ensure safety knots are in place Test rig and anchors before placing a full load

Student Performance Objective: Given information from discussion and demonstration, rope, webbing, and hardware, the student will demonstrate the construction of a single point anchor system, a simple mechanical advantage system, a Z-Rig system, a Piggyback Rig system, and a System Safety Check. The student will successfully participate in drill activities and demonstrate the construction of anchor points and mechanical advantage systems to a 70% accuracy on a skills check off sheet.

Review: Selection of Anchor Point Constructing a Single-Point Anchoring System Constructing a Simple Mechanical Advantage System (2:1) Constructing a Z-Rig System (3:1) Constructing a Piggyback Rig System (4:1) Performing a Safety Check