STRUT STABILIZATION PART 1

‘Vehicle & Machinery Rescue’ Stabilization Explain course is built around two NFPA Standards; 1006 (Chapter 10) and 1670 (Chapter 8 & 12) Course materials also include information from University of Extrication series, as originally published in Firehouse Magazine Course materials also include information from Vehicle Rescue 1-2-3 book, Moore Course materials also include information from IFSTA Essentials of Firefighting

Cribbing 2 x 4 wood 4 x 4 wood 6 x 6 wood Wedges 4 x 4 x 8’ Stepchocks Double Box Crib: 24,000 lbs. rating 2 x 4 wood 4 x 4 wood 6 x 6 wood Wedges 4 x 4 x 8’ Stepchocks Cribbing provided by TCC includes; 2 x 4 wood 4 x 4 wood 6 x 6 wood Wedges 4 x 4 x 8’ Stepchocks

Triple Box Crib Solid Bottom Layer 4” overlay @ ends 55,000 lbs. rating Interactive discussion of cribbing building and rating of cribbing Triple Box Crib with Solid Bottom Layer and 4” overlay @ ends yields 55,000 lbs. rating

Reason for overlap at ends of box crib Crush testing of various types of wood in a 55 ton press unit Note failure of cribbing and ‘flaring’ of ends Explain that overlap at ends of a box crib is to allow end flaring to lock cribbing into place under heavy load

Cribbing Safety Height of Box Crib should not exceed 2x the working width of the base of the box crib 18” cribbing = 36” box crib height Height of Box Crib should not exceed 2 times the working width of the base of the box crib 18” cribbing = 36” box crib height

Cribbing wedges should have a square base and to provide maximum strength to wedge Cribbing wedges should have a square base end to provide maximum strength to wedge 7

Stabilization with Strut Systems Conduct interactive discussion of possible or anticipated challenges faced by rescue personnel at case study incident shown Stabilization with Strut Systems

Conduct interactive discussion of possible or anticipated challenges faced by rescue personnel at case study incident shown

Strut System Deployment Deployment of typical ‘strut’ system; 4-strut stabilization shown

Light-Duty Struts Typically rated capacity of 4,000# Tensioned Buttress Stabilization Systems...commonly referred to as “Struts Industry Standard 20’ Ratchet Strap with Wire Hooks systems that generally are used with struts for tensioning at typically rated at 3 to 1 Safety Factor 3,300# Working Limit Load

“CAM Buckles” attached to base of strut only have a Working Load Limit of 700# Tensioned Buttress Stabilization Systems...commonly referred to as “Struts Industry Standard 20’ Ratchet Strap with Wire Hooks systems that generally are used with struts for tensioning at typically rated at 3 to 1 Safety Factor 3,300# Working Limit Load

Detachable 20’ Ratchet Strap with Wire Hooks 3 to 1 Safety Factor Working Load Limit of 3,300# Tensioned Buttress Stabilization Systems...commonly referred to as “Struts Industry Standard 20’ Ratchet Strap with Wire Hooks systems that generally are used with struts for tensioning at typically rated at 3 to 1 Safety Factor 3,300# Working Limit Load

(Black with Orange Hooks) Strut System Chain Kit 16‘ 7,100# WLL rating (Black with Orange Hooks) Chain Clusters- 5,400# WLL rating Grade 70 “mini T”, “mini J” & chain shortener Strut System Chain Kits typically include’ 16‘ 7,100# WLL rating (Black with Orange Hooks) Chain Clusters- 5,400# WLL rating Grade 70 “mini T”, “mini J” & chain shortener

Opposing triangles on roof side Compression Tension Creating of ‘triangles’ and tensioning of struts places the strut under compression and the strap system under tension Opposing struts form opposing triangles to support and stabilize load Opposing triangles on roof side

Set struts at 50o to 70o angle Basic “2 Strut” Setup Set struts at 50o to 70o angle Typical strut manufacturer recommends strut placement angle of 50 – 70 degrees; a ground ladder climbing angle

Stabilization Full “4 Strut” Setup X Side-resting automobile can be stabilized with a 2-strut, 3- strut, or 4-strut deployment

Side-resting automobile stabilized with a 4-strut deployment Stabilization X Side-resting automobile stabilized with a 4-strut deployment Side-resting automobile stabilized with a 4-strut deployment

“Trapezoid” Deployment: Roof-Resting Trapezoid deployment of struts for a roof-resting vehicle stabilization

“Trapezoid” Deployment for Stability Trapezoid deployment creates triangles for most effective vehicle stabilization

Improvised Struts ‘Homemade’ street sign post used to build struts shown deployed in Real World incident

Improvised Struts Improvised ‘strut’ for stabilization

Struts for Vehicle Stabilization Paratech “Green” Struts for Vehicle Stabilization One method of stabilizing a large vehicle with struts and straps using wheel, tire, and wheelwell area

Green Struts WL = 10,000# One method of stabilizing a large vehicle with struts and straps using wheel, tire, and wheelwell area

Paratech” “Grey” Struts For Stabilization of Heavier Loads One method of stabilizing a large vehicle with struts and straps using wheel, tire, and wheelwell area