Leader

Collapse

Announcement

Collapse
No announcement yet.

A Cribbing Formula

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • A Cribbing Formula

    There is a generally accepted guideline for height of cribbing vs. length being taught in heavy lifting classes around the country. It is a sort of formula for evaluating the effectiveness and safety of your box crib.

    According to the formula, the maximum height of a box crib should not exceed 3X the length of the cribbing. According to the formule, if you use 18" long blocks, your box crib can go as high as 54"(4.5 feet). Now, I don't like that. I think a stack of cribbing 4.5 feet tall at a car crash IS unstable no matter how well you build it.

    In our department, the guideline is "Build box cribbing to a height no more than twice its length". Our 18" blocks in a box crib formation are still pretty stable up to 36".

    Anyone else have cribbing guidelines or rules of thumb that you go by?

    -- <br />Ron Moore<br />Fire Training Manager<br />Plano (TX) Fire Rescue<br /> [email protected]
    Ron Moore, Forum Moderator
    www.universityofextrication.com

  • #2
    According to FEMA USAR trng. materials, a safe height for stack cribbing is 3x the 'footprint', provided all contact points are covered. There is lots more than simply height considerations.

    If you're interested, I've developed a 8 page handout for rescue cribbing operations. <img src="eek.gif" border="0">

    Comment


    • #3
      To be honest, I don't recall how it came about, but our Unit has the rule that the height is no more than the length of the crib.

      ie: a 400mm long length of crib means that the total height for the crib stack is 400mm

      It's very restrictive, but it's safe. If we need to stabilise higher, we find other methods, such as struts, accrow props, rams, jacks, etc.
      Luke

      Comment

      300x600 Ad Unit (In-View)

      Collapse

      Upper 300x250

      Collapse

      Taboola

      Collapse

      Leader

      Collapse
      Working...
      X