For years, a battle in the American fire service has raged over plastic vs. wood cribbing and the efficacy of each product. That battle continues today.
Regardless of your preference, we all know that there are different types of wood that cribbing is made from, typically depending on where in the country (or the world) you live and what types of wood are available in a given place. But, what about plastic or composite cribbing? Are there differences in it as well, or is plastic cribbing all the same? Until fairly recently, I only really knew of one plastic cribbing manufacturer and just kind of assumed that all plastic cribbing was made the same and out of the same materials. My assumption was wrong and, fortunately, I learned the differences before someone on my crew or in my training sessions got injured.
Before I go on with the plastic cribbing issue, I would be remiss if I didn’t mention a few things about wood cribbing. I know all of the “good and beneficial” things that “old schoolers” and departments with small operating budgets argue about wood, so don’t beat me up over it—I get it. Remember that every tree on the planet is unique. No two trees grow exactly the same and, as a result, no matter how nice, dried, milled, and cared for it is, wood is inconsistent. That said, have any of you been to a home improvement store or lumber yard lately and seen the quality of lumber they want us to build homes out of? If not, suffice it to say that, generally speaking, it is absolutely awful! And, we’re supposed to shore trenches, shore collapses, and crib extrication scenes with it.
Wood has no verifiable working load limit. Wood cannot be decontaminated. Remember that the reason we stopped using wooden backboards and replaced them with plastic backboards was because of the biohazard exposures and the inability to decon the wood. Is our wood cribbing any different? Does your department dispose of wood cribbing after each use? Does your department try to decon the wood cribbing ever? The answer to those questions for my department is no across the board (no pun intended). For your well-being, ask yourself a few of questions about your current cache of wood cribbing: Do I know how old it is? Do I know what it’s made of? Do I know how often it’s been used? Do I know what stresses it has endured in the past? Do I know how to tell when it’s going to fail?
OK, back to plastic cribbing. Like many firefighters, I thought all plastic cribbing was made by one company. That was until I started noticing some weird differences in plastic cribbing in the field. It was then that I learned that a number of companies were selling plastic cribbing. I also noticed vast differences in how plastic cribbing products performed under load.
Plastic cribbing is inherently heavier than wood and often a bit more cumbersome. Let’s take a plastic “step chock,” for example (photo 1). By nature of what it’s made of, a solid plastic step chock was always heavier than a wooden one. Some years ago, I came across a noticeably lighter weight plastic step chock. To my surprise, when I turned it over, I saw that it was hollowed out, thereby making it substantially lighter. I also saw that these hollow chocks were not as stable and seemed to have a much lower working load limit than the solid ones. At that time, plastic cribbing didn’t have load limit markings like it does now. As time went on, I began seeing more and more variations of plastic cribbing products on the market. Some seemed “gimmicky,” and some seemed really good. But, I wanted to learn what the real differences are (if any) between these products.
1 A step chock in use with other plastic cribbing blocks. (Photo courtesy of Turtle Plastics.)
The answers surprised me. A leading manufacturer told me, “It’s not the plastic that makes the product strong, it’s the molding process.” Apparently, one of the “mistakes” with some plastic cribbing is the reliance on the science surrounding the plastic itself. Plastic cribbing can be made with a high-compression formulation of plastic, but solely relying on high compression can result in plastic cribbing that is brittle and will break when dropped. Unlike wood cribbing that can blow apart when it fails under load, plastic cribbing will begin to bulge (technically known as “flow”). The bulge is akin to squeezing a marshmallow between your fingers. Plastic cribbing needs to be tough and resilient. In other words, it needs to be as “firefighterproof” as possible. After all, we drop and toss cribbing all the time, and it can’t be subject to breaking. Good, reliable plastic cribbing needs to have the right mix of a high-compression and high-impact formula that is combined with purpose-driven/end-user-driven molding processes. When in the market for plastic cribbing products, it’s important to do your homework and spec the cribbing in a similar way that you’d spec and demo new rescue tools.
A number of plastic cribbing manufacturers use post-consumer and recycled plastics to make their products. Environmentally, it doesn’t get any better than that. Remember however, that at the time of this writing, there are no OSHA, ANSI, or MSHA regulations regarding plastic and recycled plastic cribbing products. That said, remember that industries such as the railroads (cribbing railcars), heavy equipment manufacturers (cribbing mining haul trucks and giant bulldozers), and a number of mainstream American automakers have all switched from standard wood cribbing to recycled plastic cribbing. Usage by those aforementioned industries certainly gives fire service personnel something to think about.
CARL J. HADDON is a member of the Fire Apparatus & Emergency Equipment Editorial Advisory Board and the director of Five Star Fire Training LLC, which is sponsored, in part, by Volvo North America. He served as assistant chief and fire commissioner for the North Fork (ID) Fire Department and is a career veteran of more than 25 years in the fire and EMS services in southern California. He is a certified Level 2 fire instructor and an ISFSI member and teaches Five Star Auto Extrication and NFPA 610 classes across the country.