Cribbing Question

[Engine613]

My department is kicking around the idea of purchasing some of the pre-fabricated cribbing. This cribbing comes in 2"x4" and 4" x 4". The material is some type of plastic or polymer. Should we invest in this type of cribbing or stick with the old fashioned hard woods such as oak, ash, and maple.

[Zmagrescue]

Lets forget all the arguments about hard and soft materials, and what is the best wood for a minute. Lets just start out with some simple math. Typicaly a crib stack of 5 4x4's will be about 18 to 20 inchs high (we all know that a dimensional 4x4 is a little under 4"). However the "Lincoln Log" type plastic cribing that I have seen has the interlocking cutouts that greatly reduce your vertical gain. So a stack of 5 interlocks only gives you about 15 inchs. I'm not saying that this is good or bad, but do the math before you purchase. One of the biggest complaints that I hear is "We just don't have enough space to carry all that cribbing" Do we really want to get less in the same compartment?

Zmag

[MetalMedic]

We recently purchased some plastic cribbing though a recycled materials grant our County had. We have yet to put it on a truck since our current rescue truck is overloaded as it is. Once we replace that truck, we will likely add the plastic to the wood to keep on board. I would not recommend changing excludively to platic primariliy because it is more rigid that wood. There are times that you need the cribbing to take a "bite" to hold it in place and the plastic will not do this. The other concern I have with plastic is that if you do not have your cribs relatively level, the plastic could become unstable since it is not going to settle like wood would.

On the positive side, plastic appears to be more durable and in more ideal situations, is eassier to work with. You never can have too much cribbing, so if you can get your hands on it, I wouldn't turn down the possibility of purchasing it. If noting else, it give you another option to work with.

[greapr]

A problem that I have heard about plastic cribbing is that oil and other fluids do not absorb in, but insted stay on the surface. This may make the cribbing slide. I heard this from a salesman that sells plastic cribbing. He recomened using wood to me.

[ 07-31-2001: Message edited by: greapr ]

[MrFreeze]

If you can find a neighboring dept. or rescue service that uses it, work with them and get your hands on it. See if you dig it first. Or maybe just buy enough to test it out. I personally have never worked with plastic, but I would think it would a little slicker than I would like. Another thing about wood is availability and the ability to customize it if you want.

[res7cue]

A Mutual Aid dept purchased the plastic cribbing. PLayed with it a the County training weekend and found that it does tend to slip on any wet surface.

We have a member that gets all our cribbing custom cut from a sawmill in another county, it's free and we can customize it to our specific needs.

We have numerous lengths and sizes and we can and have customized these pieces on scene. When we return we can be politcally correct and recycle them into another size or special crib.

The other issue that I have is that you can see when a piece of wooden cribbing is in bad shape. The plastic however to me could hide the fact that it is worn out or is going bad.

The wood cribbing just works better overall and we don't spend a dime on it!!

[resqtek3]

There will always be benefits to both types of cribbing, as a user and salesman I have found that specific uses for both are there, and that they can compliment each other when purchased to do so. There are many types and designs available, you should look at them all. I am particularly proud of what I use, but still compliment it with wooden 4x4 & 6x6. Let me know if I can be of help.

[lutan1]

We're running with 4 sets of the Holmatro stabilisation packs and love them.

To supplement them, we use Oregon (I think, F7 grade???)for crib building purposes.

[buckethead101]

wood is the best material for cribbing for several reasons. 1. it is relatively inexpensive and disposable. if it breaks, wears out, becomes contaminated; just throw it out. you can purchase replacements at local lumber yards. 2. it is very strong. a properly constucted 4 by 4 cribbing can support approximately 6000 lbs per point of contact. that is a lot of weight. a box crib could then support 24000 lbs. a 3 by 3 could support 54000 lbs. with all points touching. 3. wood does not fail suddenly. it will give you warning signs such as creaking and groaning that other materials will not indicate before failure. this will allow you to reevaluate your cribbing situation and remedy and weaknesses before someone gets killed. it is important to add that only certain types of wood are appropriate for cribbing. i believe that douglas fir and southern pine are two appropriate types for cribbing, however you should verify that. oak is not appropriate for cribbing because it is subject to sudden failure. yes it is strong, but it will not provide the warning signs that other wood cribbing will. their are also other considerations such as the grain and number of knots in the wood that detract from the strength of the wood, but i will not go into them here, as they are difficult to explain in writing. good luck with whatever you choose, hope this helps.

[ 08-25-2001: Message edited by: buckethead101 ]

[mikema]

Dear Engine 613,before i can answer you post i would like to know is the plastic stuff more cost effective than the wood cribbing and also is the load bearing specs any different and at what heighth can the plastic stuff go up to be safe. last i'm a wood man for any type of cribbing. good luck with your choice mike m

[Engine613]

Thanks for all the input guys. We will probably purchase a few pieces to try, but I think we will probably stay with wood for the majority of our cribbing. Thanks again!!

[pammoore]

We use Turtle Plastic cribbing. I would never go back to wood. The oil's and fluid do not soak the cribbing and they will last forever.

[Hacksaw]

Maybe a little late to this discussion...
i'm a firie rom Oz and we tried some plastic stuff.....just didnt cut it!
Too slippery... too stiff...didn't "talk" under load...didn't bed well...
trying some new stuff...for us anyway....treated soft wood!....great to work with so far!
Yes cost is a factor in replacing bent stuff but it's outweight by useability

andy www.blacktownfirerescue.org

[mesha47]

Just one word about cribbing...Zmag..It has eliminated at least 80% of our cribbing requirements. By this I mean the need to carry 2 or 3 trees worth of blocking in our rescue.
Tim Bennett, Station Captain ( volunteer)
"mesha"
Greater Sudbury Fire Service
Ontario, Canada

[rmoore]

How has plastic cribbing eliminated carrying two or three "trees worth" of wood cribbing?

Regardless of the type of material, don't you still carry enough to do the same jobs?

[CribPac]

I feel cribbing is one of the most underestimated tools used in the Rescue Service. Cribbing is basic but important. It mainly performs two functions, one is to hold a load the outher is to stabilize a load. Anything solid can be used as cribbing. But what is the weight you want to hold? Then ask yourself, what should I use for cribbing. Being in the rescue service one never knows what to expect. So you want the most practical cribbing that can take the highest load. Hardwood is still the preferred material. Softwood can take a good load but it is brittle, that is what "Hacksaw" was referring to when he mentioned cribbing taulking. The only thing cribbing has ever said to me is "run or die". When cribbing cracks it losses load capacity and the load can shift.
Stablizing a load takes a wide stable support. I feel plastic is except able in some instances but when it is subjected to heavy loads it reverts back to what it is "oil".
Plastic cribbing doesn't talk it spits.
I think rescue deptartments that want the best, use rough ban cut hardwood, treated to prevent cracking, in 4",2"and 1" with a good supply of wedges.

1st Lieu. Maltese http://www.sover.net/~branch

[ejfd30]

I must say I like what my counterpart from Vermont said. Some of you folks may not belive this But I have seen Times when we had to IMPROVISE a bit. I.E. beg, borrow to get a Job done. One of the most common things that I can find is Wood, I will stick with it. Sorry about the Pun there, My old A.C will like it thought. I know of a Department to cut down more then one tree at an MVA. They also took it back to the house to burn it for heat, That IS REAL. If you want to use the Plastic have fun, You will find me in the wood camp.