Winter is finally gone, although as I write this column we are still dealing with wintery weather. Hopefully by the time you read this, all this weather will be gone and warm, nice days will finally be among us. That will mean it is time to get some training in while the weather is good, and before it gets hot and the summer vacations kick in.
The last article we looked at using cribbing for stabilizing large vehicles and also the amount needed for stabilization. We also considered the sizes and how much weight wood and plastic cribbing will hold. The biggest problem we encounter is having the capability of storing and transporting enough cribbing to handle a large vehicle crash. Another option to look at is the stabilization struts. These have now been around for quite a while and can save us a lot of space on the rig. They make stabilizing vehicles easy and quick, without worrying about the stacks, how high we stack, and whether they are all stacked in-line. Stabilization struts do not replace our cribbing, but they do enhance it tremendously.
Struts use what is called the buttress system, a series of triangles that make using the struts quite strong. The struts are placed at roughly a 75 degree angle to the vehicle being stabilized. This angle can vary depending on the weight being carried and how you tie in the base straps. The reason that 75 degrees is the ideal angle is because the weight is transferred down the strut without having excessive weight being applied to the base or tip. Greater angles will increase the weight on the base and strap while lesser angles may not carry the load at all. The straps should be attached as low as possible giving you the greatest possible angle between the strut and strap. This creates the triangle that we are looking for. If you think about the angle you climb a ladder, which is around 75 degrees, we do not have to strap the bottom or secure the top. This angle allows for your weight to be transferred down the axis of the ladder. The basic physics concept also applies to your struts. Once the straps are attached, they should be tightened as much as possible.
Depending on the rating on the struts, which should include the base and tip attached, will depend on where and how many you may have to use. Keep in mind that the weight of the vehicle is already being disbursed somewhere. Your struts may only be keeping it from shifting. Struts range in capacity from several thousand pounds to above 60,000 pounds. If you have struts rated at 8000 pounds, don’t feel like you can’t use them, as four would give you a 32,000-pound capacity, which would stabilize in a lot of situations. The important thing is where you place them in relation to the vehicle’s position and weight dispersion. When we looked at cribbing, we also considered that wood would creak and pop when it starts to become overloaded and give us a warning before failure. This is something that should always be considered when supporting any load. Metal struts also have the capability to give advanced warning before failure. Metal will distort and bend when the lateral load becomes excessive and give you a heads up that the load is exceeding the capability of the strut. Unfortunately, we very seldom know the weight of the vehicles we are stabilizing and have to make a trained and educated guess as to what we are dealing with.
The use of struts can greatly enhance your capability to better handle large vehicle rescues, but the use of cribbing will always be there. In most cases a combination of both can and should be used. Taking a few extra seconds to do a good assessment may save you a lot of headache, and increase the safety for the rescuers. Consider where the weight is located and where the most likely place it could shift to. Always think in a 360 degree world and consider all sides. Once you do this, your strut placement will be in the best place possible, and get the job done for you.
When you can take a heavy vehicle class, take it. Most departments don’t get the opportunity to train with large vehicles, so it is well worth the time and effort.
Next time we will continue to look at working with large vehicle rescues. Until next time, train hard, stay sharp and play safe.
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