How safe is the interior of your cab?
By Paul Abelson
We hear, and more often, see a great deal about workplace safety. We attend safety meetings. We hear about driving in construction zones, driving at the speed vehicles around you drive and proper use of lanes. We see workers wearing hard hats, safety glasses, orange and lime green vests with reflective stripes and protective gloves. But what about safety in our own workplace?
I’m not talking about the open road or city streets. I refer to that little “office” where you spend so much of your day, your truck’s cab. At the 2009 Annual Meeting of the Technology and Maintenance Council, a panel representing fleet operators, suppliers and manufacturers tried to answer the question, “How Safe is the Inside of Your Cab?” Their conclusion was that it is not nearly as safe as we want it to be.
That’s not because of the trucks. In fact, manufacturers and accessory suppliers have been engineering safety into new trucks for decades. The problems are there because of what drivers do in the cab once the truck is theirs.
To best understand the dangers, let’s review some basic science. First of all, once an object is in motion it will remain in motion until it is restrained or it strikes another object. The force with which it strikes is dependent on the weight of the object and its speed. The pressure it exerts is related to the object’s surface area. A 10-pound object with a one-square-inch (sq-in) base exerts 10 lbs per square inch (psi). Broaden the base to 2 sq-in and pressure drops to 5 psi. Narrow the base to 1⁄2 sq-in and pressure doubles to 20 psi.
Acceleration is measured in multiples of the force of gravity (g). Sitting in our seats, we experience 1g. In a crash, where an immovable object causes us to stop abruptly, we measure impact forces in multiples of g. These forces increase geometrically. If a 15 mph crash generates a 15g peak, doubling speed to 30 mph increases loads by four times, to 60g.
Now, what does this science have to do with cab safety? Until you’re in an incident, nothing. Notice I said “incident” not “crash.” If you brake or swerve to avoid a crash, g forces are exerted on everything in your cab. That means that everything not secured becomes a potential missile, all aimed at you. Here are just a few examples of what the TMC panelists found in the cabs of trucks.
TV sets were often unsecured, sitting on their shelves just as they would be at home. At around 20 lbs each, they will fly forward in a crash. With an impact force of 60g or more, that’s like getting hit with a force of 1,200 pounds flying from the sleeper. Even an unrestrained one pound drink bottle can do some damage if it launches through the air.
One enterprising driver built an in-cab “entertainment center” to hold his television (left). He even tried securing the set, but there really are no DOT-approved bungee cords. Since the woodwork, well crafted though it may be, was not secured, the entire mass could come flying forward in a crash, or even a swerve or hard-braking incident. Even a little lightweight fan, held on a hanging locker bulkhead with a spring clamp, could easily break loose and whack a driver on the head. Check your cab for loose objects. Chances are you’ll find a few.
Use secure netting. Bungee cords are convenient but not really made to restrain heavy objects. Truck makers and component suppliers go to great lengths to engineer cargo netting, secure compartment latches and nets that protect a sleeping team driver in a crash.
We get most of the information needed for driving visually, yet much critical information is often obstructed. Store books and boxes on the right side of the dashboard, and critical close-in sight lines — needed to maneuver through city traffic and shippers/receivers yards — are blocked. It doesn’t matter if you have a classic long-nose hood or a sleek aerodynamic one if the box on the dash keeps you from seeing a concrete post or an unlucky dockworker. What you don’t see can hurt.
Side mirrors are critical. Truck makers provide enlarged side windows and peep holes for better visibility and to properly locate additional convex mirrors. But some drivers disregard what the engineers gave us, creating their own obstacles to good vision. One wanted his cab convenience more than safety, so he showed up at his fleet maintenance shop with a load lock bar positioned from the passenger’s side floor to the roof. On it, he fastened plastic drink holders, totally disregarding the cup holders molded into the cab at the factory. The load bar and what was on it blocked vision to the right side mirrors.
Truck makers and sleeper cab builders make sure cabinet doors have secure latches. Openings have restraining clips, covers and nets to secure the contents of your storage spaces. Yet some drivers remove the restraints in order to retrieve their stored items more easily. Remember what these objects can do when they go flying through the air.
The chances are that you’ll never have a crash severe enough to cause serious injury. But truckers, on average, experience 2.2 incidents per one million miles. That means that if you drive long haul and run 100,000 miles a year, the odds are that you’ll be in some sort of accident once every five years.
You can put those odds in your favor by keeping your sight lines open. You can minimize chances of injury by securing all loose objects in your cab. Think about it and give your cab a safety check today.