The first time I rode in a truck was way back in 1975. A stock boy at a downtown department store, I had to clamber up into a cabover to guide an LTL driver on a somewhat convoluted route to get to the store's loading zone around back.
Back then I had a whole lot more hearing than I do now. But what I remember most about that short trip, during which our speed probably never surpassed 10 mph, is that I could not hear a damn thing the driver said to me. And forget him hearing me. I wound up literally pointing him where to go.
Truck's today are a far sight quieter than that ‘60s-vintage rattletrap. But that doesn't mean they shouldn't or can't become quieter. That's the contention of Volvo Truck Corp., the Gothenburg, Sweden-based parent of Volvo Trucks North America.
Along with detailing engine technology that will meet EPA ‘07 regs (see “Nuts & Bolts”), last month during a press tour of its Swedish facilities the OEM showcased what it is doing to further enhance the driver's working environment by quieting the cab interior.
Indeed, as Volvo sees it, the “trend towards bigger and more powerful truck engines leads to more and more effort on the development of their acoustical performance… the challenge is to give the engines the best possible noise and vibration properties and still maintain their powerfulness.”
Volvo says its NVH (Noise, Vibration and Harshness) lab in Sweden is charged with helping refine the cab environment for the driver. The goal is not just driver comfort but also highway safety.
“The human being has to function within an extremely complex entity, and every source of disruption impairs his or her concentration,” points out Volvo Trucks test engineer John Agnesson. “At the same time, we know that the human factor lies behind most traffic accidents. Not least for this reason, the driver's environment is an area of top priority in our safety-enhancement work.
“It's all about seeing the whole entity, of grasping a complete overview, in order to develop trucks that provide the best preconditions for a safe driver — one who avoids accidents and thus minimizes work-related injuries,” he adds.
It makes sense that a calmer, more collected driver — who is not being rattled by traffic noise or a rattling cab — is bound to stay in a safer frame of mind and be les fatigued to boot.
Of course, as anyone who has suffered occupational hearing damage can attest, quieting things down in the workplace has another benefit too.
“Noise, climate and vibration affect tiredness and thus also our performance potential,” says Agnesson. “In long-term exposure, these parameters can also lead to work-related injuries such as impaired hearing.”
On the other hand, noise and vibration are not just harmful to the truck driver. “On the move,” points out Agnesson, “they give the driver valuable input on the truck and on the condition of the engine, they represent contact with the road surface and convey signals from other road users. It is also important that the driver should be able to register warning signals from the instrument panel, and that he or she should be able to react in the appropriate way.
“That is why,” he adds “our ambition is to generate not necessarily the quietest — but the most optimum noise and vibration profile in the truck.”
In other words, they are not planning on building a cab that is a cocoon as quiet as a tomb.
Were I a driver, I know I'd settle for just enough quiet to focus on what's going on around me. I wouldn't mind having that in my office, come to think of it.
So why shouldn't someone whose office is moving at speeds up to 60 or 70 mph not want the same?
