KNOW BEFORE YOU GO

RVs fall into two general categories – towable RVs and motorized RVs. For many, towing is preferred because of the emergence of an affordable breed of lightweight travel trailers that retain modern conveniences like fully equipped kitchens, baths, queen-sized beds, and central heat and air conditioning. Despite increasing popularity and convenience, a dangerous but often unknown phenomenon known as “Trailer Sway” can quickly turn a family outing into a family disaster.

Trailer Sway, the fish tailing or side-to-side action of a trailer as it is being pulled behind the family vehicle, is a phenomenon that can occur when the tow vehicle/trailer combination is being passed by a tractor trailer, hit by a sudden wind gust or when the driver is forced to make an evasive maneuver. Once it begins, Trailer Sway is an extremely dangerous situation that can easily cause the tow vehicle to become unstable and roll over. There are thousands of Trailer Sway accidents which have occurred in the past, resulting in hundreds of serious injuries and deaths. Despite the RV industry’s knowledge about the dangers of Trailer Sway, the industry has done virtually nothing to warn consumers or to take measures to protect consumers from the danger.

In 1964 the federal government commissioned a study of single vehicle accidents on Route 66 (then the only major road between Los Angeles and Chicago) and concluded that vehicles pulling trailers were substantially more likely to be involved in an accident. A more modern day analysis of federal crash data shows that vehicles pulling trailers are more than twice-as-likely to experience a loss of control and crash than vehicles that are not pulling trailers. Because vehicles towing trailers have more occupants, more people are exposed to the dangers of Trailer Sway and the risk of injury and death. Each year, 283 people are seriously injured and 121 are killed.

To avoid the dangers of Trailer Sway, RV users need to understand not only the capacities and limitations of combination vehicles, but also how to deal with Trailer Sway once it occurs. However, one of the biggest problems facing RV users is that no one actually warns them about the hazards of Trailer Sway or instructs drivers how they should react if caught in a Trailer Sway situation that might result in the loss of control. RV dealers, the last point of contact with new RV buyers and renters, also fail to provide adequate warnings and instructions.

HAPPY CAMPERS BEWARE

Despite the abundance of RV devices and equipment advertised to make the RV experience safer and more enjoyable, few product manuals if any even mention the phenomenon of Trailer Sway, much less adequately warn and instruct consumers what to do if they suddenly find themselves experiencing it. The lack of information is due, in part, to the fact that these manufacturers are not actually required to test the real world performance of their products and, therefore, do not. Instead, trailer manufacturers only “self-certify” their compliance to electrical, plumbing, heating, and fire specifications established by the American National Standards Institute (ANSI). While these standards are important, they are not a counterpart to the federal safety standards that apply to auto makers.

Since RV and RV component part manufacturers are not required to test the performance of their products, they do not actually know how their products perform in foreseeable crashes. Moreover, they do not acquire important safety information essential to warn and instruct consumers how to deal with Trailer Sway once it starts.

Although there are many different kinds available, two common forms of sway control predominate: (1) Hitch Ball Systems where the trailer’s pivot point is at the hitch; and (2) Pivot Point Systems that put the trailer’s pivot point closer to the rear axle of the tow vehicle.

The trailer’s pivot point, or center of rotation, is critical to the issue of Trailer Sway because it is the point where the side forces are exerted during a sway event. The center of rotation’s proximity to the rear axle is important because it is the tow vehicle’s tire reactive forces that are responsible for resisting the destabilizing forces created by the trailer during a sway event. The closer the trailer’s center of rotation or pivot point is to the rear axle of the tow vehicle, the less susceptible the trailer is to sway and cause the tow vehicle to become involved in a crash.

The most commonly used sway control system is a Hitch Ball System that uses a “Friction Sway Control device.” As the name implies, a Friction Sway Control Device relies on friction to resist the pivotal movement of the trailer on the hitch ball. These devices have been on the market for over 40 years with little change in design. Moreover, these devices are cheap, easy for dealers to sell, and simple to install and detach. However, depending on the size of the trailer and the tow vehicle, Friction Sway Control Devices do very little to prevent Trailer Sway or the dangers associated with same.

The second type of sway control system is a Pivot Point System. In contrast to Hitch Ball Systems, Pivot Systems are designed to move the pivot point from the hitch ball forward, closer to the rear axle of the tow vehicle. By moving the pivot point closer to the rear axle, a Pivot Point System dramatically reduces the side forces the trailer exerts on the tow vehicle. The practical effect of Pivot Systems is two fold: First, because the forces on the tow vehicle are much lower, Trailer Sway is much less likely to ever become a problem. Second, once the trailer does begin to sway, a Pivot System has a much higher “damping” effect, whereby the sway is quickly eliminated. For almost all commonly used RV configurations, the Pivot Point System is dramatically more effective than Hitch Ball Systems in preventing Trailer Sway related accidents.

The leading Pivot Point hitch, manufactured by Hensley Hitch, is called the Hensley Arrow. Dynamic testing has shown that the Hensley Arrow virtually eliminates the problem of trailer sway in the real world. Available from trailer dealers throughout the country, the Hensley Arrow sells for approximately $2,500 and is easy to install. When compared to other friction type sway control devices, the Hensley Arrow has approximately a ten fold improvement in a trailer's damping ratio according to recent dynamic tests. Having been on the market for almost two decades, to date there has never been a single trailer sway accident when a trailer was equipped with a Hensley Arrow. Additional information is available from Hensley at their website, which is located at Hensley, Mfg., Inc.

WHAT TO KNOW BEFORE GETTING HITCHED

The dangers of Trailer Sway are expanded further by way in which “sway control” or “anti-sway” devices are sold. Manufacturers sell these products with claims that these devices “minimize” and “control” Trailer Sway. The majority of these devices are Hitch Type Systems and neither “minimize” nor “control” Trailer Sway. Therefore, consumers who purchase these devices are left with a false – and potentially deadly – sense of security. Testing can be conducted which demonstrates that many devices which are sold as sway “control” devices simply do not work. Using long recognized scientific protocols, the effectiveness of an anti-sway device can easily be tested by measuring the device’s improvement in a trailer’s damping ratio (or resistance to sway). A higher damping ratio means better stability for the towing combination. Recent testing has shown a dramatic difference between Pivot Point and Hitch Ball anti-sway systems. This testing showed that a Pivot Point system can “critically dampen” a trailer’s propensity to sway under foreseeable driving conditions, whereas a Hitch Ball System offered little improvement in the damping ratio.

Thus, depending on the kind of anti-sway device being used, the same vehicle/ trailer combination can have dramatically different damping ratios, which translates into dramatically different results in terms of preventing Trailer Sway accidents. Thus, consumers using such systems are operating their RVs under a false belief that the safety system they purchased will effectively protect them from Trailer Sway.

Because most RV consumers are largely unaware of the risks and dangers associated with Trailer Sway, it is essential that manufacturers provide warnings and instructions on what to do during a sway event. Unfortunately, due to concerns about how information about trailer sway might affect sales, most manufacturers provide little or no information to consumers about the hazards of Trailer Sway and the need for effective anti-sway devices.

As the number of RV sales increase year by year, there is an ever larger number of consumers pulling large trailers who are unaware of the lurking danger of Trailer Sway. Unless manufacturers begin to warn consumers about these risks, and provide information about the effectiveness – or relative ineffectiveness – of anti-sway devices, the number of Trailer Sway related accidents are certain to increase each year.