Seatbelts are arguably the single most important safety feature in your vehicle, and when properly designed and utilized save countless lives. However, when they fail to perform as intended or malfunction due to a defect in their design or manufacturer tragic results can occur. A review of reported accidents through public sources and a survey of restraint litigation across the country provide evidence that design and manufacturing defects exist that greatly undermine the performance of certain occupant restraint systems. These problems, left unaddressed by the auto industry, continue to cause significant injuries in deaths in accidents where a properly functioning restraint should have provided protection. Even though significant improvements have been made in the past few decades, advanced seat belt technologies have been largely ignored by car manufacturers and have not broadly incorporated into vehicles across the industry. Additionally, industry standards have remained largely unchanged over the past 20 years, leaving the choice of whether to integrate more advanced systems to the manufacturers themselves. Unfortunately, many automakers have opted to use simple, inexpensive and basic designs very similar to those that have been around since the inception of the seat belt. As a result, defective and inadequate restraint systems remain a very real concern. The most common occupant restraint defects involve latching issues, geometry problems, retractor failures, and the failure to incorporate pretensioners.
Poor Design
The importance of quality designs in the occupant restraints is self evident, as poor designs can lead to tragic results. In 1967, General Motors Corporation employee, Robert C. Fisher, designed a small side-release buckle that was simple, lightweight and inexpensive. Known as the RCF 67 or Type 1, it remains in use even today on some Ford model cars. This type of buckle has a spring that holds the latch in the tongue until the button is depressed. It has been alleged that the spring force of such restraint can diminish with frequent buckle use. If that happens, the force needed to operate the push button and the acceleration needed for inertial release will be lower.[1] As a result, it is believed that this type of seat belt buckle can be more prone to inertial release and false latching, and because of such defect has been the subject of much seatbelt failure litigation.[2]
False Latching
False latching occurs when the seat belt looks and feels like it is latched, but the locking mechanisms are not fully engaged.[3] If force is applied to a falsely latched seat belt buckle, it will completely release, allowing the passenger to be thrown about inside the car or be ejected. Worse still, typically the passenger will be listed as having been unbelted, unless the occupant survives and he or she or other witnesses insist that the belt was used.
Inertial Unlatching
Inertial unlatching is another seat belt defect related to the buckle.[4]Inertial unlatching stems from a poor design and occurs when a force, often a body part such as a hipbone or arm, impacts the raised or side button of the buckle, inadvertently unlatching it.[5] Inertial unlatching is due to the “inertia” that presses on the back of the buckle when there is an impact that can release the tension in the latch plate, causing the buckle to open.[6] This can occur even when “relatively low” forces are applied to the buckle, although it is more likely to occur in higher speed collisions.[7]
Seatbelt Geometry Issues
While seatbelts can be life-saving devices, if not designed to fit properly, they can cause serious injury and possibly even death. The angles created by the seatbelt, seat and anchor mounting locations are critical to proper fit. If the seat belt crosses the body too high, cutting across an occupant’s abdomen, a person can slip under the lap belt during an accident causing serious internal injuries. This “phenomenon” is known as “submarining.”[8] Poor seat belt geometry can also lead to seat belt rollout, where the shoulder strap portion of the seat belt slides off the shoulder, leaving the person retrained by only the lap belt.
Retractor Failures
Seat belt retractors keep an occupant in the seated position by a pendulum that during an accident tilts forward and locks in the sprocket to hold the seatbelt webbing and keep the occupant in place.[9] When an accident occurs, the seat belt retractor is designed to immediately lock and prevent any payout of the shoulder belt in order to prevent an occupant from moving around within the vehicle. When a retractor fails to lock properly, excess webbing is released from the retractor and results in seat belt slack or a spool out. Only a few inches of slack can be the cause of catastrophic or fatal injuries. According to NHTSA tests, even an inch of slack can substantially raise head injury force levels, and a few inches can largely eliminate the belt’s effectiveness. Further, a slack belt can promote or allow ejection or severe submarining.
Failure to Incorporate Pre-Tensioners
Although pre-tensioning technology has existed for years, it has only recently been incorporated as a vehicle safety feature, making it a possible defect claim for non-inclusion of this technology. These systems sense a possible collision “seconds in advance and activates pre-crash measures.”[10] When these systems sense a possible collision, they activate the tension in the seat belt system to hold the occupant in place.[11] Some advanced systems, like the Pre-Safe system found in Mercedes Benz S-Class sedan since 2003, move a seat from a reclined position to an upright position just before the impact.[12]
Seatbelts, while meant to protect, can fail due to poor design. When investigating a possible seat belt defect, it is important to review all aspects of the seat belt system, and closely examine the buckles, webbing and retractor components. Also, it is important to bear in mind that accident reports and witness testimony to the effect that an occupant was “unrestrained” may be inaccurate and misleading because of the failure of the system itself due to a defect. The fact is, life-saving occupant restraint technologies exist, and the goal is to see them utilized in every car on the road. When older inadequate and defective systems fail, it is critical that those failures be identified.
References
[1] See e.g., Julie Howle, Jury Begins Deliberations in Crash Trial, The Greenville News, South Carolina (Aug. 6, 2006) (describing a lawsuit that alleged that the RCF-67 seatbelt inertially unlatched during an accident, killing one woman and leaving another a quadriplegic). Continue Reading
[3] Seatbelts, Safety Forum: Product Safety News and Resources, http://www.safetyforum.com/seatbelts/ (Accessed July 22, 2004).
[4] Darrel Peters, An Invisible Killer: Inertial Release in Seat Belt Buckles, Auto Cases: Crash Course Trial (Feb. 1, 1997).
[5] Id.
[6] Id.
[7] Id.
[8] Id.
[9] Id.
[10] Rick DeMeis, New Benz ‘Reacts’ to Help Save Passengers, Design News (Nov. 18, 2002).
[11] Id.
[12] Id.
