Seat Belt “Energy Management Loops” or “Rip Stitching” Failures

The misleadingly labeled “energy management loop” consists of a portion of the seat belt webbing that is folded over itself and sewn together so that the stitching rips during a collision, adding several inches of slack to the seat belt. It was designed by automotive manufacturers in an attempt to manipulate crash test results by inducing submarining and therefore reducing head injury numbers in frontal crashes.

Rather than making vehicles safer, however, EM loops greatly increase the risk of injury in a collision.

There is a wide array of published reports about the hazards associated with seat belt slack, including slack caused by EM loops. For example, in a report on improper belt use, the Insurance Institute for Highway Safety noted that belt slack “can diminish or eliminate the effectiveness [of belts] or even induce serious injuries.”

Volkswagen, Mercedes, and Toyota have warned about the hazards of seat belt slack. Mercedes and Toyota have each described in detail how seat belt retractors could be designed to provide comfortable belt fit without the hazards of slack.

A 1988 National Transportation Safety Board report consisting of a case study of 167 automobile crashes found that when slack was present in the belt system, “the opportunity for a degraded level of occupant protection exists.” Given the reduced performance of seat belts when slack is introduced and the dangers of slack, it is no surprise that most owners’ manuals instruct drivers to pull up on the shoulder portion of the belt to ensure that there is no extra slack in the belt.

Energy Management Loop Recalls

General Motors has issued several recalls related to EM loops. For example, in 2002, General Motors issued Recall 03V117, stating that the EM loop in the driver’s seat belt buckle assembly introduced as much as 10 inches of slack into the belt in a crash, which could result in partial or complete ejection of a belted driver in a rollover. The recall covered the 1997 Chevrolet Blazer, GMC Jimmy, and Oldsmobile Bravada.

To correct this condition, the seat belt assemblies were replaced with a design that did not contain an EM loop. According to GM, the recall was initiated based on claims in which belted occupants were ejected in rollovers.

In 1979, NHTSA proposed an outright ban on seat belt slack‑inducing devices such as window shade devices. Two years later, NHTSA issued a rule to “urge manufacturers to voluntarily limit the amount of slack that can be introduced in their manual belt systems.” In November 1987, NHTSA issued another ruling, this time subjecting manual seat belts to dynamic testing, and again expressing concern about seat belt tension‑relieving devices and their potential for increased occupant injury.

Given the dangers of seat belt slack, it is no surprise that automotive manufacturers provide safety components that have the sole purpose of reducing seat belt slack—just the opposite of what the EM loop does.

For example, seat belt pretensioners retract and preload the seat belt during the first few milliseconds of a crash to compensate for any slack or spool‑out.  A number of automotive manufacturers feature weblocks, which are webbing clamps that eliminate any spool‑out of the webbing stored on the retractor spindle, either by clamping at the retractor or at the D‑ring. The purpose of these devices is to reduce as much as possible seat belt slack in a collision or rollover, because automotive manufacturers are in agreement that seat belt slack reduces performance of seat belts and subjects the wearer to partial or complete ejection.

Current Status of Energy Management Loops

As a result of these studies and reports, many manufacturers have removed seat belt systems with energy management loops from current models; however, many cars on the road today still have these systems, and many manufacturers have vehicles on the road that contain both EM loops and pretensioners that actually work against each other in a collision.

If You Have Been Injured in an Vehicle Accident, Please Call Our Firm

We will conduct a full investigation into your accident so that we can identify all those responsible, including vehicle manufacturers.  We will meet with you so that we can explain how we will represent you and the legal options available for seeking recovery.  We are not afraid to take on the big auto companies and to hold them accountable for the damages and injuries caused by their negligence and defective products.

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