In the past few years, many manufacturers of Child Restraint Systems (CRS) have included a notice in the CRS owner's manual to the effect of Typical 15-km/hr barrier equivalent crash damage— damage simulated in ICBC's tests. The CRS should be replaced if it has been in a vehicle that was involved in a collision. Typical 15-km/hr barrier equivalent crash damage— damage simulated in ICBC's tests. This notification has resulted in some confusion amongst owners of CRS whose vehicles have been in a minor collision. Typically the owner does not believe the CRS could have been damaged in a minor collision but is concerned about the replacement recommendation in the owner's manual.
The owner's manuals do not specify what the manufacturers would consider a collision to be in terms of a lower threshold. CRS manufacturers have not been willing to elaborate on this topic, and occasionally advised customers that even a 3- to 4-mile-per-hour bump in a parking lot would result in a need to replace their product. Many owners of CRS do not believe this is necessary, and are not willing to replace the seats in these circumstances. They remain concerned, however, because of the replacement recommendation.
In 1999, the California State legislature enacted a regulation requiring California insurers to pay for replacement of CRS after any collision in which CRS were involved. The concept of a minimum crash threshold for replacement was discussed at that time, but there was no research available—from the CRS manufacturers or other source—to support any minimum threshold. The only research available to the Legislative Committee was the results of high-speed crash tests (30 - 35 mph) from Canada. These high-speed tests supported replacement of CRS after serious crashes, but did not address low-speed impacts.
In response to questions from this committee, ICBC's John Gane reported indications that these seats were very durable and could easily withstand moderate- and low-speed crashes. In his testimony, Gane confirmed that there was no specific research to support those indications—so the regulations were put into place as proposed.
As a result in this gap in available research, ICBC conducted a series of low-speed sled tests to investigate the safety of CRS following a minor crash.
The tests were conducted in conjunction with B.C Research, Inc. at the University of British Columbia. The research team subjected a series of occupied CRS to repeated crash tests which simulated a 15km/hr (9.3-mph) vehicle impact into a concrete barrier. Insurers around the world use this impact, known as the RCAR test, to test cars for damagability in low-speed crashes and help to establish premium rates. Each seat was crashed 50 times and then was inspected by various means to determine if it had sustained any damage in the 50 low-speed impacts. In all, more than 450 seat crashes were conducted in this program.
The crash pulse for the testing was taken from actual vehicle crashes done by Thatcham Research in Great Britain. They generated a peak of approximately 10 g's during a 30-millisecond impact event. Impacts were also filmed on high-speed video at 500 frames per second.
The 9 CRS used in these tests included all popular configurations (except booster), and most major brand names. Three of the seats were rear-facing, the others front-facing. Front-facing models included 5-point harness, 3-point harness, and T-shield styles. They ranged in age from new to 10 years old, most being 3 - 4 years old.
Following the 50 impacts, each seat was then inspected in one of a variety of methods. Three seats were visually inspected according to normal protocol —checks for webbing stretch, plastic deformation, buckle integrity, etc. Three others were subject to X-ray analysis both before and after the crash testing to check for changes on the plastic shells, such as sub-surface stress cracks. The final three seats were subject to Dynamic Compliance Tests as specified in Federal Motor Vehicle Safety Standard 213 for New Child Seats (and CMVSS 213 in Canada). These included 30-mph crash tests, which generated 40 - 44 g chest acceleration levels.
None of the CRS showed any failure or any signs of deterioration in these tests following the 50 low speed impacts. All seats passed all tests.
The second part of this program consisted of real-world correlations. Its purpose was to relate the 15-km/hr barrier impacts used in these tests to the type of collision in which any particular vehicle in the field has been involved. In order to do that, the research results include images supplied by crash test facilities in Spain (Cesvimap) and Australia (National Roads and Motorists Association), of vehicles that they have crash-tested according to the 15-km/hr RCAR test.
A typical spoken description of the damage in this type of impact would be: "Sheet metal damage to front fenders and hood (or rear quarter panels and trunk lid), and some deformation of inner structures, but the deformation of the inner structures does not extend beyond the suspension mounting points. No deformation or dislocation of any part of the occupant compartment."
Typical 15-km/hr barrier equivalent crash damage— damage simulated in ICBC's tests.