Comparative Protocol Study between R44 and R129, I-Size Regulations for Child Restraint Systems

In spite of the reduction of road fatalities over recent years according to the EU data, children remain a vulnerable group.

The safety of children travelling in vehicles needs to be enhanced by improving the CRS in terms of the kinematics and biomechanics considered in its testing. Both anthropometry and side impact need be considered for a better representation of what is happening in real road accidents.

In order to deal with this issue, it was agreed that the old ECE R-44 regulation needs to be replaced. Therefore, a new ECE R-129 regulation was developed in 2013 and adopted by the United Nations Economic Commission for Europe (UNECE).

This comparison was presented at the SAE Brasil 2018 congress by our passive safety team. More than comparative, the intention was to illustrate to the audience in Brazil the evolution of the ECE R-44 regulation to the ECE R-129 regulation as a way to update a regulation to more realities of what happens in the road field. This, since the ECE R-129 when issued in 2013, did not immediately repeal the ECE R-44, but established a period of 5 years in which the homologation of the child restraint systems could be subordinated to either. In this way the ECE R-129 was presented as a complement to the previous one that guaranteed to cover greater risk protections for children up to 10 years of age or 125 cm of height, and those interested can opt for homologation by one or another regulation.

In Brazil, the ECE R-129 was not adopted as it was done by the UNECE and 60 countries integrated there. As of 2019, only the ECE R-127-9 would already be in force and that conference in Sao Paulo seemed appropriate for this recommendation and our trial.

The ECE R-129 collects all the kinematic considerations of its predecessor and adds new demands in this testing framework and adds other biomechanical restrictions. In the field of anthropometric representation, it includes a couple of fundamental considerations. By way of synthesis, the most relevant improvements are mentioned below:

  1. Recommendation to take children up to 15 months of age in the opposite direction (RWF).
  2. In dynamic tests, dummies of the Q family are used. SRIs are no longer classified according to age or weight, but according to height.Comparative Protocol Study between R44 and R129, I-Size Regulations for Child Restraint Systems2
  3. In dynamic tests. Capture of additional signals to those of ECE R-44:
    • Capture of forces and neck momentums
    • Capture of head accelerations. HPC restrictions in case of head contacts with rigid parts inside the vehicle in the event of a collision.
  4. In dynamic tests, those that provide protection in lateral collision tests are considered and represent 28% of the road accidents that affect children. The test can be carried out with deceleration or acceleration sledges (Hi-Gy) by mounting a sled on sled system as shown in the diagram below.
  5. Name of SRI i-size among other reasons because it no longer contemplates the anchoring of the SRI by means of the vehicle belts, but only by means of the ISOFIX system. This system is easy to use in its installation and greatly reduces the “misuse”. The SRI, in addition to being fixed with ISOFIX anchorages, incorporate anti-rotation systems (Top-tether or Support Leg) and now only with these characteristics the seats are called universal.

Comparative Protocol Study between R44 and R129, I-Size Regulations for Child Restraint Systems2

As of 2019, the approval of the SRIs must comply with the ECE R-129, a regulation that, like the ECE R-44, has obligations for both infant seat manufacturers and automobile manufacturers that must allow their assembly according to this directive. This directive, as happens with others, are the guidelines to be followed by approval laboratories.

2019 is the first year for the new ECE R-129 regulation to be applied exclusively and not only as a complement, but as the regulation that CRS and vehicle manufacturers need to approve for the corresponding releases. New cars are continually improving in terms of occupant and pedestrian safety; so child protection also needs to be part of this improvement.