R129 dynamic tests: frontal, rear and lateral impact

Which seats get which test

• Frontal impact — every ECRS in scope §7.1.3(a).
• Lateral impact — every ECRS except built-in seats and universal or specific vehicle booster cushions §7.1.3(b).
• Rear impact — all rearward- and lateral-facing ECRS §7.1.3(c).

Frontal and rear tests run on the trolley with the standard test bench, in a vehicle body shell, or (in some specific vehicle cases) in a complete vehicle; lateral tests run on the test bench only §7.1.3(d). i-Size and universal seats, i-Size booster seats and universal cushions are always tested on the bench §6.6.4.1.1, §6.6.4.1.3.

Frontal and rear pulses

The lab may use a deceleration sled or an acceleration sled §7.1.3.1.1.5:

The trolley with its seat must weigh more than 380 kg. A test at a higher speed or harsher pulse counts as a pass if the seat meets the criteria; a softer pulse only counts if it dips below the corridor for no more than 3 ms cumulatively. For rear-facing seats intended for the front seat, the dashboard is represented by a rigid bar §7.1.3.1.1.4.

Lateral impact

A padded door panel (Annex 6, Appendix 3) intrudes towards the test bench. The relative velocity between door and bench must stay within the Annex 7 Appendix 3 corridor; with a fixed door, the dummy’s ground velocity at t0 is 6.375 – 7.25 m/s §7.1.3.1.3.4. Seats are tested in their most upright position, with side-impact absorbers set to the widest position that still fits the vehicle seat fixture; the door panel starts at the minimum door-to-seat distance in Figure 6 §7.1.3(e).

Before the test, side protection must sit at the height and fore-aft position of the dummy’s head centre of gravity, between head and door §6.6.4.5.1.

Set-up rules

• Frontal and rear tests use the smallest and largest dummies for the range, in the most upright and most reclined positions for each dummy and orientation §7.1.3(f).
• Belted seats are installed with the standard belt at a preload of 50 ± 5 N §6.1.2.6, §6.1.3.5.
• Tests run no more than 10 minutes after installation, with at least 20 minutes between tests on the same bench cushion so the foam recovers §7.1.3.5.2.4.
• Seats are tested unused, and at least the worst-case test is repeated after conditioning per §7.2.6 (§6.2.1.10).
• Buckles, adjusters and retractors undergo their durability and temperature conditioning before the dynamic test §6.6.5, §6.7.

Special cases

• Specific vehicle seats using non-standard attachments are tested in a body shell or complete vehicle, for every vehicle on the fitting list (with Technical Service discretion on representative shells) §6.6.4.1.2.2.
• Luggage-area ISOFIX seats need one test with the largest dummy in a complete vehicle §6.6.4.1.4.
• Convertible seats whose restraint is meant for one orientation are also tested in the wrong orientation unless a mechanism prevents it §6.6.4.1.8.
• Seats for two or more children are tested with the heaviest dummies in all positions, then lightest plus heaviest §7.1.3.6.1.

Pass/fail in the dynamic test

No part that restrains the child may fracture, and no buckle, lock or adjuster may release — except declared load-limiting devices that perform as predicted §6.6.4.2. Dummy readings and head excursion must meet the limits on the injury criteria page. Measurements follow ISO 6487 with the SAE J211 sign convention §7.5.