Project: Airbag Interaction: Children and THOR Dummy

Reference: S0012/VF

Last update: 13/04/2006 12:31:21


This research project will provide an evaluation of the interaction of side airbags with children in child restraints and adult belts, considering not only the potential for injury but also implications for future amendments to regulations. In addition, the project will contribute to allow the performance of current child 'P' dummies to be evaluated against the more recently developed 'Q' series, with respect to the future benefits that may be offered through adoption into regulation.
It shall also assess the performance of the THOR dummy in out-of-position airbag tests for use as a possible test tool in both static and dynamic tests.


The interaction problems of front firing airbags with children in the front passenger seating position are well established and steps have been taken to highlight the dangers of using rear facing infant seats in this situation. Less well known however, is the interaction of side airbags with child restraint systems. Concerns had been raised in the USA about the potential negative effects of side airbag loading on children. Whilst European and US frontal head airbags significantly differ, it is expected that side airbags are more alike. This project was to investigate and provide an understanding of the interactions between child cars seats and side airbags, issues arising in terms of child restraint approval and implications for possible future amendments to UNECE Regulation 44. The methodology proposed for the completion of this project was to review the literature, Co-operative Crash Injury Study (CCIS) database, On-The-Spot (OTS) database, CRS Questionnaire (S082E/VF) database and Euro NCAP test films to identify cases where interaction between a side airbag and child seat had occurred. There were no suitable cases identified to complete sled test reconstructions. An investigation into performing a series of sled tests using restrained by the adult belt and in front of side firing airbags was completed, but the department did not decide to take up this option following a feasibility study. At this time the EEVC WG18 were proposing to compare new, more biofidelic child dummies ('Q' series) under UNECE Reg 44 test conditions and compare these to the currently used dummies. The 'Q' series are viewed by many to be the next generation of child crash test dummy. The remainder of the project was used to contribute 32 (of 328) sled tests to this collaborative programme. The tests looked at the 1, 1and a 1/2, 3 and 6 year old dummies in a side impact configuration, using a variety of infant seats, child seats (ISOfix and Universal), booster seats.
Frontal head airbags are increasingly prevalent in vehicles as part of the occupant restraint system. Whilst there are no legislative tests to assess specifically the risks to occupants from airbags, the frontal impact test includes a 50th percentile dummy in a normal seating position. In the 'real world' occupants may be 'out-of-position' at the time of airbag deployment and an assessment of the risks to these occupants is important. A new crash test dummy, known as THOR (Test device for Human Occupant Restraint), was assessed as a replacement for the current Hybrid III frontal impact dummy and part of this research shall assess its performance and sensitivity to out-of-position airbag loading.


TRL Limited
Crowthorne House, Nine Mile Ride, Wokingham, Berkshire, RG40 3GA
+44 (0)1344 773131

Contract details

Cost to the Department: £164,500.00

Actual start date: 25 May 2002

Actual completion date: 31 March 2005


Final Report: Improved Frontal Impact Protection through a World Frontal Impact Dummy
Author: FID Consortium
Publication date: 22/12/2003
Source: EC

Evaluation of the Performance of the THOR-Alpha Dummy
Author: Hynd et al
Publication date: 01/10/2003
Source: STAPP Car Crash Journal, Vol 47. Paper 03S-26

PR/SE/231/2005 Airbag Project Final Report
Author: M LeClaire, C Visvikis, D Hynd and P Bennett
Source: mailto:

PR/SE/699/03. Literature Review of Research on Vehicle Side Air Bag Interaction With Children
Author: TRL Ltd
Publication date: 01/06/2003
Source: Contact

UPR/SE/234/05 A Comparative Study of the Q and P Series Dummies in ECE REgulation 44 Test Conditions
Author: M LeClaire and C Visvikis
Source: Contact:

PR/SE/641/02. THOR Out-Of-Position Airbag Interaction Testing
Author: C Willis and D Hynd
Publication date: 01/12/2002
Source: Contact:

PR/SE/806/03 Initial Regulatory Impact Assessment - Airbag Interaction: Children
Author: M LeClaire and P Bennett
Source: Contact:

Summary of results

  1. Airbag Interaction: Children
    The lack of data from field investigations concerning child seats and airbag interactions identifies two clear possibilities; (1) that there are no problems associated with side airbags interacting with child seats restrained by the adult belt; or (2) that the field data simply did not contain a sufficient number of examples where children were travelling correctly restrained in the rear of vehicles next to side airbags which deployed. With an increasing prevalence of side airbags in modern vehicles, monitoring of the field data will resolve this question. At this time, side airbags do not appear to present an increased injury risk to children travelling in child seats correctly restrained in the rear of vehicles. It is thought that in some circumstances that they may provide a benefit though this is not conclusive.
    Differences in the construction of the 'P' series child dummies, currently used in regulation, and the more recently developed 'Q' series dummies lead to a recognisable difference in dummy kinematics and dummy loadings when compared under the same sled test conditions. The 'Q' series dummies (Q1, Q1.5, Q3 and Q6) are based on more accurate child anthropometry than the P series (P0.75, P1.5, P3 and P6) and are also more biofidelic in their response to loading. Dummy kinematics are better than those of the 'P' series. The 'Q' dummy has the capability of measuring loading in more body segments (specifically aligned with areas seen to be injured in real world studies), which could lead to the provision of protection in body areas that are not currently covered by the regulation. The biofidelity requirements have not yet been discussed and agreed within the EEVC.

    Airbag Interaction: THOR dummy
    The THOR dummy was found to be sensitive to the proximity of the airbag in static out-of-position airbag deployments. The repeatability of most of the THOR dummy measurements was good in both static and dynamic test series, although the upper neck forces and moments and the chest compressions were found to be more variable in comparison to other criteria. This apparent scatter was caused by variations in the airbag inflation pattern that led to markedly different interaction between the head and the airbag.
    In the dynamic sled out-of-position airbag deployment tests the THOR dummy was not sensitive to the different airbag deployment times. The different airbag deployment times produced visibly different interaction between the dummy and the airbag, but this did not result in significantly different loads on the thorax.
    The THOR chest compression (Crux) and lower abdomen (DGSP) instrumentation were found to be vulnerable to damage, but it is very difficult to check them for damage without removing them from the dummy between each test.
    THOR dummy neck and head to neck joint durability was insufficient in these tests for regulatory use.