Presentation from Mr Ellway, Euro NCAP (GTR7-06-08):

Mr Ellway presented the Euro NCAP medium-severity whiplash pulse definition, including a detailed review of the development of the current, narrow corridors. The medium-severity pulse definition started with the IIWPG definition, which had three ‘gates’ at the start, peak and end of the pulse. Euro NCAP defined a pulse to fit these requirements in terms of a mathematical expression for the rising and falling acceleration, plus a delta-v requirement. No corridor is set on the down-slope, because it was not thought necessary if the pulse meets the rise-slope and delta-v. It was noted that it took some time for all of the labs to understand how to meet the pulse specification, e.g. using a dummy on the sled for pulse tests to account for the partially coupled mass. Once each lab has adjusted the sled and can get the pulse, they do so quite consistently. It was noted that the labs found that the best way to minimise the effect of the partially coupled dummy mass was to increase sled mass to 2000 kg (from a typical mass of 1000 kg). It was also noted that all but one of the Euro NCAP labs have been able to meet the pulse specification for some time, although it is known that some OEMs have found that they cannot modify their sleds to be able to meet the pulse

Mr Frost asked what evaluation was made regarding how the tightening of the corridor affected the assessment, or whether it was simply trying to get a good compromise between tight corridor and achievability. Mr Ellway replied that it was the latter.