Update of hEN 1317-5
In 2012, the CEN published a major amendment of the EN 1317, which is the second since the approval of the standard in 2007. The goal of this amendment was to integrate in the harmonised part of the standard (Part 5) the changes already introduced in the supporting parts (1,2 and 3) since 2010. This was necessary in order for notified bodies to be able to award CE marks according to updated criteria.
The amendment also introduces performance classes concerning snow removal operations which concerns mainly Scandivian countries.
This section explains in a simple but concise manner the major changes introduced.
1. Removal of Post-Head Impact Deceleration (PHD)
In the 2007 version of the EN 1317, the Impact Severity was calculated by considering three distinct values:
- Acceleration Severity Index (ASI)
- Theoretical Head Impact Velocity (THIV)
- Post-Head Impact Deceleration (PHD)
EN 1317-5 2007
In the 2010 version, the PHD has been removed because, as a result of exentive empirical evidence, experts judged it to be unreliable as a parameter.
EN 1317-5 2012
2. Introduction of L-Class Containment levels
As shown in the table below, in the 2007 edition of the EN 1317-5, the performance of the H-class barriers was evaluated by performing a test including a Heavy Good Vehicle(different for each class) and a small passenger car (the same test for all classes).
This meant a large percentage of 'middle class' vehicles currently cicrulating on the roads was not taken into account during the testing and subseuqent certification of barriers, in particular family cars with an approximate weight between 1,500 kg and 2,000 kg.
EN 1317 Crash Test Specifications - 2007 Version
As a result, the CEN working group introduced a new range of classes called 'L-Class' which as become a testing requirement and includes a third test of a middle sized vehicle to H-Class barriers. The introduction of these new barriers will ensure a higher level of safety for users on Europe's roads.
EN 1317 Crash Test Specifications - 2012 Version
3. Normalisation of deformation indices
In order to reduce the influence of the testing tolerances in the classification of performance of safety barriers, the deformation indices (working width, dynamic deflection, vehicles intrusion) are now normalised with the actual testing values for mass, speed and angle. The table below shows the new way of calculating the deformation indices as stipulated in the EN 1317 2010 Version.
Calculation of Deformation Indices