P3U to T110/1-UTA — Aspects to be considered
A terminal with a total permanent displacement zone which was Y=1 for the ENV 1317-4:2001 Standard can now be a system with T=0.5 or T=1.0, for the new TS-terminals. The new classification of the total permanent displacement zone should be correctly updated.
The total permanent displacement zone Y=4 of the ENV 1317-4:2001 Standard considers all the systems with a Dd distance larger than 3.5 m. The TS-terminals document is now considering an upper limit for the last T class, with a maximum distance of 6 m. This aspect should be taken into account during the approval process of the old P terminal as a new T system (a system with a displacement of 7 m would not be acceptable considering the requirements of the TS-terminals document). The new reference document is stating that the total permanent lateral displacement determined according to the ENV 1317-4:2001 is acceptable for tests already carried out in accordance with the old Standard, but this could contrast with this new limit imposed by the TS-terminals document. Attention should be given to this aspect.
The permanent displacement classification was not calculated with detached elements over 2 kg in the ENV 1317-4:2001, while such parts should now be considered, according to the TS-Terminals document. In the new reference document, it is stated that for tests carried out in accordance with ENV 1317-4:2001, the total permanent lateral displacement determined according to the ENV 1317-4:2001 is acceptable. Anyway, if detached elements were present during the original crash test, but they were not recorded and considered for the evaluation of deflections, the approval of the system in accordance with the new TS-terminals would be characterised by the lack of a necessary data. For this reason, it would be better to add some additional information about this aspect. If data regarding detached parts greater than or equal to 2,0 kg could be retrieved from the documentation about the certification tests, the new total permanent lateral displacement value should be calculated and reported accordingly, together with the old one. If information regarding detached parts are not reported in the available documentation, the compliance with the requirement could not be evaluated and a sentence reporting the lack of such aspect could be advisable.
The TS-terminals now requires to calculate and report the dynamic lateral displacement of the terminal. If such value could be retrieved from the original documentation of the tests already performed, it should be reported to be compliant with the prescription of the TS-terminal, if not a sentence regarding the lack of this information should be reported.
Differences between the old and the new reference documents regarding redirection zone should be considered to correctly evaluate the performances of the terminal in accordance with the new TS-terminals document. Such differences regard the new definition of the terminal energy absorption category, the different velocity limit used for the identification of the redirection zone and the different requirements for tests with approaches 4, 5 and 6.
The line R, perpendicular to the barrier traffic side at the end of the terminal (or 16 m after the terminal datum point if the structural length of the terminal is more than 16 m), is used in test with approach 1 (or approach 2 for T50 and T80/1/2/3 terminals) to measure the exit speed, with the aim of identifying the terminal energy absorption category. This aspect of terminals was not present in the ENV 1317-4:2001 Standard. For this reason, if in tests that were carried out in accordance with ENV 1317-4:2001 line R is crossed but the exit speed cannot be derived, the terminal should be considered as a non-energy absorbing terminal. The speed value which is considered for the energy absorption category determination of the terminal is 11 km/h.
The speed limit of 11 km/h is also used as a limit for the identification of the redirection zone, in the TS-terminals document, while in the ENV 1317-4:2001 Standard the speed limit is the 10% of the prescribed impact speed. The difference in the speed limits between the old and the new reference documents might have some influence on the definition of redirection zone.
For approaches 4, 5 and 6, the TS-terminals document is requiring that the vehicle should leave the terminal after side impact so that the wheel track does not cross the line A or its extensions within 10,0 m from the point P, where the last of the vehicle wheel tracks re-crosses the original line of the traffic face of the terminal after initial impact. The ENV 1317-4:2001 Standard was requiring that only in case of approach 4 the vehicle should remain on the approach side (it was not required for approach 5), moreover the 10 m extension of the line A was not considered. As a consequence, a redirection zone determined according to ENV 1317-4:2001 Standard might be different from the same determined following the prescriptions of the TS-terminals document.
The TS-terminals document is reporting that for tests carried out in accordance with ENV 1317-4:2001, the redirection zone determined according to the ENV 1317-4:2001 is acceptable. However, it would be useful to report possible differences between the redirection zone already identified and the one which would be determined following the current document, if necessary information for this evaluation could be retrieved. A sentence clarifying this aspect should be reported.
All the requirements of the new reference document TS-Terminal should be checked and met, both for old and new tests (real or simulated). Comments and guidelines discussed in the report RPT_211018_030_0198 should be taken into account together with the leading principles and the rationale at the base of the document. The whole documentation regarding terminals (EN 1317, EN 16303, …) should be considered.