This SAE Recommended Practice describes the test procedures for conducting quasi-static frontal strength test for COE heavy truck applications. Its purpose is to establish recommended test procedures which will standardize the procedure for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
In 1998, SAE J2420 and J2421 were both issued. These RP addressed test procedures for evaluating the frontal strength of COE heavy trucks. The difference between the two was how the frontal load was imposed. SAE J2420 applied a dynamic impact to the front of the chassis and SAE J2421 applied a quasi-static load.
In 2003, SAQE J2420 incorporated pass-fail conditions that paralleled ECE Regulation 29. This also included a defined impact energy.
At the same time, SAE J2421 was also changed to reflect some fo the ECE Regulation 29 conditions, but did not establish a load to be applied. In Section 7, (Performance Requirements)( of SAE J2421, it also states "This test procedure is for the purpose of informational studies only and is not an alternative to SAE J2420 due to the lack of the prescribed magnitude of load applied to the front of the vehicle."
Since SAE J2421 is no longer an alternative to SAE J2420, there is no reason to keep both procedures active. Therefore it is recommended that SAE J2421 be cancelled as an active SAE RP.