The containment level indicates the system's ability to withhold the vehicle on impact. Each containment level is defined on the basis of impact tests that the system must be able to withstand. A new system must be tested at least twice. Once with a light vehicle to determine the hardness of the impact and once with a heavier vehicle to determine the maximum energy the system can withstand. The strength classes are classified according to impact with the heaviest vehicle.
Based on the results of collision tests, the parameters defining the system's performance are calculated.
To pass the impact test, a system must meet the following requirements:
- The system must withhold and retract the vehicle in a controlled manner
- Individual parts of the system must not penetrate the vehicle
- Deformation or penetration of the cabin which may cause serious injury is not accepted
- The center of gravity of the vehicle must not cross the centerline of the deformed system
- The vehicle must not roll around - including on the side, during or after the collision. However, “rolling pitching and yawing” is acceptable
- For tests performed with heavy vehicles, max. 5% of the mass of the ballast can detach or split until the vehicle is stationary.
- After the collision with road or bridge guards, the vehicle must not cross a line parallel to the original centerline of the system when it is thrown back. See the illustration below.