Rail E-ssentials

Since the invention of the railway, safe movement on the tracks is one of the basic requirements for the railway system. DIN EN 14363, which is currently under revision, includes the current status of requirements for the driving behaviour of the vehicles. The procedures and limits described therein are derived from various other norms and regulations, so Road-Rail Vehicles (RRV) as well as European high-speed trains have to comply with the criteria. One of the requirements for drivability is the proof of safety against derailing in twisted track sections, which can be determined by so-called stationary tests. These will not take place on the tracks of the rail network, but on test rigs and special test tracks.

For many years, the TÜV SÜD Rail test center for rolling stock has been carrying out this test based on method 1, where the vehicle is twisted by spring inserts and run through a curve with defined twist in the track with a radius of 150 m. This method is the most direct method, i.e. all critical forces are simultaneously generated during the test and the test values are directly measured. To do this, force measuring points are set up in the curved track and the guiding and vertical wheel forces are recorded. Track measuring points are also set up on the vehicle and the overriding of the wheel is recorded. The advantages of method 1 are the possibility to test complex, very long vehicles and also a simple test procedure.

As of last year, the test center in Halle (Saale) also provides tests based on method 2, where the vehicle is twisted on a twist test rig and run separately through a flat test track with a radius of 150 m. In this test, the wheel forces are separately measured, i.e. vertical wheel forces are determined on the twist test rig and the guiding forces are determined in the curved track equipped with force measuring points. Subsequently, these values are compiled and compared with the criteria. In contrast to method 1, it is not necessary to install the attachments and with the separately measured force values, more detailed vehicle performance data can be obtained.

In addition, as the twist test rig is mobile, torsional stiffness, roll coefficients or roll centre heights of narrow-gauge, standard-gauge or broad-gauge vehicles can be determined at customers’ sites, without the need to transport the vehicles to the test center.

With the continuous advancement of simulation tools for validation, method 2 has become more important in the last few years. With the possibility to carry out the test based on method 2, TÜV SÜD Rail is able to provide a wider range of solutions to prove the quality and safety of its customers’ products - either within a complex vehicle approval procedure or as an individual test.