Around 3,000 bogies for rail vehicles leave the Siemens Mobility plant in Graz every year. In addition to the production and development of new bogies, the plant has a particularly important task - the quality control of every bogie delivered. The MULTIRAIL Bogie Test Bench from the Qlar Group (formerly Schenck Process) has been in use for more than ten years. These are characterised by their measurement accuracy, high availability and fully automatic, patented bogie positioning. The latest system was commissioned in 2023.
The Graz site is Siemens Mobility's World Competence Centre for Bogies for a wide range of rail vehicles. On an area of almost 70,000 m², more than 1,600 employees work on the research, development and production of bogies, their subsystems and new technologies. As a developer and producer of high-tech technologies, the Graz location is a hub for the production of Siemens Mobility rail vehicles and an important partner for the international rail vehicle industry. The importance of the correct adjustment of the bogie under the bogie pressure level should not be underestimated, as the bogie makes an important contribution to driving safety and also has a significant influence on driving comfort and noise emissions.
Automated measuring processes accurate to tenths of a millimetre
Perfectly matched undercarriages also ensure greater safety and less wear in rail transport. To ensure the highest possible standard, no bogie leaves the factory without undergoing quality assurance testing. The wheel contact forces and geometric dimensions of bogies for passenger transport are checked using a 3D measuring arm on a test bench specially developed to meet customer requirements. This is the third time that Siemens Mobility in Graz has opted for Qlar's MULTIRAIL Bogie Test Bench. It features a patented, automatic bogie positioning system designed for pressure tests according to DIN 25043-7 (measurement of railway vehicles). Thanks to the automatic track width adjustment, the test bench is also able to test all types of bogies with two sets of wheels.
The MULTIRAIL Bogie Test Bench has a fully automated test process divided into four steps: Preparation, force measurement, measurement under load and logging and execution of the bogie. In the preparation phase, the test bench is mechanically prepared for the bogie and selected in the programme. The bogie is then loaded onto the test stand. The bogie is then automatically aligned correctly in the X, Y and Z directions. This process has been specially developed and patented by Qlar. Once aligned, the chassis is loaded and unloaded with a specified test force using mechanical spindle technology (ball screws). During this test procedure, the wheel contact forces are measured under test load and geometric measurements are automatically taken on the chassis. This includes measuring wheel backspacing, wheel set parallelism, wheel set spacing, wheel set diagonal, track parallelism and axle angle. If required, further work can now be carried out, such as measuring other z-dimensions and other geometry variables, as well as measuring the pressure drop in the air spring or brake systems of the chassis. Siemens Mobility in Graz uses 3D measuring arms on both sides of the test bench to determine the geometric parameters. The measurement results are transferred directly to the measurement protocol. This means that the measuring points in all three reference axes (X, Y and Z) on the chassis can be recorded easily and reliably directly via the operating PC.
Finally, the test bench generates a test report in accordance with DIN 25043-7, listing all the values. The Qlar test bench stands out for its high process reliability and availability. On average, the deviations are ± 0.1% for force measurements and less than 0.2 mm for geometric measurements.
MULTIRAIL Test Bench & Train Monitoring
Daily quality inspection for thousands of running gears
The Siemens Mobility plant in Graz produces around 3,000 bogies per year. These are not only bogies manufactured on site, but also repair orders from customers and operators via Customer Service. Before delivery, each bogie has to pass a quality control to ensure that it meets the applicable safety standards. To meet this responsibility, Siemens Mobility put a new test stand out to tender - and Qlar won the contract. In 2011, Siemens Mobility integrated the first MULTIRAIL Bogie Test Bench at the Graz site. Due to the steadily increasing demand for passenger trains, the number of test benches at the site was continuously adjusted - after 2014, the last test bench for the time being was installed in 2023. Qlar was able to beat the competition in every tender. One of the reasons for this is the patented process for the exact positioning of the chassis in the test bench, which is a prerequisite for obtaining precise and reproducible measurement results. The test bench also impresses with its high availability of almost 98%. By using three systems from the same series, Siemens Mobility has the flexibility to deploy its employees freely on the systems. Only the new test bench differs from the existing systems in one function. It has a newly developed traversing device that can even pull the bogies of heavy locomotives weighing up to 20 tonnes into the test stand. Previously, these always had to be pushed onto the test stand by several people working together. The new device therefore supports the ergonomics of the operating personnel.
Trust matured over a decade
Siemens Mobility in Graz has been working with test benches from Qlar for more than ten years. The standards set by the MULTIRAIL Bogie Test Bench in terms of measurement accuracy are particularly impressive. Bernhard Krug, Plant Service employee at Siemens Mobility in Graz, particularly emphasises the flexibility of the system: “Bogies are often subjected to asymmetrical loads when they are later used on the rails, as locomotives or wagons do not support an even weight distribution. With the Qlar test benches, we can simulate this situation and have only minimal deviations in the measured values even under these conditions”. The large corporation intends to continue working with Qlar in the future to make rail transport safer worldwide.
We’re there for you
Partnership for us means always being on hand to support you whenever and wherever you need us. With our global network of locations and expert partners, we make sure we are always right by your side.
