28 Sep 2020

Based on the Concept Fire Truck (CFT) concept study, Rosenbauer developed the RT (Revolutionary Technology) series, the fire fighting vehicle for the future. The first prototype was presented in June 2020. Now it was time to intensively test the first vehicles (five in total) from the Rosenbauer plant in Leonding.

The term ‘Erlkönig’ generally refers to prototype vehicles, which are supposed to conceal the final contours for the viewer with misshapen stickers on the outer shell. At the RT, too, great importance was attached to not showing the new vehicle design publicly before the product presentation, but still testing the vehicles intensively, as this is essential for the development progress.

Analyze vehicle behavior      

The extraordinary camouflage stickers also drew a lot of attentive looks, and let the tension rise, what is behind it. Vehicle testing of the RT vehicles began at the beginning of July in order to make the pre-series vehicles ready for use by customers. For this purpose, a comprehensive measuring system was installed in every vehicle. This saves the CAN signals from various systems on the vehicle for every activity of the vehicle (such as vehicle speed, engine speed, battery charge status, coolant temperatures, etc.)

This saves the CAN signals from various systems on the vehicle for every activity of the vehicle

In addition, various sensors record acceleration, pressure, temperature or flow at certain positions. Also a precise GPS signal and the recordings from the dashboard camera are helpful when evaluating measurement data in order to analyze vehicle behavior in detail. In addition, strain gauges applied to the relevant components can be used to determine the loads that occur there, and then optimize them.

Crew compartment seats

The vehicles are not only packed full of electronics, because additional weights were also installed for the driving tests to simulate the operating weight. The equipment rooms in the structure were loaded with filled water containers. The crew compartment seats were filled with ‘dummies’ in the form of simulated plastic upper bodies filled with water. Of course, the water tank under construction was also filled, which is an essential main component in the weight balance.

The vehicles were then tested on the in-house brake test bench and the steering geometry, track and headlights were precisely adjusted. Then there was a cold shower (leak test on the spray bar) before the next phase. The first dynamic vehicle tests were carried out at the MAGNA test site in St. Valentin (Lower Austria), such as acceleration, braking, driving in circles, changing lanes, etc.

Differential lock function

The new special features of this vehicle type, such as the rear-axle steering and the height-adjustable chassis, were also put into operation and the maneuverability and off-road capabilities were analyzed and evaluated. The driving dynamics and the steering system were then evaluated in a 100 km endurance run, and the entire system was run in a ‘stable’ manner.

The RT also lined up in public transport and attracted quite a few attentive glances from passers-by

In addition, all relevant screw connections were checked for strength, which is a daily evening routine during the test phase. This was followed by the parameterization of the automatic differential lock function, so even the rough road (off-road terrain) and the 40% gradient were no longer an obstacle. Another 300 km endurance run (on asphalt and unpaved ground) was then carried out before the next step was tested. Equipped with a test license plate, the RT also lined up in public transport and attracted quite a few attentive glances from passers-by thanks to its unusual stickers.

Pump test bench

During the trials in the central Linz area, the test drivers were particularly impressed by the driving performance and the good maneuverability of the vehicle. The electric traction drive allows the vehicle to move off quickly and without interruption, and when decelerating, the braking energy is converted into electrical energy through recuperation.

In hybrid mode, the range extender (diesel engine) ensures that the range and duration of use are extended accordingly. An emergency vehicle is not only driven into action, but also operated on site. It was therefore also clear that in the test phase all units that are necessary for a successful operational sequence must be tried out. Above all, the pump test bench should be mentioned here. The extinguishing water pump integrated in the vehicle is tested in conjunction with the piping. In addition to the maximum performance, pressure and flow were also determined at the required operating points.

Optional power supply

In addition, the electrical components were checked for their function, such as the warning devices (‘blue light’ and ‘siren’) as well as the LED surrounding lighting and the optional power supply (‘network simulation’), which converts electrical energy from the high-voltage battery and then provides users.

Another major innovation in this electric vehicle is the charging option (plug-in charging)

Another major innovation in this electric vehicle is the charging option (plug-in charging). After the many tests, the energy storage (high-voltage battery) also had to be refilled, and this process also requires a few tests, in which, among other things, the correct communication between the vehicle and the charger must be set correctly. This vehicle has a Combo CCS Type 2 charging plug, so it is possible to charge in AC mode (alternating current) with up to 22 kW and in DC mode (direct current) with up to 150 kW.

Dynamic vehicle tests

The testing phase of the first pre-series vehicles has not yet been completed, as testing and testing will continue until delivery. In order to maintain an overview, a comprehensive test catalog was created, which must be completed by every vehicle.

At the beginning, this includes the functional tests, followed by static and dynamic vehicle tests, then the certification tests and finally the vehicle acceptance test by the customer. The vehicles are also extensively tested at the customer's premises and the team trained in how to operate the vehicle before the RTs go into real use and are therefore ready for use the moment when technology doesn't just have to work - it matters.